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Analysis on Agrometeorological Conditions of Production of Winter Wheat and Rape Crops in Western Guizhou in 2019 认领
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作者 Lijuan LIU Zaixiang CHI +3 位作者 Yan PENG Zijiang YANG Yanlin XIAO Ruyong LONG 《气象与环境研究:英文版》 CAS 2020年第4期110-114,共5页
Whole growth period of winter wheat and rape crops in western Guizhou in 2019 was from October of 2019 to early May of 2020.Using daily temperature,rainfall and sunshine hours of three national meteorological observat... Whole growth period of winter wheat and rape crops in western Guizhou in 2019 was from October of 2019 to early May of 2020.Using daily temperature,rainfall and sunshine hours of three national meteorological observatories(Shuicheng,Panzhou and Liuzhi)of western Guizhou,the impact of meteorological conditions on growth and development of winter wheat and rape crops was analyzed.The results showed that average temperature in whole growth period of winter wheat and rape crops in western Guizhou in 2019 was between 11.1 and 13.0℃,which was 0.4-1.6℃higher than that in the same period of common year.Rainfall was between 276.0 and 309.0 mm.When compared with that in the same period of common year,rainfall was 7%-22%less in other regions except in Panzhou(1%more).Sunshine hours was between 689.2 and 1091.2 h.When compared with that in the same period of common year,sunshine hours was 14%-26%more in other regions except in Shuicheng(equal).In growth period of winter wheat and rape crops,there was good heat condition and sufficient sunshine,and rainfall was normal and slightly less,but it was mostly sunny and rainy alternating,which was favorable for the growth of crop root.During growth period of crops,there was lighter meteorological disaster.It was clear that meteorological conditions were conducive to the growth and development of winter wheat and rape crops in 2019. 展开更多
关键词 Winter wheat Winter rape Meteorological condition INFLUENCE Western Guizhou
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Mesoscale Impacts on Cold Season PM<sub>2.5</sub>in the Yukon Flats 认领
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作者 Stanley G. Edwin Nicole M?lders 《环境保护(英文)》 2020年第3期215-240,共26页
Near-surface PM2.5 and meteorological observations were performed in three rural communities in the high latitude Yukon Flats valley at various times during the cold season (October to April). These data were synthesi... Near-surface PM2.5 and meteorological observations were performed in three rural communities in the high latitude Yukon Flats valley at various times during the cold season (October to April). These data were synthesized with data from other meteorological sites, NCEP reanalysis and MAIAC retrieved aerosol optical depths data to analyze the role of mesoscale processes and radiation on air quality. Under weak large-scale forcing mountain-valley circulations develop that are driven by the differences in insolation. During the long dark nights, radiative cooling occurs in the near-surface layer of the mountain slopes of the Brooks, Ogilvie and White Mountains Ranges and at the bottom of the valley. Here surface-based inversions (SBI)—known as roof-top inversions—forms, while the cold air drains from the slopes. A frontal wedge forms when the cold air slides over the relatively colder air in the valley. Drainage of cold air from the Brooks Range governed the circulation and cold air pooling in the valley. Concentrations during times with and without SBI differed significantly (at 95% confidence) at two sites indicating that local emissions were the major contributor. At the site, which is closest to the mountains, concentrations marginally changed in the presence of inversions. At all sites, 24-h mean PM2.5 remained below the National Ambient Air Quality Standard. 展开更多
