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文章速递Assessment of Fertilising Properties of a Solid Digestate in Comparison with Undigested Cattle Slurry Applied to an Acidic Soil 认领
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作者 João Paulo Carneiro 《土壤科学期刊(英文)》 2020年第8期307-325,共19页
The use of digestates or cattle slurries as fertilisers could contribute to the recycling of nutrients and organic matter, thus meeting the goals of the circular economy in agriculture. This work aims at evaluating th... The use of digestates or cattle slurries as fertilisers could contribute to the recycling of nutrients and organic matter, thus meeting the goals of the circular economy in agriculture. This work aims at evaluating the fertilising properties of a solid digestate (DG) in comparison with undigested cattle slurry (CS) and mineral fertilisation (MF). The experiment was performed in pots with ryegrass (<em>Lolium multiflorum</em> Lam.) grown in an acidic soil during a 163 days crop cycle. The results showed that throughout the crop cycle neither DG nor CS increased soil organic matter. DG significantly increased (P < 0.001) the sum of the soil exchangeable bases and soil P availability compared with CS or MF. Also, DG significantly increased (P < 0.05) the apparent P recovery of ryegrass (43%) compared with MF (27%). In the first cut, the ryegrass yield was higher in DG and CS than in MF, decreasing in the second and third cuts as a consequence of a decrease in N availability. Nevertheless, the fertilisation with DG or CS could replace the half amount of mineral N fertilisation, without a significant decrease in the ryegrass forage production. In addition, DG enables greater efficiency in the use of P than CS or MF. 展开更多
关键词 Agronomic Efficiency Biogas Nitrogen Use Efficiency Phosphorus Use Efficiency Sustainable Agriculture
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Photoelectrochemical evaluation of SILAR-deposited nanoporous BiVO4 photoanodes for solar-driven water splitting 认领
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作者 Siti Nur'ain Haji Yassin Adrian Soong Leong Sim James Robert Jennings 《纳米材料科学:英文版》 CAS 2020年第3期227-234,共8页
We report a photoelectrochemical investigation of BiVO4 photoanodes prepared by successive ionic layer adsorption and reaction(SILAR),a facile method that yields uniform nanoporous films.After characterization of the ... We report a photoelectrochemical investigation of BiVO4 photoanodes prepared by successive ionic layer adsorption and reaction(SILAR),a facile method that yields uniform nanoporous films.After characterization of the phase,morphology,composition,and optical properties of the prepared films,the efficiencies of charge separation(ηsep)and water oxidation(ηox)in solar water splitting cells employing these photoanodes were estimated following a previously reported procedure.Unexpected wavelength and illumination direction dependencies were discovered in the derived efficiencies,casting doubt on the validity of the analysis.An alternative approach using a diffusion–reaction model that explicitly considers the efficiency of electron collection resolved the discrepancies and explained the illumination direction dependence of the photocurrent.Electron diffusion lengths(Ln)of 0.45μm and 0.55μm were derived for pristine and cobalt phosphate(Co-Pi)modified BiVO4,respectively,which are much shorter than the film thickness of~2.1μm.The Co-Pi treatment also increasedηoxfrom 0.86 to~1,which is the main reason for the overall performance enhancement caused by adding Co-Pi.These findings suggest that there is little scope for improving the performance of SILAR-deposited BiVO4 photoanodes by further catalyzing water oxidation,but enhanced performance is achievable if electron transport can be improved. 展开更多
关键词 Bismuth vanadate BIVO4 Solar water splitting Electron diffusion length Charge collection efficiency Water oxidation efficiency Charge separation efficiency
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Design of Experiment (DoE): Implementation in Determining Optimum Design Parameters of Portable Workstation 认领
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作者 Nafisa Ali Anika Nadia Tanzeem Himadri Sen Gupta 《工程(英文)(1947-3931)》 2020年第1期25-32,共8页
