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Topology and topological sequence entropy
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作者 L'ubomír Snoha Xiangdong Ye Ruifeng Zhang 《中国科学:数学英文版》 SCIE CSCD 2020年第2期205-296,共92页
Let X be a compact metric space and T:X-→X be continuous.Let h*(T)be the supremum of topological sequence entropies of T over all the subsequences of Z+and S(X)be the set of the values h*(T)for all the continuous map... Let X be a compact metric space and T:X-→X be continuous.Let h*(T)be the supremum of topological sequence entropies of T over all the subsequences of Z+and S(X)be the set of the values h*(T)for all the continuous maps T on X.It is known that{0}■S(X)■{0,log 2,log 3,...}∪{∞}.Only three possibilities for S(X)have been observed so far,namely S(X)={0},S(X)={0,log 2,∞}and S(X)={0,log 2,log 3,...}∪{∞}.In this paper we completely solve the problem of finding all possibilities for S(X)by showing that in fact for every set{0}?A?{0,log 2,log 3,...}∪{∞}there exists a one-dimensional continuum XAwith S(XA)=A.In the construction of XAwe use Cook continua.This is apparently the first application of these very rigid continua in dynamics.We further show that the same result is true if one considers only homeomorphisms rather than continuous maps.The problem for group actions is also addressed.For some class of group actions(by homeomorphisms)we provide an analogous result,but in full generality this problem remains open. 展开更多
关键词 topological sequence entropy rigid continuum Cook continuum
A Novel Ratio-Based Parallel DEA Approach for Evaluating the Energy and Environmental Performance of Chinese Transportation Sectors
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作者 Xiyang Lei Lin Li +2 位作者 Xuefei Zhang Qianzhi Dai Yelin Fu 《系统科学与系统工程学报:英文版》 SCIE EI CSCD 2019年第5期621-635,共15页
As a high-energy-consumption and high-CO2-emission industry in China,the transportation sector has been under increasing pressure to improve its performance.This paper develops a novel parallel DEA approach to measure... As a high-energy-consumption and high-CO2-emission industry in China,the transportation sector has been under increasing pressure to improve its performance.This paper develops a novel parallel DEA approach to measure Chinese transportation sector's energy and environmental performance (EEP) over all possible weights,which is to avoid the risk of using the extreme or the most favorable weights in performance evaluation.In our method,the transportation sector is consisted of two parallel subsystems (passenger transportation and freight transportation) with shared inputs and undesirable shared outputs.All possible weights are considered in the EEP evaluation,then the EEP of a transportation sector is represented by a ranking interval.Finally,the proposed approach is applied to the transportation sectors in 30 Chinese provinces.Results show that the best and the worst ranking of most provinces vary greatly.Besides,the EEP of most provinces is hard to dominate others strictly,but the general tendency is the EEP of eastern provinces better than western provinces.Furthermore,the EEP difference of some adjacent provinces with similar features is distinct.These findings are not all the same as previous studies,which verifies the necessity of considering all possible weights in performance evaluation.Therefore,our method provides a new point of view in performance evaluation and can give more robust results for decision makers. 展开更多
关键词 Data envelopment analysis energy and environmental PERFORMANCE TRANSPORTATION SECTOR PARALLEL system RANKING INTERVAL
Wide tunable laser based on electrically regulated bandwidth broadening in polymer-stabilized cholesteric liquid crystal
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作者 HONGBO LU CHENG WEI +8 位作者 QIANG ZHANG MIAO XU YUNSHENG DING GUOBING ZHANG JUN ZHU KANG XIE XIAOJUAN ZHANG ZHIJIA HU LONGZHEN QIU 《光子学研究:英文版》 CSCD 2019年第2期137-143,共7页
