吉林省西部沙化土地持续农业体系建立的实践

吉林省沙化土地的８７．９％分布在吉林省西部白城、松原半干旱地区，统属科尔沁和松嫩沙地，面积９２１６．５ｋｍ２，占吉林省西部总面积的１９．６％。８年（１９８６年～１９９３年）实践证明：针对沙地环境特点建立的“乔、灌、草”、“果、药、杂”、“田、林、草”为主体的三种持续农业体系效果明显。     

弹性波CT技术及应用

弹性波ＣＴ技术是一种新的物探方法。本文简单地介绍了该技术的方法原理及影响图像重建的因素，并以实例说明了弹性波ＣＴ技术在煤矿井下的应用效果     

原生金矿成矿年龄测定研究

金成矿年龄和矿源同位素组成的准确测定，对金矿地质研究和找矿具有重要意义。本文根据３年多野外和室内工作的总结，获得了多个典型矿床的年龄和同位素测定结果：华北古陆北缘北侧槽区乌花敖包金矿测定为１３０—１２０Ｍａ的晚期造山作用成矿；南侧台区赛乌素金矿为２１１±１５Ｍａ的再循环古陆改造成矿；中段台区后沟一黄土梁金矿为２４３±７Ｍａ的古陆再造成矿；胶东焦家－乳山金矿为１２２．７±３．４Ｍａ和１２８±２３Ｍａ的燕山期成矿；华夏古陆八宝山金银矿为１４０±５Ｍａ的火山热液成矿。     

Coal-generated oil in Tuha Basin

The Turpan-Harmi (abbreviated to Tuha below) Basin is a typical basin of coal-generated oil accumulation in China. The Middle-Lower Jurassic coal measures are considered the main source beds. Hence, both desmocollinite and suberinite are considered the contributors for coal-generated oil. Principal geochemical features of the crude oil in the Tuha Basin are rich in alkanes (70%—80%), high pristane/phytane ratio (6—8), abundant heavy carbon isotope (δ¹³C PDB= -26%–-23%) and absolute GP sterane predominance. The hydrocarbon generation process from the coal series is characterized by multistages, early generation and early expulsion.     

榆林风沙滩区水资源可持续利用对策与建议

本文在对榆林风沙滩区内水资源条件、开发利用现状及存在问题等调查研究资料进行深入分析的基础上,结合国民经济各业未来发展对水资源的需求情况,确定了未来不同水平年的需水量和供水量,并通过供需平衡分析,提出了解决水资源短缺的途径和实现水资源合理开发利用的建议.     

Sedimentary environment and development controls of the hydrocarbon source beds:Middle and Upper Proterozoic in northern North China

Problem on development control of marine source bed hold in Chinese petroleum industry progression. The Hongshuizhuang Formation,Tieling Formation and Xiamaling Formation in the Middle and Upper Proterozoic are important hydrocarbon source beds in northern North China, and investigation of their sedimentary environments and the controls has great significance for petroleum exploration in North China. Based on sedimentology (sequence stratigraphy), palaeoecology, sedimentary geochemistry, and sedimentary palaeogeography, their development pattern is discussed. All these studies indicate that the development controls of the hydrocarbon source beds include a favorite palaeogeographic location, exceeding propagation of biomes in low and middle latitudes, anoxic environments, enrichment of phosphorus element and the adsorption of clay minerals during the preservation of organic matter in the marine carbonates.     

New palaeointensity results from Cretaceous basalt of Inner Mongolia, China

We present new Thellier-Thellier palaeointensity results from three cooling units (32 samples) of Inner Mongolia lava flows (91.7 Ma) emplaced during the Cretaceous Normal Superchron (CNS). Based on rock-magnetic and microscopy observations the magneto-mineralogy of all samples is determined to be primary and unaltered high-Ti titanomagnetite. Accepted palaeointensity determinations, obtained in the 80-200 °C temperature interval, are of good technical quality with positive standard partial thermoremanent magnetisation (pTRM) checks and pTRM-tail checks. Obtained palaeointensity estimates range from 14.7 to 28.0 μT, with virtual axial dipole moments (VADM) of 2.4 to 4.6 (× 10²² Am²). The data agree well with recently published results from the same region and, combining the two datasets, we obtain independent estimates from six different cooling units yielding a time-averaged VADM of 3.2 ± 1.6 (× 10²² Am²). These data suggest a relatively low dipole moment towards the end of the Cretaceous Normal Superchron.     

Electron microscopy study of the sakhaite from endogenous borate deposit in Hunan, China

Sakhaite was first discovered by Ostrovskaya, Pertsev and Nikitina at Siberia in the former Soviet Union. By using the X-ray diffraction technique, they proved that the crystal system of sakhaite was cubic (a = 1.464 nm), its possible space groups were Fm3m, F432, F43m, Fm3, F23, and its crystal chemical for-mula was Ca48Mg16(CO3)16(BO3)28Cl4(OH)8 4H2O[1]. Chichagov, Simonov and Belov studied the crystal structure of synthetic sakhaite and determined that its space group was F4132, …     

Study of charge structure and radiation characteristic of intracloud discharge in thunderstorms of Qinghai-Tibet Plateau

The comprehensive observations on lightning discharges were conducted in Naqu area of Qinghai-Tibet Plateau in summer of 2002. The electric structures of thunderstorms and the characteristics of lightning discharges at initial stage were analyzed by using the observation data. The results show that most of intracloud (IC) lightning flashes were polarities inverted in thunderstorms with tripole electric charge structure and occurred between negative charge region located in the middle of the thunderstorm and positive charge region located at the bottom of the thunderstorm. The radiation characteristics of discharge processes in cloud with longer lasting time involved in Cloud-to-Ground (CG) lightning flashes were similar to that of IC discharges. A lot of radiation pulses were produced in these discharge processes. Because the IC discharges took place at the bottom of thundercloud and were near the ground, they may produce more serious damage to equipment on the ground therefore should not be neglected in lightning protection.