In the modern era of manufacturing, it is important to optimize every design parameter in product development stage to reduce cost, material usage and to achieve the desired efficacy level. There are various models wh... In the modern era of manufacturing, it is important to optimize every design parameter in product development stage to reduce cost, material usage and to achieve the desired efficacy level. There are various models which serve those purposes, for instance, Design of Experiment (DoE) is used to check the parameters after adopting optimization tactics which results in reduced cost or saving operating time. In this regard, this research aims to construct a DoE model on a portable workstation to optimize its design parameters. The methodology of DOE would be a 2 level 3 factors full factorial DOE which is conducted to determine the optimal value for three design parameters (factors) which are material density, the length of the table and the length of the table stand in terms of the response which is the required time of fold ability function of the portable workstation. Based upon the evaluated interactions between the parameters, the optimized parameters are chosen for responses. Here, the resultant design parameters are at their lowest level, so the goal of time efficiency in fold ability function is achieved. This similar sort of DoE can be implemented in the furniture and other manufacturing industries who wish to optimize their material usage as well as increase efficiency and reduce cycle time. 展开更多
关键词 DESIGN of EXPERIMENT (DoE) PORTABLE WORKSTATION DESIGN Parameters Response Time Efficiency Improvement
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Reduction of Environmental Impact of Drum Machine Washing 认领
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作者 Pieter Broer van der Weg (Peter) 《应用数学与应用物理(英文)》 2020年第1期132-157,共26页
An improvement of efficiency of the horizontally rotating drum washing machine is possible by using a more open type of drum, essentially without suds in the annulus, by using a pump to wet the clothes during rotation... An improvement of efficiency of the horizontally rotating drum washing machine is possible by using a more open type of drum, essentially without suds in the annulus, by using a pump to wet the clothes during rotation and fall. Modelling and simulation are used to quantify these claims and further optimize the design of the horizontal washing machine. The flow of suds inside the deforming clothes at impact with the drum is calculated. The wash performance is shown to be largely proportional to the open perforation area in the drum. The traditional design uses 1/8 of drum area for the perforation holes. A significant reduction of water, detergent, electrical energy, and wash time, with parity in wash performance, provides a step towards a cleaner and more sustainable future. 展开更多
关键词 DRUM WASH Machine Design Efficiency Poroelastics DARCY Simulation MODELLING
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Gravimetric Studies of Ni Electrodeposition with Additives from Deep Eutectic Solvents Using Electrochemical Quartz Crystal Microbalance EQCM 认领
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作者 K. Elttaib A. Benhmid 《物理化学期刊(英文)》 2020年第2期87-98,共12页
The gravimetric analysis of electrodeposited nickel is demonstrated using electrochemical quartz crystal microbalance (EQCM) where the nickel coatings come from a solution of the metal chloride salt separately in eith... The gravimetric analysis of electrodeposited nickel is demonstrated using electrochemical quartz crystal microbalance (EQCM) where the nickel coatings come from a solution of the metal chloride salt separately in either a1choline chloride: 2 ethylene glycol (ethaline) or 1 choline chloride: 2 urea (reline) based ionic liquid. The possibility of adapting the Quartz Crystal Microbalance EQCM (which measures the mass attached to the electrode) to probe kinetics of electrochemically-driven solid state phase transformations has been explored in a Ni electrodeposition in absence and presence of complexing agents ethylene diamine en and acetylacetonate acac from both electrolytes ethaline and reline. The study shows that the current efficiency and the rate of deposition of nickel coatings obtained from ethaline and reline baths in absence of brighteners en and acac are different, and the addition of en and acac to both ionic liquid solutions results in a significant decrease current. And the associated growth rate will also be decreased, suggesting that the en acac stops the formation and growth of Ni nuclei. This suggests that the mechanism of growth is changed. 展开更多
