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174篇 您的检索式:作者名="FengQin"
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1Application of nonlinear chemical fingerprinting to identification,evaluation and clinical use of Glycyrrhiza显示文摘Nonlinear chemical fingerprinting is a new technique for analyzing traditional Chinese medicines (TCMs). We developed such a method and applied it to Glycyrrhiza, a significant TCM. Nonlinear chemical fingerprints were obtained for Glycyrrhiza from four different production areas, and for 14 other TCMs with similar induction time. The calculation of their similarities was based on similarity system theory. Using intuitive visual comparison of the data and the similarity calculation results, Glycyrrhiza was discriminated from the 14 other TCMs. There was a linear relationship between the content of active TCM components and the induction time. This was used to compare the content of active components in Glycyrrhiza from the four different production areas, and establish an equivalent-dose relationship for these four samples. This method provides a new tool for discrimination and evaluation of Glycyrrhiza, and a dosage reference for clinical application of Glycyrrhiza from the four regions studied.FANG XuanQi ZHANG TaiMing ZHAO Zhe XIANG FengQin LIANG YiZeng WANG Mei ZHU Rong CHEN Su QIAO JunXi 2010Chinese Science Bulletin2010,55,26:20
2Identification of coastal wetlands of international importance for waterbirds:a review of China Coastal Waterbird Surveys 2005–2013显示文摘Background:China's coastal wetlands belong to some of the most threatened ecosystems worldwide.The loss and degradation of these wetlands seriously threaten waterbirds that depend on wetlands.Methods:The China Coastal Waterbird Census was organized by volunteer birdwatchers in China's coastal region.Waterbirds were surveyed synchronously once every month at 14 sites,as well as irregularly at a further 18 sites,between September 2005 and December 2013.Results:A total of 75 species of waterbirds met the 1 % population level Ramsar listing criterion at least once at one site.The number of birds of the following species accounted for over 20 % of the total flyway populations at a single site:Mute Swan(Cygnus olor),Siberia Crane(Grus leucogeranus),Far Eastern Oystercatcher(Haematopus osculans),Bar-tailed Godwit(Limosa lapponica),Spotted Greenshank(Tringa guttifer),Great Knot(Calidris tenuirostris),Spoon-billed Sandpiper(Calidris pygmeus),Saunders' s Gull(Larus saundersi),Relict Gull(Larus relictus),Great Cormorant(Phalacrocorax carbo),Eurasian Spoonbill(Platalea leucorodia),Black-faced Spoonbill(Platalea minor) and Dalmatian Pelican(Pelecanus crispus).A total of 26 sites supported at least one species of which their number met the1 % criterion.Forty-two species met the 1 % criterion in the Yellow River Delta,Shandong;29 at the Cangzhou coast,Hebei and 26 species at the Lianyungang coast,Jiangsu.Conclusions:The results highlight the international importance of China's coastal wetlands for waterbirds.This study also demonstrates that participation of local birdwatchers in waterbird surveys results in data that are invaluable not only for understanding the current status of waterbirds in China's coastal regions but also for waterbird conservation and management.Qingquan Bai Jianzhong Chen Zhihong Chen Guotai Dong Jiangtian Dong Wenxiao Dong Vivian Wing Kan Fu Yongxiang Han Gang Lu Jing Li Yang Liu Zhi Lin Derong Meng Jonathan Martinez Guanghui Ni Kai Shan Renjie Sun Suixing Tian Fengqin Wang Zhiwei Xu Yat-tung Yu Jin Yang Zhidong Yang Lin Zhang Ming Zhang Xiangwu Zeng 2015Chinese Birds2015,,3:20
3COVID-19 Outbreak Caused by Contaminated Packaging of Imported Cold-Chain Products—Liaoning Province,China,July 2020显示文摘Summary What is known about this topic?Few major outbreaks of coronavirus disease 2019(COVID-19)have occurred in China after major nonpharmaceutical interventions and vaccines have been deployed and implemented.However,sporadic outbreaks that had high possibility to be linked to cold chain products were reported in several cities of China..What is added by this report?In July 2020,a COVID-19 outbreak occurred in Dalian,China.The investigations of this outbreak strongly suggested that the infection source was from COVID-19 virus-contaminated