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Identification on threshold and efficiency of rainfall replenishment to soil water in semi-arid loess hilly areas

Science China Earth Sciences 2018年第3期61卷 292-301页

作者： Lei YANG Handan zhang liding CHEN State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

As one critical source of water for maintaining ecosystems in arid and semi-arid regions, rainfall replenishment to soil water can determine vegetation growth and ecosystem functions. However, the limited rainfall resources were often not used effectively in the semi-arid loess hilly areas due to random temporal and spatial distribution of rainfall and specific vegetation features. Thus, it is highly significant to determine the threshold and efficiency of rainfall replenishment to soil water under different vegetation types. The threshold and efficiency can offer scientific evidence for rehabilitating vegetation and improving efficiency of using rainfall resources. In this study, the efficiency and threshold of rainfall replenishment to soil water were determined under natural grassland, wheat, artificial grassland, sea buckthorn shrubland and Chinese pine forestland based on consecutive measurements. The results indicated that the lag-time, rate, efficiency of rainfall replenishment to soil water were closely related to vegetation type, with significant differences existing among different vegetation types. The lag-time for natural grassland in the soil horizon of 20 cm was the shortest one(26.4 h), followed by wheat(27.8 h), sea buckthorn(41.8 h), artificial grassland(50.0 h) and Chinese pine(81.8 h).The value of replenishment rate, followed the order of wheat(0.40 mm h^(-1))> natural grassland(0.30 mm h(-1))> sea buckthorn(0.17 mm h(-1))> artificial grassland(0.14 mm h(-1))> Chinese pine(0.09 mm h(-1)). As for the efficiency of rainfall replenishment to soil water, natural grassland was the most efficient one(35.1%), followed by wheat(29.2%), sea buckthorn(16.8%), artificial grassland(11.5%), Chinese pine(4.2%). At last, it was found that wheat had the lowest threshold(6.8 mm) of rainfall replenishment to soil water, which was followed by natural grassland(10.5 mm), sea buckthorn(20.5 mm), artificial grassland(22.6 mm) and Chinese pine(26.4 mm). These results implied that soil water in natural grassland was s

关键词：降雨资源土壤水半干旱阀值黄土生态系统功能植被生长鉴定

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Regional-scale Identification of Three-dimensional Pattern of Vegetation Landscapes

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Chinese Geographical Science 2014年第1期24卷 104-112页

作者： SUN Ranhao zhang Baiping CHEN liding State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of Sciences State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences

The altitudinal pattern of vegetation is usually identified by field surveys,however,these can only provide discrete data on a local mountain.Few studies identifying and analyzing the altitudinal vegetation pattern on a regional scale are available.This study selected central Inner Mongolia as the study area,presented a method for extracting vegetation patterns in altitudinal and horizontal directions.The data included a vegetation map at a 1∶1 000 000 scale and a digital elevation model at a 1∶250 000 scale.The three-dimensional vegetation pattern indicated the distribution probability for each vegetation type and the transition zones between different vegetation landscapes.From low to high elevations,there were five vegetation types in the southern mountain flanks,including the montane steppe,broad-leaved forest,coniferous mixed forest,montane dwarf-scrub and sub-alpine shrub-meadow.Correspondingly,only four vegetation types were found in the northern flanks,except for the montane steppe.This study could provide a general model for understanding the complexity and diversity of mountain environment and landscape.

关键词：植被景观立体图案亚高山灌丛识别垂直分布格局植被格局数字高程模型植被类型

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抗苗勒管激素免疫磁珠的制备及其初步应用

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细胞与分子免疫学杂志 2020年第4期36卷 310-316页

作者：陈聪洁易华山张立定陈志鑫何淑桢韩芹芹夏雪山赵瑶宋玉竹张金阳昆明理工大学生命科学与技术学院云南昆明650500 西南大学动物科学学院重庆402460

目的制备人的抗苗勒管激素(AMH)免疫磁珠及酶标抗体,初步建立一种基于纳米磁珠的双抗体夹心ELISA快速检测方法。方法构建人AMH重组蛋白表达载体,表达和纯化AMH重组蛋白,将获得的重组蛋白免疫BALB/c小鼠,制备多克隆抗体。通过聚乙二醇将... 详细信息