关键词 ELECTRODEPOSITION Quartz Crystal MICROBALANCE Ethaline Reline Eth-ylene DIAMINE ACETYLACETONATE Current Efficiency IONIC Liquids
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Safety in Surgery: Evaluation of Safety and Efficiency in Use of Aminoglycosides in Acute Appendicitis 认领
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作者 Tadeja Pintar Bojana Beovi? 《外科学(英文)》 2020年第5期99-110,共12页
Background: Aminoglycosides are used as empirical antibiotic treatment of intraabdominal infections which are caused by Gram negative bacteria and for which the treatment of choice is surgery. Aminoglycosides maintain... Background: Aminoglycosides are used as empirical antibiotic treatment of intraabdominal infections which are caused by Gram negative bacteria and for which the treatment of choice is surgery. Aminoglycosides maintain good efficacy against these bacteria and reduce the need for prescribing fluoroquinolone, cephalosporin and carbapenem antibiotics which contribute to the development of resistant bacterial strains. In recent years, several clinical trials and international guidelines have advised against the use of aminoglycosides owing largely to doubts about their effectiveness and to the concern for their known nephrotoxicity and ototoxicity. Aim: In our study, we aimed to prove whether aminoglycosides are appropriate agents in the treatment of acute appendicitis. Methods: Retrospectively, patients with acute appendicitis we included in the trial. Demographic characteristics, comorbidities, clinical signs and symptoms, the type of antibiotic and surgical treatment were analyzed. The effect of independent variables on the occurrence of complications was calculated using Student’s T-test and Fisher’s precise test. The effect of aminoglycosides on the loss of kidney function was determined by means of a linear regression method. Results: 300 patients proved acute appendicitis were included in the study. Univariate statistical analysis showed that the risk factors for postoperative complications in treating acute appendicitis were: age over 76 years (p Conclusion: Aminoglycoside antibiotics are a safe and effective treatment of acute appendicitis;our not published data are positive of AGs use in acute cholecystitis and left colon diverticulitis which requires surgery. If used for a limited time period, they do not increase the risk for kidney injury and remain a stable low level of all over complications. 展开更多
关键词 IAI (Intraabdominal Infections) AMINOGLYCOSIDES Acute APPENDICITIS SAFETY Use and Efficiency
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Polycrystalline Silicon Solar Cell p-n Junction Capacitance Behavior Modelling under an Integrated External Electrical Field Source in Solar Cell System 认领
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作者 Adama Ouedraogo Boukaré Ouedraogo +1 位作者 Boureima Kaboré Dieudonné Joseph Bathiebo 《能源与动力工程(英文)》 2020年第5期143-153,共11页
The state of the p-n junction is very important to explain the performances of a solar cell. Some works give the influence of the electric field on the junction capacitance. However, these works do not relate the qual... The state of the p-n junction is very important to explain the performances of a solar cell. Some works give the influence of the electric field on the junction capacitance. However, these works do not relate the quality of the p-n junction under the electic field. The present manuscript is about a theoretical modelling of the p-n junction capacitance behavior of the polycrystalline silicon solar cell under an integration of the external electrical field source. An external electrical source is integrated in a solar cell system. The electronic carriers charge generated in the solar cell crossed mainly the junction with the great strength external electrical field. In open circuit, this crossing of the