|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Diel and seasonal variation of methane and carbon dioxide fluxes at Site Guojiaba, the Three Gorges Reservoir显示文摘In order to investigate the CH4and CO2fluxes across the water-gas interface and identify their controlling factors, four diel field campaigns and one monthly sampling campaign during June 2010–May 2011 were carried out at a site near the Three Gorges Dam,China. The averaged CH4and CO2fluxes across the air-water interface from the site were much less than those reported from reservoirs in tropic and temperate regions, and from the natural river channels of the Yangtze River. CH4Fluxes at the site were very low compared to most other reservoirs or natural lakes. One of the most important reasons may be due to the oxidation of CH4in the water column owing to the great water depth and high DO in water in the Three Gorges Reservoir. The averaged monthly CH4and CO2fluxes at the site during the observation year were 0.05 mg/(m2·hr) and 104.43 mg/(m2·hr) respectively with the maximum occurred in July 2010. The monthly CO2fluxes during the observation year were positively correlated to the surface water temperature, and negatively correlated to the air pressure and the surface water pH. The CO2flux showed a positive correlation with DOC to some extent, although not significantly, which indicated that allochthonous organic C was a major source of CO2and biogeochemical processes in this reservoir were C-limited. The significantly positive correlation between the reservoir outflow and the seasonal gas flux indicate the disturbance condition of the water body dominated the seasonal gas emission. | Shangbin Xiao Yuchun Wang Defu Liu Zhengjian Yang Dan Lei Cheng Zhang | 2013 | Journal of Environmental Sciences2013，25，10： | 20 |
| 2 | Optimal guidance of extended trajectory shaping显示文摘To control missile's miss distance as well as terminal impact angle, by involving the timeto-go-nth power in the cost function, an extended optimal guidance law against a constant maneuvering target or a stationary target is proposed using the linear quadratic optimal control theory.An extended trajectory shaping guidance(ETSG) law is then proposed under the assumption that the missile-target relative velocity is constant and the line of sight angle is small. For a lag-free ETSG system, closed-form solutions for the missile's acceleration command are derived by the method of Schwartz inequality and linear simulations are performed to verify the closed-form results. Normalized adjoint systems for miss distance and terminal impact angle error are presented independently for stationary targets and constant maneuvering targets, respectively. Detailed discussions about the terminal misses and impact angle errors induced by terminal impact angle constraint, initial heading error, seeker zero position errors and target maneuvering, are performed. | Wang Hui Lin Defu Cheng Zhenxuan Wang Jiang | 2014 | Chinese Journal of Aeronautics2014，27，5： | 11 |
| 3 | Development of the Array Transient Electromagnetic System and Its Experiments显示文摘Transient electromagnetic (TEM) technique plays a significant role in mineral exploration. To accommodate the complicated survey environments in the west part of China, we developed a portable array TEM equipment (ATEM-1), which was implemented based upon the idea to apply the GPS timing signal for the synchronization among transmitters and receivers. The structure of the system and its performance are discussed and the case study is also described. | Lin Jun Cheng Defu Liu Guoxing Duan Qingming Zhang Linhang Yu Shengbao | 2000 | Global Geology2000，5，1： | 3 |