目的制备人的抗苗勒管激素(AMH)免疫磁珠及酶标抗体,初步建立一种基于纳米磁珠的双抗体夹心ELISA快速检测方法。方法构建人AMH重组蛋白表达载体,表达和纯化AMH重组蛋白,将获得的重组蛋白免疫BALB/c小鼠,制备多克隆抗体。通过聚乙二醇将脾细胞与骨髓瘤Sp2/0细胞融合,采用ELISA筛选阳性杂交瘤细胞株,体内腹水诱生法制备抗体,结合Western blot法评价单克隆抗体。利用蛋白A(Protein A)对抗体进行亲和层析纯化,将多克隆抗体作为捕获抗体偶联至纳米级羧基聚合物磁珠,以高碘酸钠法对单克隆抗体进行辣根过氧化物酶标记作为抗体探针,建立并优化基于纳米磁珠的双抗体夹心ELISA。结果获得一株具有良好特异性的抗AMH单克隆抗体,其亚型为IgG2b,纯化的多克隆抗体和单克隆抗体的效价均可达1∶51200。与磁珠偶联后的捕获抗体以及酶标记后的探针抗体仍然具有较好的活性。建立的方法可在1 h左右检测出AMH抗原,检测下限在50 ng/mL左右。结论制备的AMH免疫磁珠能够用于重组AMH的检测,具有快速、可视化的优点。

关键词：抗苗勒管激素单克隆抗体纳米磁珠 ELISA

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Analysis and assessment of heavy metal contamination in surface water and sediments： a case study from Luan River, Northern China

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Frontiers of Environmental Science & Engineering 2015年第2期9卷 240-249页

作者： Zhaoming WANG Ranhao SUN Haiping zhang liding CHEN State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China University of Chinese Academy of Sciences Beijing 100049 China

Concentrations of the heavy metals Cu, Ni, Pb, Zn, Cd, and Cr were examined in surface water and sediment from the Luan River inChina,. With a decline in Cu and Ni concentration found in surface water at downstream stations. This finding suggests that water currents are a major explanatory factor in heavy metal contamination. The abundance of Cr, Pb, and Cd observed in the middle reaches of the river indicates heavy metal contamination in local areas, although there was an obvious decrease in concentrations in the water downstream of the Daheiting Reservoir. The significant rising trend in Cu, Pb, and Ni seen the sediment farther away from the river also suggests that anthropogenic activities contribute to heavy metal pollution Sediments were therefore used as environmental indicators, with sediment assessment was conducted using the geo-accumulation index （Igeo） and the potential ecological risk index （R/）. The Igeo values revealed that Cd （3.13） and Cr （2.39） had accumulated significantly in the Luan River. The R/values for most （89%） of the sampling stations were higher than 300, suggesting that sediment from the Luan River poses a severe ecological risk, with the potential ecological risks downstream higher than that in the upper and middle streams. Good correlations among Pb/Ni, Pb/Cd, Cu/Pb, and Cu/Cd in the water and Cr/Ni in the sediment were observed. Cluster analysis suggested that Cd may have various origins, being derived from anthropogenic sources.

关键词： tion index heavy metal water sediment geo-accumula- Luan River

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Effect of Agricultural Land Use Changes on Soil Nutrient Use Efficiency in an Agricultural Area,Beijing,China

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Chinese Geographical Science 2011年第4期21卷 392-402页

作者： CHEN liding QI Xin zhang Xinyu LI Qi zhang Yanyan State Key Laboratory of Urban and Regional Ecology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 101101China Department of Environmental Science and Engineering Nanjing University of Information Science and TechnologyNanjing 210044China

Agricultural land use and management practices may affect soil properties,which play a critical role in sustaining crop production.Since the late 1970s,several new agricultural land use types had been introduced in the rural areas of China.The purpose of this study is to evaluate the effect of these land use changes on the soil properties,nu-trient absorption rate,and nutrient use economic efficiency ratio in an agricultural area of Beijing.Specifically,the cropland,the orchard and the vegetable field were examined.Results of this study suggest that land use and farming management practices significantly affect the content of soil organic carbon (SOC),total nitrogen (TN),total phos-phorus (TP),and available phosphorus in the surface layer of 0-25 cm (p<0.05) in the Yanqing Basin,northwestern Beijing.Soil nutrients in each agricultural land use type decrease rapidly with the increasing soil depth.Orchard and vegetable field tend to have higher soil nutrients than the cropland does.However,the soil nutrient-absorption rate (NAR) of the orchard and vegetable field is lower than that of the cropland,even though orchard and vegetable field may provide much higher economic benefit.While increasing SOC,TN,and TP in the orchard and vegetable field by intensive farming may be a valuable option to improve soil quality,potential increase in the risk of nutrient loss,or agricultural non-point source pollution can be a tradeoff if the intensive practices are not managed appropriately.

