oalib

Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99

Submit

Any time

2020 ( 1 )

2019 ( 338 )

2018 ( 2811 )

2017 ( 2744 )

Custom range...

Search Results: 1 - 10 of 176686 matches for " Wei-Zheng Li "
All listed articles are free for downloading (OA Articles)
Page 1 /176686
Display every page Item
THE ACCEPTOR PROPERTIES OF UN-INTENTIONALLY DOPED p-TYPE MBE-GROWN Hg1-xCdxTe
非掺杂p型MBE—Hg1—xCdxTe材料的受主性质

FANG Wei-zheng,YANG Jian-rong,CHEN Xin-Qiang,WANG Shan-Li,HE Li,
方维政
,杨建荣

红外与毫米波学报 , 1998,
Abstract: 对经250℃P型热处理获得的Hg1-xCdxTeMBE材料进行变温霍耳测量和理论拟合计算,由此得到HgCdTe-MBE材料的受主浓度为2-3×10^16cm^-3,残余施主浓度为5×10^15cm^-3左右,两才相比显示材料的补偿度较低,拟合得到的汞空位受主能级为15-18meVdisplay structure
Bioassays on selection and feeding responses of Holotrichia oblita adults to different plant species

Wei-Zheng Li,Ying-Hua Yuan,Shi-Heng An,Guo-Hui Yuan,Mei-Hao Luo,Xian-Ru Guo,

生态学报 , 2009,
Abstract: Bioassays on selection and feeding responses of Holotrichia oblita adults to different plant species were conducted both in laboratory and under field conditions. The selection response bioassay showed that the adults were significantly attracted to Ricinus communis. In paired tests of the field cages, more than 60% adults were attracted to R. communis plants, while only 35.55%, 34.45%, 33.35%, and 26.65% were attracted to plants of Glycine max, Arachis hypogaea, Ipomoea batatas, and Gossypium hirsutum, respectively. In the laboratory, the selection response percentage of the adults to R. communis leaves reached up to 93% in the presence of other host plant leaves and still arrived at 70% in the absence of other host plant leaves. Feeding deterrence bioassay showed that the adults preferred to I. batatas leaves with 229.90 ± 4.25 mg leaf consumption and 41.30 ± 5.19 mg faeces excretion after 12 h, followed by the leaves of G. hirsutum and A. hypogaea. The adult did not prefer leaves of R. communi with only 7.10 ± 0.23 mg leaf consumption and corresponding 4.00 ± 0.84 mg fecal excretion. In summary, all experimental results suggested that the attraction of H. oblita adults to R. communi is not triggered for feeding.
Theory analysis of steady magnetic field on rotational stability of electromagnetic levitation melting
直流磁场控制电磁悬浮熔炼旋转稳定性的理论分析

Ma Wei-Zheng,Ji Cheng-Chang,Li Jian-Guo,
马伟增
,季诚昌,李建国

物理学报 , 2002,
Abstract: 在没有直流磁场和存在直流磁场两种情况下,对悬浮于高频磁场的导电球在旋转扰动情况下的稳定性进行了理论分析.悬浮感应器电流的无量纲角频率为ω-.在不存在直流稳定磁场的固态球悬浮情况下,存在一个临界无量纲角频率ω-c.当ω-<ω-c,球形悬浮试样对于旋转干扰是稳定的;当ω->ω-c,球形悬浮试样对于旋转干扰是不稳定的.在直流稳定磁场的固态球悬浮情况下,存在一个无量纲角频率下限ω-c,1和上限ω-c,2.当ω-<ω-c,1或者ω->ω-c,2,球形悬浮试样对于旋转干扰是稳定的;当ω-c,1<ω-<ω-c,2,球形
The significance of solar magnetic field direction variation on anomalous variability of the atmosphere temperature on the earth
太阳磁场方向变化对于地球大气温度异常变化的意义

QU Wei-Zheng,HUANG Fei,ZHAO Jin-Ping,DENG Sheng-Gui,LIU Ying-Chen,LI Shu-Jiang,
曲维政

地球物理学报 , 2007,
Abstract: 本文根据苏黎世天文台太阳黑子11年周期资料和太阳黑子磁场磁性变化周期特征,构建了太阳黑子磁场磁性指数MI(Magnetic Index)时间序列.分析表明:太阳活动磁性周期平均长度为22.2年,但是每个周期长度是不相等的;多数情况周期短时磁性指数较大,对应太阳活动水平强;周期变长时磁性指数较小,对应太阳活动水平较弱;太阳黑子磁场磁性指数序列也具有80~90年的世纪周期.进一步研究指出,太阳黑子磁场磁性指数曲线由极小值升至极大值时期,太阳磁场南向,行星际磁场磁力线与地磁场磁力线重联,此时磁层为开磁层,太阳风将携带大量等离子体从向阳面进入地球磁层,从而使输入的动量、能量和物质大幅度增加,与北半球对流层增温时期对应;太阳黑子磁场磁性指数曲线由极大值下降至极小值时期,太阳磁场北向,与磁层顶地磁场同向,行星际磁场不会与地磁场发生重联,此时磁层为闭磁层,这种情况下,只有少数带电粒子能够穿越磁力线进入地球磁层,与北半球对流层降温时期对应.
Longtoushan Gold Deposit of Subvolcanic-Cryptoexplosion Breccia Type, Guangxi
广西龙头山次火山-隐爆角砾岩型金矿床

