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基于Pareto熵的多目标粒子群优化算法 被引量:137
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作者 胡旺 Gary G. YEN 张鑫 《软件学报》 EI CSCD 北大核心 2014年第5期1025-1050,共26页
粒子群优化算法因形式简洁、收敛快速和参数调节机制灵活等优点,同时一次运行可得到多个解,且能逼近非凸或不连续的Pareto最优前端,因而被认为是求解多目标优化问题最具潜力的方法之一.但当粒子群优化算法从单目标问题扩展到多目标问题... 粒子群优化算法因形式简洁、收敛快速和参数调节机制灵活等优点,同时一次运行可得到多个解,且能逼近非凸或不连续的Pareto最优前端,因而被认为是求解多目标优化问题最具潜力的方法之一.但当粒子群优化算法从单目标问题扩展到多目标问题时,Pareto最优解集的存储与维护、全局和个体最优解的选择以及开发与开采的平衡等问题亦随之出现.通过目标空间变换方法,采用Pareto前端在被称为平行格坐标系统的新目标空间中的分布熵及差熵评估种群的多样性及进化状态,并以此为反馈信息来设计进化策略,使得算法能够兼顾近似Pareto前端的收敛性和多样性.同时,引入格占优和格距离密度的概念来评估Pareto最优解的个体环境适应度,以此建立外部档案更新方法和全局最优解选择机制,最终形成了基于Pareto熵的多目标粒子群优化算法.实验结果表明:在IGD性能指标上,与另外8种对等算法相比,该算法在由ZDT和DTLZ系列组成的12个多目标测试问题集中表现出了显著的性能优势. 展开更多
关键词 多目标优化问题 粒子群优化 平行格坐标系统 Pareto熵 自适应参数
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Rates of litter decomposition in terrestrial ecosystems:global patterns and controlling factors 被引量:108
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作者 Deqiang Zhang Dafeng Hui +1 位作者 Yiqi Luo Guoyi Zhou 《Journal of Plant Ecology》 SCIE 2008年第2期85-93,共9页
Aims We aim to construct a comprehensive global database of litter decomposition rate(k value)estimated by surface floor litterbags,and investigate the direct and indirect effects of impact factors such as geographic ... Aims We aim to construct a comprehensive global database of litter decomposition rate(k value)estimated by surface floor litterbags,and investigate the direct and indirect effects of impact factors such as geographic factors(latitude and altitude),climatic factors(mean annual tempePlrature,MAT;mean annual precipitation,MAP)and litter quality factors(the contents of N,P,K,Ca,Mg and C:N ratio,lignin:N ratio)on litter decomposition.Methods We compiled a large data set of litter decomposition rates(k values)from 110 research sites and conducted simple,multiple regression and path analyses to explore the relationship between the k values and impact factors at the global scale.Important findings The k values tended to decrease with latitude(LAT)and lignin content(LIGN)of litter but increased with temperature,precipitation and nutrient concentrations at the large spatial scale.Single factor such as climate,litter quality and geographic variable could not explain litter decomposition rates well.However,the combination of total nutrient(TN)elements and C:N accounted for 70.2%of the variation in the litter decomposition rates.The combination of LAT,MAT,C:N and TN accounted for 87.54%of the variation in the litter decomposition rates.These results indicate that litter quality is the most important direct regulator of litter decomposition at the global scale.This data synthesis revealed significant relationships between litter decomposition rates and the combination of climatic factor(MAT)and litter quality(C:N,TN).The global-scale empirical relationships developed here are useful for a better understanding and modeling of the effects of litter quality and climatic factors on litter decomposition rates. 展开更多
关键词 climatic factors geographic factors litter decomposition rate litter quality path analysis terrestrial ecosystems
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果园风送喷雾精准控制方法研究进展 被引量:64
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作者 翟长远 赵春江 +4 位作者 Ning Wang John Long 王 秀 Paul Weckler 张海辉 《农业工程学报》 EI CAS CSCD 北大核心 2018年第10期1-15,共15页
果园风送喷雾技术与装备正在朝着精准化和智能化方向发展。果园喷雾控制对象主要为喷施药量和风力供给量,二者需要协同精准调控,其按需调控的前提是果园靶标精准探测。该文从果园靶标探测方法、喷施药量控制方法、风力调控方法 3个方面... 果园风送喷雾技术与装备正在朝着精准化和智能化方向发展。果园喷雾控制对象主要为喷施药量和风力供给量,二者需要协同精准调控,其按需调控的前提是果园靶标精准探测。该文从果园靶标探测方法、喷施药量控制方法、风力调控方法 3个方面对现有研究进展进行综述,阐述了基于光电感知、超声波传感、激光雷达、图像、光谱和电子鼻技术探测果树位置、冠层外形轮廓、冠层体积、冠层内部结构、枝叶稠密程度、病虫害程度等特征信息的技术方法;分析了喷施药量调控方法中管道总药量控制方法在管道设计、混药方式、药液流量控制策略方面技术和产品化上取得的巨大突破,以及喷头药量独立控制方法研究方面获得的大量成果;综述了果园风送喷雾风速风量需求理论原则、风场雾场建模方法、风力调控方法与调控装备研究进展,指出了其基本理论原则、建模调控方法等科学问题还有待深入探索。同时,还分析了目前研究在果园靶标探测方法、喷施药量调控方法和风送喷雾风力调控方法中面临的困难和挑战,主要包括冠层稠密程度和病虫害程度高效感知方法探索、靶标风力需求普适模型构建、风场建模风力按需调控方法研究和精准喷雾技术与系统集成开发。最后指出了果园风送喷雾精准控制方法未来发展方向:1)果园靶标冠层枝叶稠密程度和病虫害程度在线探测方法将成为新的研究热点;2)果园风送喷雾风速风量供给需求理论原则、风场快速模拟仿真和风力调控方法与装备是未来重要研究方向;3)随着高新科技的涌现,科研院所和公司有望在果园喷雾药量和风力调控系统优化设计及精准喷雾机系统集成研发方面获得更大发展。 展开更多
