CINRAD/SA雷达频综故障检修方法

频综是多普勒全相参天气雷达的核心部件,其组件工艺水平高且价格昂贵,它提供了整个雷达工作所需的基准信号,共有5路输出,它们分别是9.6MHz主时钟信号、COHO信号、RF DRIVE信号、STALO信号、RF TEST SIGNAL信号.由于不同地区雷达发射机工作频率不同,因此频综不能通用,在台站,备份频综组件不太现实.由于厂家没有提供频综图纸,使得故障判别难度加大.因此通过剖析频综内部结构,给出频综的内部原理简图.针对十多个CINRAD/SA雷达频综出现的故障,划分出三种故障类型,并提出具体维修方法,在此基础上,归纳出该型号雷达在使用过程中频综出现故障时,雷达操作、维护人员应掌握的故障排查方法及技巧,以提高台站的保障能力.     

地磁场水平梯度的计算与分析

In this paper，based on the Gauss theory of geomagnetism and the spherical harmonic mi}del of the geomagnetic field，the horizontal gradients of the geomagnetic field in north一south and west-;east dlrections were calculated in Chinese and"its surrounding regions, the contour maps of the horizontal gradients of the geomagnetic components were constracted，and its regularities of distributions were analysed.
The horizontal gradients of the total intensity (F)，horizontal intensity (H) and vertical intensity (Z ) vary mainly with lat相似文献   

东昆仑山东段北坡河流阶地发育及其与构造隆升的关系

河流系统的发育往往能反映相关地质作用的细节.对东昆仑山东段北坡众多河流阶地及其沉积物的研究表明, 该区在早更新世晚期昆仑-黄河运动之后形成的东西向盆岭相间的地貌特征奠定了早期河流为东西向外流水系的基础; 中更新世晚期以来的又一次强烈构造抬升事件———共和运动, 导致昆仑山北坡各主要河流迅速溯源侵蚀发展, 伴随河流袭夺而形成现今的水系格局; 晚更新世晚期存在一段相对较长的构造稳定期, 河谷普遍发生堆积作用, 形成分布广泛且厚度较大的晚更新世冲积层; 接近全新世以来构造运动频繁而隆升的幅度趋于减弱, 形成了5级河流阶地, 并且阶地的发育类型普遍为以高级阶地(T₅) 为基座的上叠阶地, 河流至今未能切穿晚更新世稳定期形成的厚冲积层.      

Formation of the adakite-like granitoid complex and porphyry copper-gold deposit in Shaxi from southern Tancheng-Lujiang fault belt： A clue to the West Pacific plate subduction

On the basis of the geological and geochemical studies, including chemical analysis of bulk rocks, rare-earth and trace element studies, fluid inclusion, and S and O isotopic analyses, the authors described the geo-logical background of the deposit in detail and presented significant proofs for the conditions of formation of the Shaxi porphyry copper-gold deposit. Compared with other large and supper-large porphyry copper deposits in China and the adjacent Cu-Au mineralized areas, the ore-forming processes and conditions were analyzed; and the possibil-ity of forming large porphyry copper deposits in the Shaxi area was discussed. The present study indicated that the ore-forming fluid and material were mainly of magmatic origin, while meteoric water played a certain role in the ore-forming processes. Interactions between subducting and overriding plates provided a major driving force for the formation of igneous rocks and the deposition of metal elements in East China since Jurassic. Based on the geo-chemical data of the Shaxi intrusive, it is found that the copper (gold) mineralization is closely related to the genesis of adakite-like intrusive in the Shaxi area. This adakite-like intrusive was formed in the subduction environment as a result of the subduction of the West Pacific plate toward the East China continent, where there is a great potential-ity to form a large porphyry copper deposit.     

黄河源区陆面过程观测和模拟研究进展

陆面过程对黄河源区水资源变化有重要的影响,探索黄河源区陆面过程和水分循环特征的关联机理有十分重要的意义.首先简述了黄河源区气候变化背景和陆面过程的基本特征,并详细介绍了近年来在黄河源区开展的一系列陆面过程野外观测试验及相关研究主题和研究进展;进一步给出了在野外试验观测资料分析、卫星遥感、数据同化应用和数值模拟等方面取得...     