关键词 YUKON Flats AIR Quality Winter Roof-Top Inversions High Latitudes MESOSCALE Circulations Radiative Cooling COLD AIR Pooling Aerosols PM2.5
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急性ST段抬高型心肌梗死全程心电图表现并“de Winter”探讨 认领
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作者 褚庆民 唐娜 +1 位作者 金政 李荣 《中国全科医学》 CAS 北大核心 2020年第21期2719-2723,共5页
de Winter心电图表现被视为急性ST段抬高型心肌梗死(STEMI)的心电图,证据源于患者临床冠状动脉造影提示左前降支(LAD)近端严重狭窄或完全闭塞,这与既往STEMI典型四期心电图表现内在关系如何不明确。本文收集了1例急性STEMI患者全程心电... de Winter心电图表现被视为急性ST段抬高型心肌梗死(STEMI)的心电图,证据源于患者临床冠状动脉造影提示左前降支(LAD)近端严重狭窄或完全闭塞,这与既往STEMI典型四期心电图表现内在关系如何不明确。本文收集了1例急性STEMI患者全程心电图演变及国内外相关文献,试分析急性STEMI与de Winter心电图的内在联系,旨在为进一步认识de Winter心电图提供新思路。 展开更多
关键词 心肌梗死 DE WINTER 急性病 心电描记术 冠状动脉闭塞
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Study on the Effects of Extreme Precipitation for Seven Growth Stages of Winter Wheat in Northern Weihe Loess Plateau, China 认领
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作者 Ouk Sereyrorth Baowen Yan +2 位作者 Khem Chunpanha Porn Lybun Pich Linvolak 《水资源与保护(英文)》 2020年第4期358-380,共23页
The research on the characteristic frequency of precipitation is a great significance for guiding regional agricultural planning, water conservancy project designs, and drought and flood control. Droughts and floods o... The research on the characteristic frequency of precipitation is a great significance for guiding regional agricultural planning, water conservancy project designs, and drought and flood control. Droughts and floods occurred in northern Weihe Loess Plateau, affecting growing and yield of winter wheat in the area. Based on the daily precipitation data of 29 meteorological stations from 1981 to 2012, this study is to address the analysis of three different frequencies of annual precipitation at 5%, 50%, and 95%, and to determine the amount of rainfall excess and water shortage during seven growth stages of winter wheat at 5%, 10%, and 20% frequencies, respectively. Pearson type III curve was selected for this study to analyze the distribution frequency of annual rainfall and rainfall amount following seven growth stages of winter wheat crop in 29 stations of Northern Weihe loess plateau. As a result of our study, annual precipitation is gradually increasing from southwest to northeast of Northern Weihe loess plateau. The highest amount of annual precipitation occurred in the Baoji area and the lowest precipitation covered by the northwest area of Northern Weihe loess plateau. Moreover, the amount of rainfall of seven growth stages indicates that excessive rainfall occurs not only in the first stage (sowing to tillering) and seventh stage (flowering to ripening) but also in second stage (tillering to wintering). In the seventh stage, a large amount of excessive rainfall occurred in Changwu, Bin, Qianyang, Fengxiang, Baojiqu, and Baojixian. Moreover, water shortage is distributed in the third stage (from wintering to greening), the fourth stage (from greening to jointing), the fifth stage (from jointing to heading), and the sixth stage (from heading to flowering). Furthermore, the worst water shortages occurred in Hancheng, Heyang, Chengcheng, Pucheng, Dali, Tongchuan, and Fuping in the fourth stage (greening to jointing stage). Even though we study the crop water requirement under extreme rainfall conditions, the am 展开更多
关键词 Extreme PRECIPITATION Annual PRECIPITATION SEVEN Growth Stages Winter Wheat Crop Rainfall Excess Water SHORTAGE NORTHERN Weihe Loess Plateau
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文章速递下颌智齿阻生类型及其邻牙远中邻面患龋情况的对称性初探 认领
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作者 张炜崎 俞维君 +3 位作者 姜滨 胡淑澄 郁利 陆尔奕 《口腔材料器械杂志》 2020年第4期207-211,共5页
