电子工作台在模拟电子技术中的应用

本文简要地介绍了电子工作台的特点和使用方法，结合我们设计具体模拟电子线路的实践，说明了电子工作台在模拟电子技术中的应用。     

DNA damage and repair in oncogenic transformation by heavy ion radiation.

Energetic heavy ions are present in galactic cosmic rays and solar particle events. One of the most important late effects in risk assessment is carcinogenesis. We have studied the carcinogenic effects of heavy ions at the cellular and molecular levels and have obtained quantitative data on dose-response curves and on the repair of oncogenic lesions for heavy particles with various charges and energies. Studies with repair inhibitors and restriction endonucleases indicated that for oncogenic transformation DNA is the primary target. Results from heavy ion experiments showed that the cross section increased with LET and reached a maximum value of about 0.02 micrometer2 at about 500 keV/micrometer. This limited size of cross section suggests that only a fraction of cellular genomic DNA is important in radiogenic transformation. Free radical scavengers, such as DMSO, do not give any effect on induction of oncogenic transformation by 600 MeV/u iron particles, suggesting most oncogenic damage induced by high-LET heavy ions is through direct action. Repair studies with stationary phase cells showed that the amount of reparable oncogenic lesions decreased with an increase of LET and that heavy ions with LET greater than 200 keV/micrometer produced only irreparable oncogenic damage. An enhancement effect for oncogenic transformation was observed in cells irradiated by low-dose-rate argon ions (400 MeV/u; 120 keV/micrometer). Chromosomal aberrations, such as translocation and deletion, but not sister chromatid exchange, are essential for heavy-ion-induced oncogenic transformation. The basic mechanism(s) of misrepair of DNA damage, which form oncogenic lesions, is unknown.     

企业标准体系的建立与完善及对策

介绍企业标准体系的基本构成、特征和建立的原则,就建立完善的企业技术标准体系、制定企业管理标准体系和工作标准等阐述体系建立的途径,并对企业标准体系的管理、完善和改进等有关的几个问题进行探讨。     

减压活门性能试验台系统方案设计

主要介绍了减压活门性能试验台的实现机理、采用的方案。     

数控车削加工仿真系统结构研究

根据实际加工情况提出了一种虚拟NC车削加工的仿真系统的设计及实现原理。在Visual C++平台上利用OpenGL技术建立虚拟加工机床数字化模型,用C++语言实现物理仿真相关的各个数学模型的建立,进行虚拟环境下数控车削加工的几何仿真及物理仿真,实现产品的虚拟车削制造。     

INITIALIZATION METHODS FOR GROUP TRACKING

ＩＮＩＴＩＡＬＩＺＡＴＩＯＮＭＥＴＨＯＤＳＦＯＲＧＲＯＵＰＴＲＡＣＫＩＮＧＹａｎｇＣｈｅｕｇｙａｎｇ；ＱｕＪｉａｎｍｉｎｇ；ＭａｏＳｈｉｙｉ（ＢｅｉｊｉｎｇＵｎｉｖｅｒｓｉｔｙｏｆＡｅｒｏｎａｕｔｉｃｓａｎｄＡｓｔｒｏｎａｕｔｉｃｓ，Ｂｅｉｊｎｇ，Ｃ...     

航天产品工艺定型阶段工艺文件的编制与审查

从编制《工艺定型标准化要求》、审定有关工艺定型文件和编写《工艺定型标准化审查报告》等方面浅述航天产品工艺定型阶段应做好的标准化文件的编制与审查,并对其工作内容作了介绍。     

液冷头盔致冷效能的医学研究

在45℃高温条件下,应用液冷头盔给10名被试者的头颈部致冷,散热效能较高,可带走安静时30.9％～48.3％的代谢产热。降低身体的热蓄积,减少出汗,减慢心率、直肠温度和皮肤温度的上升速率。对头颈部致冷可降低身体的热紧张度50％～70％,明显改善对温热的舒适感觉。同时表明,致冷液温、流量及液流走向,对致冷效能均有显著影响。为液冷头盔及致冷装置的设计,提供了医学实验依据。     

Further study of the Pencil-MUSIC algorithm

For finding 2-D angles and polarizations of waves arriving at a rectangular array of crossed dipoles, the Pencil-MUSIC method can achieve the near optimum performance with much less computational burden than the MUSIC (multiple signal classification). Following an angle-only ESPRIT (estimation of signal parameters via rotational invariance techniques) method, an angle-only Pencil-MUSIC can be easily formulated which is far more accurate than the former especially in the coherent case. The angle-only Pencil-MUSIC is analyzed and compared with the original Pencil-MUSIC. The new version sacrifices the polarization estimation to achieve about 8 times more efficient computation The accuracy of the new version seems no more than 4 times worse in terms of estimation deviation     

高燃速丁羟推进剂配方研究

通过多种途径的试验,对高燃速丁羟推进剂配方进行了研究.试验结果表明,采用超细防结块氧化剂和液固组合燃速催化剂能使推进剂的燃速达到70mm/s以上(在6.864Mpa压强下);采用组合工艺助剂可改善推进剂工艺性能.本推进剂燃烧稳定,压强指数和温度敏感系数较低,力学性能良好,为高燃速推进剂的研制奠定了良好的基础.