关键词 农业机械 喷雾 果园 靶标探测 变量技术 风力调控
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高光谱图像技术在水果品质无损检测中的应用 被引量:50
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作者 洪添胜 李震 +3 位作者 吴春胤 刘敏娟 乔军 Wang Ning 《农业工程学报》 EI CAS CSCD 北大核心 2007年第11期280-285,共6页
传统的近红外光谱分析法和可见光图像技术应用于水果品质无损检测中存在的检测区域小、检测时间长、仅能检测表面情况等局限性。高光谱图像技术结合光谱技术与计算机图像技术两者的优点,可获得大量包含连续波长光谱信息的图像块,其图像... 传统的近红外光谱分析法和可见光图像技术应用于水果品质无损检测中存在的检测区域小、检测时间长、仅能检测表面情况等局限性。高光谱图像技术结合光谱技术与计算机图像技术两者的优点,可获得大量包含连续波长光谱信息的图像块,其图像信息可检测水果的外部品质,光谱信息则可用于水果内部品质的检测,达到根据水果内、外部综合品质进行分类的目的。根据不同的采集设备,简介了两种获得高光谱图像的方法。综述了国内外将该技术应用于水果品质检测方面的研究进展,检测内容包括外观品质、损伤与缺陷,成熟度和坚实度,含糖量、含水率等内部品质,着重介绍了各高光谱图像的成像波段范围、分辨率、成像源,实验数据处理的方法以及实验结果等。根据综述所得提出了高光谱图像技术应用中需要解决的光谱降维、降低样品差异影响和实时检测平台搭建等问题。 展开更多
关键词 高光谱图像技术 水果品质 无损检测 机器视觉 水果分级
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农田土壤含水率监测的无线传感器网络系统设计 被引量:52
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作者 李震 Wang Ning +2 位作者 洪添胜 文韬 刘志壮 《农业工程学报》 EI CAS CSCD 北大核心 2010年第2期212-217,共6页
为解决传统土壤含水率监测中所存在的监测区域面积小、采样率低等问题,设计和开发了基于无线传感器网络技术的土壤含水率监测系统,包括10个传感器节点,1个簇首和1个基站节点,可按任意时间间隔全自动地采集、处理、传输和存储地表以下4... 为解决传统土壤含水率监测中所存在的监测区域面积小、采样率低等问题,设计和开发了基于无线传感器网络技术的土壤含水率监测系统,包括10个传感器节点,1个簇首和1个基站节点,可按任意时间间隔全自动地采集、处理、传输和存储地表以下4个不同土层土壤含水率变化状况;各类节点采用TinyOS操作系统,节点间通信遵循ZigBee协议;含水率测量采用EC-5传感器;太阳能供电模块的供电能力满足传感器节点及簇首的能耗需求;进行了数据包传输率试验,10个传感器节点中有7个的数据包正确传输率高于90%,1个节点的数据包正确传输率为89.2%,2个节点的传输率低于70%。造成2个节点数据包传输率较低的主要原因是太阳能供电电路制作,通过更换电路板解决了该问题。试验结果表明,系统能够实现稳定的数据传输,适合农田土壤含水率的实时监测。 展开更多
关键词 精细农业 无线传感器网络 土壤含水率 TINYOS
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Heavy Metal Transfer from Soil to Vegetable in Southern Jiangsu Province, China 被引量:47
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作者 HAO Xiu-Zhen ZHOU Dong-Mei +3 位作者 HUANG De-Qian CANG Long ZHANG Hai-Lin WANG Hui 《Pedosphere》 SCIE CAS CSCD 2009年第3期305-311,共7页
Vegetable fields in peri-urban areas receive large amounts of extraneous heavy metals because of rapid urbanization and industrialization in China. The concentrations of Cu, Zn, and Pb in 30 soil samples and 32 vegeta... Vegetable fields in peri-urban areas receive large amounts of extraneous heavy metals because of rapid urbanization and industrialization in China. The concentrations of Cu, Zn, and Pb in 30 soil samples and 32 vegetable samples, collected from 30 different sites in southern Jiangsu Province of China, were measured and their transfer from soil to vegetable was determined. The results showed that the soil samples had wide ranges of pH (4.25-7.85) and electrical conductivity (EC) (0.24-3.42 dS m^-1). Among the soil samples, there were four soil samples containing higher Cu and two soil samples containing higher Zn concentrations than those specified in the Chinese Soil Environmental Quality Standard II. However, no vegetable sample was found to contain a high level of Cu or Zn. In contrast, one vegetable sample contained 0.243 mg Pb kg^-1 FW, which was above the Chinese Food Hygiene Standard, whereas the corresponding soil Pb concentration was lower than the Chinese Soil Environmental Quality Standard II. The transfer coefficients of Cu of all vegetable samples exceeded the suggested coefficient range, implying that extraneous Cu had high mobility and bioavallability to vegetables. There was no significant correlation between extractable soil heavy metal concentrations with four kinds of extractants and soil pH, EC, heavy metal concentrations in vegetables and soils, except that soil pH correlated well with the extractable soil Cu, Zn, and Pb concentrations with 1.0 mol L-1 NH4NO3. Moreover, diethylenetriamine pentaacetic acid (DTPA) extraction method was a more efficient method of extracting heavy metals from the soils independent of soil pH and EC than other three methods used. 展开更多