目的调查下颌第三磨牙生长情况的对称性及其对相邻第二磨牙远中邻面龋患病情况的影响,为临床早期预防性拔除下颌智齿提供依据。方法纳入2019年11月1日至2019年11月23日在上海交通大学医学院附属仁济医院口腔科拍摄的全景片196张,调查其... 目的调查下颌第三磨牙生长情况的对称性及其对相邻第二磨牙远中邻面龋患病情况的影响,为临床早期预防性拔除下颌智齿提供依据。方法纳入2019年11月1日至2019年11月23日在上海交通大学医学院附属仁济医院口腔科拍摄的全景片196张,调查其双侧下颌第三磨牙的对称性,通过卡方检验分析不同阻生类型的下颌第三磨牙与相邻第二磨牙远中邻面龋患病情况之间的关系。结果双侧下颌第三磨牙对称者187例,占比95.41%。Winter分类中垂直阻生对称性(79.2%)显著高于近中阻生(47.6%)与水平阻生(59.1%)(P=0.001);Winter分类为近中阻生(46.4%)和水平阻生(38.4%)的下颌第三磨牙,其相邻第二磨牙远中邻面龋发生率显著高于垂直阻生(23.6%)(P=0.001)。结论下颌智齿具有对称性;为预防相邻第二磨牙远中邻面龋,近中阻生及水平阻生的下颌第三磨牙应在临床上早期预防性拔除。 展开更多
关键词 下颌第三磨牙 阻生齿 龋齿 Winter 分类
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INTEGRATION OF PARTY DIPLOMACY,PING-PONG DIPLOMACY AND TEA TALK DIPLOMACY--A RECORD OF THE 11TH CHINA-U.S.POLITICAL PARTY LEADERS DIALOGUE 认领
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作者 SONG SIZE 《当代世界:英文版》 2020年第1期37-40,共4页
It was an early winter,and golden leaves of ginkgo had piled up by the riverbanks of Kunyu.Inside the building of the International Department of the CPC Central Committee(IDCPC),the atmosphere was exciting.Around 50 ... It was an early winter,and golden leaves of ginkgo had piled up by the riverbanks of Kunyu.Inside the building of the International Department of the CPC Central Committee(IDCPC),the atmosphere was exciting.Around 50 political leaders,think-tank scholars and entrepreneurs were here for the 11th China-U.S.Political Party Leaders Dialogue,an event themed with“Political Parties and China-U.S.Relations”,to exchange their ideas and seek consensus. 展开更多
关键词 PING DIP winter
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Improved soil characteristics in the deeper plough layer can increase grain yield of winter wheat 认领
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作者 CHEN Jin PANG Dang-wei +4 位作者 JIN Min LUO Yong-li LI Hao-yu LI Yong WANG Zhen-lin 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第5期1215-1226,共12页
In the North China Plain(NCP), soil deterioration threatens winter wheat(Triticum aestivum L.) production. Although rotary tillage or plowing tillage are two methods commonly used in this region, research characterizi... In the North China Plain(NCP), soil deterioration threatens winter wheat(Triticum aestivum L.) production. Although rotary tillage or plowing tillage are two methods commonly used in this region, research characterizing the effects of mixed tillage on soil characteristics and wheat yield has been limited. A fixed-site field trial was carried out during 2011–2016 to examine the impacts of three tillage practices(5-year rotary tillage with maize straw removal(RT);5-year rotary tillage with maize straw return(RS);and annual RS and with a deep plowing interval of 2 years(RS/DS)) on soil characteristics and root distribution in the plough layer. Straw return significantly decreased soil bulk density, increased soil organic carbon(SOC) storage and SOC content, macro-aggregate proportion(R_(0.25)) and its stability in the plough layer. The RS/DS treatment significantly increased the SOC content, total nitrogen(TN), and root length density(RLD) in the 10–40 cm layer, and enhanced the proportion of RLD in the 20–30 and 30–40 cm layers. In the 20–30 and 30–40 cm layers, an increase in SOC and TN could lead to higher grain production than commensurate increases in the surface layer, resulting in a sustainable increase in grain yield from the RS/DS treatment. Thus, the RS/DS treatment could lead to high productivity of winter wheat by improving soil characteristics and root distribution at the deeper plough layer in the NCP. 展开更多
关键词 soil CHARACTERISTICS root length density TILLAGE practice STRAW RETURN winter wheat
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高食性重叠度对同域物种生境分离的影响——以马鹿和狍为例 认领
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作者 吕忠海 冯源 +2 位作者 于沿泽 张明海 张玮琪 《东北林业大学学报》 CAS CSCD 北大核心 2020年第2期72-75,共4页