关键词：养分利用效率土壤性质北京中国农业土地利用土地利用类型农业非点源污染农地

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A nanonewton-scale biomimetic mechanosensor

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Microsystems & Nanoengineering 2023年第4期9卷 45-56页

作者： Chi zhang Mengxi Wu Ming Li Lixuan Che Zhiguang Tan Di Guo Zhan Kang Shuye Cao Siqi zhang Yu Sui Jining Sun liding Wang Junshan Liu State Key Laboratory of High-performance Precision Manufacturing Dalian University of Technology116024 DalianLiaoningChina Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of Technology116024 DalianLiaoningChina State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology116024 DalianChina

Biomimetic mechanosensors have profound implications for various areas,including health care,prosthetics,human‒machine interfaces,and robotics.As one of the most important parameters,the sensitivity of mechanosensors is intrinsically determined by the detection resolution to mechanical force.In this manuscript,we expand the force detection resolution of current biomimetic mechanosensors from the micronewton to nanonewton scale.We develop a nanocrack-based electronic whisker-type mechanosensor that has a detection resolution of 72.2 nN.We achieve the perception of subtle mechanical stimuli,such as tiny objects and airflow,and the recognition of surface morphology down to a 30 nm height,which is the finest resolution ever reported in biomimetic mechanosensors.More importantly,we explore the use of this mechanosensor in wearable devices for sensing gravity field orientation with respect to the body,which has not been previously achieved by these types of sensors.We develop a wearable smart system for sensing the body’s posture and movements,which can be used for remote monitoring of falls in elderly people.In summary,the proposed device offers great advantages for not only improving sensing ability but also expanding functions and thus can be used in many fields not currently served by mechanosensors.

关键词： mec expanding profound

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敌草胺随滴灌水施用对不同品种烟草性状的影响

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种业导刊 2016年第2期 13-17页

作者：张立顶程功李剑秋王维超王典魏义长河南省烟草公司许昌市分公司河南许昌461000 华北水利水电大学资源与环境学院

为探讨随滴灌水施用敌革胺对不同品种烟草经济性状和农艺性状的影响，选用五个品种烟草：豫烟5号、豫烟7号、中烟100、NC89、KRK28，随滴灌水施用敌草胺除草剂，敌草胺施用量分别为：Okg／hm^2、1．50kg／hm^2、2．25kg／hm^2、3．00kg... 详细信息

为探讨随滴灌水施用敌革胺对不同品种烟草经济性状和农艺性状的影响，选用五个品种烟草：豫烟5号、豫烟7号、中烟100、NC89、KRK28，随滴灌水施用敌草胺除草剂，敌草胺施用量分别为：Okg／hm^2、1．50kg／hm^2、2．25kg／hm^2、3．00kg／hm^2、3．75kg／hm^2。结果表明，不同品种烟草随滴灌水施用敌草胺的处理经济性状烟叶产量和上等烟产量均较对照有所增加，但随着敌草胺施用量的增加，烟叶产量增加的幅度变小，当敌草胺施用量大于3．00kg／hm^2时，烟叶产量增加缓慢。随滴灌水施用敌草胺对不同烟草品种农艺性状的影响不尽相同，但同一烟草品种随滴灌水施用敌草胺的处理与对照比，株高、有效叶片数、叶面积系数均有不同程度增加，大多数差异达到了显著或极显著水平。生产中豫中地区选用表现较好的豫烟5号和KRK28两个烟草品种，随滴灌水施用敌草胺以2．25～3．00kg／hm^2为宜。

关键词：烟草敌草胺除草剂滴灌经济性状农艺性状

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Deep-blue organic light-emitting diodes based on a doublet d-f transition cerium(Ⅲ) complex with 100% exciton utilization efficiency

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Light(Science & Applications) 2020年第1期9卷 521-529页

作者： liding Wang Zifeng Zhao Ge Zhan Huayi Fang Hannan Yang Tianyu Huang Yuewei zhang Nan Jiang Lian Duan Zhiwei Liu Zuqiang Bian Zhenghong Lu Chunhui Huang Beijing National Laboratory for Molecular Sciences(BNLMS) State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsBeijing Engineering Technology Research Centre of Active DisplayCollege of Chemistry and Molecular EngineeringPeking University100871 BeijingChina Tianjin Key Lab for Rare Earth Materials and Applications School of Materials Science and EngineeringNankai University300350 TianjinChina Department of Physics Yunnan University2 Cuihu Bei Lu650091 KunmingChina Key Lab of Organic Optoelectronics and Molecular Engineering of Ministry of Education Department of ChemistryTsinghua University100084 BeijingChina

Compared to red and green organic light-emitting diodes(OLEDs),blue OLEDs are still the bottleneck due to the lack of efficient emitters with simultaneous high exciton utilization efficiency(EUE)and short excited-state lifetime.Different from the fluorescence,phosphorescence,thermally activated delayed fluorescence(TADF),and organic radical materials traditionally used in OLEDs,we demonstrate herein a new type of emitter,cerium(Ⅲ)complex Ce-1 with spin-allowed and parity-allowed d-f transition of the centre Ce^(3+) ion.The compound exhibits a high EUE up to 100% in OLEDs and a short excited-state lifetime of 42 ns,which is considerably faster than that achieved in efficient phosphorescence and TADF emitters.The optimized OLEDs show an average maximum external quantum efficiency(EQE)of 12.4% and Commission Internationale de L’Eclairage(CIE)coordinates of(0.146,0.078).

