用于高压动态校准的快开阀装置

介绍一种高压快开阀装置。它可产生３７０ＭＰａ上升时间小于２０μｓ的阶跃压力，用于对高压传感器进行动态校准。     

GPS based onboard and onground orbit operations for small satellites

In extension to common applications such as groundtrack displays and antenna steering, the SGP4 orbit model is proposed for operational orbit determination in small satellite missions. SGP4 is an analytical orbit model for Low-Earth orbiting satellites that is widely used for the propagation of NORAD twoline elements. Twoline elements may hence be generated completely independent of NORAD. Their use as exclusive source of orbital information simplifies the operations concept and reduces mission costs through the extensive use of existing low-cost mission support software. Due to small computer resource requirements of 8–10kByte, the SGP4 model may also be applied for onboard orbit computations making use of e.g. a 80186 processor, thus ensuring full compatibility of ground-based and onboard operations. The proposed approach is particularly suited in combination with a space-borne GPS receiver, were the C/A-code navigation solutions are treated as measurements that are adjusted in a least-squares sense using the SGP4 model. As consequence, inherent drawbacks of the pure navigation solutions such as data gaps and scatter as well as limited velocity accuracy are avoided, while the operational navigation activities are kept at a minimum. The feasibility of the concept is illustrated based on real GPS navigation data from the TOPEX/Poseidon and the MIR space station with an inherent data quality of 50–100 m. It is shown that 3 hours of data within a 4 day period are sufficient to keep the position error within 4 km, that is considered sufficient for most applications.     

气动力星座保持的闭环控制研究

本文研究了利用气动力进行星座保持的闭环控制问题。提出了一种改进的半全局指数收敛闭环控制律，对于指定的任意大的有界域，利用不变集定理论上证明了该控制律的稳定性和抗干扰性，又提出了双ε法以提高响应速度。     

Use of combined light flash and plasma measurements to study hypervelocity impact processes

We present new measurements concerning generation of light flash during hypervelocity impacts. We use iron particles (10⁻¹³ to 10⁻¹⁷ kg) with velocities over the range 1 to 42 km/s impacting semi-infinite targets (aluminium and molybdenum). The main results of previous work in the field are found to be reproduced with some slight deviations. For iron projectiles with given mass and velocity the energy of the flash (normalized to mass) is proportional to velocity to the power of 3.5 for aluminium targets and 3.9 for molybdenum targets. The duration of the flash is of order 1 microsecond. Simultaneous measurements of the generation of impact plasma do not change this. The onset of plasma generation of the bulk target material does not affect the total light flash energy. We discuss the duration of the flash compared to a simple calculation of temperature in the target and plasma vs time.     

Nanotechnology-based molecular test equipment (MTE)

This paper describes original research efforts in the design, simulation, and development of nanotechnology-based molecular test equipment (MTE). This is a research effort for testing printed circuit boards independent of traditional automatic test equipment (ATE) through the fabrication of MTE within integrated circuits (ICs). The MTE is embedded within the IC substrate and encapsulated within nanoprobes that connect between the surface and the substrate of the IC at various functional areas. A process is followed whereby IC device simulation is performed to assess the electrical, chemical, and structural properties of integrated and adjacent substrate devices. Through this approach the nominal and failed device performance parameters of interest to substrate-based MTE are found. Discussion of the development and application of MTE within IC architectures is provided, including such topics as the effect of substrate composition on the design and realization of MTE, interfaces between MTE and IC devices, and reporting of MTE results to the IC surface and technician. Potential application areas within different device functions will also be identified. A chemical structure diagram is also provided to illustrate the implementation of MTE using discrete device configurations with MTE-augmented logic     

Molecular alterations in tumorigenic human bronchial and breast epithelial cells induced by high LET radiation.

Carcinogenesis is a multi-stage process with sequence of genetic events governing the phenotypic expression of a series of transformation steps leading to the development of metastatic cancer. In the present study, immortalized human bronchial (BEP2D) and breast (MCF-10F) cells were irradiated with graded doses of either 150 keV/micrometer alpha particles or 1 GeV/nucleon 56Fe ions. Transformed cells developed through a series of successive steps before becoming tumorigenic in nude mice. Cell fusion studies indicated that radiation-induced tumorigenic phenotype in BEP2D cells could be completely suppressed by fusion with non-tumorigenic BEP2D cells. The differential expressions of known genes between tumorigenic bronchial and breast cells induced by alpha particles and their respective control cultures were compared using cDNA expression array. Among the 11 genes identified to be differentially expressed in BEP2D cells, three (DCC, DNA-PK and p21(CIP1)) were shown to be consistently down-regulated by 2 to 4 fold in all the 5 tumor cell lines examined. In contrast, their expressions in the fusion cell lines were comparable to control BEP2D cells. Similarly, expression levels of a series of genes were found to be altered in a step-wise manner among tumorigenic MCF-10F cells. The results are highly suggestive that functional alterations of these genes may be causally related to the carcinogenic process.     

三轴稳定遥感卫星姿控系统故障情况下的系统重构

论述三轴对地稳定遥感卫星姿控系统中部分轮子或部分陀螺故障情况下的姿控系统重构。文中论述了只在俯仰通道有一偏置动量轮正常工作，而滚动和偏航通道轮子故障条件下的系统重构。另外还论述了偏航陀螺故障，姿控系统其它部件正常情况下，控制系统采用Whecon原理与PIM控制相结合的设计。以上两种系统重构拟用于实际系统中，经过数学仿真验证，姿控系统在故障情况下能够完成基本任务。     

Coarse attitude determination from Earth albedo measurements

Attitude estimation algorithms for the Thrusted Vector Mission which determine attitude based on Sun sensor and very coarse albedo sensor measurements are presented. On the basis of these measurements, it has been demonstrated by comparison with more accurate gyro-based attitude that it is possible to estimate three-axis attitude with an average error per axis of 11 deg. Most of this error is about the Sun direction. Both deterministic quick-look and optimal estimates are examined     

拓宽周转齿轮系的应用

本文为拓宽创新设计机构的思路,扼要地介绍了一种利用空间周转轮系,实观机械手臂的公转与自转动作要求的机构运动分析、设计方案及结构参考图。