2013年和2014年的1月份,在黑龙江穆棱东北红豆杉国家级自然保护区野外调查、采集东北马鹿(Cervus elaphus xanthopygus)与狍(Capreolus pygargus)的粪便,应用粪便显微组织学分析技术对马鹿、狍粪便组成成分对比分析,探讨同域分布的马鹿... 2013年和2014年的1月份,在黑龙江穆棱东北红豆杉国家级自然保护区野外调查、采集东北马鹿(Cervus elaphus xanthopygus)与狍(Capreolus pygargus)的粪便,应用粪便显微组织学分析技术对马鹿、狍粪便组成成分对比分析,探讨同域分布的马鹿和狍的生境选择及食性的差异。结果表明:马鹿除采食东北红豆杉外,其余采食植物与狍的完全相同,二者食性重叠度高达84.8%。马鹿与狍采食植物多样性指数都较高,而营养生态位宽度则很低。在高食物重叠性的影响下,马鹿与狍对生境因子选择发生明显的分离。马鹿主要选择人为干扰距离大于1 km,海拔、食物丰富度、隐蔽度较高,阳坡,对于坡位要求并不十分严格的针阔混交林生境;而狍主要选择人为干扰距离小于1 km,海拔、食物丰富度、隐蔽度相对较低,阳坡,中坡位及上坡位的灌丛生境。 展开更多
关键词 穆棱林区 冬季 马鹿 生境选择 食性
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霜冻天气条件下浅层土壤温度变化特征分析 认领
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作者 韩湘云 钱晰 《农业灾害研究》 2020年第1期41-42,共2页
选择江苏海安市为研究对象,研究春、冬季浅层土壤温度的变化规律及在发生霜冻情况下土壤温度的动态变化特征。结果表明,从季节变化来看,近地层土壤温度变化趋势与气温一致,变化幅度没有气温剧烈,土层越深,土壤温度变化趋势越来越平缓;... 选择江苏海安市为研究对象,研究春、冬季浅层土壤温度的变化规律及在发生霜冻情况下土壤温度的动态变化特征。结果表明,从季节变化来看,近地层土壤温度变化趋势与气温一致,变化幅度没有气温剧烈,土层越深,土壤温度变化趋势越来越平缓;各层土温日内变化均呈现正弦曲线状态,其中地表温度的变幅较大,且出现极值的时间比20 cm土层出现极值的时间早4 h左右;春季地气间热量交换比冬季大,极易发生晚霜冻。 展开更多
关键词 土壤温度 春季 冬季 霜冻 变化特征
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TO LOVE AND BE LOVED 认领
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作者 Yang Yue 《中国东盟报道(英文)》 2020年第7期58-59,共2页
The campus of Yangon University of Foreign Languages(YUFL)is quite pleasant in December.People comfortably walk and chat across the campus as cool winter breezes gently ruffle their clothes including the longyi,a trad... The campus of Yangon University of Foreign Languages(YUFL)is quite pleasant in December.People comfortably walk and chat across the campus as cool winter breezes gently ruffle their clothes including the longyi,a traditional Myanmar dress.Lazy winds caress layers of green leaves bathed in sunlight,splashing gold glitter on an empty wooden bench.Next to it,a woman in an indigo blue Myanmar dress emerges from the Department of Chinese building.It is immediately clear that she is a teacher because of the outfit designed for all female teachers at YUFL. 展开更多
关键词 DRESS winds WINTER
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2022冬奥会——相聚北京 认领
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作者 吕品 《疯狂英语:读写版》 2020年第7期13-16,共4页
第24届冬奥会将于2022年2月4日至2022年2月20日在中国北京和张家口举行。Having won the bid for the 2022 Winter Olympic Games on July 31, 2015, Beijing is set to become the first city in the world to have hosted both the su... 第24届冬奥会将于2022年2月4日至2022年2月20日在中国北京和张家口举行。Having won the bid for the 2022 Winter Olympic Games on July 31, 2015, Beijing is set to become the first city in the world to have hosted both the summer and winter editions of the Olympic Games. 展开更多
关键词 冬奥会 WINTER EDITION
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Effects of Different Line Spacing and Seedling Belt Width on Yield Formation of Broad-Width Fine Sowing Wheat 认领
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作者 Minmin SHAO Leiming SUN +5 位作者 Kai ZHAO Xingke XU Ling HUANG Lin WANG Lu YAN Zhengchun JU 《农业生物技术:英文版》 CAS 2020年第3期29-33,共5页
In order to explore the interaction effects of line spacing and seedling belt width on wheat yield formation and improve the cultivation techniques of broadwidth and fine seeding of wheat,a high-yielding winter wheat ... In order to explore the interaction effects of line spacing and seedling belt width on wheat yield formation and improve the cultivation techniques of broadwidth and fine seeding of wheat,a high-yielding winter wheat cultivar Shannong 28 was selected as material. Using the split plot design,the main plot was set with line spacing as 20,25 and 30 cm,respectively,and the sub-plot was set with seedling belt width as 3,5,7,9 and 11 cm,respectively. Then,the population dynamics,dry matter accumulation and translocation and yield of wheat were studied under