electronic charge carriers causes the thermal heating of the p-n junction by Joule effect. The p-n junction capacitance plotted versus the junction dynamic velocity and the photo-voltage for different external electrical fields. The electric field causes the decrease of the photo-voltage mainly the open-circuit photo-voltage. The decrease of the photo-voltage translates the narrowing of the Space Charge Region (SCR). The average value of the external electric field used in this study is not sufficient to cause the breakdown of the p-n junction of the solar cell system under integration of the external electrical field production source. The increase of the electrical field causes rather the narrowing of the SCR. That can provide an improvement of the solar cell’s electrical outputs. 展开更多
关键词 POLYCRYSTALLINE Silicon Solar Cell Space Charge Region Photo-Current Photo-Voltage Conversion Efficiency pn-Junction CAPACITANCE EXTERNAL ELECTRICAL Field
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A Framework for an Energy-Efficient Bandwidth Allocation Approach through Dynamic ONTs Grouping in Flexible GPON Access Networks 认领
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作者 Ali A. Hammadi 《通讯、网络与系统学国际期刊(英文)》 2020年第1期1-14,共14页
The growing demands for high speed connectivity to keep pace with bandwidth intensive applications and services have spawned the idea of developing PONs with capabilities beyond those of copper and wireless-based tech... The growing demands for high speed connectivity to keep pace with bandwidth intensive applications and services have spawned the idea of developing PONs with capabilities beyond those of copper and wireless-based technologies in access network. In this article, an approach for the design of an energy efficient bandwidth allocation mechanism for the shared upstream communication link in the Fiber to the Home (FTTH) access network is presented and evaluated using Mixed Integer Linear Programming (MILP) model. In the MILP model, two objective functions for minimization of power consumption and minimization of blocking were evaluated. The results have shown that with the objective of power minimization approach, Optical Network Terminals (ONTs) are efficiently grouped to the minimum number of active networking Optical Line Terminal (OLT) switches, traffic is groomed, ports are efficiently utilized, and hence total power consumption is minimized. Results have shown that with energy efficient bandwidth allocation approach consideration, energy savings can reach up to 80% for different examined traffic loads following uniform distribution. 展开更多
关键词 Fiber to the Home (FTTH) GIGA Passive Optical Network (GPON) Energy Efficiency BLOCKING PROBABILITY Optimization
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Electroless Plating of Palladium Membranes on Porous Substrates for Hydrogen Separation and the Effects of Process Factors on Plating Rate and Efficiency: A Review 认领
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作者 Abubakar Alkali 《电力能源(英文)》 2020年第2期1-19,共19页
The electroless plating of palladium and palladium alloy membranes is fast becoming an important and enabling technology. This is more so when juxtaposed with the rising demand for high purity hydrogen for application... The electroless plating of palladium and palladium alloy membranes is fast becoming an important and enabling technology. This is more so when juxtaposed with the rising demand for high purity hydrogen for applications particularly in proton exchange membrane fuel cells (PEMFC). The effect of process factors such as sensitization and activation during surface modification, concentration of the reducing agent, plating temperature, time, pH, additives, air aeration on plating efficiency, quality of the palladium film and deposit morphology is reviewed with the aim of identifying areas requiring further investigation. The paper also reviews how these process factors could be optimised for better plating efficiency and overall membrane quality. The concentration of the reducing agent has been identified as the limiting factor on plating efficiency albeit other process factors separately impact on the plating efficiency. Furthermore, bulk precipitation caused by concentration of the reducing agent has been identified as a major problem during electroless plating with hydrazine based plating baths. To ameliorate this problem, a multi step addition of the hydrazine reducer in separate portions has been recommended. 展开更多
