检索结果-南通市图书馆

Journal of Environmental Sciences 2009年第8期21卷 1125-1128页

作者： SU Dechun xing jianping JIAO Weiping WONG Woonchung College of Resources and Environmental Sciences China Agricultural University Beijing 100193 China Department of Biology Hong Kong Baptist University Kowloon Tong Hong Kong SAR China

Characteristics of cadmium （Cd） uptake kinetics and distribution of Cd speciation in the rhizosphere for Cd accumulator and nonaccumulator oilseed rape varieties were investigated under nutrient solution and rhizobox soil culture conditions. The results showed that the maximal influx （Vmax） for Cd^2＋ and Km were significantly different for the two oilseed rape varieties. The value of Vmax for Cd accumulator oilseed rape Zhucang Huazi was two-fold greater than that for oilseed rape Chuan you Ⅱ-93. The exchangeable Cd concentration in the rhizosphere was significantly lower than in non-rhizospheric soils supplemented with CdSO4 for both the varieties. Carbonate-bound Cd in the rhizosphere of Cd accumulator oilseed rape was significantly higher than that in the rhizosphere of nonaccumulator oilseed rape and non-rhizospheric soil. Cd accumulator oilseed rape had a higher Cd^2＋ affinity and more ability to uptake insoluble Cd in the soil than the non-accumulator oilseed rape.

关键词： cadmium oilseed rape rhizosphere uptake kinetics

Study on video intelligent early warning and tracking system based on ARM

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2016年第3期22卷 266-272页

作者：刘岩松 Xu Yihong xing jianping School of Mechanical and Electrical Engineering Shandong Management University Jinan 250357 P. R. China School of Information Science and Engineering Shandong University Jinan 250014 P. R. China

The protrusion of the planning of numerical intelligent early-warning and tracking system in this study which can ease triggerman's work strength,lay the next generation intelligence supervision system foundation and expand effectively the video resources use etc. In the numerical intelligent early-warning matrix sub-system,the authors have designed a kind dual-core system which includes both ARM and DSP,and designed detailedly traffic dynamics affairs early-warning arithmetic which bases on that system. And then,this system will carry quickly on fixing the right position of license plate,correcting the inclination degree of license plate,and thinning it to get the number of this license and severity grade. Secondly,in the rotated dome camera sub-system,the authors have designed three-dimensional trajectory mathematical model which makes use of a fuzzy PID controller to achieve the high- speed track. At last,Simulation shows that the proposed control method has high profile tracking precision,accuracy and robustness of the disturbance.

关键词： embedded dual-core system intelligent early warning accident recognition tracking and monitoring simulation

Zinc phosphate dissolution by bacteria isolated from an oligotrophic karst cave in central China

在线全文

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2013年第3期7卷 375-383页

作者： Hongmei WANG Qiang DONG jianping ZHOU xing XIANG State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Wuhan 430074 China

Biogeochemical processes are fundamental to sustain the ecosystem in subsurface caves, but to date they are still far from well understood. To investigate micro-bially mediated phosphorus and zinc cycles, we isolated three bacterial strains from the dripping water in Heshang cave, central China, identified as Exiguobacterium aurantiacum E11, Pseudomonas fluorescens P35, and Pseu- domonas poae P41, respectively. Microbial capabilities in the dissolution of phosphorus-containing minerals were tested with zinc phosphate （Zn3（PO4）2） in batch culture at 30~C. A spectrophotometer, atomic absorption spectrum, and scanning electronic microscopy were used to measure the microbial growth, soluble Zn（II） concentration, and to observe the morphology of Zn3（PO4）2 before and after microbial dissolution. P. fluorescens and P. poae, the well- known phosphorus solubilizing bacteria （PSB）, are observed to solubilize Zn3（PO4）2 with an efficiency of 16.7% and 17.6%, respectively. To our knowledge, E. aurantiacum is firstly reported in this study to dissolve phosphorous-containing minerals with a higher efficiency of 39.7%, expanding our understanding about the ubiquitous occurrence of PSB in natural environments. Aqueous Zn（II） concentration positively correlates with H＋ activity, confirming the presence of acidification mechanisms widely exploited by PSB. Few itching pits were observed on the surface of Zn3（PO4）2 after microbial dissolution, inferring that microbial dissolution is not always associated with the direct contact with minerals. Even though the soluble Zn（II） concentration reached up to 370 mg/L in the system inoculated with E. aurantiacum Ell, inhibition of microbial growth was not detected by spectrophotometer. Our laboratory data revealed the importance of microbially-mediated P and Zn cycles in the subsurface ecosystem.