the experimental conditions. The results showed that under the line spacing of 20 cm,the dry matter accumulation and yield of winter wheat were higher with the seedling belt width of 5 cm. When the line spacing was 25 cm,the dry matter accumulation and yield under the seedling belt width of 9 cm reached a high level. Under the line spacing of 30 cm,Shannong 28 achieved higher dry matter accumulation and yield with the seedling belt width of 11 cm. Comprehensive analysis revealed that the suitable treatment for Shannong 28 was 25 cm of line spacing with 9 cm of seedling belt width,which could realize the coordination of the three factors of yield composition and get higher yield. Therefore,the reasonable line spacing and seedling belt width were the important technical ways to realize high yield of wheat. 展开更多
关键词 Winter wheat Wide planting Row space form Seedling belt width YIELD
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贺兰山马麝冬季生境选择 认领
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作者 孙嘉 赵唱 +4 位作者 孟德怀 米书慧 李宗智 滕丽微 刘振生 《野生动物学报》 北大核心 2020年第3期573-579,共7页
2014—2016年在内蒙古贺兰山,采用样线法与样方法,对马麝(Moschus chrysogaster sifanicus)的冬季生境选择进行了研究。生境选择数据表明:贺兰山马麝在冬季对生境具有选择性。通过使用拟合优度卡方检验对3种非数值型的生态因子(植被类... 2014—2016年在内蒙古贺兰山,采用样线法与样方法,对马麝(Moschus chrysogaster sifanicus)的冬季生境选择进行了研究。生境选择数据表明:贺兰山马麝在冬季对生境具有选择性。通过使用拟合优度卡方检验对3种非数值型的生态因子(植被类型、优势乔木、坡向)进行研究,分析数据得出:(1)在冬季贺兰山马麝对植被类型具有选择性(P<0.01),其中偏好利用山地针叶林,对亚高山灌丛草甸带随机利用,对山地混交林带与山地疏林草原带无选择性。(2)对优势乔木有选择性(P<0.01),在优势乔木中偏好利用青海云杉林生境,随机利用混合型生境,避免选择杜松、油松、山杨、旱榆这4种优势乔木生境。(3)马麝对坡向具有选择性(P<0.01),偏好利用半阴半阳坡,随机利用阴坡生境,避免选择阳坡。采用Mann-Whitney U检验对马麝冬季的利用样方与对照样方中的13种数值型生境因子进行比较,得出马麝在冬季更偏好选择。偏好利用海拔高度高、乔木密度大、高乔木、灌木密度低、灌木高度高、灌木距离大、植被盖度小、坡度低、雪被深、隐蔽级高的生境类型。 展开更多
关键词 贺兰山 马麝 冬季 生境选择
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Strip rotary tillage with subsoiling increases winter wheat yield by alleviating leaf senescence and increasing grain filling 认领
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作者 Jianning He Yu Shi +1 位作者 Junye Zhao Zhenwen Yu 《作物学报:英文版》 SCIE CAS CSCD 2020年第2期327-340,共14页
Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of ... Sustainable agriculture in the Huang–Huai–Hai Plain of China is threatened by subsoil compaction and the decline of winter wheat productivity induced by inappropriate tillage regimes. We investigated the effects of optimizing the tillage regime on grain filling and its relationship with flag leaf senescence post-anthesis in winter wheat. Four treatments were compared: rotary tillage, strip rotary tillage, strip rotary tillage with a 2-year subsoiling interval(STS), and conventional plowing tillage. STS produced higher chlorophyll content and leaf area indexes than other treatments, resulting in a greater photosynthetically active radiation capture ratio. The net photosynthesis rate of flag leaves from 14 to 28 days after anthesis and dry matter accumulation at maturity were higher in STS than in other treatments. Sucrose content and sucrose phosphate synthase activity of flag leaves first increased and then decreased during grain filling and were highest in STS. STS increased superoxide dismutase activity, increased soluble protein content, and reduced malondialdehyde concentrations in flag leaves after the middle grain-filling stages,resulting in reduced premature senescence. This consequence extended the active grain filling period and increased grain weight. The highest yields were observed in STS, reaching10,451 kg ha-1 in 2014–2015 and 10,074 kg ha-1 in 2015–2016, owing to increased spike numbers and 1000-kernel weight. Overall, our study suggested that STS could substantially increase photosynthetic capacity and delay leaf senescence, thus promoting grain filling rate and increasing winter wheat yields. 展开更多
关键词 soil TILLAGE winter