关键词 ELECTROLESS PLATING Hydrogen PALLADIUM Membranes PLATING EFFICIENCY PROCESS FACTORS
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新形势下提升农业科研单位办公室工作效能的思考 认领
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作者 李彦平 李耀宇 +3 位作者 程泽强 王红军 张昭 田明津 《农业科技管理》 2020年第3期87-89,93,共4页
文章认真研判了新形势下农业科研单位办公室工作要求,分析了办公室工作中存在的问题,并从人才队伍建设、明确岗位职责、完善规章制度、健全激励机制、推行办公自动化等方面提出了提升农业科研单位办公室工作效能的建议,以期为新形势下... 文章认真研判了新形势下农业科研单位办公室工作要求,分析了办公室工作中存在的问题,并从人才队伍建设、明确岗位职责、完善规章制度、健全激励机制、推行办公自动化等方面提出了提升农业科研单位办公室工作效能的建议,以期为新形势下农业科研单位做好办公室工作提供参考。 展开更多
关键词 新形势 农业科研单位 办公室工作 效能 高效 创新 优质
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可对抗联合攻击的设备无关量子安全直接通信 认领
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作者 周澜 盛宇波 龙桂鲁 《科学通报:英文版》 SCIE EI CSCD 2020年第1期12-20,M0003共10页
本文提出了第一个设备无关量子安全直接通信(DI-QSDC)方案,并分析其在联合攻击模式下的安全性和通信效率.DI-QSDC不仅能免除对实验设备的高要求,还能增强通信的安全性.然而,在实际噪声量子信道条件下,信道噪声引起的光子传输丢失和退相... 本文提出了第一个设备无关量子安全直接通信(DI-QSDC)方案,并分析其在联合攻击模式下的安全性和通信效率.DI-QSDC不仅能免除对实验设备的高要求,还能增强通信的安全性.然而,在实际噪声量子信道条件下,信道噪声引起的光子传输丢失和退相干效应导致DI-QSDC的通信效率较低、通信距离短,且可能出现信息丢失及信息错误.同时,光子传输丢失和退相干效应还可能导致部分信息泄露,威胁DI-QSDC的绝对安全性.为克服光子传输丢失和退相干效应,本文在DI-QSDC方案中引入量子态指示放大及纠缠纯化方案.改良后的DI-QSDC方案能完全消除信息丢失,有效延长通信距离,提高信息正确度,并完全消除信息泄露,保证通信的绝对安全.因此,改良的DI-QSDC方案在未来量子通信领域具有较大的应用潜力. 展开更多
关键词 QUANTUM CRYPTOGRAPHY Device-independent QUANTUM secure direct COMMUNICATION Information security COMMUNICATION efficiency
汽车用交流发电机72槽整流桥 认领
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作者 刘军 孔繁秋 《汽车电器》 2020年第3期46-47,51共3页
本文介绍一款新型72槽整流桥,结构简单,使用可靠,提升了发电机输出功率及效率。
关键词 汽车发电机 整流桥 效率提升 高效二极管 散热性能好 点焊
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创新驱动发展战略下中国财政科技支出效率评价——基于三阶段超效率SBM-DEA模型 认领
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作者 王谦 董玥 董艳玲 《科技管理研究》 CSSCI 北大核心 2020年第5期23-33,共11页
基于省际面板数据,构建包括科技成果、经济效益和社会效益的效率评价体系,采用三阶段超效率SBM-DEA模型对中国30个省(区、市)财政科技支出效率进行测度。研究表明:全国整体财政科技支出效率未实现DEA相对完全有效;经济发展水平、地方政... 基于省际面板数据,构建包括科技成果、经济效益和社会效益的效率评价体系,采用三阶段超效率SBM-DEA模型对中国30个省(区、市)财政科技支出效率进行测度。研究表明:全国整体财政科技支出效率未实现DEA相对完全有效;经济发展水平、地方政府干预度对提高财政科技支出效率具有正向作用,而对外开放水平、财政分权度不利于财政科技支出效率的提高;剔除外界环境和随机干扰因素后,多数省(区、市)技术效率和纯技术效率上升,规模效率下降,全国整体及各省(区、市)财政科技资金投入没有达到最优规模;中国财政科技支出效率存在地区差异。 展开更多
关键词 财政科技支出 效率 创新驱动发展 三阶段超效率SBM-DEA模型
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基于SE-DEA-NT的高校协同创新效率分异研究 认领
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作者 吴和成 李犟 《科技管理研究》 CSSCI 北大核心 2020年第5期39-47,共9页
基于2012—2016年教育部直属高校协同创新数据,运用超效率DEA模型测度高校协同创新效率和资源冗余程度,并借助非参数统计方法对效率进行分析。研究发现,样本高校中有16.9%的高校在分析期内保持持续的协同创新高效率,有28.8%的样本高校... 基于2012—2016年教育部直属高校协同创新数据,运用超效率DEA模型测度高校协同创新效率和资源冗余程度,并借助非参数统计方法对效率进行分析。研究发现,样本高校中有16.9%的高校在分析期内保持持续的协同创新高效率,有28.8%的样本高校其协同创新活动在分析期内持续表现为无效状态;高校协同创新平均效率在分析期内的变化在统计上不显著;样本高校协同创新效率表现为10类不同的分布状况;仅有4所高校的经费和人力投入冗余率均较小,超过50%的样本高校在经费与人力投入冗余率上相当,其余高校则在经费和人力冗余率指标上差异显著。 展开更多
关键词 协同创新 效率 分布状况 超效率模型
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Container Terminal Land-Utilisation Efficiency in Ghana 认领
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作者 George Kobina vanDyck Stephen Anokye Domfeh George Konney 《交通科技期刊(英文)》 2020年第1期1-15,共15页
Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study an... Land-use efficiency is essential in ports, in particular those that are constrained for space and experiencing congestion. In such situations, ports have been noted to invest in off-dock container yards. This study analysed land use efficiency of four off-dock yards located near the Port of Tema, Ghana’s largest seaport responsible for 85 percent of its trade. The study found that the terminals utilised 0.13 to 0.52 hectares of land, largely influenced by the dwell time and stacking height of containers. It was recommended that regulatory agencies need to coordinate better to reduce the time spent on cargo inspection and validation. In addition, terminals may need to incentivise customers to clear their import containers within shorter periods. 展开更多
关键词 LAND UTILISATION Container Terminal Off DOCK YARD Ghana EFFICIENCY DWELL Time
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具有类叶绿体多孔核壳结构的铋基催化剂用于高效CO2电还原 认领
