100赫～10兆赫脉冲发生器

这里介绍的一种脉冲发生器,电路简单、性能良好、便于制作,现将该电路介绍于下. (一)电路特点 1.采用普通的小规模集成块与非门,成本低. 2.整形级、放大级及输出级之间均采用稳压管来实现电平匹配,避免了电容耦合带来的波形失真,从而工作频率高. (二)主要技术指标 1.重复频率,100赫～10兆赫,分六档粗调、细     

成功救治特大面积烧伤伴多种并发症1例

1病历简介男,25岁,钢水烧伤全身6小时,于1999年6月5日入院。神清,烦躁,口渴,声音嘶哑伴刺激性咳嗽。T37.3℃,P120次/min,R22次/min,BP112/75。mmHg(1mmHg=0.133kPa)。全身除头顶、双足掌面及腰部(系腰带处)外,均有不同程度烧伤。诊断:①钢水烧伤95%,浅Ⅱ度5%,深Ⅱ度40%,Ⅲ度50%;②中度吸入性损伤。立即行气管切开术,常规抗休克、抗生素、对症及创面处理。第2天胃管内引出咖啡样液体,排出柏油样大便;伤后第3天行双上肢、左下肢切痂自体微粒皮移植术,右下肢切痂,戊二醛皮覆盖术。5天后出现烦躁、谵语等精神症状,呼吸时快时慢,血气分析提示低氧     

率先提出勘探管理理念的石油人——写在石油地质学家陈贲蒙冤36周年之际

当人们在领略石油企业现代管理的多元形态为中国石油工业带来前所未有的巨大进步的时候,一些老石油人、老石油科技工作者,不能不怀念曾在45年前就提出,石油地质勘探工作要“搞经济核算”,要求“投资的经济总效果”等一系列科学管理理念的老石油人——陈贲。     

宝珠寺水电站中孔闸墩预应力锚索施工质量控制

宝珠寺水电站中孔孔口尺寸和总水推力在全国名列前茅，所宣泄洪水占枢纽总泄量的２／５，为了承受弧门支铰传来的巨大水推力，闸墩采用了预应力锚索结构。文章结合中孔闸墩预应力锚索张拉吨位大，技术含量高，施工工艺复杂等特点，全面地介绍了预应力锚索施工工序间的质量控制标准和措施，供类似工程参考。     

Suppression of runaway current by electrode biasing and limiter biasing on J-TEXT

The avoidance of runaway electrons (REs) generated during plasma disruption is of great concern for the safe operation of tokamak devices. Experimental study on the suppression of runaway current by electrode biasing (EB) and limiter biasing (LB) has been performed on the J-TEXT tokamak, which could be an alternative way to suppress the runaway current. The experimental results show that the higher the voltage value, the smaller the runaway current in both EB and LB experiments. The runaway current can be completely suppressed at an electrode biased voltage of +450 V and a limiter biased voltage of +300 V. The comparison of the energy spectra during the runaway plateau phase shows that the maximum energy max (ERE) and radiation temperature THXR of hard x-rays (HXRs) are significantly reduced after the application of +200 V limiter biased voltage. The electric field generated by the biased voltage may be the key factor to suppress the runaway current, and the measured radial electric field increases obviously after the voltage is applied. This may result in an increase in the loss of REs to realize the suppression of runaway current.     

球差对多色部分空间相干光衍射引起的光谱开关的影响

基于空间频率域交叉谱密度函数的传输公式,推导了有球差多色部分空间相干光被光阑衍射后轴上点光谱的解析表达式,而完全空间相干光的结果可作为本公式的特例。着重分析了球差对一阶光谱开关的影响,结果表明,球差会引起光谱移动的不同和光谱开关临界位置的变化。     

传奇英才秦同洛

在新中国石油工业发展的历史进程中,数以百计的石油科技专家在大漠戈壁、茫茫草原,奉献了他们的青春年华和聪明才智,其中一位被尊称为“秦教授”的油田开发专家,颇有一些传奇色彩。说起石油人对“秦教授”的尊称,要比他正式获得“教授”职称早30年。 秦教授虽仙逝多年,但依然活在海峡两岸石油人的心中,活在国际石油友人心中。     

Study of the fast electron behavior in electron cyclotron current driven plasma on J-TEXT

In J-TEXT tokamak, fast electron bremsstrahlung diagnostic with 9 chords equipped with multi-channel analyzer enables detailed studies of the generation and transport of fast electrons. The spatial profiles and energy spectrum of the fast electrons have been measured in two ECCD cases with either on-axis or off-axis injection, and the profiles processed by Abel-inversion are consistent with the calculated power deposition locations. Moreover, it is observed that the energy of fast electrons increases rapidly after turning off the ECCD, which may be attributed to the acceleration by the recovered loop voltage at low electron density.     

天然气水合物沉积物分解过程中本构关系研究

天然气水合物具有储量大、分布广泛、清洁燃烧等优点,近年来受到研究人员的广泛关注。为了实现天然气水合物资源的安全高效开采,对其沉积层的力学稳定性进行系统评估是十分必要的。本研究在实验室内重塑了40%孔隙度的天然气水合物沉积物试样,并基于力学实验设备,对其在不同围压条件下分解过程中的力学强度及变形进行了一系列测试,获取了相应的应力应变数据。研究结果表明,水合物分解会造成沉积层强度的降低。此外,基于实验数据,在借鉴土力学邓肯-张本构模型的基础上,考虑了围压及分解时间对沉积物力学特性的影响,本文构建了适用于不同围压条件下天然气水合物沉积物分解过程中的本构模型,研究结果表明,该模型可以较好地模拟沉积物试样在分解过程中的应力应变关系,可为实现天然气水合物的安全开采提供一定的理论依据。     

Photon Temperatures of Hard X-Ray Emission of LHCD Plasmas in HT-7 Tokamak

A detailed study of photon temperatures （Tph） of hard X-ray emission in lower hybrid current drive （LHCD） plasmas is presented. The photon temperature increases with the increase in plasma current and decreases with the increase in plasma density. In lower hybrid power and phase scanning experiments; there is no appreciable change in the photon temperature. The numerical results based on ray-tracing calculation and Fokker-Planck solver gives reasonable explanation for the experimental observation. Both experimental and numerical results reveal that the photon temperature depends mainly on global effects of the fast electron population, synergy between the fast electron and the loop voltage and the Coulomb slowing down.