关键词 heavy metal SOIL transfer coefficients VEGETABLE
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基于单目视觉的田间菠萝果实识别 被引量:40
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作者 李斌 Ning Wang +1 位作者 汪懋华 李莉 《农业工程学报》 EI CAS CSCD 北大核心 2010年第10期345-349,共5页
菠萝果实的准确识别是菠萝采摘机器人视觉系统的关键。针对田间复杂环境中的青色菠萝,采用图像处理技术、数学形态学方法,识别菠萝果眼,并获取果眼的中心点信息;引入层次聚类分类方法,对多个中心点进行聚类分析;求取最多点集的中心坐标... 菠萝果实的准确识别是菠萝采摘机器人视觉系统的关键。针对田间复杂环境中的青色菠萝,采用图像处理技术、数学形态学方法,识别菠萝果眼,并获取果眼的中心点信息;引入层次聚类分类方法,对多个中心点进行聚类分析;求取最多点集的中心坐标,作为菠萝区域的近似形心。选用在广东湛江菠萝田间拍摄的35幅图像作为评价样本,经过运算,迎光条件下形心识别正确率达到85%。本研究为菠萝采摘机器人的田间果实识别提供了有效的技术方案。 展开更多
关键词 图像处理 视觉 形态学 菠萝 识别 层次聚类
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A comparative review of HLA associations with hepatitis Band C viral infections across global populations 被引量:32
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作者 Rashmi Singh Rashmi Kaul +1 位作者 Anil Kaul Khalid Khan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第12期1770-1787,共18页
Hepatitis B (HBV) and hepatitis C (HCV) viral infection or co-infection leads to risk of development of chronic infection, cirrhosis and hepatocellular carcinoma (HCC). Immigration and globalization have added t... Hepatitis B (HBV) and hepatitis C (HCV) viral infection or co-infection leads to risk of development of chronic infection, cirrhosis and hepatocellular carcinoma (HCC). Immigration and globalization have added to the challenges of public health concerns regarding chronic HBV and HCV infections worldwide. The aim of this study is to review existing global literature across ethnic populations on HBV and HCV related human leukocyte antigen (HLA) associations in relation to susceptibility, viral persistence and treatment. Extensive literature search was conducted to explore the HLA associations in HBV and HCV infections reported across global populations over the past decade to understand the knowledge status, weaknesses and strengths of this information in different ethnic populations. HLA DR13 is consistently associated with HBV clearance globally. HLADRB1*11/*12 alleles and DQB1*0301 are associated with HBV persistence but with HCV clearance worldwide. Consistent association of DRB1*03 and *07 is observed with HCV susceptibility and non-responsiveness to HBV vaccination across the population. HLA DR13 is protective for vertical HBV and HCV transmission in Chinese and Italian neonates, but different alleles are associated with their susceptibility in these populations. HLA class I molecule interactions with Killer cell immunoglobulin like receptors (KIR) of natural killer (NK) cells modulate HCV infection outcome via regulating immune regulatory cells and molecules. HLA associations with HBV vaccination, interferon therapy in HBV and HCV, and with extra hepatic manifestations of viral hepatitis are also discussed. Systematic studies in compliance with global regulatory standards are required to identify the HLA specific viral epitope, stage specific T cell populations interacting with different HLA alleles during disease progression and viral clearance of chronic HBV or HCV infections among different ethnic populations. These studies would facilitate stage specific therapeutic stra 展开更多
关键词 Human leukocyte antigen HBV persistence HCV persistence Interferon response to HBV and HCV HBV vaccination response
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秦岭天然次生油松林冠层降雨再分配特征及延滞效应 被引量:30
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作者 陈书军 陈存根 +3 位作者 邹伯才 张硕新 王得祥 侯琳 《生态学报》 CAS CSCD 北大核心 2012年第4期1142-1150,共9页
为了研究秦岭典型地带性植物油松林冠层降雨再分配特征及延滞效应,选择陕西宁陕县秦岭森林生态系统国家野外科学观测研究站55龄天然次生油松林,从2006—2008年(5—10月份)对林外降水、穿透降雨和树干茎流进行定位观测。利用其中100次实... 为了研究秦岭典型地带性植物油松林冠层降雨再分配特征及延滞效应,选择陕西宁陕县秦岭森林生态系统国家野外科学观测研究站55龄天然次生油松林,从2006—2008年(5—10月份)对林外降水、穿透降雨和树干茎流进行定位观测。利用其中100次实测数据进行分析研究,结果表明:总降雨量为1576.4 mm,穿透降雨量为982.9 mm,树干茎流量为69.5 mm,冠层截留量为524.0mm,分别占总降雨量的62.4%、4.4%和33.2%。降雨分配与降雨量级密切相关,降雨量级增大,穿透降雨率和茎流率呈增大趋势,截留率呈降低趋势,变化幅度分别为46.6%—68.9%、0.8%—9.2%、53.4%—22.0%。穿透降雨量、树干茎流量和林冠截留量与林外降雨量之间的关系分别为:TF=0.6548P-0.4937,R2=0.9596;SF=-0.2796+0.0452P+0.0005P2,R2=0.8179;I=0.5958P0.8175,R2=0.8064。降雨事件发生后,穿透降雨和树干茎流出现的时间与降雨发生的时间并不同步,均表现出一定的延滞性,随着降雨量级增大,滞后时间表现出逐渐缩短的趋势((78.5±8.8)—(16.0±0.0)min,(111.0±33.0)—(41.2±0.0)min)。降雨终止时,特别是当降雨量>10.0 mm,穿透降雨终止时间也存在一定的延滞性((3.2±2.6)—(12.0±0.0)min)。但树干茎流终止时间先于降雨终止时间,降雨量级越小,树干茎流终止时间愈早((-58.3±21.5)—(-9.8±0.0)min)。 展开更多