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Deriving Temporal and Vertical Distributions of Methane in Xianghe Using Ground-based Fourier Transform Infrared and Gas-analyzer Measurements 认领
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作者 Denghui JI Minqiang ZHOU +6 位作者 Pucai WANG Yang YANG Ting WANG Xiaoyu SUN Christian HERMANS Bo YAO Gengchen WANG 《大气科学进展:英文版》 SCIE CAS CSCD 2020年第6期597-607,共11页
Methane(CH4)is one of the most important greenhouse gases in the atmosphere,making it worthwhile to study its temporal and vertical distributions in source areas,e.g.,North China.For this purpose,a ground-based high-r... Methane(CH4)is one of the most important greenhouse gases in the atmosphere,making it worthwhile to study its temporal and vertical distributions in source areas,e.g.,North China.For this purpose,a ground-based high-resolution Fourier transform infrared spectrometer(FTIR),the Bruker IFS 125 HR,along with an in-situ instrument,the Picarro G2301,were deployed in Xianghe County(39.8°N,117.0°E),Hebei Province,China.Data have been recorded since June2018.For the FTIR measurements,we used two observation modes to retrieve the mole fraction of CH4:the Total Carbon Column Observing Network(TCCON)method(retrieval algorithm:GGG2014),and the Network for the Detection of Atmospheric Composition Change(NDACC)method(retrieval algorithm:SFIT4).Combining FTIR with in-situ measurements,we found the temporal and vertical distributions of atmospheric CH4 within three vertical layers(near the ground,in the troposphere,and in the stratosphere),and throughout the whole atmosphere.Regarding the diurnal variation of CH4 near the ground,the concentration at night was higher than during the daytime.Regarding the seasonal variation,CH4 was low in spring and high in summer,for all three vertical layers.In addition,there was a peak of CH4 in winter near the ground,both in the troposphere and the whole atmosphere.We found that variation of CH4 in the tropospheric column was close to that of the in-situ measurements near the ground.Furthermore,the variations of CH4 in the stratospheric column could be influenced by vertical motions,since it was higher in summer and lower in winter. 展开更多
关键词 WINTER VERTICAL COLUMN
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集中供暖与非集中供暖城市的冬季大气污染状况——以天津和上海为例 认领
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作者 张晶 朱兆洲 杨鑫鑫 《天津师范大学学报:自然科学版》 CAS 北大核心 2020年第1期60-66,共7页
为了解集中供暖和非集中供暖2种不同模式对空气质量的影响,基于天津和上海冬季采暖期及非采暖期的空气质量数据,分析不同供热模式下大气污染物的长时间变化和日变化特征及其影响因素.结果表明:天津和上海采暖期PM2.5、PM10、CO、NO2和SO... 为了解集中供暖和非集中供暖2种不同模式对空气质量的影响,基于天津和上海冬季采暖期及非采暖期的空气质量数据,分析不同供热模式下大气污染物的长时间变化和日变化特征及其影响因素.结果表明:天津和上海采暖期PM2.5、PM10、CO、NO2和SO2的质量浓度均高于非采暖期.天津采暖期PM2.5、PM10、CO和SO2浓度较高主要是受到集中供暖消耗的化石燃料燃烧排放和大气逆温层2个方面因素的影响.上海虽然处于非集中供暖区,但也受到了北方城市供暖区远距离污染物传输的影响.天津集中供暖模式产生的PM2.5、PM10、CO和SO2排放对空气质量的影响高于非集中供暖城市上海.与非采暖期相比,天津和上海采暖期NO2浓度的增加量几乎一致,说明供暖活动对大气中NO2的贡献并不明显;天津和上海采暖期O3浓度均低于非采暖期,表明供暖活动未对O3排放产生显著作用.采暖活动明显改变了天津PM2.5、PM10和CO的日变化特征;受采暖活动和逆温层的影响,SO2和NO2浓度均在夜间呈现升高趋势;O3的日变化趋势未受采暖活动影响.与非采暖期对比,采暖期上海的非集中供暖未对污染物的日变化趋势产生显著影响. 展开更多
关键词 大气污染 冬季 集中供暖 非集中供暖 天津 上海
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Calibration and validation of SiBcrop Model for simulating LAI and surface heat fluxes of winter wheat in the North China Plain 认领
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作者 CHEN Ying LIU Feng-shan +4 位作者 TAO Fu-lu GE Quan-sheng JIANG Min WANG Meng ZHAO Feng-hua 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第9期2206-2215,共10页