Successional stages of biological soil crusts and their microstructure variability in Shapotou region (China)

In order to investigate succession of biological soil crusts (BSCs) and their microstructure variability, we conducted this work in Shapotou revegetation region at the southeast edge of Tengger Deser. The results showed that BSCs generally succeeded as a pathway of “Algae crusts, algae–lichen crusts, lichen crusts, lichen–moss crusts and moss crusts”. Occasionally mosses directly occurred on algae crusts, and BSCs succeeded from algae crusts to moss crusts. Crust vertical stratification was a common phenomenon, from top to bottom an inorganic layer, algae-dense layer and algae-sparse layer were divided in algae crusts; a thallus layer, rhizoid layer and sub-rhizoid layer in lichen crusts; a “stem-leaf” layer, rhizoid layer and sub-rhizoid layer in moss crusts, respectively. The main crust binding organisms varied from filamental cyanobacteria (dominated by Microcoleus) in algae crusts to lichen rhizoids, free-living cyanobacterial filaments and fungal hyphaes in lichen crusts, and to moss rhizoids and fungal hyphaes in moss crusts. The dominant phototrophic organisms varied from Microcoleus (algae) in algae crusts to Collema (lichens) in lichen crusts, and to Bryum (or Didymodon and Tortula; mosses) in moss crusts. Total phototrophic biomass increased while the free-living algal biomass decreased with the succession of BSCs. In addition, exopolysaccharides and fine particles accumulated in the course of development and succession of BSCs, all of which lead to a gradual increase in crust thickness and porosity, while decrease in the bulk density.     

The effects of soil sand contents on characteristics of humic acids along soil profiles

It is generally accepted that the compositions and properties of soil organic matter (SOM) are influenced by many factors. In order to reveal the effects of soil texture on characteristics and dynamics of SOM and its sub-fraction, humic acid (HA), along two soil profiles, a yellow soil profile and a purplish soil profile, under the same climate and vegetation conditions were determined. Results indicate that the decomposition and humification degrees of SOM and HA of the purplish soils are higher than those of the corresponding yellow soils indicated by A/O–A ratios of HAs, TOCs and HA yields of bulk soil samples, nevertheless, the development degree of the purplish soil is lower than that of the yellow soil. The variations of E₄/E₆ ratios of HAs along the soil profiles indicate the overall molecular sizes of HAs decreased downward along the soil profiles. A/O–A ratios of HAs decreased downward along both the soil profiles indicate that humification processes decrease downward along both the soil profiles. Leaching of SOM shows significant effects on the distribution and characteristics of HAs in the yellow soil profile but the purplish soil profile, which is consistent with the higher hydrophobicity of HAs in purplish soils, shows that the distribution characteristics of SOM along the soil profiles are a complex result of the combination of soil texture and characteristics of SOM itself. The remarkably different sand contents are concluded tentatively as one of reasons to the different distributions and dynamics of HAs along the soil profiles, however, to profoundly understand the evolution and transport of SOM along soil profiles needs more researches.     

川西北早志留世陆源碎屑──碳酸盐混积缓坡

研究区位于扬子地块西北缘，由一套巨厚的页岩、泥岩层夹生物礁及透镜状和不规则层状风暴生屑灰岩、瘤状灰岩组成。根据区内特征的岩石类型及其组合、分布和相应的化石生态，作者认为本区兰多维列期至早温洛克期时为一典型的陆源碎屑－－碳酸盐混积均斜缓坡，并且从浅到深划分为滨岸、浅缓坡、深缓坡及盆地等亚环境。滨岸区位于潮间带，以潮坪碳酸盐岩为代表；浅缓坡位于浪基面至风暴浪基面之间，岩性组合为Ａ、Ｂ类风暴岩，Ａ、Ｂ类瘤状灰岩、生物礁灰岩及粘结岩；深缓坡位于风暴浪基面至最大风暴浪基面之间，岩性以Ｄ、Ｅ类风暴岩、Ｃ类瘤状灰岩及泥页岩组合为特征；盆地处于最大风暴浪基面之下，为黑色泥页岩沉积。结合早志留世时全球冰川作用，文中讨论了海平面变化的原因及对环境的影响。     

新疆塔里木托云盆地沉积环境与聚煤规律

以1：5万地质填图和钻探验证为基础，经分析研究塔里木托云盆地的地层特征、聚煤期、古地理环境，从而建立起该区的沉积模式，总结出该盆地煤层发育于下侏罗统康苏组上段地层之中，含煤11层，煤层为不稳定发育，但分布具有一定的规律可寻，对进一步找煤具有一定的指导意义。     

大气污染物SOx输送方程的尺度分析

文中用量纲分析方法分析了控制大气污染物输送方程的动力学特性。提出了 6种反映大气污染物输送过程中各种动力、物理和化学过程相对重要性的动力学参数。并以硫氧化物为例进行了各参数量级大小分析 ,尤其对 3种起汇作用 (去除机理 )的机理 (化学转化、干沉降和湿清除 )在不同尺度大气污染过程中的作用进行了详细分析。结果表明 :在一般情况下 ,SO2 的气相化学作用小于干沉降和湿清除的作用 ;干沉降作用很依赖于模式最底层厚度的选取 ;在有降雨时湿清除作用一般较大。文中还对大气污染物SOx 输送方程各项特征量的量级作了分析对比 ,得出了控制不同尺度大气污染物输送过程的零级近似方程和一级近似方程 ,并指出了这些方程的基本特征