关键词： karst cave phosphate solubilizing bacteria (PSB) zinc toxicity biogeochemical process subsurface biosphere

Influences of Geometric Parameters upon Nozzle Performances in Scramjets

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2008年第6期21卷 506-511页

作者： Li jianping Song Wenyan xing Ying Luo Feiteng School of Power and Energy Northwestern Polytechnical University Xi 'an 710072 China

This article investigates and presents the influences of geometric parameters of a scramjet exerting upon its nozzle performances. These parameters include divergent angles, total lengths, height ratios, cowl lengths, and cowl angles. The flow field within the scramjet nozzle is simulated numerically by using the CFD software--FLUENT in association with coupled implicit solver and an RNG k-ε turbulence model.

关键词： scramjet nozzle numerical simulation geometric parameters

Upgrade of Goosy Data Acquisition System

在线全文

学校读者我要写书评

暂无评论

IMP & HIRFL Annual Report 1996年第1期 110-111页

作者： Wang Shujin Wang Yanyu xing jianping Guo Tianrui and Jiao Dunpang

ＵｐｇｒａｄｅｏｆＧｏｏｓｙＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＷａｎｇＳｈｕｊｉｎ；ＷａｎｇＹａｎｙｕ；ＸｉｎｇＪｉａｎｐｉｎｇ；ＧｕｏＴｉａｎｒｕｉａｎｄＪｉａｏＤｕｎｐａｎｇＡｄａｔａａｃｑｕｉｓｉｔｉ...

ＵｐｇｒａｄｅｏｆＧｏｏｓｙＤａｔａＡｃｑｕｉｓｉｔｉｏｎＳｙｓｔｅｍ￥ＷａｎｇＳｈｕｊｉｎ；ＷａｎｇＹａｎｙｕ；ＸｉｎｇＪｉａｎｐｉｎｇ；ＧｕｏＴｉａｎｒｕｉａｎｄＪｉａｏＤｕｎｐａｎｇＡｄａｔａａｃｑｕｉｓｉｔｉｏｎｓｙｓｔｅｍｎａｍｅｄＧｏｏｓ...

关键词：

A new coupled method for pseudolite system-augmented GNSS real-time kinematic PPP

在线全文

学校读者我要写书评

暂无评论

A new coupled method for pseudolite system-augmented GNSS re...

随机通信半径下无线传感器网络中三维节点定位算法(英文)

第十四届中国卫星导航年会

作者： Caoming Fan Zheng Yao Yanchen Dong jianping xing Shandong University Tsinghua University

A long convergence time for Global Navigation Satellite System(GNSS) Precise Point Positioning(PPP) is a critical obstacle to its wide *** pseudolites(PLs) are relatively close to receivers,moving receivers can produce rapid spatial geometry variations,which facilitates fast convergence of ***,considering the limited coverage of pseudolite system(PLS),the augmentation time is *** is therefore crucial to make the GNSS PPP parameters(especially the GNSS ambiguity parameters) converge within the limited augmentation ***,the potential of PLS should be explored as much as possible,and the gains brought by PLS should be effectively *** order to use the fixed solution of PLS more safely and reliably,a dual-filter tightly coupled(DF-TC) model is *** the number of PLs is sufficient and the augmentation time is long enough,the positioning performances of all the couple models are not significantly *** the case of short-time augmentation,the DF-TC model exhibits the best augmentation performance,it can significantly reduce the augmentation time required by GNSS,which means that the required coverage of PLS can be smaller and will be more flexible and convenient for applications.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

传感技术学报 2011年第1期24卷 88-92页

作者：刘洋邢建平山东大学信息科学与工程学院济南250100

在无线传感器网络三维节点定位问题中,节点通信半径是一个关键参数,通过这个参数,节点建立整个网络的连接度,以实现自身定位。大多数的定位算法中,这个参数通常被设定为一个常数,但这种假设有悖于事实,一般情况下这个参数很难控制,它受... 详细信息

在无线传感器网络三维节点定位问题中,节点通信半径是一个关键参数,通过这个参数,节点建立整个网络的连接度,以实现自身定位。大多数的定位算法中,这个参数通常被设定为一个常数,但这种假设有悖于事实,一般情况下这个参数很难控制,它受到很多因素的影响,比如检测区域中的障碍物阻隔,节点硬件设计的限制以及功率控制等。正是考虑到了这个特殊的问题,介绍了一种最优空间跳跃距离获取以及最优锚节点选择机制,而为了更好的模拟真实环境中的多变情况,每一个节点的通信半径都被设置为20 m至90 m之间的一个随机值。在最后,通过仿真结果,验证了文中提出的三维节点定位算法非常适合无线传感器网络中节点拥有随机半径的问题。