关键词 秦岭 油松林 穿透降雨 树干茎流 林冠截留
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路面裂缝图像自动识别算法综述 被引量:30
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作者 彭博 蒋阳升 +1 位作者 韩世凡 罗楠欣 《公路交通科技》 CAS CSCD 北大核心 2014年第7期19-25,共7页
路面裂缝自动检测对于路面养护管理、路面性能评价与预测、路面材料和结构设计具有重要的实用价值,但快速、准确、全面且稳定地识别路面裂缝一直是个难题。为此,对路面裂缝自动检测研究现状进行综述,包括以图像增强和去噪为目的的预处... 路面裂缝自动检测对于路面养护管理、路面性能评价与预测、路面材料和结构设计具有重要的实用价值,但快速、准确、全面且稳定地识别路面裂缝一直是个难题。为此,对路面裂缝自动检测研究现状进行综述,包括以图像增强和去噪为目的的预处理方法,基于阈值分割、边缘检测和种子生长的空间域识别算法,以小波变换为代表的频域识别算法,基于有监督学习的识别算法及其他裂缝识别方法;指出既有裂缝识别算法存在易受光照和油污等因素的影响、裂缝识别图像连续性差和识别速度和精度较低等不足。最后,提出综合考虑边界和区域特征消除纹理和噪声干扰、基于局部和全局信息设计优化识别算法和基于三维图像进行裂缝识别等研究展望,为裂缝自动识别算法的改进提供参考。 展开更多
关键词 道路工程 自动识别算法 图像处理 路面裂缝 图像分割 边缘检测 裂缝种子 有监督学习
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Reflective chiral meta-holography: multiplexing holograms for circularly polarized waves 被引量:26
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作者 Qiu Wang Eric Plum +5 位作者 Quanlong Yang Xueqian Zhang Quan Xu Yuehong Xu Jiaguang Han Weili Zhang 《Light(Science & Applications)》 SCIE EI CAS CSCD 2018年第1期825-833,共9页
By allowing almost arbitrary distributions of amplitude and phase of electromagnetic waves to be generated by a layer of sub-wavelength-size unit cells,metasurfaces have given rise to the field of meta-holography.Howe... By allowing almost arbitrary distributions of amplitude and phase of electromagnetic waves to be generated by a layer of sub-wavelength-size unit cells,metasurfaces have given rise to the field of meta-holography.However,holography with circularly polarized waves remains complicated as the achiral building blocks of existing meta-holograms inevitably contribute to holographic images generated by both left-handed and right-handed waves.Here we demonstrate how planar chirality enables the fully independent realization of high-efficiency meta-holograms for one circular polarization or the other.Such circular-polarization-selective meta-holograms are based on chiral building blocks that reflect either left-handed or right-handed circularly polarized waves with an orientation-dependent phase.Using terahertz waves,we experimentally demonstrate that this allows the straightforward design of reflective phase meta-holograms,where the use of alternating structures of opposite handedness yields independent holographic images for circularly polarized waves of opposite handedness with negligible polarization cross-talk. 展开更多
关键词 circular POLARIZED CHIRAL
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BOTTOM MESONS(B=±1)B^+=u,B^0=d,B^0=db,B^-=b,similarly for B~*'s 被引量:20
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作者 K.A.Olive K.Agashe +138 位作者 C.Amsler M.Antonelli J.-F.Arguin D.M.Asner H.Baer H.R.Band R.M.Barnett T.Basaglia C.W.Bauer J.J.Beatty V.I.Belousov J.Beringer G.Bernardi S.Bethke H.Bichsel O.Biebe E.Blucher S.Blusk G.Brooijmans O.Buchmueller V.Burkert M.A.Bychkov R.N.Cahn M.Carena A.Ceccucci A.Cerr D.Chakraborty M.-C.Chen R.S.Chivukula K.Copic G.Cowan O.Dahl G.D'Ambrosio T.Damour D.de Florian A.de Gouvea T.DeGrand P.de Jong G.Dissertor B.A.Dobrescu M.Doser M.Drees H.K.Dreiner D.A.Edwards S.Eidelman J.Erler V.V.Ezhela W.Fetscher B.D.Fields B.Foster A.Freitas T.K.Gaisser H.Gallagher L.Garren H.-J.Gerber G.Gerbier T.Gershon T.Gherghetta S.Golwala M.Goodman C.Grab A.V.Gritsan C.Grojean D.E.Groom M.Grnewald A.Gurtu T.Gutsche H.E.Haber K.Hagiwara C.Hanhart S.Hashimoto Y.Hayato K.G.Hayes M.Heffner B.Heltsley J.J.Hernandez-Rey K.Hikasa A.Hocker J.Holder A.Holtkamp J.Huston J.D.Jackson K.F.Johnson T.Junk M.Kado D.Karlen U.F.Katz S.R.Klein E.Klempt R.V.Kowalewski F.Krauss M.Kreps B.Krusche Yu.V.Kuyanov Y.Kwon O.Lahav J.Laiho P.Langacker A.Liddle Z.Ligeti C.-J.Lin T.M.Liss L.Littenberg K.S.Lugovsky S.B.Lugovsky F.Maltoni T.Mannel A.V.Manohar W.J.Marciano A.D.Martin A.Masoni J.Matthews D.Milstead P.Molaro K.Monig F.Moortgat M.J.Mortonson H.Murayama K.Nakamura M.Narain P.Nason S.Navas M.Neubert P.Nevski Y.Nir L.Pape J.Parsons C.Patrignani J.A.Peacock M.Pennington S.T.Petcov Kavli IPMU A.Piepke A.Pomarol A.Quadt S.Raby J.Rademacker G.Raffel B.N.Ratcliff 《Chinese Physics C》 SCIE CAS CSCD 2014年第9期1042-1223,共182页
