Geogas prospecting – an ideal industrial application of PIXE

In geogas prospecting the extremely small concentrations of trace elements, in an upward gas stream, are measured with high sensitivity using the PIXE technique. The measured elemental composition in the geogas across geological formations reveals much about the bedrock composition and the possible presence of concealed mineralizations and ore bodies. The possible origin and transportation of the geogas matter through the bedrock are discussed. The sampling procedure, the data analysis and the normalisation procedures are described. Finally, the possibility to extract three-dimensional information from a two-dimensional measurement is demonstrated as an example from a field experiment.     

The Storing Matter technique applied to PVC: Effect of the primary ion fluence on the sputter-deposition

The Storing Matter technique is derived from SIMS (Secondary Ion Mass Spectrometry) and consists in decoupling the sputtering of the specimen from the subsequent analysis step. PVC samples were sputtered by an Ar⁺ beam with different fluences, and the emitted particles were deposited on a dedicated Ag collector. In a second step, the matter deposited on the collector was analyzed by static SIMS.For each deposit, several analysis points were chosen across a diameter of the collector in order to show the changes in the mass spectra as the deposit coverage changes. It was shown that the Storing Matter technique is sensitive enough to observe some well-known consequences of increasing the primary ion fluence, namely an increasing contribution of aromatic fragments and a decrease in sputtering yield.     

应用锆石裂变径迹方法研究夹皮沟本区金矿成矿时代

由于锆石裂变径迹封闭温度与吉林省夹皮沟金矿的成矿温度相近,相比其他年代学分析技术,锆石裂变径迹技术具有更好的适用性,其年龄恰可反映金矿成矿年龄,因此本文应用锆石裂变径迹技术探讨夹皮沟本区成矿时代。通过实验获得了8个样品的锆石裂变径迹年龄测试结果,其年龄值在(78±8)~(190±2)Ma之间变化,并可分为2组:190~153 Ma和106~78 Ma。两组年龄揭示了中生代以来区内主成矿时代以及后期叠加成矿年龄,体现出夹皮沟金矿田具有多期次成矿作用。同时,两组年龄还分别体现了太平洋板块与欧亚板块对研究区共同影响的地质事件,并为此提供了年代学的新证据。     

综合地质-地球物理方法在金矿中的应用

河北省丰宁县坝州营金矿床赋存于五台期侵位的“变闪长岩”中,该区从太古代到中生代长期处于构造隆升剥蚀状态,发育多期岩浆侵位事件,为金矿提供了充分的成矿条件.根据区域地质背景及围岩蚀变、矿化等特征,推断本矿床属于受构造控制的中-低温热液石英脉型金矿.结合矿区地质特征开展地球物理工作,以高密度电法圈定了地下矿化体的范围,辅以音频大地电磁测量,实现探测相对深部断裂构造,并以钻探证实,取得了找矿突破,达到了推断控矿构造的走向和找矿前景等目的.     

Experiments at the T-11M device in support of the tokamak concept with closed Li cycle

The lithium emitter-collector concept, supposed the creation of steady state lithium circulation loop close the first wall and plasma periphery, seems as a solution of tokamak reactor first wall problem. This concept of renewable PFC (plasma facing components) has four characteristically steps: Li emission from PFC into the plasma (emitter), the boundary plasma cooling by non-coronal Li radiation, Li ions capture by collector before their deposit on a tokamak vessel wall and Li return from collector and first wall into emitter again. The main subject of the last T-11M experiments was investigations of the lithium collection by limiters. The lithium behavior in shadow of lithium limiter, based on the lithium filled CPS (capillary porous systems), was studied by the analysis of the witness-samples, and by use a mobile graphite probe. It was showed: (1) lithium deposit on the Li-limiter sides is proportional to the total Li emission from the lithium rail limiter (emitter). (2) Lithium deposit on the ion-drift side of Li-limiter to 3-5 times more as on electron side. (3) The total efficiency of Li collection by T-11M limiters can be 70 ± 20% of lithium integral emission from the lithium emitter during plasma operations while the theoretically limit can be 90%.     