| 4 | cDNA cloning and expression pattern of two enolase genes from the Chinese oak silkworm, Antheraea pernyi显示文摘在这研究,二 enolase 基因从中国橡树蚕被孤立并且描绘, Antheraea perny,它被指定为 enolase 我和 II 分别地。enolase 我 cDNA 顺序是有编码 433 氨基酸的 1302 bp 的一个开的读物框架(ORF ) 的 1712 bp。enolase II cDNA 顺序是有编码 431 氨基酸的 1296 bp 的 ORF 的 1549 bp。二基因的氨基酸序列分享 enolase 的几个保存特征 / 地点。我显示出的 Antheraea pernyi enolase 93%97% 顺序身份到迄今为止可得到的 lepidopterans 的 enolases,到另外的无脊椎动物的 enolases 的 75%82% 身份,到包括脊椎动物的另外的有机体的 enolases 的 60%72% 身份,植物,和真菌。Antheraea pernyi enolase II 显示出 84% 身份到 Bombyx mori enolase II,而是 60% 身份到 A。pernyi enolase 我。在种系发生的树上, enolase II 从 A 定序。pernyi 和 B。mori 清楚地包括 A 与更高的有机体的 enolase 序列的多数被分开。pernyi 和 B。我定序的 mori enolase。由顺序比较和种系发生的分析,我们从 A 建议那 enolase II。pernyi 和 B。mori 可以是 enolase 总科的一个新成员。Antheraea pernyi enolase 我而 enolase II mRNA 在睾丸和卵巢明确地被表示, mRNA 在所有测试纸巾被发现,建议 enolase II 基因的产品可能与复制有关。抄本许多 A。pernyi enolase 我基因在冷吃惊以后并且显著地是显著地下面调整的在热吃惊以后起来调整,建议那 A。pernyi enolase 我基因可能由温度应力是可诱导的。 | Yanqun Liu Yuping Li Huan Wang Runxi Xia Xisheng Li Haolei Wan Li Qin Defu Jiang Cheng Lu Zhonghuai Xiang | 2010 | Acta Biochimica et Biophysica Sinica2010，42，11： | 2 |
| 5 | Time-to-go weighted optimal trajectory shaping guidance law 显示文摘 | Wang Hui Lin Defu Cheng Zhenxuan | 2011 | Journal of Beifing Institute of Technology2011，20，3： | 1 |
| 6 | Output performance optimization for RTD fluxgate sensor based on dynamic permeability显示文摘The output performance of residence times difference(RTD) fluxgate may vary under different driving conditions(driving currents and frequencies) and core materials. To optimize the RTD fluxgate and simplify its design process, an analytical model is employed to select the parameters and identify the effective factors that dominate the performance. The dynamic permeability parameters(Pi), which reflect the changes in the magnetization curve, are mathematically analyzed in detail. The linear variation functions of Pi in different driving conditions are fitted by using the dynamic arctangent hysteresis model. Consequently, the selection of driving conditions and core materials, which are assessed by comparing the experiment and simulation results,has an important role in achieving the optimal output performance of the RTD fluxgate. | Yanzhang WANG Shujun WU Hao LU Defu CHENG Chen CHEN Na PANG Yunxia WAN Zhijian ZHOU Siyu CHEN | 2016 | Science China(Information Sciences)2016，59，11： | 0 |
| 7 | Research Status and Key Technologies of Geo-Electromagnetic Magnetic Induction Sensor显示文摘According to different applications,the performance parameters of the several Geo-Electromagnetic Magnetic Induction Sensors( GEMISs) which are the most representative in the world are compared. After discussing the several key technologies for improving the performance of GEMISs,the main conclusions are as follows: the application bandwidth can be expanded by adopting flux negative feedback( 1 m Hz-10 k Hz);'laminated'core structure is useful for suppressing eddy current loss; the effective permeability of the core has increased observably after adding flux concentrators to the two ends of the core; the chopper amplifier is a useful method to suppress 1/f noise for reducing the GEMIS's output noise; the indoor calibration scheme based on'long straight solenoid'proposed to obtain sensor sensitivity. Accordingly,the problem how to reduce the noise of GEMIS is urgent need to be solved,which will improve the performance of GEMIS. And there is plenty of work requires further study on parameters ' optimization of coil and core. In the future,miniaturization,intelligence and three-axis measurement are the development directions of GEMIS. | Yanzhang Wang Yunxia Wan Chen Chen Hongyu Shi Jun Lin Defu Cheng | 2017 | Journal of Harbin Institute of Technology(New Series)2017，24，4： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员