Many measurements of B decays involve admixtures of B hadrons. Previously we arbitrarily included such admixtures in the B±section, but because of their importance we have created two new sections:
关键词 B~0=db B HBC BOTTOM MESONS B~0 b similarly for B
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Impact of Land Use and Soil Fertility on Distributions of Soil Aggregate Fractions and Some Nutrients 被引量:23
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作者 LIU Xiao-Li HE Yuan-Qiu +4 位作者 H. L. ZHANG J. K. SCHRODER LI Cheng-Liang ZHOU Jing ZHANG Zhi-Yong 《Pedosphere》 SCIE CAS CSCD 2010年第5期666-673,共8页
The size distribution of water-stable aggregates and the variability of organic C,N and P contents over aggregate size fractions were studied for orchard,upland,paddy,and grassland soils with high,medium,and low ferti... The size distribution of water-stable aggregates and the variability of organic C,N and P contents over aggregate size fractions were studied for orchard,upland,paddy,and grassland soils with high,medium,and low fertility levels.The results showed that > 5 mm aggregates in the cultivated upland and paddy soils were 44.0% and 32.0%,respectively,less than those in the un-tilled orchard soil.Organic C and soil N in different size aggregate fractions in orchard soil with high fertility were significantly higher than those of other land uses.However,the contents of soil P in different size aggregates were significantly greater in the paddy soil as compared to the other land uses.Soil organic C,N and P contents were higher in larger aggregates than those in smaller ones.The amount of water-stable aggregates was positively correlated to their contribution to soil organic C,N and P.For orchard and grassland soils,the > 5 mm aggregates made the greatest contribution to soil nutrients,while for upland soil,the 0.25-0.053 mm aggregates contributed the most to soil nutrients.Therefore,the land use with minimum disturbance was beneficial for the formation of a better soil structure.The dominant soil aggregates in different land use types determined the distribution of soil nutrients.Utilization efficiency of soil P could be improved by converting other land uses to the paddy soil. 展开更多
关键词 fertility levels land use types red soil water-stable aggregates
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Role of sex steroid receptors in pathobiology of hepatocellular carcinoma 被引量:18
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作者 Mamta Kalra Jary Mayes +2 位作者 Senait Assefa Anil K Kaul Rashmi Kaul 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第39期5945-5961,共17页
The striking gender disparity observed in the incidence of hepatocellutar carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise ro... The striking gender disparity observed in the incidence of hepatocellutar carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise role of sex hormones and the significance of their receptors in HCC still remain poorly understood and perhaps contribute to current controversies about the potential use of hormonal therapy in HCC. A comprehensive review of the existing literature revealed several shortcomings associated with the studies on estrogen receptor (ER) and androgen receptor (AR) in normal liver and HCC. These shortcomings include the use of less sensitive receptor ligand binding assays and