Electrically responsive photonic crystals represent one of the most promising intelligent material candidates for technological applications in optoelectronics. In this research, dye-doped polymer-stabilized cholester... Electrically responsive photonic crystals represent one of the most promising intelligent material candidates for technological applications in optoelectronics. In this research, dye-doped polymer-stabilized cholesteric liquid crystals(PSCLCs) with negative dielectric anisotropy were fabricated, and mirrorless lasing with an electrically tunable wavelength was successfully achieved. Unlike conventional liquid-crystal lasers, the proposed laser aided in tuning the emission wavelength through controlling the reflection bandwidth based on gradient pitch distribution. The principal advantage of the electrically controlled dye-doped PSCLC laser is that the electric field is applied parallel to the helical axis, which changes the pitch gradient instead of rotating the helix axis, thus keeping the heliconical structure intact during lasing. The broad tuning range(~110 nm) of PSCLC lasers,coupled with their stable emission performance, continuous tunability, and easy fabrication, leads to its numerous potential applications in intelligent optoelectronic devices, such as sensing, medicine, and display. 展开更多
关键词 WIDE TUNABLE laser electrically polymer-stabilized
Considering Monopoly Maintenance Cost for an Automobile Purchase in China:A DEA-Based Approach
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作者 DAI Qianzhi LI Lin +2 位作者 LEI Xiyang AN Qingxian TANG Xiao 《系统科学与复杂性学报:英文版》 SCIE EI CSCD 2019年第4期1167-1179,共13页
With the fast growing economy,China has become the biggest automobile market in the world.Many Chinese families buy automobiles to promote individual wellbeing and facilitate the convenience of lives.Automobile purcha... With the fast growing economy,China has become the biggest automobile market in the world.Many Chinese families buy automobiles to promote individual wellbeing and facilitate the convenience of lives.Automobile purchase has become a general and important decision for a Chinese family.However,it is always difficult to make a decision on the automobile purchase that balance the automobiles performance and its cost.Moreover,the automobile maintenance market in China is monopolistic.Thus,the maintenance cost is a significant consideration in automobile purchase decision.This paper employs the concept of data envelopment analysis(DEA)to measure cost performance of the automobile with considering the monopoly maintenance cost.The RCA(ratio of the total price of accessories of an automobile to the price of the automobile)100 index system is used to represent the maintenance cost of each automobile.The structure of the automobile maintenance market can be reflected with including the RCA 100 index system in the performance evaluation.Results of the case study of 28 automobiles in China verify the necessity of considering the maintenance cost in automobile purchase decision. 展开更多
关键词 AUTOMOBILE PURCHASE business ANALYTICS COST performance data envelopment analysis(DEA) MONOPOLY maintenance COST
大学生完美主义在父母教养方式与反刍思维间的中介作用
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作者 李艳 朱蓉蓉 +3 位作者 何畏 潘莉 张贤 任颖 《中华行为医学与脑科学杂志》 CAS CSCD 北大核心 2019年第8期746-750,共5页
目的探讨大学生完美主义在父母教养方式和反刍思维之间的中介作用.方法采用Nolen-Hoeksema反刍思维量表(ruminative responses scale,RRS)中文版、简式父母教养方式问卷中文版(S-EMBU)、大学生一般完美主义量表对915名大学生团体施测.... 目的探讨大学生完美主义在父母教养方式和反刍思维之间的中介作用.方法采用Nolen-Hoeksema反刍思维量表(ruminative responses scale,RRS)中文版、简式父母教养方式问卷中文版(S-EMBU)、大学生一般完美主义量表对915名大学生团体施测.结果大学生追求高标准、在乎错误、症状反刍、强迫思考、反省深思、反刍思维总分得分分别为[(26. 35±4. 13)分、(17. 14±4. 86)分、(22. 27±4. 64)分、(11. 10±2. 71)分、(10. 38±2. 71)分、( 43. 75±8. 37 )分];大学生反刍思维与父亲/母亲拒绝(r=0. 23、0. 29,P<0. 01)、父亲/母亲过度保护( r=0. 16、0. 20,P<0. 01)、在乎错误( r=0. 36,P<0. 01)显著正相关;大学生反刍思维与父亲/母亲情感温暖显著负相关( r=-0. 07、-0. 09,P<0. 05);在乎错误与父亲/母亲拒绝(r=0. 12、0. 19,P<0. 01)、父亲/母亲过度保护( r=0. 16、0. 12,P<0. 01)显著正相关,与父亲/母亲情感温暖显著负相关(r=-0. 18、-0. 20,P<0. 01).结构方程模型显示,在乎错误在父母拒绝和反刍思维间起部分中介作用(χ2/df=8. 45,RMSEA=0. 09,CFI=0. 96,GFI=0. 97),中介效应值为0. 112(95%CI=0. 048~0. 194),占总效应比例28. 95%.结论在乎错误在父/母亲拒绝与大学生反刍思维间起部分中介作用,减少母亲/父亲拒绝、完美主义,可有效降低大学生反刍思维水平. 展开更多
关键词 反刍思维 完美主义 自杀风险 父母教养方式 大学生
Aggravation of membrane fouling and methane leakage by a three-phase separator in an external anaerobic ceramic membrane bioreactor
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作者 Chao Pang Chunhua He +2 位作者 Zhenhu Hu Shoujun Yuan Wei Wang 《环境科学与工程前沿(英文)》 SCIE EI CAS CSCD 2019年第4期35-43,共9页
