Genetic differentiation induced by spaceflight treatment of Cistanche deserticola and identification of inter-simple sequence repeat markers associated with its medicinal constituent contents

The dried, fleshy stems of Cistanche deserticola (Orobanchaceae) are popular tonics in Traditional Chinese Medicine (TCM) to treat the inability of kidney in expelling extra fluid in the body, causing fluid retention, and reform reproductive system. However, the wild plants of C. deserticola have become endangered due to habitat downsizing and over-harvesting for its medicinal usages. The present research was carried out for the following purposes: (1) promoting the space-breeding research; (2) providing molecular evidence for agricultural selective breeding; and (3) protecting this endangered herbal medicine and conserving its genetic resources.     

Avoid online radiation risk: Theoretical simulation of chromosome breaks in cells exposed to heavy ions

In this study, we report an easy and quick method on simulating chromosome breaks in cells exposed to heavy charged particles. The theoretical value of chromosome break was calculated, and validated comparison with experimental value by using premature chromosome condensation technique. A good consistency was found between theoretical and experimental value. This suggested that higher relative biological effectiveness of heavy ions was closely correlated with its physical characteristics. Also, a safe approach on predicting chromosome breaks in cells exposed to heavy ions at off-line environment can be considered. Furthermore, three key factors influencing the theoretical simulation was investigated and discussed.     

基于非线性变换的加速度计误差标定与补偿CSCD

为提高三轴加速度计测量精度,分析其误差来源和产生机理,建立了误差模型;根据误差模型和重力场幅值不变特性,推导出非线性观测方程。引入两个未知的参数向量,通过数学变换把非线性观测方程变形为关于新未知参数的线性方程;然后采用批量最小二乘法求出新的未知参数,并根据误差模型参数和新未知参数之间的关系,利用逆解析运算求出对应的零点偏差、灵敏度误差和三轴不正交误差。实验结果表明,加速度计正负误差峰值间距可以减小100倍左右,精度可达10-3m/s2,并具有很好的可重复性。该方法算法效率较高,补偿效果显著。     

Delcam三维模具设计软件专家系统

Delcam Toolmaker的一个独到之处是在模具设计的任何阶段,用户都可以退出进行中的自动设计模式,切换到PowerSHAPE对设计进行手工修改,随后可继续回到自动设计模式继续完成模型设计。这意味着用户不仅可以得益于高自动化设计所带来的简单、高速自动化设计,同时可根据自身需要,不受模型尺寸和复杂程度的限制,获得精度极高的模型设计结果。     

供热系统集约化运行的能耗监测及节能调节问题探讨

对我校供热系统的现状进行了分析；指出了锅炉热效率及能耗监控方面的不足，并针对锅炉热效率提高和二次网循环泵变频调节进行了节能分析计算；同时根据我校实际情况对循环泵设备配置及控制进行了分析，提出了要加强技术指标量化考核和能耗监测，提高效率、节能降耗，实现供热系统的科学化、集约化运行。     

ENERGY-SAVING MATCHING STRATEGY AND EXPERIMENTAL STUDY OF PUMPING SYSTEM FOR TRUCK-MOUNTED CONCRETE PUMP

Aiming at the high fuel consumption and use-cost of truck-mounted concrete pump , an energy-saving matching strategy of pumping system is presented and the experimental study is conducted.Since pumping system occupies most resources of engine , the matching strategy between engine and main pump is analyzed to meet the load demand and reduce the engine rational speed drop.The testing method is established to measure the fuel consumption of engine under various working conditions , and the experimental data are analyzed to find the law of the fuel consumption of engine.The system performance can be improved by adjusting the system input value.Finally , the energy-saving matching strategy is established to reduce the fuel consumption of truck for unit workload , which provides a new approach for the energy-saving of truck-mounted concrete pump.     

基于干扰观测器的天基观测航天器姿态控制设计

与地基空间目标监视系统相比,天基观测系统具有监视范围广,不受国界限制,观测精度高等优点,是未来空间目标观测技术的重要发展方向。但天基观测航天器工作时,相机转台的运动,太阳能帆板挠性部件的弹性振动与航天器的姿态运动相互影响,构成强耦合的非线性系统,传统的控制方案无法实现对这类天基观测航天器的高精度姿态控制。文章针对某一空间观测航天器的任务要求,设计了基于干扰观测器的前馈补偿航天器姿态控制系统,仿真实验结果表明:姿态角控制精度小于 0.06°,姿态角速度精度小于 0.03(°)/s,达到了精度要求。     

基于改进WKNN的位置指纹室内定位算法

位置指纹算法是目前解决室内定位问题的主要方法,指纹特征和匹配算法为影响算法精度的两大因素.针对室内复杂环境下Wi-Fi信号强度波动较大的现象,提出了基于方差的加权距离以改进WKNN算法.在离线特征提取阶段,选择了均值和方差两个特征值,既反映该采样点的RSS幅值,也反映该点RSS的波动情况;在线阶段,根据方差提出了加权距离进行相似度的计算,查找距离最近的K近邻点,并以实际环境下采集的数据验证了改进WKNN算法在RSS波动大的情况下对定位效果的改善,在综合考虑了AP组合的影响后,实现了误差均值为1.456m的定位效果.     

不同分子量聚碳硅烷的性能及对Ｃ/ Ｃ－ＳｉＣ 复合材料增密的影响

以四种分子量级别聚碳硅烷(PCS)为浸渍剂,采用CVD和浸渍-裂解工艺制备了C/C-Si C复合材料,分析了四种分子量级别PCS的分子量、软化点,分子结构和热失重性能,采用压汞法测试试件的孔隙分布特性。分析表明,PCS的软化点和800℃转化率都随着分子量的提高而提高;四种分子量级别的PCS热分解过程基本相同,分子的支化程度差异不大。数均分子量为1 178、1 333的PCS的整体致密化效率要高于数均分子量为1 550的PCS,经过7个周期致密后,分子量为1 178的PCS所致密试样的累积孔隙容积最高,分子量为1 550的PCS所致密的试样最低。前5个浸渍裂解致密周期采用分子量为1 550的PCS,以后周期采用分子量为1 178或1 333的PCS,可以达到较高的致密效率。