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Identifying the limiting factors driving the winter wheat yield gap on smallholder farms by agronomic diagnosis in North China Plain

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Journal of Integrative Agriculture 2019年第8期18卷 1701-1713页

作者： CAO Hong-zhu LI Ya-nan chen guang-feng chen Dong-dong QU Hong-rui MA Wen-qi College of Resources and Environmental Science Hebei Agricultural University Baoding 071000 P.R.China College of Resources and Environmental Sciences China Agricultural University Beijing 100193 P.R.China National Agricultural Technology Extension and Service Center Ministry of Agriculture and Rural Affairs Beijing 100125 P.R.China

North China Plain(NCP) is the primary winter wheat production region in China, characterized by smallholder farming systems. Whereas the winter wheat average yield of smallholder farmers is currently low, the yield potential and limiting factors driving the current yield gap remain unclear. Therefore, increasing the wheat yield in NCP is essential for the national food security. This study monitored wheat yield, management practices and soil nutrient data in 132 farmers’ fields of Xushui County, Baoding City, Hebei Province during 2014–2016. These data were analyzed using variance and path analysis to determine the yield gap and the contribution of yield components(i.e., spikes per hectare, grain number per spike and 1 000-grain weight) to wheat yield. Then, the limiting factors of yield components and the optimizing strategies were identified by a boundary line approach. The results showed that the attainable potential yield for winter wheat was 10 514 kg ha^–1. The yield gaps varied strongly between three yield groups(i.e., high, middle and low), which were divided by yield level and contained 44 farmers in each group, and amounted to 2 493, 1 636 and 814 kg ha^–1, respectively. For the three yield components, only spikes per hectare was significantly different(P<0.01) among the three yield groups. For all 132 farmers’ fields, correlation between yield and spikes per hectare(r=0.51, P<0.01), was significantly positive, while correlations with grain number per spike(r=–0.16) and 1 000-grain weight(r=–0.10) were not significant. The path analysis also showed that the spikes per hectare of winter wheat were the most important component to the wheat yield. Boundary line analysis showed that seeding date was the most limiting factor of spikes per hectare with the highest contribution rate(26.7%), followed by basal N input(22.1%) and seeding rate(14.5%), which indicated that management factors in the seeding step were the most important for affecting spikes per hectare.

关键词： yield gaps smallholder limiting factors path analysis boundary line analysis

Hepatic non-parenchymal cells and extracellular matrix participate in oval cell-mediated liver regeneration

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World Journal of Gastroenterology 2009年第5期15卷 552-560页

作者： Wei Zhang Xiao-Ping chen Wan-guang Zhang feng Zhang Shuai Xiang Han-Hua Dong Lei Zhang Hepatic Surgery Center Tongji Hospital Tongji Medical College HuazhongUniversity of Science and Technology Wuhan 430030 HubeiProvince China

AIM： To elucidate the interaction between non- parenchymal cells, extracellular matrix and oval cells during the restituting process of liver injury induced by partial hepatectomy （PH）. METHODS： We examined the localization of oval cells, non-parenchymal cells, and the extracellular matrix components using immunohistochemical and double immunofluorescent analysis during the proliferation and differentiation of oval cells in N-2- acetylaminofluorene （2-AAF）/PH rat model. RESULTS： By day 2 after PH, small oval cells began to proliferate around the portal area. Most of stellate cells and laminin were present along the hepatic sinusoids in the periportal area. Kupffer cells and fibronectin markedly increased in the whole hepatic Iobule. From day 4 to 9, oval cells spread further into hepatic parenchyma, closely associated with stellate cells, fibronectin and laminin. Kupffer cells admixed with oval cells by day 6 and then decreased in the periportal zone. From day 12 to 15, most of hepatic stellate cells （HSCs）, laminin and fibronectin located around the small hepatocyte nodus, and minority of them appeared in the nodus. Kupffer cells were mainly limited in the pericentral sinusoids. After day 18, the normal liver Iobule structures began to ***： Local hepatic microenvironment may participate in the oval cell-mediated liver regeneration through the cell-cell and cell-matrix interactions.

关键词： Oval cells Liver regeneration Extracellularmatrix Hepatic stellate cells Kupffer cells

Developing sustainable summer maize production for smallholder farmers in the North China Plain: An agronomic diagnosis method

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Journal of Integrative Agriculture 2019年第8期18卷 1667-1679页

作者： chen guang-feng CAO Hong-zhu chen Dong-dong ZHANG Ling-bo ZHAO Wei-li ZHANG Yu MA Wen-qi JIANG Rong-feng ZHANG Hong-yan ZHANG Fu-suo College of Resources and Environmental Sciences China Agricultural University Beijing 100193 P.R.China College of Resources and Environment Science Hebei Agricultural University Baoding 071001 P.R.China Key Laboratory of Plant-Soil Interactions Ministry of Education Beijing 100193 P.R.China National Agricultural Technology Extension and Service Center Ministry of Agriculture and Rural Affairs Beijing 100125 P.R.C hina