The three-phase separator is a critical component of high-rate anaerobic bioreactors due to its significant contribution in separation of biomass, wastewater, and biogas. However, its role in an anaerobic membrane bio... The three-phase separator is a critical component of high-rate anaerobic bioreactors due to its significant contribution in separation of biomass, wastewater, and biogas. However, its role in an anaerobic membrane bioreactor is still not clear. In this study, the distinction between an external anaerobic ceramic membrane bioreactor (EAnCMBR) unequipped (R1) and equipped (R2) with a three-phase separator was investigated in terms of treatment performance, membrane fouling, extracellular polymers of sludge, and microbial community structure. The results indicate that the COD removal efficiencies of Rl and R2 were 98.2%±0.4% and 98.1%±0.4%, respectively, but the start-up period of R2 was slightly delayed. Moreover, the membrane fouling rate of R2 (0.4 kPa/d) was higher than that of Rl (0.2 kPa/d). Interestingly, the methane leakage from R2 (0.1 L/d) was 20 times higher than that from Rl (0.005 L/d). The results demonstrate that the three-phase separator aggravated the membrane fouling rate and methane leakage in the EAnCMBR. Therefore, this study provides a novel perspective on the effects of a three-phase separator in an EAnCMBR. 展开更多
关键词 ANAEROBIC MEMBRANE BIOREACTOR Three-phase separator MEMBRANE fouling METHANE LEAKAGE Sludge property
Mechanical Response and Energy Dissipation Analysis of Heat-Treated Granite Under Repeated Impact Loading 预览
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作者 Zhiliang Wang Nuocheng Tian +2 位作者 Jianguo Wang Shengqi Yang Guang Liu 《计算机、材料和连续体(英文)》 2019年第4期275-296,共22页
The mechanical behaviors and energy dissipation characteristics of heat-treated granite were investigated under repeated impact loading.The granite samples were firstly heat-treated at the temperature of 20℃,200℃,40... The mechanical behaviors and energy dissipation characteristics of heat-treated granite were investigated under repeated impact loading.The granite samples were firstly heat-treated at the temperature of 20℃,200℃,400℃,and 600℃,respectively.The thermal damage characteristics of these samples were then observed and measured before impact tests.Dynamic impact compression tests finally were carried out using a modified split-Hopkinson pressure bar under three impact velocities of 12 m/s,15 m/s,and 18 m/s.These test results show that the mineral composition and the main oxides of the granite do not change with these treatment temperatures.The number of microcracks and microvoids decreases in the sample after 200℃ treatment.The mechanical properties of a sample after 600℃ treatment were rapidly deteriorated under the same impact velocity.The average of peak stress is much smaller than those after 20℃,200℃ and 400℃ treatments.The heat-treated samples have an energy threshold each.When the dissipated energy of a sample under a single impact is less than this threshold,the repeated impacts hardly lead to further damage accumulation even if its total breakage energy dissipation(BED)density is large.Under the same number of repeated impacts,the cumulative BED density of a sample after 600℃ treatment is the largest and its damage evolves most quickly.The total BED density of the sample after 200℃ treatment is the highest,which implies that this sample has better resistance to repeated impact,thus having less crack initiation and growth. 展开更多
关键词 GRANITE heat treatment repeated impact dynamic response energy dissipation
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Novel Approach for Improved Tribological Behavior of Biodiesel Soot in Liquid Paraffin 预览
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作者 Li Chuan Song Hui +4 位作者 Zhang Jun Wu Bo Zhang Qiangqiang Zhuang Yuan Hu Xianguo 《中国炼油与石油化工:英文版》 SCIE CAS 2019年第1期101-109,共9页
To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved th... To improve the tribological behavior of biodiesel soot(BDS) in liquid paraffin(LP), the order of biodiesel soot was increased through thermally oxidized treatment at 500 ℃, and the oil solubility was then improved through a modification using oleylamine(OLA). The BDS and thermally oxidized oleylamine-modified BDS(T-BDS-OLA)were characterized through various methods including the use of TG, FETEM, Raman spectroscopy, FTIR, and a zeta potentiometer. The tribological properties and mechanisms of the BDS before and after the thermally oxidized treatment modification were investigated using a ball-on-disc reciprocating tribometer, FESEM, 3 D laser-scanning microscopy, and Raman spectroscopy. The results showed that T-BDS-OLA has a higher degree of order than the BDS, with an onion-like microstructure. BDS and T-BDS-OLA can both improve the antifriction and antiwear properties of LP at a soot content of 0.1%-0.4%, while T-BDS-OLA in LP shows better antifriction and antiwear properties than BDS. The tribological mechanisms can be attributed to both types of soot acting as spacing and roll bearing between the friction surfaces. In addition, the exfoliated graphitic sheets from T-BDS-OLA can form a carbon lubrication layer providing easy sliding. 展开更多
