Upregulation of erythropoietin receptor in UT-7/EPO cells inhibits simulated microgravity-induced cell apoptosis

Hematopoietic progenitor cell proliferation can be altered in either spaceflight or under simulated microgravity experiments on the ground, however, the underlying mechanism remains unknown. Our previous study showed that exposure of the human erythropoietin (EPO)-dependent leukemia cell line UT-7/EPO to conditions of simulated microgravity significantly inhibited the cellular proliferation rate and induced cell apoptosis. We postulated that the downregulation of the erythropoietin receptor (EPOR) expression in UT-7/EPO cells under simulated microgravity may be a possible reason for microgravity triggered apoptosis. In this paper, a human EPOR gene was transferred into UT-7/EPO cells and the resulting expression of EPOR on the surface of UT-7/EPO cells increased approximately 61% (p < 0.05) as selected by the antibiotic G418. It was also shown through cytometry assays and morphological observations that microgravity-induced apoptosis markedly decreased in these UT-7/EPO–EPOR cells. Thus, we concluded that upregulation of EPOR in UT-7/EPO cells could inhibit the simulated microgravity-induced cell apoptosis in this EPO dependent cell line.     

基于B/S架构的设备全寿命周期管理系统技术研究

研究了基于B/S架构(Browser/Server结构)的设备全寿命周期管理系统相关技术,论述了构成设备全寿命周期管理系统的架构设计与模块划分。将网络、多媒体、数据库等技术通过计算机软件系统开发的理论、技术和方法建立起的B/S架构应用于航空聚合物基复合材料厂的设备管理。该系统可使相关基础管理工作以信息化手段简化、固化与落实。     

Kalman filtering for GPS/magnetometer integrated navigation system

This paper investigated the data processing method for a GPS/IMU/magnetometer integrated system with Kalman filtering (KF). As a result of GPS/IMU/magnetometer land vehicle system, dead-reckoning of magnetometer and accelerometer integrated subsystem bridged very well the GPS signal outage due to the trees on the two sides of the road. Both differential GPS data processing method and the carrier-phase method with magnetometers’ outputs for predicting the car position, velocity, and acceleration (PVA) are presented. The results from DGPS with Kinematical Positioning (KINPOS) software shown that the averages of the north, east, and down direction standard deviation (short for “std”) are 0.014, 0.010, and 0.018 m, respectively. The std of velocities and accelerations derived by the position and velocity differentiation are 10, 7, 13 mm/s, 7, 5, 9 mm/s², respectively. This method for getting velocities and accelerations requires higher accurate position coordinates. But the position accuracy has frequently been degraded in this case when the car drove under the trees or other similar kinematical environments. That caused the larger velocity and acceleration errors. While the results from the carrier-phase method are std of the velocities = 2.1 mm/s, 1.3 mm/s, 3.7 mm/s in north, east, down, and std of the accelerations = 1.5 mm/s², 0.9 mm/s², 2.3 mm/s² for the static test period; as compared with KINPOS software results, std of the velocity difference between the carrier-phase method and the DGPS method = 7 mm/s, 6.9 mm/s, 9.7 mm/s in north, east, down direction, and std of acceleration difference = 5.0 mm/s², 4.5 mm/s², 7.5 mm/s² in north, east, down direction for the kinematical test period. Obviously, errors come from both the carrier-phase method and DGPS velocity and acceleration results derived directly by the position differentiation. In addition, better accuracy of positions than that before KF has been got by means of velocities and accelerations derived by the carrier-phase method after KF.     

A review of 9-year performance and operation of the MOPITT instrument

The MOPITT (Measurements of Pollution in the Troposphere) instrument has provided more than nine years of global carbon monoxide (CO) measurements on a continuous basis since its launch aboard the Terra Spacecraft on December 18th, 1999. This paper gives an overview of the core sub-system performance and major issues of the in-flight instrument over the mission period. Some of the instrument anomalies are also discussed. The major successes are: (1) the concept of using a combination of correlation systems such as Length Modulated Cells (LMCs) and Pressure Modulated Cells (PMCs) to retrieve CO profiles in the troposphere; (2) the redundant design in the instrumentation which was crucial for coping with unexpected in-flight anomalies and for continuing the mission in the case of component failure; (3) the thermal environment on orbit that is so stable that some calibration procedures are not necessary; and (4) the recent production of CO total column retrieved from the MOPITT 2.3 μm channel.     

激光冲击处理技术最新动态及发展趋势

激光冲击处理是一项新兴的的表面强化技术,在某些场合具有不可替代的作用,潜在巨大的经济市场。目前,只有美国将此技术应用到实际生产领域,并产生了显著的经济效益和国防效益。国内目前还没有应用实例,但已具有良好研究基础,该技术必将在国内踏上产业化的征途。     

基于H∞理论的二级倒立摆控制研究

二级倒立摆是一种典型的非线性不稳定系统，被广泛用于研究和验证各种控制方法。基于H∞理论控制方法的特点是鲁棒性很强，以尝试采用基于H∞理论控制方法对二级倒立摆进行运动控制，经过仿真实验证明，该控制方法可行并且有效。     

喷注器出口附近液膜运动及破碎过程的理论分析

研究锥形液膜在受限空间内的运动,该液膜由离心式喷嘴产生,并受到高速环形气流的冲击。根据空气动力学理论,建立了用于分析液膜运动规律的理论模型,提出了运动液膜的破碎准则和运动液膜破碎后形成的液滴平均直径的计算公式,计算结果可作为喷注器设计的参考依据。     

在匀速扩展剪切载荷作用下1/4空间的动力响应问题

 本文采用自相似方法第一次以封闭形式给出了在匀速扩展剪切载荷作用下1/4空间的动力响应,探讨了冲击波产生和发展的条件,以及在超高速冲击下材料破坏的不同机理。     

内腔辐射热损失对喷管壁温的影响

本文利用排气管内腔表面的表观黑度 ,计算了内腔表面向外界环境的辐射热损失及其对喷管壁温的影响。结果表明 ,喷管下游端的壁面辐射损失高达壁面总热流的 2 0～ 30 % ,在壁温计算时不容忽略。     

一种新型ZOC智能化测压系统

介绍一种国内最新的智能测压系统,这是一个模块化、小型化的电子压力自动扫描系统。它包括电子扫描阀、工作传感器组合、标准传感器、自动校准单元、放大电路、A/D转换、采样接口及单片微机系统。用它可以实现多点压力的实时数据采集与处理、实时对传感器的零点(Z)、工作点(O)、及标准点(C)等状态进行自动转换,并实时地对传感器的零点、灵敏度、线性度、温漂、时漂等误差进行自动补偿与修正。 对该系统的原理、结构特点及实验结果分析进行了简要叙述。这种系统测量精度高、自动化程度高,特别适用于航空发动机试车台及风洞试验中的压力测量与处理。