关键词： diodes emitter transition

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环境温度对双滚轮-导轨式渐开线测量仪的影响

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仪器仪表学报 2022年第12期43卷 104-111页

作者：凌明凌四营张衡王奉涛王立鼎大连理工大学微纳米技术及系统辽宁省重点实验室大连116023 大连理工大学精密与特种加工教育部重点实验室大连116023 汕头大学智能制造技术教育部重点实验室汕头515063

双滚轮-导轨式渐开线测量仪是一种无阿贝误差、误差源少、测量精度高的渐开线测量仪器,常用来测量高精度标准齿轮和齿轮渐开线样板。本文研究了环境温度对双滚轮-导轨式渐开线测量仪及齿轮渐开线样板的影响,发现当双滚轮-导轨式渐开线... 详细信息

双滚轮-导轨式渐开线测量仪是一种无阿贝误差、误差源少、测量精度高的渐开线测量仪器,常用来测量高精度标准齿轮和齿轮渐开线样板。本文研究了环境温度对双滚轮-导轨式渐开线测量仪及齿轮渐开线样板的影响,发现当双滚轮-导轨式渐开线测量仪的滚轮与待测齿轮渐开线样板的热膨胀系数相同时,环境温度的变化不会带来齿廓倾斜偏差,而滚轮与齿轮渐开线样板的热膨胀系数不同时,在20℃±5℃范围内环境温度的变化带来的齿廓倾斜偏差是随环境温度线性变化的,而且上述两种情况环境温度的变化均只带来纳米量级的齿廓形状偏差,可以忽略。通过ANSYS进行了渐开线样板、滚轮和导轨的热膨胀仿真验证,并通过GCr15钢和SiC陶瓷材料的滚轮对材料为GCr15钢的渐开线样板的同一齿面进行了不同环境温度下的齿廓偏差测量实验,环境温度变化时,GCr15钢材料滚轮测得的齿廓倾斜偏差未发生明显改变,SiC陶瓷材料滚轮测得的齿廓倾斜偏差的变化量为0.71μm/℃,与理论值0.73μm/℃基本一致,两种材料滚轮测得的齿廓形状偏差均未发生明显改变。

关键词：渐开线齿廓偏差齿轮测量热膨胀误差补偿

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测头半径对1级渐开线样板齿廓偏差测量的影响

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仪器仪表学报 2022年第4期43卷 121-128页

作者：凌明凌四营刘远航张志豪王立鼎大连理工大学微纳米技术及系统辽宁省重点实验室大连116023 大连理工大学精密与特种加工教育部重点实验室大连116023

按齿轮渐开线样板国家标准推荐,1级齿轮渐开线样板的齿廓形状偏差需从展开长度3或5 mm开始计值,齿根部非计值区间对应渐开线弧长仅为0.03~0.18 mm,导致1级齿轮渐开线样板齿根部的渐开线齿廓难以精确测量。为了能更好发挥1级齿轮渐开线... 详细信息

按齿轮渐开线样板国家标准推荐,1级齿轮渐开线样板的齿廓形状偏差需从展开长度3或5 mm开始计值,齿根部非计值区间对应渐开线弧长仅为0.03~0.18 mm,导致1级齿轮渐开线样板齿根部的渐开线齿廓难以精确测量。为了能更好发挥1级齿轮渐开线样板的量值精准传递作用,分析了1级齿轮渐开线样板结构的特殊性以及测头半径对渐开线齿廓偏差测量结果的影响,结果表明,在齿根展开角误差时,测头半径引入的测量误差会随着测头半径的增大而增大,并随着展开长度的减小而增大,在基圆附近的测量误差可以达到齿廓偏差的50%~200%;当仅渐开线齿面存在加工误差时,测头半径引入的测量误差和展开长度受影响的范围会随着测头半径的增大和被测渐开线基圆半径的增大而增大,在齿根部展开长度10%的范围内测量误差约齿廓形状偏差的10%~60%。通过选取测头半径r_(p)=0.5和2.5 mm的测头对同一齿轮渐开线样板验进行了测量实验验证了上述结论。研究为1级齿轮渐开线样板的精密制造、精密测量及使用展开长度区间选取提供了支持。

关键词：齿轮渐开线样板渐开线齿廓偏差齿轮测量量值传递

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