关键词 BIODIESEL SOOT liquid PARAFFIN ANTIFRICTION and ANTIWEAR carbon ONION
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Achieving high-performance phosphorescent organic light-emitting diodes using thermally activated delayed fluorescence with low concentration
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作者 胡俊涛 陆超超 +3 位作者 王鹏 李杰 许凯 王向华 《光电子快报:英文版》 EI 2019年第5期347-351,共5页
We fabricated phosphorescent organic light-emitting diodes(Ph OLEDs) using thermally activated delayed fluorescence(TADF) material 10,10’-(4,4’-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine)(DMAC... We fabricated phosphorescent organic light-emitting diodes(Ph OLEDs) using thermally activated delayed fluorescence(TADF) material 10,10’-(4,4’-sulfonylbis(4,1-phenylene)) bis(9,9-dimethyl-9,10-dihydroacridine)(DMAC-DPS) with low concentration, which showed better performance compared with 1,3-bis(carbazole-9-yl) benzene(m CP) based devices. When the concentration of DMAC-DPS was 1 wt%, the driving voltage of the device was only 3.3 V at 1 000 cd/m2, and the efficiency and lifetime of the device were effectively improved compared with those of m CP based devices. The result indicated that DMAC-DPS could effectively improve the performance of phosphorescent devices. We believe that the better device performance can be attributed to the optimization of the energy transfer process in the emitter layer and lifetime of triplet excitons by DMAC-DPS. The study may provide a simple and effective strategy to achieve high-performance OLEDs. 展开更多
关键词 PHOSPHORESCENT organic LIGHT-EMITTING diodes(Ph OLEDs) thermally ACTIVATED delayed fluorescence(TADF) DMAC-DPS
Vibration Performance Analysis of a Mining Vehicle with Bounce and Pitch Tuned Hydraulically Interconnected Suspension 预览
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作者 Jie Zhang Yuanwang Deng +3 位作者 Nong Zhang Bangji Zhang Hengmin Qi Minyi Zheng 《中国机械工程学报:英文版》 SCIE EI CAS CSCD 2019年第1期195-211,共17页
The current investigations primarily focus on using advanced suspensions to overcome the tradeo design of ride comfort and handling performance for mining vehicles. It is generally realized by adjusting spring sti nes... The current investigations primarily focus on using advanced suspensions to overcome the tradeo design of ride comfort and handling performance for mining vehicles. It is generally realized by adjusting spring sti ness or damping parameters through active control methods. However, some drawbacks regarding control complexity and uncertain reliability are inevitable for these advanced suspensions. Herein, a novel passive hydraulically interconnected suspension(HIS) system is proposed to achieve an improved ride-handling compromise of mining vehicles. A lumped-mass vehicle model involved with a mechanical–hydraulic coupled system is developed by applying the free-body diagram method. The transfer matrix method is used to derive the impedance of the hydraulic system, and the impedance is integrated to form the equation of motions for a mechanical–hydraulic coupled system. The modal analysis method is employed to obtain the free vibration transmissibilities and force vibration responses under di erent road excitations. A series of frequency characteristic analyses are presented to evaluate the isolation vibration performance between the mining vehicles with the proposed HIS and the conventional suspension. The analysis results prove that the proposed HIS system can e ectively suppress the pitch motion of sprung mass to guarantee the handling performance, and favorably provide soft bounce sti ness to improve the ride comfort. The distribution of dynamic forces between the front and rear wheels is more reasonable, and the vibration decay rate of sprung mass is increased e ectively. This research proposes a new suspension design method that can achieve the enhanced cooperative control of bounce and pitch motion modes to improve the ride comfort and handling performance of mining vehicles as an e ective passive suspension system. 展开更多
关键词 Hydraulically interconnected SUSPENSION Transfer matrix method Modal VIBRATION analysis RIDE comfort Handling performance MINING VEHICLE
