中国科学院机构知识库网格系统: 检索

Global sensitivity and uncertainty analysis of the VIP ecosystem model with an expanded soil nitrogen module for winter wheat-summer maize rotation system in the North China Plain 期刊论文 OAI收割
PEDOSPHERE, 2021, 卷号: 31, 期号: 5, 页码: 822-838
作者: He, Lihong; Mo, Xingguo; Hu, Shi; Liu, Suxia

|

收藏 | 浏览/下载：128/0 | 提交时间：2021/08/19

ammonia volatilization denitrification rate global sensitivity analyses shuffled complex evolution developed at the University of Arizona (SCE-UA) algorithm vegetation interface processes model

Global sensitivity and uncertainty analysis of the VIP ecosystem model with an expanded soil nitrogen module for winter wheat-summer maize rotation system in the North China Plain 期刊论文 OAI收割
PEDOSPHERE, 2021, 卷号: 31, 期号: 5, 页码: 822-838
作者: He, Lihong; Mo, Xingguo; Hu, Shi; Liu, Suxia

|

收藏 | 浏览/下载：28/0 | 提交时间：2021/08/19

ammonia volatilization denitrification rate global sensitivity analyses shuffled complex evolution developed at the University of Arizona (SCE-UA) algorithm vegetation interface processes model

Effect of design parameters on the reduction of top piston ring friction (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Computer-Aided Design, Manufacturing, Modeling and Simulation, CDMMS 2012, September 21, 2012 - September 23, 2012, Chongqing, China
作者: Wang P.

收藏 | 浏览/下载：138/0 | 提交时间：2013/03/25

In order to reduce ring-liner interface friction power loss this paper focuses on the structure parameters of the top ring and investigates how the value of those parameters will influence top ring-liner friction power loss and the minimum thickness of oil film at top ring-liner interface. A mixed lubrication model is developed to simulate the effect of varying design parameters on ring-liner friction. Case study shows that ring-liner friction power loss will be reduced with decreased axial ring height and barrel height. This study provides a theoretical basis for design the top ring with reduced friction power loss at ring-liner interface. (2013) Trans Tech Publications Switzerland.

Bidirectional structural mapping models for constructing rule-based systems 会议论文 OAI收割
31st Chinese Control Conference, CCC 2012, Hefei, China, July 25, 2012 - July 27, 2012
作者: Yuan J(袁杰); Shang WL(尚文利); Jiang B(姜波); Lou, Yi

收藏 | 浏览/下载：23/0 | 提交时间：2013/04/21

UnApplied research Developed model Fuzzy colored Petri nets Fuzzy production rules Inverse mapping Mapping functions Mapping mechanism Mapping model Structural mapping

Numerical simulation on efficient spinning technology based on multi-point adjusting principle (EI CONFERENCE) 会议论文 OAI收割
2nd International Conference on Manufacturing Science and Engineering, ICMSE 2011, April 9, 2011 - April 11, 2011, Guilin, China
Gong X. P.

收藏 | 浏览/下载：28/0 | 提交时间：2013/03/25

In order to realize high efficiency and flexible manufacturing for rotary surfaces equivalent stress in sheet metal's center region and bendable rollers active region exceeds yield stress efficient spinning technology (EST) is researched. It is the combination of multi-point forming and traditional spinning. Principle of EST is described and plastic deformation is generated traditional spinning method is compared with it experimental result accords with simulation result. Feasibility of EST is validated by simulation and experimental results. (2011) Trans Tech Publications. and characteristics of it are analyzed. Finite element analysis (FEA) model of disc-shape part is established EST process is analyzed equivalent stress and plastic strain distributions are analyzed. EST equipment is developed and the experiments are made. Results indicate: EST process consists of four stages

Study on the servo system of large telescope based on the internal model pid control strategy (EI CONFERENCE) 会议论文 OAI收割
IEEE 2011 10th International Conference on Electronic Measurement and Instruments, ICEMI 2011, August 16, 2011 - August 18, 2011, Chengdu, China
Li H.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

This paper developed the internal model PID control for large telescope control system considerations in more parameters adjustment in servo control loop at present. The large electro-optic telescope system belongs to a big inertia system. This simplifies the debug process the feasibility and robustability are also verified by the analyses and simulation results that satisfy the high precision demand. The practicability of this algorithm is verified in an actual project that only two parameters need adjusted. The application shows that this system runs stably with high accuracy. The technology and methods adopted in the system are practical and worthy of using abroad. 2011 IEEE.