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作者 王艺蓉 杨汝欣 +4 位作者 陈宜法 高广阔 王玉洁 李顺利 兰亚乾 《科学通报:英文版》 SCIE EI CAS CSCD 2020年第19期1635-1642,M0003,M0004,共10页
二氧化碳的过量排放引发了一系列的环境和能源问题.如何将CO2转化为我们生活所需的能源产品对于人类社会的发展具有重大意义.从能量输入和市场价值等方面考虑,利用电化学方法将CO2电还原为甲酸是一种较为理想且绿色的解决途径.本文设计... 二氧化碳的过量排放引发了一系列的环境和能源问题.如何将CO2转化为我们生活所需的能源产品对于人类社会的发展具有重大意义.从能量输入和市场价值等方面考虑,利用电化学方法将CO2电还原为甲酸是一种较为理想且绿色的解决途径.本文设计合成了一系列具有类叶绿体多孔核壳结构的铋基催化剂(简写为CPBC-x)用于CO2电还原.在电催化过程中,CPBC-x外层的多孔碳可以将CO2富集并转移到催化中心Bi@Bi2O3中,Bi可以提供电子,Bi2O3可以转化为高活性的亚稳态,高效地将CO2电催化转化为甲酸.CPBC-x表现出很好的化学稳定性和优异的电催化活性,其中,CPBC-1在较宽的电位范围(-0.65~-1.0 V)内法拉第效率可以达到94%以上,其能量效率在-0.7 V下高达76.7%,是目前已报道的铋基材料中能量效率最高的.此外,这类催化剂具有良好的催化稳定性,能够保持高催化效率循环使用72 h以上.这一工作为新型CO2电还原催化剂的设计和制备提供了新思路. 展开更多
关键词 Chloroplast-like porous structure Bi-based activated metastable layer CO2 electroreduction High energy efficiency FORMATE
青藏高原边缘区地震灾后的经济韧性及恢复效率——以汶川Ms 8.0地震极重灾区为例 认领
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作者 周侃 刘宝印 樊杰 《地理学报:英文版》 SCIE CSCD 2020年第8期1363-1381,共19页
The border areas of the Tibetan Plateau and the neighboring mountainous areashave a high incidence of earthquakes with a magnitude greater than Ms 5.0, as well as havinga dense distribution of geological disasters suc... The border areas of the Tibetan Plateau and the neighboring mountainous areashave a high incidence of earthquakes with a magnitude greater than Ms 5.0, as well as havinga dense distribution of geological disasters such as collapses, landslides, and debris flows.Revealing the post-disaster economic development and recovery process is very importantfor enhancing disaster prevention and response capacity in order to formulate control policiesand recovery methods for post-disaster economic reconstruction based on economic resilience.Using long-term socioeconomic data and the autoregressive integrated moving average(ARIMA) model, this paper calculated the economic resilience index of the areas mostseverely affected by the Wenchuan Earthquake of 2008 and adopted the improved variablereturns to scale (VRS) date envelopment analysis (DEA) model and the Malmquist productivityindex to analyze the efficiency and effect of annual post-disaster recovery. The resultsshow that: (1) the economic resilience index of the areas most severely affected by theWenchuan Earthquake was 0.877. The earthquake resulted in a short-term economic recessionin the affected areas, but the economy returned to pre-quake levels within two years. Inaddition, the industrial economy was less resilient than agriculture and the service industry. (2)The comprehensive economic recovery efficiency of the disaster-stricken area in the yearfollowing the disaster was 0.603. The comprehensive efficiency, the pure technical efficiency,and the scale efficiency of the plain and hilly areas were significantly greater than those of theplateau and mountain areas. (3) The annual fluctuation in total factor productivity (TFP) followingthe disaster was considerable, and the economic recovery efficiency decreased significantly,resulting in a short-term economic recession. The TFP index returned to steadystate following decreases of 33.7% and 15.2%, respectively, in the two years following thedisaster. (4) The significant decrease in the post-disaster recovery efficiency 展开更多
关键词 economic resilience recovery efficiency Malmquist productivity index post-disaster reconstruction area Wenchuan Earthquake border areas of the Tibetan Plateau
中美电力行业的技术效率和生产率比较 认领
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作者 李彦豪 《电力系统装备》 2020年第14期165-166,共2页
随着我国可持续发展意识的日益增强,人们对碳排放也越来越重视,由此催生的清洁能源发电也在快速发展,与美国的电力行业技术差距正在日益缩小,并且在输电方面还具有一些优势。但对于以煤电为主的我国电力产业而言,煤电基数大,行业结构并... 随着我国可持续发展意识的日益增强,人们对碳排放也越来越重视,由此催生的清洁能源发电也在快速发展,与美国的电力行业技术差距正在日益缩小,并且在输电方面还具有一些优势。但对于以煤电为主的我国电力产业而言,煤电基数大,行业结构并没有发生根本性的改变。2002年中国电力行业实施了“厂网分开”的重大改革,而考虑到行政指导定价下的电价,此改革的效果颇受质疑。所以现今社会与学术界广泛关注的问题已然变成电力产业技术效率在改革前后的变迁评价。本文旨在对中美电力行业技术效率上进行对比,以希望找到今后可以改进的地方,为将来的电力技术发展贡献一份力量。 展开更多
关键词 电力行业 效率 生产效率
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Analysis of Decoupling of Economic Growth and Resource Consumption in China’s Marine Fishery 认领
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作者 Zixiao Su Yannan Wang Jianwen Ji 《地球科学和环境保护期刊(英文)》 2020年第3期10-21,共12页
