Input Parameters for Models of Energetic Electrons Fluxes at the Geostationary Orbit

The results of cross-correlation analysis between electrons fluxes (with energies of > 0.6MeV, > 2.0 MeV and > 4.0MeV), geomagnetic indices and solar wind parameters are shown in the paper. It is determined that the electron fluxes are controlled not only by the geomagnetic indices, but also by the solar wind parameters, and the solar wind velocity demonstrates the best relation with the electron fluxes. Numerical value of the relation efficiency of external parameters with the highly energetic electrons fluxes shows a periodicity. It is presented here the preliminary results of daily averaged electrons fluxes forecast for a day ahead on the basis of the model of neuron networks.     

硅微机械陀螺的性能和设计方案

英国宇航系统和设备公司与其合作伙伴Ｓｕｍｉｔｏｍｏ精密设备有限公司共同开发了一种商用微硅陀螺。该产品设计上充分利用电子技术，适于大规模生产，从而使满足广泛商业应用尤其是汽车工业需求的低成本传感器进入市场成为现实。     

AS1051S射频信号发生器在收音机实验教学中的应用

利用AS1051S射频信号发生器构建适合教学的广播电台,解决了收音机实验教学受天气、地理位置等因素制约的问题,提高了收音机实验教学的效果。     

Investigation of low-energy proton effects on aptamer performance for astrobiological applications

Biochips are promising instruments for the search for organic molecules in planetary environments. Nucleic acid aptamers are powerful affinity receptors known for their high affinity and specificity, and therefore are of great interest for space biochip development. A wide variety of aptamers have already been selected toward targets of astrobiological interest (from amino acids to microorganisms). We present a first study to test the resistance of these receptors to the constraints of the space environment. The emphasis is on the effect of cosmic rays on the molecular recognition properties of DNA aptamers. Experiments on beam-line facilities have been conducted with 2 MeV protons and fluences much higher than expected for a typical mission to Mars. Our results show that this irradiation process did not affect the performances of DNA aptamers as molecular recognition tools.     

Iron-sulfide-bearing chimneys as potential catalytic energy traps at life's emergence

The concept that life emerged where alkaline hydrogen-bearing submarine hot springs exhaled into the most ancient acidulous ocean was used as a working hypothesis to investigate the nature of precipitate membranes. Alkaline solutions at 25-70°C and pH between 8 and 12, bearing HS(-)±silicate, were injected slowly into visi-jars containing ferrous chloride to partially simulate the early ocean on this or any other wet and icy, geologically active rocky world. Dependent on pH and sulfide content, fine tubular chimneys and geodal bubbles were generated with semipermeable walls 4-100?μm thick that comprised radial platelets of nanometric mackinawite [FeS]±ferrous hydroxide [～Fe(OH)(2)], accompanied by silica and, at the higher temperature, greigite [Fe(3)S(4)]. Within the chimney walls, these platelets define a myriad of micropores. The interior walls of the chimneys host iron sulfide framboids, while, in cases where the alkaline solution has a pH>11 or relatively low sulfide content, their exteriors exhibit radial flanges with a spacing of ～4?μm that comprise microdendrites of ferrous hydroxide. We speculate that this pattern results from outward and inward radial flow through the chimney walls. The outer Fe(OH)(2) flanges perhaps precipitate where the highly alkaline flow meets the ambient ferrous iron-bearing fluid, while the intervening troughs signal where the acidulous iron-bearing solutions could gain access to the sulfidic and alkaline interior of the chimneys, thereby leading to the precipitation of the framboids. Addition of soluble pentameric peptides enhances membrane durability and accentuates the crenulations on the chimney exteriors. These dynamic patterns may have implications for acid-base catalysis and the natural proton motive force acting through the matrix of the porous inorganic membrane. Thus, within such membranes, steep redox and pH gradients would bear across the nanometric platelets and separate the two counter-flowing solutions, a condition that may have led to the onset of an autotrophic metabolism through the reduction of carbon dioxide.     

核电站输送口后浇无裂缝砼墙

核电站反应堆的蒸汽发生器是要更换的。因为不可能通过反应堆外壳的闸门把蒸汽发生器运出来，只好在防护外壳的墙上开一个洞。如果重新浇筑砼的封口墙而无任何养护措施的话，那么在新浇砼冷却时，沿着施工缝就会发生裂缝。该文介绍了国外采用的一种新技术，顺利地解决这个问题的成功经验。     

Solidworks 2003在机械设计方面的应用

文章详细分析了Solidworks 2003的技术特点,介绍了其在机械设计方面的应用.     

高压涡轮工作叶片叶型设计研究

针对高压涡轮工作叶片叶栅型面特征,采用可压燃气黏性流2维计算方法对高压涡轮工作叶片叶型进行了气动研究,并通过试验验证了优化设计,得到了叶栅气动设计参数。经与初始叶型对比,优化叶型在各状态下损失特性变化更为平缓,在超临界状态下效率更高,在λ2is=1.20状态下的损失减少了2.8%。该方法缩短了设计时间,并且节省了平面叶栅吹风试验的成本。     

Nemaline rod and degeneration of Z band of muscle cell in weightlessness at spaceflight

There are some studies demonstrating the skeletal muscle degeneration associated with the degeneration of Z band and appearance of nemaline rods in experimental animals of the simulation model for spaceflight but not in human heart tissues. In the present study, therefore, we investigated the pathological changes or degeneration in left auricular heart muscles obtained during operations of mitral valves replacement using both electron and light microscopies. The degeneration of Z band even in the myofibrils of comparatively little damaged cell was found. Furthermore, nemaline rods were detected in most of the heart muscle cells. These results suggest that the existence of nemaline rods is involved in the cell injury in the heart muscle of patients with heart disease without nemaline myopathy. Further study is necessary to know whether the similar pathological findings are observed not only in the skeletal muscle but also in the cardiac muscle in experimental animals of the simulation model for spaceflight or in a prolonged spaceflight.     

大滑速下合成润滑油的摩擦牵引力研究

本文采用部分弹性流体动力润滑理论和Ree—Eyring流变学模型研究了国产航空合成润滑油的摩擦牵引特性,获得了合成润滑油的牵引力系数随载荷、速度、材料、润滑油粘度及环境温度变化的规律。