With an increasing population and changing diet structure, summer maize is increasingly becoming an important energy crop in China. However, traditional farmer practices for maize production are inefficient and unsustainable. To ensure food security and sustainable development of summer maize production in China, an improved, more sustainable farmer management system is needed. Establishing this system requires a comprehensive understanding of the limitations of current farming practice and the ways it could be improved. In our study, 235 plots from three villages in the North China Plain(NCP) were monitored. Maize production on farms was evaluated;our results showed that the maize yield and nitrogen partial factor productivity(PFPN) were variable on smallholder farms at 6.6–13.7 t ha^–1 and 15.4–88.7 kg kg^–1, *** farming practices also have a large environmental impact(nitrogen surplus:–64.2–323.78 kg ha^–1). Key yield components were identified by agronomic diagnosis. Grain yield depend heavily on grain numbers per hectare rather than on the 1 000-grain weight. A set of improved management practices(IP) for maize production was designed by employing a boundary line(BL) approach and tested on farms. Results showed that the IP could increase yield by 18.4% and PFPN by 31.1%, compared with traditional farmer practices(FP), and reduce the nitrogen(N) surplus by 57.9 kg ha^–1. However,in terms of IP effect, there was a large heterogeneity among different smallholder farmers’ fields, meaning that, precise technologies were needed in different sites especially for N fertilizer management. Our results are valuable for policymakers and smallholder farmers for meeting the objectives of green development in agricultural production.

关键词： smallholder farmers sustainable production yield gap agronomic diagnosis North China Plain

Synthesis and Structural Characterization of [Mn(phen)_2(H_2O)_2](OAc)_26H_2O

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Chinese Journal of Structural Chemistry 2003年第5期22卷 525-528页

作者： ZHANG Xiao-feng HUAND De-guang chen feng chen Chang-Neng LIU Qiu-Tian② (State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, The Chinese Academy of Sciences, Fuzhou 350002, China) State Key Laboratory of Structural Chemistry Fujian Institute of Research

The title complex [Mn(phen)2(H2O)2](OAc)26H2O (phen = 1,10-phenanthroline, C12H8N2, OAc = acetate, C2H3O2) with formula C28H38MnN4O12 and Mr = 677.56 has been syn- thesized and structurally characterized by X-ray diffraction. The crystal is of triclinic, space group P ?with a = 9.6201(5), b = 13.4663(7), c = 14.5375(8) , a = 108.428(1), b =93.898(1), g = 110.492(1), V = 1639.5(2) ?, Dc = 1.373 g/cm3, F(000) = 710, = 0.468 cm-1 and Z = 2. The final refinement gave R = 0.0522 and wR = 0.1259 for 4714 observed reflections with I > 2s(I). It consists of discrete [Mn(phen)2(H2O)2]2+ cation, two acetate anions and six lattice water molecules. The MnII ion coordinated by four nitrogen atoms from two chelating phen and two oxygen atoms from two cis-related water molecules is in a distorted octahedral coordination environment. Two OAc- anions and six water molecules exist outside the [Mn(phen)2(H2O)2]2+ cation as counter ions and solvate molecules, respectively. The cations and anions are interconnected by the solvate water molecules which are hydrogen bonded to both aqua ligands and acetate oxygen atoms, building up the crystals of this compound to be a supramolecule-like aggregate.

关键词： manganese crystal structure synthesis 1 10-phenanthroline acetate

A new species of Triplophysa(Cypriniformes,Nemacheilidae) from Weihe River in Gansu Province, China

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Zoological Research 2020年第4期41卷 465-470页

作者： chen-guang feng Yu Zhang Chao Tong Bing-Zheng Zhou Xiao-Hui Li Yong-Tao Tang Wen-Zhu Song Kai Zhao Key Laboratory of Adaptation and Evolution of Plateau Biota Laboratory of Plateau Fish Evolutionary and Functional Genomicsand Qinghai Key Laboratory of Animal Ecological GenomicsNorthwest Institute of Plateau BiologyChinese Academy of SciencesXining 810008China School of Ecology and Environment Northwestern Polytechnical UniversityXi'an 710072China University of Chinese Academy of Sciences Beijing 100049China Biology Department University of PennsylvaniaPhiladelphiaPennsylvania 19104USA College of Fisheries Henan Normal UniversityXinxiang 453007China

DEAR EDITOR,A new species of Tibetan loach,Triplophysa weiheensis ***.,is described from the Weihe River in Gansu Province,China,based on morphological and molecular *** new species can be distinguished from all known congeners by a unique combination of the following characters:scaleless;snout abruptly sloping downward,anterior to anterior nostril;lower jaw crescentic,not sharp;body without obvious mottling;lateral line interrupted on posterior trunk at pelvic-fin distal extremity.