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Data-driven group decision making for diagnosis of thyroid nodule
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作者 Chao FU Wenjun CHANG +1 位作者 Weiyong LIU Shanlin YANG 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第11期147-169,共23页
Emerging information technologies’ integration into various fields has enhanced the development of these fields. Large volumes of data have been accumulated in this process. The accumulated data offer opportunities a... Emerging information technologies’ integration into various fields has enhanced the development of these fields. Large volumes of data have been accumulated in this process. The accumulated data offer opportunities and challenges for people facing practical problems. On the one hand, it is essential to depend on a group’s capabilities rather than an individual’s capabilities to handle practical problems because the individual may lack sufficient expertise and experience to use data. In this situation, the practical problems can be considered as group decision making(GDM) problems. On the other hand, the accumulated data can help generate quality solutions to GDM problems. To obtain such solutions under the assumption that the accumulated data regarding a specific decision problem are available, this paper proposes a data-driven GDM method. In the method, decision makers’ weights are learned from historical overall assessments and the corresponding gold standards, while criterion weights are learned from historical overall assessments and the corresponding decision matrices. The learned expert weights and criterion weights are used to produce the aggregated assessments, from which alternatives are compared or the overall conclusion is made. In a tertiary hospital located in Hefei, Anhui Province, China, the proposed method is applied to aid radiologists in diagnosing thyroid nodules. 展开更多
关键词 DATA-DRIVEN group decision making interval number LEARNING of expert WEIGHTS LEARNING of criterion WEIGHTS DIAGNOSIS of THYROID NODULE
Earth observation satellite scheduling for emergency tasks 预览
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作者 SUN Haiquan XIA Wei +1 位作者 HU Xiaoxuan XU Chongyan 《系统工程与电子技术:英文版》 SCIE EI CSCD 2019年第5期931-945,共15页
The earth observation satellites(EOSs)scheduling problem for emergency tasks often presents many challenges.For example,the scheduling calculation should be completed in seconds,the scheduled task rate is supposed to ... The earth observation satellites(EOSs)scheduling problem for emergency tasks often presents many challenges.For example,the scheduling calculation should be completed in seconds,the scheduled task rate is supposed to be as high as possible,the disturbance measure of the scheme should be as low as possible,which may lead to the loss of important observation opportunities and data transmission delays.Existing scheduling algorithms are not designed for these requirements.Consequently,we propose a rolling horizon strategy(RHS)based on event triggering as well as a heuristic algorithm based on direct insertion,shifting,backtracking,deletion,and reinsertion(ISBDR).In the RHS,the driven scheduling mode based on the emergency task arrival and control station time window events are designed to transform the long-term,large-scale problem into a short-term,small-scale problem,which can improve the schedulability of the original scheduling scheme and emergency response sensitivity.In the ISBDR algorithm,the shifting rule with breadth search capability and backtracking rule with depth search capability are established to realize the rapid adjustment of the original plan and improve the overall benefit of the plan and early completion of emergency tasks.Simultaneously,two heuristic factors,namely the emergency task urgency degree and task conflict degree,are constructed to improve the emergency task scheduling guidance and algorithm efficiency.Finally,we conduct extensive experiments by means of simulations to compare the algorithms based on ISBDR and direct insertion,shifting,deletion,and reinsertion(ISDR).The results demonstrate that the proposed algorithm can improve the timeliness of emergency tasks and scheduling performance,and decrease the disturbance measure of the scheme,therefore,it is more suitable for emergency task scheduling. 展开更多
关键词 EMERGENCY TASK rolling HORIZON SHIFTING RULE backtrackingrule