immunohistochemistry studies for ERα alone until 1996 when ERβ isoform was identified. The animal models of HCC utilized for studies were primarily based on chemical-induced hepatocarcinogenesis with less similarity to virus-induced HCC pathogenesis. However, recent in vitro studies in hepatoma cells provide newer insights for hormonal regulation of key cellular processes including interaction of ER and AR with viral proteins. In light of the above facts, there is an urgent need for a detailed investigation of sex hormones and their receptors in normal liver and HCC. In this review, we systematically present the information currently available on androgens, estrogens and their receptors in normal liver and HCC obtained from in vitro, in vivo experimental models and clinical studies. This information will direct future basic and clinical research to bridge the gap in knowledge to explore the therapeutic potential of hormonal therapy in HCC. 展开更多
关键词 Sex hormones Estrogen receptor Androgen receptor Hepatocellular carcinoma HEPATOCARCINOGENESIS
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REVIEW OF PARTICLE PHYSICS 被引量:13
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作者 K.A.Olive K.Agashe +138 位作者 C.Amsler M.Antonelli J.-F.Arguin D.M.Asner H.Baer H.R.Band R.M.Barnett T.Basaglia C.W.Bauer J.J.Beatty V.I.Belousov J.Beringer G.Bernardi S.Bethke H.Bichsel O.Biebe E.Blucher S.Blusk G.Brooijmans O.Buchmueller V.Burkert M.A.Bychkov R.N.Cahn M.Carena A.Ceccucci A.Cerr D.Chakraborty M.-C.Chen R.S.Chivukula K.Copic G.Cowan O.Dahl G.D'Ambrosio T.Damour D.de Florian A.de Gouvea T.DeGrand P.de Jong G.Dissertor B.A.Dobrescu M.Doser M.Drees H.K.Dreiner D.A.Edwards S.Eidelman J.Erler V.V.Ezhela W.Fetscher B.D.Fields B.Foster A.Freitas T.K.Gaisser H.Gallagher L.Garren H.-J.Gerber G.Gerbier T.Gershon T.Gherghetta S.Golwala M.Goodman C.Grab A.V.Gritsan C.Grojean D.E.Groom M.Grnewald A.Gurtu T.Gutsche H.E.Haber K.Hagiwara C.Hanhart S.Hashimoto Y.Hayato K.G.Hayes M.Heffner B.Heltsley J.J.Hernandez-Rey K.Hikasa A.Hocker J.Holder A.Holtkamp J.Huston J.D.Jackson K.F.Johnson T.Junk M.Kado D.Karlen U.F.Katz S.R.Klein E.Klempt R.V.Kowalewski F.Krauss M.Kreps B.Krusche Yu.V.Kuyanov Y.Kwon O.Lahav J.Laiho P.Langacker A.Liddle Z.Ligeti C.-J.Lin T.M.Liss L.Littenberg K.S.Lugovsky S.B.Lugovsky F.Maltoni T.Mannel A.V.Manohar W.J.Marciano A.D.Martin A.Masoni J.Matthews D.Milstead P.Molaro K.Monig F.Moortgat M.J.Mortonson H.Murayama K.Nakamura M.Narain P.Nason S.Navas M.Neubert P.Nevski Y.Nir L.Pape J.Parsons C.Patrignani J.A.Peacock M.Pennington S.T.Petcov Kavli IPMU A.Piepke A.Pomarol A.Quadt S.Raby J.Rademacker G.Raffel B.N.Ratcliff 《Chinese Physics C》 SCIE CAS CSCD 2014年第9期1-4,共4页
The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the ... The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,283 new measurements from 899 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as heavy neutrinos, supersymmetric and technicolor particles, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Supersymmetry, Extra Dimensions, Particle Detectors, Probability, and Statistics. Among the 112 reviews are many that are new or heavily revised including those on: Dark Energy, Higgs Boson Physics, Electroweak Model, Neutrino Cross Section Measurements, Monte Carlo Neutrino Generators, Top Quark, Dark Matter, Dynamical Electroweak Symmetry Breaking, Accelerator Physics of Colliders, High-Energy Collider Parameters, Big Bang Nucleosynthesis, Astrophysical Constants and Cosmological Parameters. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http ://pdg. lbl. gov. 展开更多
关键词 REVIEW OF PARTICLE PHYSICS
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Probiotic properties of lactic acid bacteria isolated from traditionally fermented Xinjiang cheese 被引量:17
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作者 Ramila AZAT Yan LIU +4 位作者 Wei LI Abdurihim KAYIR Ding-bo LIN Wen-wen ZHOU Xiao-dong ZHENG 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2016年第8期597-609,共13页