关键词： Gansu Tibetan sharp

Opah(Lampris megalopsis)genome sheds light on the evolution of aquatic endothermy

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Zoological Research 2022年第1期43卷 26-29页

作者： Jing Bo Wen-Qi Lv Ning Sun cheng Wang Kun Wang Pan Liu chen-guang feng Shun-Ping He Lian-Dong Yang Institute of Deep Sea Science and Engineering Chinese Academy of SciencesSanyaHainan 572000China State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhanHubei 430072China University of Chinese Academy of Sciences Beijing 100049China School for Ecological and Environmental Sciences Northwestern Polytechnical UniversityXi’anShaanxi 710000China College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingYunnan 650223China

Endothermy is the ability to generate and conserve metabolic heat to maintain body temperature above that of the surrounding *** enhances the physiological and ecological advantages of mammals,birds,and certain fish *** opah,Lampris megalopsis(Lampridiformes),is the only known fish to exhibit whole-body ***,however,the underlying molecular mechanism for this remains ***,the opah offers an excellent opportunity to study the evolutionary mechanism of whole-body endothermy in aquatic *** this study,we assembled a *** genome(1.09 Gb in size)and performed comparative genomic analysis with ectothermic fish to reveal the genetic basis of *** on analysis of positive selection,rapid evolution,and gene family expansion,we discovered several genes that likely contributed to thermogenesis and heat *** the first reported *** genome,our results not only clarify the possible molecular and genetic mechanisms involved in endothermic adaptation but also increase our understanding of endothermic fish biology.

关键词： evolution likely maintain

Gene expression responses in zebrafish to short-term high-hydrostatic pressure

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Zoological Research 2022年第2期43卷 188-191页

作者： Ming-Liang Hu Bao-Sheng Wu Wen-Jie Xu cheng-Long Zhu Yuan Yuan Wen-Qi Lv Qiang Qiu Hai-Bin Zhang Kun Wang chen-guang feng School of Ecology and Environment Northwestern Polytechnical UniversityXi’anShaanxi 710072China Key Laboratory of Aquatic Biodiversity and Conservation of the Chinese Academy of Sciences Institute of HydrobiologyChinese Academy of SciencesWuhanHubei 430072China Institute of Deep-Sea Science and Engineering Chinese Academy of SciencesSanyaHainan 572000China University of Chinese Academy of Sciences Beijing 100049China

Hydrostatic pressure is one of the main factors limiting the vertical range of marine ***,little is known about the level of hydrostatic pressure that shallow-water fish can tolerate or how they respond to this potential ***,we applied high-hydrostatic pressure treatment to wild-type AB line zebrafish(Danio rerio)and analyzed transcriptome data following treatment.

关键词： fish treatment hydrostatic

Breeding Methodology and Practice of Super Rice in China

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Rice science 2010年第2期17卷 87-93页

作者： CAO Li-yong ZHAN Xiao-deng chen Shen-guang feng Yue Wu Wei-ming SHEN Xi-hong chenG Shi-hua State Key Laboratory of Rice Biology/Chinese National Center for Rice Improvement China National Rice Research InstituteHangzhou 310006 China

To meet the growing demand for rice production, the Ministry of Agriculture, P. R. China initiated a nationwide project on the development of super rice in 1996. Through efforts in research, super rice breeding in China has gained significant advances in the aspects of breeding theories, creation of breeding materials and selection and promotion of elite rice varieties. A creative super rice breeding path of the construction of harmonious plant type combined with the utilization of heterosis was proposed. Super rice plays more and more important roles in rice production. Totally, 71 super rice varieties in China have been successfully developed and released to production. These varieties have 12 t/hm2 yield potential in on-farm demonstration fields, 8% to 15% higher than the check varieties with high resistance to pest and medium to high level of grain quality, the total growing area of which has reached 23.7 million hectares, and rice grain production increased by 17.7 million tons from 1996 to 2009. This paper reviewed the development and achievements of super rice breeding in aspects of the breeding methodology and breeding practices, summarized the successful experience of super rice breeding in China and proposed the developmental strategies of super rice for the future.

关键词： achievements experience super rice breeding methodology

基于Radon变换的目标主体信号与微动信号的分离

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科学技术与工程 2013年第20期21卷 5811-5814页

作者：陈广锋西安文理学院数学与计算机工程学院西安710065

针对微动特征的有效分析和提取,研究了基于Radon变换的目标主体信号与微动信号分离方法。首先对回波信号进行时频变换,然后在时频平面上通过Radon变换来分离目标主体信号与微动信号,再通过逆Radon变换得到分离信号的时频分布,最后通过... 详细信息

针对微动特征的有效分析和提取,研究了基于Radon变换的目标主体信号与微动信号分离方法。首先对回波信号进行时频变换,然后在时频平面上通过Radon变换来分离目标主体信号与微动信号,再通过逆Radon变换得到分离信号的时频分布,最后通过仿真验证了方法的有效性。

关键词： Radon变换时频分析微动信号分离