元素迁移的模拟模型实验

从野外不同地质体上，观察到地壳中元素是以纳米微粒状态被上升气流迁移的。为了进一步研究，设计了模拟以上升气流通过矿层、矿层加盖及围岩的模型层。实验结果显示，在模型中上升气流迁移的粒子仍是纳米微粒，并且采样片上含量也是随时间积累而增加。当有水层和玻璃盖层时，部分元素仍能穿透盖层，部分元素迁移受阻挠。纯扩散实验说明纯扩散迁移也存在，不过迁移量很小。列出模型实验中用扫描探针显微术观察到的纳米微粒照片。     

新疆阿尔泰地区哈巴河花岗岩体及邻近金矿床中石英的释光特征及其意义

对新疆阿尔泰地区哈巴河花岗岩体及邻近金矿床中的石英进行了二维热释光,三维热释光和光释光分析,结果表明,花岗岩中石英,金矿含金石英及无矿石英脉的热释光和光释光特征具有显著差异,反映出金矿的形成与热液液体有关,晚于花岗岩的形成而与花岗岩没有直接的成因关系。     

基于ASTER数据的巴什布拉克铀矿区油气还原蚀变信息提取与分析

从新疆巴什布拉克铀矿床油气还原蚀变岩石的光谱特征分析入手,开展了基于ASTER遥感数据的油气还原蚀变信息提取技术研究,发现了研究区存在3个与已知铀矿区油气还原蚀变遥感异常相类似的遥感蚀变异常带。在此基础上,进一步利用ASTER数据在短波红外的多波段优势,对增强的各个遥感蚀变异常带进行了深入的分析和地质含义讨论,排除了非蚀变作用产生的遥感蚀变假异常,明确了与铀矿找矿密切相关的遥感蚀变异常信息,为铀矿区外围的铀矿找矿提供了重要依据。     

Probabilistic evaluation of lateral extent of soil liquefaction under earthquake loading

A Monte Carlo simulation method for calculating the probability of soil liquefaction of a finite area in which the ground motion is propagated upward from the bedrock through the soil layers is presented. The vertical propagation of the ground motion through the soil layers is analyzed using random vibration analysis. To account for the variability of soil properties with depth, the soil deposit is divided into layers. Within each layer the horizontal statistical correlation of the undrained cyclic shearing strength against liquefaction is taken into consideration by describing it as a two-dimensional homogeneous random field. The method computes the probability of liquefaction spreading over a specified area under a given earthquake loading considering the effects of spatial correlation of soil properties.     

Radiation Effects on Multiplier Phototubes

A multiplier phototube is an extremely sensitive device used to measure ultraviolet, visible and near infrared radiant energy. Physically, multiplier phototubes are high vacuum tubes which are comprised of a photo-cathode; an electron lens, which directs the photo-electrons onto the first dynode; a series of dynodes or amplifying stages; and an anode or collector. The use of multiplier phototubes in photometric and nuclear detectors for satellite systems has increased dramatically within the last few years. Because many of these systems are subjected to either natural or artificially created radiation, such as encountered in the Van Allen belts, or the South Atlantic anomaly, or galactic or solar cosmic radiation, a study of the behavior of these tubes under such conditions has become necessary. This paper summarizes the work of EMR and that of many other investigators, and discusses degradation of optical windows used; effects on photocathodes and dynodes; effects on noise, dark current and resolution. A list of conclusions is given.     

地气测量技术寻找隐伏断裂带的研究

论述了以仪器中子活化分析技术为检测手段的地气测量技术在双流－成都－德阳隐伏断裂带上的研究成果，地气异常主要出现在隐伏断裂的正上方，其元素组合为Ｗ，Ｓｂ，Ｌａ，Ｓｍ，Ｃｏ，Ｋ和Ｎａ等微量元素和造岩元素。     

Synchrotron radiation X-ray fluorescence analysis on altered mineral muscovite in gold deposit