packaging of frozen seafood during inbound unloading personnel contact.What are the implications for public health practice?Virus contaminated paper surfaces could maintain infectivity for at least 17–24 days at-25℃.Exposure to COVID-19 virus-contaminated surfaces is a potential route for introducing the virus to a susceptible population.Countries with no domestic transmission of COVID-19 should consider introducing prevention strategies for both inbound travellers and imported goods.Several measures to prevent the introduction of the virus via cold-chain goods can be implemented.Huilai Ma1 Jianqun Zhang Ji Wang Ying Qin Cao Chen Yang Song Liang Wang Jun Meng Lingling Mao Fengqin Li Ning Li Jian Cai Yong Zhang Dayan Wang Yunting Xia Hong Wang Shaofeng Jiang Xiang Zhao Peihua Niu Wenjie Tan Tao Ma Yecheng Yao Naiying Mao Zhen Zhu Tianjiao Ji Qian Yang Baoying Huang Li Zhao Jianxing Yu Li Bai Shuangli Zhu Dongyan Wang Yan Zhang Yingwei Sun Mingchun Luan Yanhai Wang Haibo Sun Shihong Yang Zhijian Bo Xiang Ren Zhongjie Li George Fu Gao Wei Yao Wenqing Yao Zijian Feng Wenbo Xu 2021China CDC weekly2021,3,21:16
4Determining method,conditional factors,traits and applications of nonlinear chemical fingerprint by using dissipative components in samples显示文摘The thermodynamic systems and dynamic model suitable for determining the nonlinear chemical fingerprints of samples were analyzed.The results indicated that the damp nonlinear chemical reactions in close systems away from the equilibrium and open systems without the complementarity of the dissipation substances have important significance for the throng characterization and whole content analysis of chemical components in samples.Various factors influencing on nonlinear chemical fingerprint,such as reactant species and their concentrations,electrode types,temperature,stir rate,the sort,dosage and granularity of the sample,etc.were amply researched by a nonlinear chemistry reaction,namely,damp B-Z oscillation which used acetone and glucose as the main dissipative substances.In addition,the quantitative information on the whole of chemical components in samples and the traits and applications of the fingerprint were investigated.The method and its important conditions for determining nonlinear chemistry fingerprint used in distinguishing and evaluating complex samples were successfully put forward.ZHANG TaiMing ZHAO Zhe FANG XuanQi QIAO JunXi XIANG FengQin ZHU Rong LIANG YiZeng DING Feng 2012Science China Chemistry2012,55,2:16
5Molecular fossil and paleovegetation records of paleosol S4 and adjacent loess layers in the Luochuan loess section, NW China显示文摘Using gas chromatography-mass spectrometry (GC-MS) technique, a series of biomarkers were identi- fied, including n-alkanes, n-alkane-2-ones, isoprenoid etc. from the loess-paleosol samples collected from the S4 and adjacent L5, L4 of the Luochuan loess section, Northwestern China. Based on these data, especially n-alkanes and high-resolution magnetic susceptibility and grain size data, the pa- leoenvironment and paleovegetation history during S4 was reconstructed. The CPI (Carbon Predomi- nance Index) and correlation between n-alkanes and magnetic susceptibility and grain size data dem- onstrated that the molecular fossils in paleosol and loess layers can reflect the vegetation condition during the loess-paleosol formation, if the allochthonous organic inputs could be excluded reasonably. The ACL (average chain length) index is correlated well with paleomagnetic susceptibility and grain size variations, displaying their good synchrony with warm and humid climate. However, it relatively lagged behind the paleomagnetic susceptibility and the grain size variations when the climate began to deteriorate. During the formation period of paleosol, the n-alkanes was dominated by C31 homologue, indicating that the primary organic input originated from herbs. Our study also demonstrated that the herbs were more flourish than wood plants in Loess Plateau, especially in the Luochuan area during the warm and humid phase, and there was no typical forest vegetation developed in the studied period.ZHANG HuCai YANG MingSheng ZHANG WenXiang LEI GuoLiang CHANG FengQin PU Yang FAN HongFang 2008Science China Earth Sciences2008,51,3:15