The marine fishery resources are declining with the increase of fishing intensity, and the sustainable development of marine fishery economy has become the focus of attention. In this paper, the economic loss of marin... The marine fishery resources are declining with the increase of fishing intensity, and the sustainable development of marine fishery economy has become the focus of attention. In this paper, the economic loss of marine natural fishery resources is taken as the undesired output. The SBM model is used to evaluate the economic efficiency of marine fisheries in 11 provinces and cities in China’s coastal areas from 2004 to 2015. Based on this, decoupling theory is adopted to analyze the spatial and temporal evolution pattern of marine fishery economic efficiency and resource consumption in various provinces and cities. The results show that: 1) Based on the perspective of time and space, the economic efficiency of marine fisheries in 11 provinces and cities along the coast of China is polarized and has not been effectively improved, indicating that the level of fishery economic development in China’s coastal areas is unbalanced;2) Based on the overall perspective, the overall economic efficiency of China’s marine fisheries is low, indicating that China’s marine fishery economy is developing at a slower rate;3) Based on the perspective of decoupling theory, the economic efficiency of marine fisheries in China and the consumption of fishery resources have shown a trend in the research period. The structure of China’s marine fishery industry, which is dominated by traditional fisheries, needs to be adjusted. 展开更多
关键词 ECONOMIC Efficiency of Marine FISHERIES Undesired OUTPUT SBM DECOUPLING Theory
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Analysis of the Effectiveness and Efficiency of the VA Solution on Offshore Pipelines and Ship Materials 认领
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作者 Samson Nitonye Prince Ugboga 《海洋科学期刊(英文)》 2020年第1期16-31,共16页
The analysis of the effectiveness and efficiency of Vernomia amydalina (VA) solution as an inhibitor on offshore pipeline and Ship materials (Steel) was carried out with the preparation of the specimen and the VA solu... The analysis of the effectiveness and efficiency of Vernomia amydalina (VA) solution as an inhibitor on offshore pipeline and Ship materials (Steel) was carried out with the preparation of the specimen and the VA solution. The specimens were kept in a workable state and the VA Solution (inhibitor) prepared from 1200 g of bitter leaf was plucked, weighed and crushed separately. 600 cl of water was added to each of the crushed leaves. The mixture was put in a filter cloth and squeezed with hand to filter out the active concentration ingredients responsible for corrosion inhibition, which produced a 2 M concentration of VA extract solution. After the experiment was carried out the specimen was air-dried and weighed to determine the corrosion rate and weight loss. This was followed by the determination of the inhibitor efficiency at the different hours and at different percentage/concentration of the VA solution on the specimen. Results were obtained for different hours and at different percentage (0%, 5%, 10%, 15%, 20% and 25% inhibitor)/concentration of the VA solution and graphs plotted. It was observed that at the first week of exposure to corrosive medium there was a substantial reduction in weight of coupons but over the next three weeks there was a gradual decline in weight loss and the corrosion rate reduced evenly. It can be said that the percentage of inhibitor to corrosive medium is insufficient. From the graphs plotted, the inhibitor efficiency is considered high when the concentration of the VA solution is high, which implies a right percentage of inhibitor needs to be administered to obtain good efficiency of the solution. Hence as the weeks go by it was clear that the inhibitor was gradually losing its effectiveness. This means that inhibitors need to be added at regular intervals to sustain the effectiveness of the inhibitor. It is also of vital interest to apply the right concentration of inhibitor since CR increases at high concentrations and temperature. This process did not take into consideration 展开更多
关键词 Vernomia amydalina INHIBITORS EFFICIENCY MILD Steel CORROSION ENVIRONMENT
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