HUANG Min-zhi,CHEN Wei-shi,LI Wei-zheng,XU Fang-shi,LI Xian-yue,
黄民智
,陈伟十,李蔚铮,许仿实,李先粤

地球学报 , 1999,
Abstract: The Longtoushan gold deposit is related to late Yanshanian subvolcanic rocks such as rhyolitic porphyry and breccia lava. According to the wall rocks and structural conditions the ore bodies may be divided into three types :subvolcanic-cryptoexplosion breccia type,contact zone-structural breccia type,and wall rock-structural breccia type.There is a close relationship between gold mineralization and tourmalinization and silicification. According to a study on the ore composition,distributive characteristics of gold and its associated elements,stable isotopes(S,Pb,H,O and C),geochemistry of fluid inclusions and physical-chemical conditions for mineralization,the authors conclud that the Longtoushan deposit is a pneumato-hypothermalgold deposit related to subvolcanic-cryptoexplosion breccia.
Relationship between lattice parameters and compositions of molecular beam epitaxial Hg1- x CdxTe films
Hg1-xCdxTe分子束外延薄膜晶格参数与组分关系的研究

WANG Qing-xue,YANG Jian-rong,Sun Tao,WEI Yan-feng,FANG Wei-zheng,He Li,
王庆学
,杨建荣,孙涛,魏彦锋,方维政,何力

物理学报 , 2005,
Abstract: High-resolution x-ray diffraction technology is applied to the measurement of lattice parameters and the study of strain for Hg_ 1-xCd_xTe films grown by molecular beam epitaxy. The results show that there exist both perpendicular strain and shear strain in Hg_ 1-xCd_xTe films. Based on crystal elastic theory, strain states in Hg_ 1-xCd_xTe films are analyzed and calculated, and the lattice parameters of Hg_ 1-xCd_xTe films at the relaxation state are obtained. It is found that the relationship between lattice parameters and compositions of Hg_ 1-xCd_xTe films agrees with Vegard's law, rather than Higgins formula proposed in earlier research. It is also found that the lattice parameters can be derived from the measured data of (224) plane spacing, and that the compositions of Hg_ 1-xCd_xTe films can also be evaluated by using Vegard's law with an error about 0.01.
Effects of improved traditional rice-fish system productivity on field water environment
传统稻鱼系统生产力提升对稻田水体环境的影响

DING Wei-Hu,LI Na-N,REN Wei-Zheng,HU Liang-Liang,CHEN Xin,TANG Jian-Jun,
丁伟华
,李娜娜,任伟征,胡亮亮,陈 欣,唐建军

中国生态农业学报 , 2013,
Abstract: World agriculture currently faces great challenges in producing sufficient food while minimizing negative environmental effects of crop cultivation, requiring us to rethink current agricultural production processes. Traditional agricultural systems based on local species diversity and interactions have contributed to food and livelihood security throughout the world for centuries. As human population increased, however, traditional agricultural systems faced daunting challenges in food demand and supply due to the lower economic benefits of the systems. Thus improving the productivity of traditional agricultural systems in a sustainable way has been of great concerned to producers and decision-makers. To determine the feasibility of increasing traditional agricultural productivity without corresponding increase in negative environment impacts, two experiments were conducted at a traditional rice-fish co-culture site that had been operated for over 1 200 years in southern Zhejiang Province. In the first experiment, three treatments without pesticide, including rice monoculture (RM), rice-fish co-culture (RF) and fish monoculture (FM), were compared. In addition to measured rice yield (in RM and RF), fish yield (in RF and FM), and surveyed input-output economics, focus was put on total nitrogen (TN), total phosphorus (TP), total ammonia nitrogen (NH4+-N) and chemical oxygen demand (COD) in field water. Four fish density treatments, including with target fish yields in rice-fish co-culture fields of 750 kg·hm-2 (RF750), 1 500 kg·hm-2 (RF1500), 2 250 kg·hm-2 (RF2250) and 3 000 kg·hm-2 (RF3000), were designed in the second experiment. Rice and fish yields, input and output of economics, and TN, TP, NH4+-N and COD were measured in the field water. The first experiment showed no significant difference in rice yield between RM and RF. There was also no significant difference in fish yield between RF and FM in the experiment. However, total and net income of the system were higher in RF than in RM and FM. Field water contents of TN, TP, NH4+-N and COD were not significantly different between RF and RM. The second experiment showed that rice yield, fish yield, and total and net economic output increased with increasing fish stock density and fish feed input. Increase in fish stock density increased target yield of fish by 1 500 kg·hm-2 (50%), significantly increased net income of rice-fish co-culture systems by 25.2%~101.4%, and also increased COD, TN, TP and NH4+-N content in field water. When target yield was 3 000 kg·hm -2, TP and COD contents became significantly higher than in other treatments; which enhanced risk of environmental pollution. Economic analysis indicated that target fish yield of 2 250 kg·hm-2 gave higher economic income and with little impact on field water environment.
Removing Nitrogen from Low-C/N-Piggery-Wastewater Using Shortcut Nitrification/denitrification-ANAMMOX
低碳氮比猪场废水短程硝化反硝化-厌氧氨氧化脱氮