6THE LEARNER-CENTERED APPROACH——AN EFFECTIVE WAY TO DEVELOP STUDENTS'COMMUNICATIVE ABILITY显示文摘This paper will first focus on a brief evaluation ofthe teacher-centered and the learner-centered method-ologies.Then,it presents the practical ways of teach-ing based on the learner-centered approach in class-rooms to show how students’initiative is given fullplay.Finally,it presents the guidance from fellowstudents and teachers in group activitis.The purposeof the learner-centered approach is to develop students’communicativeZhang Fengqin Qiqihar University 2000Chinese Journal of Applied Linguistics2000,23,2:15
7Principle of nonlinear chemical fingerprint by using dissipative components in samples as well as calculation and evaluation of similarity显示文摘Under the conditions of constant temperature and pressure,different influences of samples with different chemical components on the mechanism of nonlinear chemical reaction will cause different changes of the potential-time relationship curve of the nonlinear chemical reaction system.Using it as the character,and using the B-Z nonlinear chemical system to use acetone and substrates in samples as main dissipative substances qua an example,the principle of nonlinear chemical fingerprint has been researched and discussed in detail.At the same time,the general method for calculating the system similarity about nonlinear chemical fingerprint was also put forward,and similarities of nonlinear chemistry fingerprints of different batches of Guhan Yangshengjing and 18 sorts of other samples were calculated by Euclidean distance,correlation coefficient,included angle cosine and system similarity,at the same time,the various similarities were analyzed.The results showed that,both of correlation coefficient and included angle cosine are unable to be used as the criterion for quantitatively evaluating the similarity of nonlinear chemistry fingerprint;as non-parametric similarity,Euclidean distance can accurately reflect the feature differences in the fingerprints,but as parametric similarity,sometimes,Euclidean distance can not accurately reflect the relative extent of characteristic difference in the nonlinear chemical fingerprints;system similarity can most truthfully reflect the characteristic difference in the nonlinear chemical fingerprints,and is the best evaluating method among the four ones.Therefore,system similarity can be used to quantitatively calculate the similar extent between the nonlinear chemical fingerprints.An economical,simple and convenient,easy pushing and effective method for identifying and evaluating complicated samples has successfully been put forward.ZHANG TaiMing ZHAO Zhe FANG XuanQi QIAO JunXi XIANG FengQin ZHU Rong LIANG YiZeng DING Feng 2012Science China Chemistry2012,55,2:13
8COVID-19: Challenges to GIS with Big Data显示文摘The outbreak of the 2019 novel coronavirus disease(COVID-19)has caused more than 100,000 people infected and thousands of deaths.Currently,the number of infections and deaths is still increasing rapidly.COVID-19 seriously threatens human health,production,life,social functioning and international relations.In the fight against COVID-19,Geographic Information Systems(GIS)and big data technologies have played an important role in many aspects,including the rapid aggregation of multi-source big data,rapid visualization of epidemic information,spatial tracking of confirmed cases,prediction of regional transmission,spatial segmentation of the epidemic risk and prevention level,balancing and management of the supply and demand of material resources,and socialemotional guidance and panic elimination,which provided solid spatial information support for decision-making,measures formulation,and effectiveness assessment of COVID-19 prevention and control.GIS has developed and matured relatively quickly and has a complete technological route for data preparation,platform construction,model construction,and map production.However,for the struggle against the widespread epidemic,the main challenge is finding strategies to adjust traditional technical methods and improve speed and accuracy of information provision for social management.At the data level,in the era of big data,data no longer come mainly from the government but are gathered from more diverse enterprises.As a result,the use of GIS faces