The accurate representation of surface characteristic is an important process to simulate surface energy and water flux in land-atmosphere boundary layer.Coupling crop growth model in land surface model is an importan... The accurate representation of surface characteristic is an important process to simulate surface energy and water flux in land-atmosphere boundary layer.Coupling crop growth model in land surface model is an important method to accurately express the surface characteristics and biophysical processes in farmland.However,the previous work mainly focused on crops in single cropping system,less work was done in multiple cropping systems.This article described how to modify the sub-model in the SiBcrop to realize the accuracy simulation of leaf area index(LAI),latent heat flux(LHF)and sensible heat flux(SHF)of winter wheat growing in double cropping system in the North China Plain(NCP).The seeding date of winter wheat was firstly reset according to the actual growing environment in the NCP.The phenophases,LAI and heat fluxes in 2004–2006 at Yucheng Station,Shandong Province,China were used to calibrate the model.The validations of LHF and SHF were based on the measurements at Yucheng Station in 2007–2010 and at Guantao Station,Hebei Province,China in 2009–2010.The results showed the significant accuracy of the calibrated model in simulating these variables,with which the R2,root mean square error(RMSE)and index of agreement(IOA)between simulated and observed variables were obviously improved than the original code.The sensitivities of the above variables to seeding date were also displayed to further explain the simulation error of the SiBcrop Model.Overall,the research results indicated the modified SiBcrop Model can be applied to simulate the growth and flux process of winter wheat growing in double cropping system in the NCP. 展开更多
关键词 winter wheat LAI crop growth model SiBcrop North China Plain latent heat flux sensible heat flux
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I Love Sports and Science——陈正行 认领
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《小学生时代:英文版》 2020年第2期F0003-F0004,共2页
Hello,everyone!I am Steven.Do you like sports?I do.I like playing basketball best.Our school basketball team practices hard every day after class.And we won a champion(冠军)last winter.That was a very proud(自豪的)mom... Hello,everyone!I am Steven.Do you like sports?I do.I like playing basketball best.Our school basketball team practices hard every day after class.And we won a champion(冠军)last winter.That was a very proud(自豪的)moment for everyone. 展开更多
关键词 EVERYONE WINTER SPORTS
Utilizing comprehensive decision analysis methods to determine an optimal planting pattern and nitrogen application for winter oilseed rape 认领
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作者 DU Ya-dan CUI Bing-jing +3 位作者 ZHANG Qian SUN Jun WANG Zhen NIU Wen-quan 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第9期2229-2238,共10页
Oilseed rape is one of the most important oil crops globally.Attaining the appropriate cultivation method(planting pattern and nitrogen level)is necessary to achieve high yield,quality and resource utilization efficie... Oilseed rape is one of the most important oil crops globally.Attaining the appropriate cultivation method(planting pattern and nitrogen level)is necessary to achieve high yield,quality and resource utilization efficiency.However,the optimal method for oilseed rape varies across countries and regions.The objective of the present study was to determine an appropriate cultivation method,including planting pattern and nitrogen application,for winter oilseed rape in northwestern China.Two planting patterns:ridge film mulching and furrow planting(RFMF)and flat planting(FP),and six nitrogen(N)amounts:0(N0),60(N60),120(N120),180(N180),240(N240),and 300(N300)kg N ha–1 were applied across three growing seasons(2014–2017).Three comprehensive decision analysis methods:principal component analysis,grey correlation degree analysis and the combined entropy weight and dynamic technique for order preference by similarity to ideal