WANG Huan,PEI Wei-zheng,LI Xu-dong,HAO Chun,ZENG Kang-mei,
王欢
,裴伟征,李旭东,郝纯,曾抗美

环境科学 , 2009,
Abstract: Aiming at the problem of deficiency of organic carbon source in piggery wastewater treatment by traditional method,shortcut nitrification/denitrification-ANAMMOX was used to remove nitrogen in piggery wastewater with low C/N in SBBR reactors.The results showed that shortcut nitrification/denitrification provided good influent conditions for ANAMMOX.High nitrogen removal efficiency of piggery wastewater by ANAMMOX was achieved and the average removal percentage of ammonium,nitrite and total nitrogen reached ...
Double Exchange Genetic Algorithm for the Synthesis of Linear Array
Zhang Jian-Hua,Pang Wei-zheng
Research Journal of Applied Sciences, Engineering and Technology , 2012,
Abstract: The development of Synthesis of Linear array put forward higher request for complex optimization solutions. This article improves the basic genetic algorithm according to the traditional genetic algorithm easily prematuring convergence and later evolution slow convergence shortcoming. And then, adopt double exchange operator in reproductive strategies and implement dynamic mutation rate in variation operations. Combined characteristics of guarantee to the population diversity based on fitness shared niche while iteration times exponential diminishing, this article creats niche double exchangegenetic algorithm, and applies in pattern synthesis of homogeneous linear array, and simulates multi-objective complex array problem. The result turns out much better in effectively preventing premature and improving the searching efficiency of genetic algorithm than original genetic algorithm and immune genetic algorithm, what will achieve the broad prospect in the antenna array comprehensive field.
黑龙江松嫩地块北缘晚三叠世—早侏罗世火山岩的发现及地质意义
The Discovery of Late Triassic-Early Jurassic Volcanic Rocks and Their Geological Implications in Northern Songnen Block, Heilongjiang Province

吕长禄,肖庆辉,冯俊岭 ,李新鹏,邓昌州,任凤和,郑卫政
Lv Chang-lu
,XIAO Qing-hui,FENG Jun-ling,LI Xin-peng,DENG Chang-zhou,REN Feng-he,ZHENG Wei-zheng

- , 2015,
Abstract: 摘要: 黑龙江省松嫩地块北缘大面积分布的玄武安山岩的时代厘定对讨论区域构造演化具有重要意义。对该区原划为早白垩世板子房组的玄武安山岩进行了LA-ICP-MS 锆石U-Pb年代学、岩石学和地球化学等研究,获得两个样品的锆石U-Pb年龄分别为(200.0±1.4)Ma和(200.0±1.3)Ma,表明其形成时代为晚三叠世—早侏罗世,并非早白垩世。岩石地球化学研究表明,玄武安山岩属准铝质,以高钾钙碱性系列为主,富集Ba、Rb、K、Pb等大离子亲石元素和轻稀土元素,亏损Nb、Ce、Nd、Ti等高场强元素和重稀土元素,为典型的大陆弧火山岩,表明松嫩地块小兴安岭—张广才岭存在一条近南北向展布的晚三叠世—早侏罗世火山岩带,该火山岩带与同时代略晚的花岗岩一起构成近南北向带状展布的中生代岩浆岩带。
Abstract: Basaltic andesites are widely distributed in the northern Songnen Block, Heilongjiang Province and their ages are critical to understand the regional tectonic evolution in this area. This study presents LA-ICP-MS zircon U-Pb age data and geochemical data for the basaltic andesite from the Banzifang Formation previously considered to be Early Cretaceous. Two samples yield U-Pb ages of (200.0±1.4)Ma and (200.0±1.3) Ma respectively,demonstrating that they were formed in Late TriassicEarly Jurassic rather than Early Cretaceous. The basaltic andesites are metaluminous, mainly high-K calc-alkaline. They are characterized by enrichment of large ion lithophile elements (LILE) such as Ba, Rb, K, Pb and LREE, depletion of high field strength elements (HFSE) such as Nb, Ce, Nd, Ti and HREE, indicating that the basaltic andesites belong to continental arc volcanic rocks. The results demonstrate that there has been Late Triassic-Early Jurassic volcanic belts in Xiaoxinganling-Zhangguangcailing, these occurrence, together with synchronous granites, comprise a Mesozoic N-S-striking magmatic belt
Page 1 /176686
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.