difficulties in data acquisition and the integration of heterogeneous data,which requires governments,businesses,and academic institutions to jointly promote the formulation of relevant policies.At the technical level,spatial analysis methods for big data are in the ascendancy.Currently and for a long time in the future,the development of GIS should be strengthened to form a data-driven system for rapid knowledge acquisition,which signifies ts that GIS should be used to reinforce the social operation parameterization of models and methods,especially when providing support for social management.Chenghu Zhou Fenzhen Su Tao Pei An Zhang Yunyan Du Bin Luo Zhidong Cao Juanle Wang Wen Yuan Yunqiang Zhu Ci Song Jie Chen Jun Xu Fujia Li Ting Ma Lili Jiang Fengqin Yan Jiawei Yi Yunfeng Hu Yilan Liao Han Xiao 2020Geography and Sustainability2020,1,1:13
9Branched aliphatic alkanes of shell bar section in Qarhan Lake,Qaidam Basin and their paleoclimate significance显示文摘Biomarkers of paleolake deposits from Qarhan Salt Lake in Qaidam Basin,northwest China were sys-tematically analyzed and the A―C series compounds of branched aliphatic alkanes with quaternary substituted carbon atom(BAQCs) were identified. The homologous distinguished three series,A―C,were identified as 5,5-diethylalkanes,6,6-diethylalkanes and 5-butyl,5-ethylalkanes series,and their relative abundance was A > B > C. Series A and C were characterized by odd carbon numbers,whereas series B was characterized by even carbon numbers. The high values of series A corresponded with the high values of series B and C. Therefore,it can be concluded that series A,B and C possess a similar biological origin. The abundance of series A was relatively low in the lower part of the section compared with that in the upper part,implying that these series originated from bacteria and/or algae more prevalent in fresh-mesohaline water,and such kinds of bacteria and/or algae are most likely to be thermophilous species. The A25/nC25 ratio differences in the section show that such branched aliphatic alkanes can be treated as one kind of environmental change proxy for paleolake evolution and may provide important information for the climate reconstruction of the Late Pleistocene.ZHANG HuCai CHANG FengQin LI Bin LEI GuoLiang CHEN Yue ZHANG WenXiang NIU Jie FAN HongFang YANG MingSheng 2007Chinese Science Bulletin2007,52,9:13
10Baicalin extracted from Huangqin(Radix Scutellariae Baicalensis) induces apoptosis in gastric cancer cells by regulating B cell lymphoma(Bcl-2)/Bcl-2-associated X protein and activating caspase-3 and caspase-9显示文摘OBJECTIVE:To evaluate the effects of baicalin in human gastric cancer cells, including apoptosis-inducing effects, and to investigate its underlying mechanisms of action.METHODS:Cell proliferation and apoptosis assays were performed to investigate the anti-proliferation effects of baicalin in human gastric cancer BGC-823 and MGC-803 cells.Real time-quantitative polymerase chain reaction and Western blotting analysis were performed to elucidate the molecular mechanisms underlying the anti-tumor properties of baicalin.RESULTS:In BGC-823 and MGC-803 gastric cancer cells treated with 80, 120, and 160 μmol/L baicalin for 48 h, a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay showed that baicalin significantly inhibited cell proliferation in a dose-dependent manner, while flow cytometric analysis demonstrated that baicalin could induce apoptosis, also in a dose-dependent manner.Moreover, baicalin up-regulated the expression of caspase-3, caspase-9, and B cell lymphoma(Bcl-2)-associated X protein and down-regulated the expression of Bcl-2 at both the m RNA and protein level.CONCLUSION:Baicalin has potential as a therapeutic agent for gastric cancer by inducing apoptosis in cancer cells.Wang Hongwei Li Hailong Chen Fengqin Luo Jun Gu Jing Wang Huping Wu Hongyan Xu Yan 2017Journal of Traditional Chinese Medicine2017,37,2:13