Six lactic acid bacterial (LAB) strains were isolated from traditionally fermented Xinjiang cheese and evaluated for functional and probiotic properties and potentials as starter cultures. The isolated six LAB strai... Six lactic acid bacterial (LAB) strains were isolated from traditionally fermented Xinjiang cheese and evaluated for functional and probiotic properties and potentials as starter cultures. The isolated six LAB strains com- prised Lactobacillus rhamnosus (one strain), Lactobacillus helveticus (one strain), and Enterococcus hirae (four strains). All of the six strains were tolerant to acidic and bile salt conditions. Among which, the L. rhamnosus R4 strain showed more desirable antimicrobial, auto-aggregation, and hydrophobic activity. In addition, the strain L. rhamnosus R4 exhibited the highest level of free radical scavenging activity (53.78% of 1,1-dipheny1-2-picrylhydrazyl (DPPH) free radicals and 45.79% of hydroxyl radicals). L. rhamnosus R4 also demonstrated cholesterol and triglyceride degrada- tion by 50.97% and 28.92%, respectively. To further examine the health-promoting effects of these LAB strains on host lifespan, Caenorhabditis elegans was used as an in vivo model. Worms fed LAB as a food source had significant differences in lifespan compared to those fed Escherichia coil OP50 (as a negative control). Feeding of L. rhamnosus R4 extended the mean lifespan of C. elegans by up to 36.1% compared to that of the control. The results suggest that the strains isolated from Xinjiang fermented dairy products have high potential as starter cultures in the cheese industry. 展开更多
关键词 Xinjiang cheese Lactic acid bacterial (LAB) strains Probiotic properties Caenorhabditis elegans LIFESPAN
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基于太赫兹光谱技术的山核桃内部虫害检测初步研究 被引量:17
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作者 李斌 WANG Ning +2 位作者 张伟立 赵春江 张保华 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2014年第5期1196-1200,共5页
美洲山核桃是美国最重要的坚果之一,内部虫害是影响山核桃质量的重要因素。为了实现美洲山核桃内部虫害的有效快速、无损检测,初步探索应用太赫兹光谱技术检测山核桃虫害研究。收集山核桃样本并制作核桃仁1,2,3mm均匀厚度的切片,... 美洲山核桃是美国最重要的坚果之一,内部虫害是影响山核桃质量的重要因素。为了实现美洲山核桃内部虫害的有效快速、无损检测,初步探索应用太赫兹光谱技术检测山核桃虫害研究。收集山核桃样本并制作核桃仁1,2,3mm均匀厚度的切片,切片大小为2cm×1cm,按照同样的尺寸制作核桃壳和核桃仁中间夹层的切片;利用太赫兹时域光谱设备采集不同切片0~2T Hz波段的太赫兹吸收光谱,并对比分析了所测切片的光谱特性;采集了活体烟草天蛾切片和干燥的山核桃虫害切片的太赫兹时域光谱,由于活体害虫的较高含水量以及太赫兹光谱对水分等极性分子的强吸收特性,与山核桃切片对比发现,活体虫害呈现非常明显的光谱吸收特性;最后,对整个山核桃样本进行了无损透射试验。研究表明,太赫兹光谱技术在检测山核桃内部虫害方面具有较好的应用潜力,为进一步认识太赫兹光谱性质,掌握样品制备方法、实验测试方法和数据获取及光学参数计算方法,应用太赫兹光谱技术开展山核桃内部虫害快速无损检测提供参考。 展开更多
关键词 太赫兹 山核桃 无损检测 内部虫害
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Tillage, crop residue, and nutrient management effects on.soil organic carbon in rice-based cropping systems: A review 被引量:14
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作者 Rajan Ghimire Sushil Lamichhane +2 位作者 Bharat Sharma Acharya Prakriti Bista Upendra Man Sainju 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第1期1-15,共15页
Soil organic carbon (SOC) sequestration is one of the major agricultural strategies to mitigate greenhouse gas (GHG) emissions, enhance food security, and improve agricultural sustainability. This paper synthesize... Soil organic carbon (SOC) sequestration is one of the major agricultural strategies to mitigate greenhouse gas (GHG) emissions, enhance food security, and improve agricultural sustainability. This paper synthesizes the much-needed state- of-knowledge on the effects of tillage, crop residue, and nutrient management practices on SOC sequestration and identifies potential research gap, opportunities, and challenges in studying SOC dynamics in rice (Oryza sativa L.)