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Mode-locked fiber laser with MoSe2 saturable absorber based on evanescent field
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作者 张仁栗 王俊 +6 位作者 张晓艳 林锦添 李夏 关珮雯 周延 廖梅松 高伟清 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期406-410,共5页
An all-fiber mode-locked fiber laser was achieved with a saturable absorber based on a tapered fiber deposited with layered molybdenum selenide(MoSe2). The laser was operated at a central wavelength of 1558.35 nm with... An all-fiber mode-locked fiber laser was achieved with a saturable absorber based on a tapered fiber deposited with layered molybdenum selenide(MoSe2). The laser was operated at a central wavelength of 1558.35 nm with an output spectral width of 2.9 nm, and a pulse repetition rate of 16.33 MHz. To the best of our knowledge, this is the first report on mode-locked fiber lasers using MoSe2 saturable absorbers based on tapered fibers. 展开更多
关键词 FIBER LASERS mode LOCKING MOLYBDENUM DISELENIDE
Behavior of noncircular tunnels excavated in stratified rock masses-Case of underground coal mines 预览
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作者 Ngoc Anh Do Daniel Dias +4 位作者 Van Diep Dinh Tien Tung Tran Van Canh Dao Viet Doan Dao Phuc Nhan Nguyen 《岩石力学与岩土工程学报:英文版》 CSCD 2019年第1期99-110,共12页
The amount of tunnels excavated along stratified/sedimentary rock masses in Quangninh coal mine area,Vietnam,is gradually increasing.Rock mass in Quangninh is characterized by beddings between rock layers.The behavior... The amount of tunnels excavated along stratified/sedimentary rock masses in Quangninh coal mine area,Vietnam,is gradually increasing.Rock mass in Quangninh is characterized by beddings between rock layers.The behavior of stratified rock masses surrounding the tunnels depends on both the intact rock and the beddings between rock layers.The main characteristics of stratified rock masses that need to be considered are their heterogeneity and anisotropy.Depending on the dip angle of rock layers,movements and failure zones developed surrounding the tunnels can be asymmetrical over the vertical axis of tunnel.This asymmetry causes adverse behaviors of the tunnel structures.The objective of this study is to highlight convergences and yielded zones developed in rock masses surrounding noncircular tunnels in Quangninh coal mine area using a finite element method.The presence of bedding joints is explicitly simulated.The numerical results indicated that with the increase in dip angle of bedding joints,the stress asymmetry over the tunnel vertical axis increases.It gradually leads to an asymmetry of the failure zone surrounding the tunnel.An increase of rock mass quality means a decrease of rock mass sensitivity to the discontinuities.In addition,a dip angle of the bedding joints of approximately 45 could be considered as the critical angle at which the rock mass mechanism changes between sliding and bending. 展开更多
关键词 TUNNEL BEDDING STRATIFICATION ANISOTROPIC HETEROGENEITY
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New Zircon U-Pb Ages of the Shirenshan Gneiss,North Qinling and Their Geological Implications 预览
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作者 WANG Jingya REN Shenglian +7 位作者 JIANG Dazhi DONG Shuwen LI Jiahao LI Longming GE Can SONG Chuanzhong HAN Xu LI Zhenqiang 《地质学报:英文版》 SCIE CAS CSCD 2019年第1期238-240,共3页
The Qinling Orogenic Belt(QOB)is a composite continental orogenic belt that has experienced many tectonic events.The QOB is subdivided into the following three litho-tectonic units:the North Qinling terrane,the Middle... The Qinling Orogenic Belt(QOB)is a composite continental orogenic belt that has experienced many tectonic events.The QOB is subdivided into the following three litho-tectonic units:the North Qinling terrane,the Middle Qinling microplate and the South Qinling terrane.The North Qinling Terrane(NQT)underwent destruction and lithospheric thinning during the late Mesozoic,accompanied by extensive magmatic activity and increased surface heat flux,led to large-scale tectonic extension(e.g.,Ren Shenglian et al.,2016).The Shirenshan gneiss is located along the contact between the NQT and the North China Block(Fig.1).Previous studies suggested that it was produced as a result of the northward subduction of the NQT beneath the North China Block(e.g.,Wang Jingya et al.,2017).Therefore,it is significant to study its structural geology,petrology,geochemistry and chronology in order to understand the tectonic settings and the interaction between the Middle Qinling microplate and the North China Block. 展开更多