11Geochemical fractionation of rare earth elements in lacustrine deposits from Qaidam Basin显示文摘Based on the concentration and distribution pattern analysis of the rare earth elements (REEs) at the Shell Bar section from Qaidam Basin, we studied the geochemical fractionations of REE in paleolake deposits and their paleo-environmental significance. Our results show that the REE concentration in AS (acid soluble) and AR (acid residual) fractions are 20.9 μg/g and 95.4 μg/g (except element Y) individually, showing a strong REE differentiation between AS and AR fractions. However, the two types of fractions (AS & AR) have similar REE distribution patterns, which are slightly rich in light earth rare elements (LREEs), with slightly right-tilting and negative Eu anomaly. The LREE of AR is richer than that of AS. There were no significant correlations between the REE in AS, AR and other proxies. It indicated that the lacustrine deposition had different material sources and experienced varying geochemical procedures. Correlation analysis between the REE and the content of fine grain-size (<4 μm) of the sediments, Rb/Sr ratio and Mn concentration showed high correlation coefficients. Our results demonstrated that the REE in acid soluble and residual fractions bear different environmental significances, which are strongly dependent on local environment. The REE of acid soluble fraction is closely related to the paleoclimatic changes in the lake catchment and the evolutionary processes of lake itself. Our results suggest that δCe and (La/Yb)n could be used as proxies of the reduction-oxidation conditions and furthermore the temperature change and the lake level fluctuations. Using these proxies, we reconstructed the paleoclimate and water level fluctuation history during the high lake level period lasting between 43.5 and 22.4 cal. ka BP.ZHANG HuCai ZHANG WenXiang CHANG FengQin YANG LunQing LEI GuoLiang YANG MingSheng PU Yang LEI YangBin 2009Science China Earth Sciences2009,52,11:9
12Climate variability recorded by n-alkanes of paleolake sediment in Qaidam Basin on the northeast Tibetan Plateau in late MIS3显示文摘Here we combine n-alkanes preserved in a shell bar section from Qarhan paleolake, Qaidam Basin with the other sedimentary proxies to elucidate the lake evolution process during the period 39.7 to 17.5 14C ka BP (calibrated age ranges from 43.5 to 22.4 cal. ka BP). In different stages, the n-alkane homologues exhibited different distribution modes indicative of variations in the surrounding vegetation and the hydrologic condition of the lake. The n-alkanes proxies (CPIh, ACLh, Paq) have the same trends as the summer solar insolation variation, implying that the summer insolation is the most important climatic factor driving the environmental changes and also indirectly controls lake evolution on the Tibetan Plateau. CPIh and ACLh as well as the total pollen concentration appear to show a trend comparable with methane concentration record from the GRIP ice core that reflected the Dansgaard-Oeschger events. This demonstrates that the paleoclimate variations in Qarhan area generally agree with global climate change and show rapid oscillations in late MIS3. These findings provide the latest molecular fossil evidence from paleolake sediments to confirm that lake evolution on Tibetan Plateau in late MIS3 was closely associated with enhanced summer insolation.PU Yang ZHANG HuCai LEI GuoLiang CHANG FengQin YANG MingSheng ZHANG WenXiang LEI YanBin YANG LunQing PANG YouZhi 2010Science China Earth Sciences2010,53,6:8
13Effect on platelet aggregation activity: extracts from 31 Traditional Chinese Medicines with the property of activating blood and resolving stasis显示文摘OBJECTIVE: To evaluate the anti-platelet aggregation effects of extracts from 31 Traditional Chinese Medicines(TCM) with the property of activating blood and resolving stasis in terms of TCM theory.METHODS: The 31 TCMs extracts were prepared using water, 90% ethanol and ethyl acetate., and the effects on anti-platelet aggregation were tested on a platelet aggregation analyzer in vitro with adenosine 5'-diphosphate, bovine thrombin and arachi-donic acid(AA) as aggregation inducers, respectively. Aspirin was the positive control.RESULTS: Lots of the tested TCMs had inhibitory effects with concentration-dependent manner on platelet aggregations induced by various agonists.Especially, some of the TCMs such as Chuanxiong(Rhizoma Chuanxiong), Yanhusuo(Rhizoma Corydalis Yanhusuo) and Danshen(Radix Salviae Miltiorrhizae) showed good anti-platelet aggregation effect similar or higher than that in positive control group.CONCLUSION: The study provided scientific references that several TCMs such as Chuanxiong(Rhizoma Chuanxiong), Yanhusuo(Rhizoma Corydalis Yanhusuo) and Danshen(Radix Salviae Miltiorrhizae),possess the property of anti-platelet aggregation.Chen Cen Wang Fengqin Xiao Wen Xia Zhining Hu Guang Wan Jianbo Yang Fengqing 2017Journal of Traditional Chinese Medicine2017,37,1:7