Analysis of zenith pass problem in a roll-pitch optics seeker (EI CONFERENCE) 会议论文 OAI收割
2011 International Conference on Electronics and Optoelectronics, ICEOE 2011, July 29, 2011 - July 31, 2011, Dalian, China
作者: Jiang H.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

There are mainly two kind of structures for a missile two-axes seeker which is always mentioned as elevate-azimuth and roll-pitch. The elevate-azimuth structured seeker has been studied for a long time and it is applied in all sort of missiles. Not only structure design but also control algorithm of the elevate-azimuth seeker are deeply developed. But for elevate-azimuth seeker there are several disadvantages such as big size and large abaxial angle blind. So the elevate-azimuth seeker gimbal angle is designed up to 65 according to relative references. In modern air war it is important for a missile to have the ability of "first recognize" and "first attack". That means the air to air missile seeker is required to be a system with large gimbal angle and large abaxial launch angle. With the mentioned requirement roll-pitch seeker with its advantages smart size and large gimbal angle is studied widely and deeply. The pitch angle of roll-pitch is up to 90 while its roll angle up to n 360. But there are also some disadvantages for the roll-pitch seeker the most troublesome one is the zenith pass problem. The zenith pass problem is brought about from the gimbal kinematics it is said that when target moves in the center of image plane roll servo command gotten from the kinematics algorithm will go to infinite. Math model of zenith pass problem is proposed in this paper and two ways to solve the problem are brought forward. 2011 IEEE.

A micromechanical model for deformation behavior of nanocrystalline copper 会议论文 OAI收割
2010 International Conference on Advances in Materials and Manufacturing Processes, ICAMMP 2010, Shenzhen, China, NOV 06-08, 2010
作者: Lan JX(兰姣霞); Wu YZ(吴永中); Hong YS(洪友士); Lan JX

收藏 | 浏览/下载：24/0 | 提交时间：2013/02/26

Algorithms Copper Deformation Grain boundaries Grain size and shape Materials Micromechanics Molecular dynamics Strain energy Deformation behavior Deformation mechanism Developed model Experimental values Grain shapes Grain size Internal variable theory Iteration algorithms Micromechanical model Molecular dynamics simulations Nanocrystalline copper Nanocrystallines Pure copper Statistical distribution Stress strain relation Uniaxial tensions

A 3-axis simulator for spacecraft attitude control research (EI CONFERENCE) 会议论文 OAI收割
2010 IEEE International Conference on Information and Automation, ICIA 2010, June 20, 2010 - June 23, 2010, Harbin, Heilongjiang, China
作者: Dai L.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

This article presents the details of a new 3-axis simulator for spacecraft attitude control research and simulation. The air bearing allows the test bed to rotate about three axes with tiny friction. The attitude determination system consists of three fibre optical gyros an inclinometer and a magnetometer. The actuator of the system consists of three reaction flywheels and four control moment gyros (CMG). Mathematical models of the sensors and actuators are given to help algorithm design. An extended Kalman filter was designed to provide attitude information for controller. Mathematical simulation results prove the attitude determination system can achieve high precision. A coulomb friction model of reaction wheels is given with experimental results. A friction compensation algorithm was developed to raise the pointing accuracy of the control system. The article also describes the details of the hardware structure. A PD stabilizing controller is implemented to test the validation of the whole control system at last. 2010 IEEE.

Design of ground-based physical simulation system for satellite-borne TDI-CCD dynamic imaging (EI CONFERENCE) 会议论文 OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者: Zhang L.; Zhang L.; Sun Z.

收藏 | 浏览/下载：24/0 | 提交时间：2013/03/25

As we know the existence of image motion has a bad effect on the image quality of satellite-borne TDI CCD camera. Although many theories on image motion are proposed to cope with this problem few simulations are done to justify the proposed theories on ground. And thus in this paper a ground-based physical simulation system for TDI CCD imaging is developed and specified which consists of a physical simulation subsystem for precise satellite attitude control based on a 3-axis air bearing table and an imaging and simulation subsystem utilizing area-array CCD to simulate TDI CCD. The designed system could realize not only a precise simulation of satellite attitude control whose point accuracy is above 0.1 and steady accuracy above 0.01/s but also an imaging simulation of 16-stage TDI CCD with 0.1s its integration time. This paper also gives a mathematical model of image motion of this system analogous with satellite-borne TDI CCD and detailed descriptions on the principle utilizing area-array CCD to simulate TDI CCD. It is shown that experiment results are in accordance with mathematical simulation and that the image quality deteriorate seriously when the correspondence between the image velocity and signal charges transfer velocity is broken out which suggest not only the validity of the system design but also the validity of the proposed image motion theory of TDI CCD. 2010 SPIE.