关键词 The QINLING OROGENIC Belt(QOB) subdivided The NORTH QINLING Terrane(NQT)
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Kiwifruit(Actinidia chinensis)R1R2R3-MYB transcription factor AcMYB3R enhances drought and salinity tolerance in Arabidopsis thaliana 预览
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作者 ZHANG Ya-bin TANG Wei +3 位作者 WANG Li-huan HU Ya-wen LIU Xian-wen LIU Yong-sheng 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第2期417-427,共11页
Kiwifruit is an important fruit crop that is highly sensitive to environmental stresses,such as drought,heat,cold,water logging and phytopathogens.Therefore it is indispensable to identify stress-responsive candidate ... Kiwifruit is an important fruit crop that is highly sensitive to environmental stresses,such as drought,heat,cold,water logging and phytopathogens.Therefore it is indispensable to identify stress-responsive candidate genes in kiwifruit cultivars for the stress resistance improvement.Here we report the isolation and characterization of a novel kiwifruit R1R2R3-MYB homolog(AcMYB3R)whose expression was induced by drought,salinity and cold stress.In vitro assays showed that AcMYB3R is a nuclear protein with transcriptional activation activity by binding to the cis-element of the kiwifruit orthologue of G2/M phase-specific gene KNOLLE.The Arabidopsis transgenic plants overexpressing AcMYB3R showed drastically enhanced tolerance to drought and salt stress.The expressions of stress-responsive genes such as RD29A,RD29B,COR15A and RD22 were prominently up-regulated by ectopic expression of Ac MYB3R.Our study provides a valuable piece of information for functional genomics studies of kiwifruit and molecular breeding in improving stress tolerance for crop production. 展开更多
关键词 KIWIFRUIT R1R2R3-MYB DROUGHT ABIOTIC STRESS
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Initiation of ice jam in front of bridge piers-An experimental study 预览
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作者 Jun Wang Jian Hua +3 位作者 Pang-pang Chen Jueyi Sui Peng Wu Todd Whitcombe 《水动力学研究与进展:英文版》 SCIE EI CSCD 2019年第1期117-123,共7页
The presence of bridge piers in natural rivers significantly changes the flow and boundary conditions.As a consequence,ice jams can often be initiated in front of bridge piers.With the changes in flow conditions,two t... The presence of bridge piers in natural rivers significantly changes the flow and boundary conditions.As a consequence,ice jams can often be initiated in front of bridge piers.With the changes in flow conditions,two types of ice jam formation may appear:surface accumulation of ice blocks (surface ice blockage) and thickened accumulation of ice blocks (vertical ice blockage).In the present study,the initiation process of ice jam was studied based on experiments.It is found that the critical ice concentration for ice jam blockage depends on the ice block dimension,channel opening and flow conditions.Under surface blockage conditions,a larger ratio of ice cube dimension to channel opening (between piers) can result in a smaller critical ice concentration for ice jam blockage,which has no obvious relation with flow conditions.Under vertical blockage conditions,the critical ice concentration for ice jam blockage increases with flow Froude number and decreases with the ratio of ice dimension to channel opening (between piers).Based on experiments conducted in laboratory,equations for determining critical ice concentration for these two types of ice jam blockage have been developed. 展开更多
关键词 BRIDGE PIERS surface ICE BLOCKAGE vertical ICE BLOCKAGE critical ICE CONCENTRATIONS
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Enhancing the cycling stability of Na-ion batteries by bonding MoS2 on assembled carbon-based materials 预览
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作者 Pin Song Jun Di +14 位作者 Lixing Kang Manzhang Xu Bijun Tang Jun Xiong Jiewu Cui Qingsheng Zeng Jiadong Zhou Yongmin He Qundong Fu Juan Peng Shasha Guo Bo Lin Jingyu Zhang Peng Meng Zheng Liu 《纳米材料科学(英文版)》 CAS 2019年第4期310-317,共8页