14Preparation of Styrene-acrylate Latex Used in Ultralow VOC Building Internal Wall Coating显示文摘有高玻璃转化温度(T g ) 的 Styrene-acrylate 乳胶,低最小的电影形成温度(MFT ) ;好稳定性经由核心壳乳液聚合被准备。与半连续法,单体的高转化速率;低胶化率被完成。到壳单体的核心单体的重量比率是约 1.35。这被发现许多因素象 emulsifiers 那样,开始者,反应温度,酸碱值价值;聚合技术在 styrene-acrylate 乳胶的 permormance 上有影响。准备乳胶被 TEM 描绘;FTIR。有 20.57 °的 T g 的获得的乳胶, 5.0 °的 MFT,;好稳定性,电影形成的有的好稳定性。陈立军 WU Fengqin ZHUANG Xinyu YANG Jian LI Rongxian 2008Journal of Wuhan University of Technology(Materials Science)2008,23,1:6
15Kinetics of serum HBsAg in Chinese patients with chronic HBV infection with long-term adefovir dipivoxil treatment显示文摘Li Minran Xi Hongli Wang Qinhuan Hou Fengqin Huo Na Zhang Xiaxia Li Fang Xu Xiaoyuan 2014Chinese Medical Journal2014,,11:5
16Assessment of High-standard Farmland Construction Effectiveness in Liaoning Province During 2011–2015显示文摘At present, the large-scale construction of high-standard farmland in China has improved the quality of cropland and crop production and enhanced the eco-environmental security. To obtain a comprehensive understanding of high-standard farmland construction in Liaoning Province of China during the 12 th five-year period(2011–2015), through on-the-spot investigations and remote sensing monitoring, this study assessed the construction effectiveness of ten typical sampling projects in Liaoning Province and then presented practical suggestions. The main conclusions were as follows. 1) The ranges of increase in productivity of the ten sampling projects in Liaoning Province all surpassed the goal of 1500 kg/ha. 2) Among all sampling project areas, the levels of productivity stability of nine sampling projects were higher than that of the surrounding farmland in a severe drought year. However, the productivity stability of the high-standard farmland construction project in Faku County, Yiniupu Town, declined by 1.04% compared with the surrounding farmland. 3) Except for the high-standard farmland construction project in Dengta City, Dengta Irrigation Region, the productivity uniformity of the other nine sampling projects increased by 3.30%–88.10%. 4) Eight of the ten sampling projects belonged to Class 1, and two projects belonged to Class 2, showing that the effectiveness of high-standard farmland construction in Liaoning Province was quite good.There were some suggestions for high-standard farmland construction in the future. All departments should strengthen cooperation and formulate corresponding protection and development strategies suitable for local conditions. Additionally, lasting management mechanisms should also be established. Using remote sensing monitoring to assess the high-standard farmland construction effectiveness during the 12 th five-year period could provide experience and decision-making support for high-standard farmland construction in the future.PU Luoman ZHANG Shuwen YANG Jiuchun YAN Fengqin CHANG Liping 2019Chinese Geographical Science2019,29,4:4
17New Bulb Turbine with Counter-rotating Tandem-runner显示文摘With the increasing demand for the clean sustainable power, the turbine design urgently turns to increase the capability significantly toward higher head for generating larger power. Currently, there are many studies in the field of the bulb turbine with single-stage runner, though reports about counter-rotating tandem-runner are rare. However, the further high-head application with the single-stage runner is very difficult to achieve due to the limit of the specific speed. In this paper, a new bulb turbine with the tandem-runner is designed in order to substantially increase the applicable limit toward higher head with larger power. A half of the net head is absorbed by the frontal runner which can generate output power, while the remaining half is absorbed by the rear runner. To generate the Euler energy required for the rear runner, the frontal runner has the counter-rotation against the rear runner so that the counter-rotating tandem-runner can meet the purpose of double head and