关键词：无线传感器网络随机通信半径最优空间跳跃距离锚节点选择

^_(57)Fe Mossbauer Effect Study of Sm_(2)Fe_(17) under Different Heat Treatment Conditions

在线全文

学校读者我要写书评

暂无评论

IMP & HIRFL Annual Report 1995年 170-171页

作者： Chen Xiaoxi Liu Guichuan Niu Mulin Meng Qinghua xing jianping Xu Zhengjia Zu Kailing 不详 San Huan Research Laboratory Chinese Academy of SciencesBejing

５７Ｆｅ　Ｍｏｓｓｂａｕｅｒ　Ｅｆｆｅｃｔ　Ｓｔｕｄｙ　ｏｆ　Ｓｍ２Ｆｅ１７　ｕｎｄｅｒ　Ｄｉｆｆｅｒｅｎｔ　Ｈｅａｔ　Ｔｒｅａｔｍｅｎｔ　Ｃｏｎｄｉｔｉｏｎｓ５７ＦｅＭ■ｓｓｂａｕｅｒＥｆｆｅｃｔＳｔｕｄｙｏｆＳｍ... 详细信息

５７Ｆｅ　Ｍｏｓｓｂａｕｅｒ　Ｅｆｆｅｃｔ　Ｓｔｕｄｙ　ｏｆ　Ｓｍ２Ｆｅ１７　ｕｎｄｅｒ　Ｄｉｆｆｅｒｅｎｔ　Ｈｅａｔ　Ｔｒｅａｔｍｅｎｔ　Ｃｏｎｄｉｔｉｏｎｓ５７ＦｅＭ■ｓｓｂａｕｅｒＥｆｆｅｃｔＳｔｕｄｙｏｆＳｍ２Ｆｅ１７ｕ...

关键词： C?

在线全文

学校读者我要写书评

暂无评论

无线传感网的分布式非测距三维定位算法

北京航空航天大学学报 2010年第2期36卷 206-209页

作者：王德华邢建平张军山东大学信息科学与工程学院济南250100 北京航空航天大学电子信息工程学院北京100191

为解决三维空间无线传感器网络节点定位问题,基于区域立体网格化表示的思想,提出一种分布式非测距三维定位算法3D-DRL(three-Dimensional Distributed Range-free Localization).通过对立体网格投票,选取得票值最高的所有网格的质心作... 详细信息

为解决三维空间无线传感器网络节点定位问题,基于区域立体网格化表示的思想,提出一种分布式非测距三维定位算法3D-DRL(three-Dimensional Distributed Range-free Localization).通过对立体网格投票,选取得票值最高的所有网格的质心作为未知节点的估计位置.3D-DRL无需未知节点间相互通信,具有较小的通信开销,不依赖于锚节点比例,且对网络拓扑结构具有鲁棒性.仿真结果表明,在无线传播环境理想、未知节点通信半径R=50 m、所有节点均随机部署在100 m×100 m×100 m三维区域的情况下,定位误差小于未知节点通信半径的8%,且通过调整VANR,能够实现所有节点的定位.

关键词：无线传感器网络三维非测距定位分布式区域网格化

Design of CERNET2-One of the Core Networks in CNGI

在线全文

学校读者我要写书评

暂无评论

ZTE Communications 2005年第4期3卷 11-16页

作者： Wu jianping, Li xing, Li Chongrong (China Education and Research Network Center, Tsinghua University, Beijing 100084, China)

This article presents the network design schemes of CERNET2 including overall architecture, the backbone, core nodes, access solutions and the CNGI peer centers. CERNET2 connects 25 core nodes distributed in 20 cities of China at the speed of 2.5-10 Gb/s. CERNET2 has four unique features. First, its backbone adopts native IPv6 protocols, rather than IPv4/IPv6 dual stack. It is the largest pure IPv6 network in the world. Second, it provides an environment for testing and trial operation of China-made IPv6 core routers. It also allows tests of interconnection, interworking and interoperation among multiple vendors. Third, the large IPv6 address space enables the study on network addresses in a real network environment, which ensures the construction of a secured and trusted CNGI. Last, it is a test-bed for NGI applications.

关键词： CERNET Design of CERNET2-One of the Core Networks in CNGI Core