-based cropping systems in South Asia, mainly in Bangladesh, Bhutan, India, Nepal, Pakistan, and Sri Lanka. Improved management prac- tices such as reduced- and no-tillage management, nitrogen (N) fertilizer and farmyard manure (FYM) application, and crop residue addition can improve SOC accumulation. Positive effects of no-tillage, crop residue addition, N addition through manure or compost application, and integration of organic and chemical fertilizers on SOC accumulation in rice-based cropping systems have been documented from South Asia. However, limited data and enormous discrepancies in SOC measurements across the region exist as the greatest challenge in increasing SOC sequestration and improving agricultural sustainability. More research on SOC as influenced by alternative tillage, crop residue, and nutrient management systems, and development of SOC monitoring system for existing long-term experiments will advance our understanding of the SOC dynamics in rice-based cropping systems and improve agricultural system sustainability in South Asia. 展开更多
关键词 carbon mapping carbon sequestration crop residue NO-TILLAGE rice-wheat system
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Dynamics of Soil and Grain Micronutrients as Affected by Long-Term Fertilization in an Aquic Inceptisol 被引量:13
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作者 LI Ben-Yin HUANG Shao-Min +4 位作者 WEI Ming-Bao H. L. ZHANG SHEN A-Lin XU Jian-Ming RUAN Xin-Ling 《Pedosphere》 SCIE CAS CSCD 2010年第6期725-735,共11页
Micronutrient status in soils can be affected by long-term fertilization and intensive cropping.A 19-year experiment (1990-2008) was carried out to investigate the influence of different fertilization regimes on micro... Micronutrient status in soils can be affected by long-term fertilization and intensive cropping.A 19-year experiment (1990-2008) was carried out to investigate the influence of different fertilization regimes on micronutrients in an Aquic Inceptisol and maize and wheat grains in Zhengzhou,China.The results showed that soil total Cu and Zn markedly declined after 19 years with application of N fertilizer alone.Soil total Fe and Mn were significantly increased mainly due to atmospheric deposition.Applications of P and organic fertilizer with incorporation of straws resulted in dramatic increases in soil total Cu,Zn,Fe,and Mn.Soil diethylenetriamine pentaacetic acid (DTPA)-extractable Cu in all treatments sharply decreased from initially 1.12 to about 0.8 mg kg -1 .The treatments with organic fertilizer had the highest soil DTPA-extractable Cu,Zn,Fe,and Mn after 19 years of cropping and fertilization,thus demonstrating the important role of organic fertilizer application in improving available micronutrient status.Cu and Zn contents in wheat grains in the no-P treatments were significantly higher than those of the treatments with P application.In addition,Fe and Mn contents in wheat grains were positively correlated with their soil DTPA-extractable concentrations.These indicated that the long-term application of organic fertilizer resulted in significant increases in soil total and available micronutrient concentrations and remarkable reduction in wheat grain Cu and Zn contents,which was due to high soil available P. 展开更多
关键词 Cu organic fertilizer soil available P WHEAT Zn
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基于各向异性测度的路面三维图像裂缝识别 被引量:13
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作者 彭博 WANG Kelvin C.P. +1 位作者 陈成 蒋阳升 《西南交通大学学报》 EI CSCD 北大核心 2014年第5期888-895,共8页
为准确而完整地识别路面裂缝,提出了基于1 mm/像素的路面三维图像裂缝自动识别算法.该算法主要包括各向异性测度计算与自适应优化阈值分割、深度验证和多分辨率去噪处理3个部分.首先,针对路面图像像素特征,基于0°、45°、90... 为准确而完整地识别路面裂缝,提出了基于1 mm/像素的路面三维图像裂缝自动识别算法.该算法主要包括各向异性测度计算与自适应优化阈值分割、深度验证和多分辨率去噪处理3个部分.首先,针对路面图像像素特征,基于0°、45°、90°和135°四个方向的线性邻域的均值和标准差计算每个像素的各向异性测度(表征方向性的强弱),并应用最大类间方差法确定最优阈值,将路面图像分为强方向性和弱方向性像素两类;其次,根据半径为d的正方形邻域深度均值设定阈值,用方向性强且深度低于或等于该阈值的像素形成初步的裂缝图像;最后,将裂缝图像划分为多个子块,设计去噪模板对裂缝图像进行滑动窗口去噪处理,获得最终裂缝图像.基于166幅含有各类裂缝的三维路面图像(2 048×2 048像素)进行测试分析,结果显示,本文算法获得了较高的准确率(均值91.57%)和召回率(均值81.29%),最终以84.26%的F1均值优于种子识别算法(F1均值69.19%)、Canny边缘检测(F1均值8.15%)和OTSU分割(F1均值5.11%). 展开更多
关键词 道路工程 识别算法 图像处理 路面裂缝 各向异性检测 三维图像
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