solution method were used to evaluate the growth and physiological indicators,nutrient uptake,yield,quality,evapotranspiration,and water use efficiency of winter oilseed rape.Planting pattern,nitrogen amount and their interaction significantly affected the indicators aforementioned.The RFMF pattern significantly increased all indicators over the FP pattern.Application of N also markedly increased all the indicators except for seed oil content,but the yield,oil production and water use efficiency were decreased when N fertilizer exceeded 180 kg N ha–1 under FP and 240 kg N ha–1 under RFFM.The evaluation results of the three comprehensive decision analysis methods indicated that RFMF planting pattern with 240 kg N ha–1 is an appropriate cultivation method for winter oilseed rape in northwestern China.These findings are of vital significance to maximize yield,optimize quality and improve resource use efficiencies of winter oilseed rape. 展开更多
关键词 appropriate cultivation method comprehensive decision analysis method northwestern China winter oilseed rape
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Genetic progress in stem lodging resistance of the dominant wheat cultivars adapted to Yellow-Huai River Valleys Winter Wheat Zone in China since 1964 认领
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作者 ZHANG Hong-jun LI Teng +9 位作者 LIU Hong-wei MAI Chun-yan YU Guang-jun LI Hui-li YU Li-qiang MENG Ling-zhi JIAN Da-wei YANG Li LI Hong-jie ZHOU Yang 《农业科学学报:英文版》 SCIE CAS CSCD 2020年第2期438-448,共11页
Analysis of genetic progress for lodging-related traits provides important information for further improvement of lodging resistance.Forty winter wheat cultivars widely grown in the Yellow-Huai River Valleys Winter Wh... Analysis of genetic progress for lodging-related traits provides important information for further improvement of lodging resistance.Forty winter wheat cultivars widely grown in the Yellow-Huai River Valleys Winter Wheat Zone(YHWZ)of China during the period of 1964–2015 were evaluated for several lodging-related traits in three cropping seasons.Plant height,height at center of gravity,length of the basal second internode,and lodging index decreased significantly in this period,and the average annual genetic gains for these traits were–0.50 cm or–0.62%,–0.27 cm or–0.60%,–0.06 cm or–0.63%,and–0.01 or–0.94%,respectively.Different from other traits,stem strength showed a significant increasing trend with the breeding period,and the annual genetic gains were 0.03 N or 0.05%.Correlation analysis showed that lodging index was positively correlated with plant height,height at center of gravity,and length of the basal second internode,but negatively correlated with stem strength.Meanwhile,significantly positive correlations were observed between plant height,height at center of gravity,and length of the basal first and second internodes.By comparison with the wild types,dwarfing genes had significant effects on all lodging-related traits studied except for length of the basal first internode and stem strength.Principle component analysis demonstrated that plant height and stem strength were the most important factors influencing lodging resistance.Clustering analysis based on the first two principle components further indicated the targets of wheat lodging-resistant breeding have changed from reducing plant height to strengthening stem strength over the breeding periods.This study indicates that the increase of stem strength is vital to improve lodging resistance in this region under the high-yielding condition when plant height is in an optimal range. 展开更多
关键词 Triticum aestivum lodging resistance STEM strength GENETIC PROGRESS Yellow-Huai River VALLEYS Winter Wheat ZONE
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