Room temperature Na-ion batteries(SIBs) show great potential for use as renewable energy storage systems.However, the large-scale application of SIBs has been hindered by the lack of an ideal SIBs anode material. We s... Room temperature Na-ion batteries(SIBs) show great potential for use as renewable energy storage systems.However, the large-scale application of SIBs has been hindered by the lack of an ideal SIBs anode material. We synthesized MoS2 on carbonized graphene-chitosan(G-C) using the hydrothermal method. The strong interaction between the MoS2 and the G-C greatly improved the electron transport rate and maintained the structural stability of the electrode, which lead to both an excellent rate capability and long cycle stability. The G-C monolith was proven to enhance the electrical conductivity of the composites and served as a matrix for uniformly dispersing active MoS2 nanosheets(NSs), as well as being a buffer material to adapt to changes in volume during the cycle.Serving as an anode material for SIBs, the MoS2-G-C electrode showed good cycling stability(527.3mAh g-1 at100 m A g-1 after 200 cycles), excellent rate capability, and a long cycle life(439.1 m Ah g-1 at 1 A g-1 after 200 cycles). 展开更多
关键词 Na-ion batteries Carbon-based materials MOS2 Long cycle life
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Theoretical analyses of stock correlations affected by subprime crisis and total assets:Network properties and corresponding physical mechanisms
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作者 朱世钊 王玉青 汪秉宏 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第10期609-621,共13页
In the field of statistical mechanics and system science, it is acknowledged that the financial crisis has a profound influence on stock market. However, the influence of total asset of enterprise on stock quote was n... In the field of statistical mechanics and system science, it is acknowledged that the financial crisis has a profound influence on stock market. However, the influence of total asset of enterprise on stock quote was not considered in the previous studies. In this work, a modified cross-correlation matrix that focuses on the influence of total asset on stock quote is introduced into the analysis of the stocks collected from Asian and American stock markets, which is different from the previous studies. The key results are obtained as follows. Firstly, stock is more greatly correlated with big asset than with small asset. Secondly, the higher the correlation coefficient among stocks, the larger the eigenvector is. Thirdly, in different periods, like the pre-subprime crisis period and the peak of subprime crisis period, Asian stock quotes show that the component of the third eigenvector of the cross-correlation matrix decreases with the asset of the enterprise decreasing.Fourthly, by simulating the threshold network, the small network constructed by 10 stocks with large assets can show the large network state constructed by 30 stocks. In this research we intend to fully explain the physical mechanism for understanding the historical correlation between stocks and provide risk control strategies in the future. 展开更多
关键词 complex networks total ASSETS SUBPRIME CRISIS STOCK CORRELATIONS
Experimental study on the velocity-dependent dispersion of the solute transport in different porous media 预览
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作者 YAN Xiao-san QIAN Jia-zhong MA Lei 《地下水科学与工程:英文版》 2019年第2期106-114,共9页
The hydrodynamic dispersion is an important factor influencing the reactive solute transport in the porous media, and many previous studies assumed that it linearly varied with the average velocity of the groundwater ... The hydrodynamic dispersion is an important factor influencing the reactive solute transport in the porous media, and many previous studies assumed that it linearly varied with the average velocity of the groundwater flow. Actually, such linear relationship has been challenged by more and more experimental observations, even in homogeneous media. In this study, we aim to investigate the relationship between hydrodynamics dispersion and the flow velocity in different types of porous media through a laboratory-controlled experiment. The results indicate that (1) the dispersion coefficient should not be a linear function of the flow velocity when the relationship between the flow velocity and the hydraulic gradient can be described by Darcy's law satisfactorily;(2) Power function works well in describing the dispersion coefficient changing with the flow velocity for different types of porous media, and the power value is between 1.0-2.0 for different particle sizes. 展开更多
关键词 SOLUTE transport POROUS media Flow VELOCITY DISPERSION COEFFICIENT
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