Synchrotron radiation X-ray fluorescence (SRXRF) microprobe was used to ananlyse altered mineral muscovite and its surrounding feldspar in Yuerya gold deposit. The major, minor and trace elements of the two minerals were detected and analyzed. SRXRF analysis showed that the Yuerya muscovite had a complex chemical composition. containing K, Fe, Ca, Ti, Cr, Mn, Co, Cu, Zn and many trace or ultra-trace elements. Since muscovite resulted from the alteration of hydrothermal ore fluid acting on feldspar (plagioclase), the difference of chemical composition between the two minerals shows the components of ore fluid, which are characterized by the enrichment of alkaline and alkaline-earth metal elements K, Ca and ore-associated elements Fe, Cu, Zn. And gold. silver and platinum, invisible under microscope, were detected in some areas of muscovite but not found in feldspar. Especially platinum, a mantle material is rarely seen in the earth crust but now found in the gold deposit of magmatic sources; its appearance approves the idea of mantle flux participating in the gold mineralization, which suggests that the tectonic event controlling gold mineralization in the Yuerya district is a mantle phenomenon.     

Electrical output parameters of efficient cylindrical thermionic energy converters

Electrical output parameters are presented for four one-element cylindrical TEC operating with cesium plasmas and electrode gaps from 0.3 to 0.8 mm. The cylindrical emitters have been made by vapor-phase epitaxial deposition of tungsten on cylindrical molybdenum substrates having [111] axial orientation under the conditions where the deposit is automatically formed faced with (110) planes. The average vacuum work function is up to 5.3 eV. The collector is made of a molybdenum-ruthernium alloys. Tests have been made on how the vacuum work function of the emitter influences the output parameters. Calculations combined with experiment have been used to estimate the work functions and electron temperatures in the plasma. Translated from Atomnaya énergiya, Vol. 87, No. 2, pp. 129–133, August, 1999.     

偏压电荷收集器测量HPIB的原理和实验

介绍了偏压电荷收集器的结构，分析了利用其测量HPIB束流强度的原理，利用KARAT PIC软件模拟了偏压电荷收集器内部的电荷输运过程，模拟结果表明HPIB在偏压电荷收集器内部电荷中和而电流不中和，从而证实了电荷中和假设和这种装置测量HPIB的准确性。另外还分别对几何参数和偏置电压对偏压电荷收集器的影响进行了模拟，在德拜长度范围内，孔径的大小为0．6-0．8mm比较合适，偏压为-800V就可满足峰值能量为500keV HPIB的测量要求，实验验证了偏压大小与离子收集效率之间的关系。     

Identification of the factors determining thermionic energy converter efficiency

A method of using the experimental current–voltage characteristics to perform diagnostics on the parameters of a thermionic energy converter in the arc regime without setting up special experiments and perturbing actual processes was developed. The current–voltage characteristics measured in a wide range of the collector temperatures make it possible to determine the main physical parameters responsible for the efficiency of the energy conversion process: the electron temperature in the plasma near the collector, the heat of evaporation of the electrons from the emitter, the heat of condensation of the electrons on the collector, and the effective work function of the collector.     

土壤氡测量在连山关祁家堡子地区铀矿勘查中的应用

连山关祁家堡子地区岩体接触带为一条重要的控矿构造带,由于地表第四系覆盖较厚以及矿体埋藏较深,前人开展的地面γ能谱测量未能发现有意义的异常。通过土壤氡测量,发现了5条氡浓度异常带,其中P-5号氡浓度异常带已经钻探查证,发现铀异常孔2个、矿化孔1个。     

Thermionic Energy Converter with Low Radiation Losses

A conceptual scheme is proposed for a cylindrical thermionic energy converter with reduced radiation losses. The decrease in losses was achieved by using a perforated collector.The geometric dimensions of the thermionic energy converter with a perforated collector are optimized to obtain maximum efficiency by decreasing radiation losses with a small increase in losses in the plasma. Comparing the parameters of the converter with a perforated collector with the parameters of the conventional variant of a cylindrical thermionic energy converter showed that for the same power the former has a higher efficiency in almost the entire range of the electrode temperature and a more than two times greater power per unit total mass of the electrodes.