power under the same size as the conventional bulb turbine. Supply and demand of Euler energy between the two runners are thoroughly optimized through the detailed flow analysis, in order to secure the stable operation. As a result, the interference of Euler energies between the outflow from the frontal runner and the inflow to the rear runner is confirmed to be very small on the counter-rotating interface between the two runners. The prediction method of on-cam performance between the two adjustable runners is also developed numerically, which provides optimal flow between the two runners. This research provides a theoretical basis for the optimal design and operation of the counter-rotating tandem-runner bulb turbines.HAN Fengqin YANG Lijing YAN Shijie KUBOAT Takashi 2012Chinese Journal of Mechanical Engineering2012,25,5:4
18MULTIPLICITY OF POSITIVE SOLUTIONS TO MULTIPOINT BOUNDARY VALUE PROBLEM WITH ONE-DIMENSIONAL p-LAPLACIAN显示文摘In this paper, we consider a multipoint boundary value problem for one-dimensional p-Laplacian. Using a fixed point theorem due to Bai and Ge, we study the existence of at least three positive solutions to the boundary value problem. In this problem, the nonlinear term explicitly involves a first-order derivative, which is different from some previous ones.Zhiyu Zhang (Dept. of Math., Taiyuan Institute of Technology, Taiyuan 030008) Youfeng Zhang (Yuncheng Middle School, Yuncheng 044000, Shanxi) Fengqin Zhang (Dept. of Math., Yuncheng University, Yuncheng 044000, Shanxi) 2010Annals of Differential Equations2010,26,4:4
19Nutrient Composition and Distance from Point Placement to the Plant Affect Rice Growth显示文摘Point placement of urea is an efficient technology to improve urea use efficiency in transplanted rice(Oryza sativa L.), but it is largely unknown how nutrient composition in the point placement and the distance from placement site to the plant influence rice root distribution and growth, nutrient uptake, and rice grain yield. A controlled greenhouse experiment was conducted using both N-and P-deficient soil with point placement of N only or N and P together(N + P) at a distance close to or far from the plant,in comparison to an N-spilt application and a no-N control. Both nutrient composition and distance significantly affected rice root growth. Compared with the N point placement, the N + P point placement led to smaller root length and mass densities, higher specific root length(SRL) around the placement site, smaller root system, higher straw mass and grain yield, and higher N and P uptake. The difference between the N + P and N point placements was greater when close to the plant than when far from the plant. It is suggested that higher SRL around the placement site is essential for improving nutrient uptake and rice grain yield, and simultaneous point placement of N and P has a synergistic effect on rice growth.HU Fengqin WANG Huoyan MOU Pu ZHOU Jianmin 2018Pedosphere2018,28,1:4
20China's Wetland Databases Based on Remote Sensing Technology显示文摘Wetland databases can provide the basic data that necessary for the protection and management of wetlands. A large number of wetland databases have been established in the world as well as in China. In this paper, we review China's wetland databases based on remote sensing(RS) technology after introducing the background theory to the application of RS technology in wetland surveys. A key conclusion is that China's wetland databases are far from sufficient in fulfilling protection and management needs. Our recommendations focus on the use of the hyper-spectral imagery, microwave data, multi-temporal images, and automatic classifications in order to improve the accuracy and efficiency of wetland inventory. Further, attention should also be paid to detect major biophysical features of wetlands and build wetland databases in years after the 1980 s in China. Considering that great gap exists between RS experts and wetland experts, further cooperation between wetland scientists and RS scientists are needed to promote the application of RS in the foundation of wetland databases.YAN Fengqin LIU Xingtu CHEN Jing YU Lingxue YANG Chaobin CHANG Liping YANG Jiuchun ZHANG Shuwen 2017Chinese Geographical Science2017,27,3:4
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