用于县级规划管理的微机系统设计     

舒宁 《测绘信息与工程》1996,(3)

论述了研制适于县级规划管理的微机系统的必要性，主要设计思想和关键技术，介绍了目前研制的成果。  相似文献   

Simulations of seasonal variations of sulfur compounds in the remote marine atmosphere   总被引：1，自引：0，他引：1  

Seizi Koga  Hiroshi Tanaka 《Journal of Atmospheric Chemistry》1996,23(2):163-192

A photochemical box model is used to simulate seasonal variations in concentrations of sulfur compounds at latitude 40° S. It is assumed that the hydroxyl radical (OH) addition reaction to sulfur in the dimethyl sulfide (DMS) molecule is the predominant pathway for methanesulfonic acid (MSA) production, and that the rate constant increases as the air temperature decreases. Concentration of the nitrate radical (NO₃) is a function of the DMS flux, because the reaction of DMS with NO₃ is the most important loss mechanism of NO₃. While the diurnally averaged concentration of OH in winter is a factor of about 8 smaller than in summer, due to the weak photolysis process, the diurnally averaged concentration of NO₃ in winter is a factor of about 4–5 larger than in summer, due to the decrease of DMS flux. Therefore, at middle and high latitudes in winter, atmospheric DMS is mainly oxidized by the reaction with NO₃. The calculated ratio of the MSA to SO₂ production rates is smaller in winter than in summer, and the MSA to non-sea-salt sulfate (nssSO₄ ^2-) molar ratio varies seasonally. This result agrees with data on the seasonal variation of the MSA/nssSO₄ ^2- molar ratio obtained at middle and high latitudes. The calculations indicate that during winter the reaction of DMS with NO₃ is likely to be a more important sink of NO_x (NO+NO₂) than the reaction of NO₂ with OH, and to serve as a significant pathway of the HNO₃ production. If dimethyl sulfoxide (DMSO) is produced through the OH addition reaction and is heterogeneously oxidized in aqueous solutions, half of the nssSO₄ ^2- produced in summer may be through the oxidation process of DMSO. It is necessary to further investigate the oxidation products by the reaction of DMS with OH, and the possibility of the reaction of DMS with NO₃ during winter.  相似文献   

邢台震源区波速比异常与地震的关系   总被引：5，自引：2，他引：5       下载免费PDF全文

嘉世旭  刘昌铨 《地球物理学报》1996,39(Z1):205-215

通过对忻州─泰安人工地震测深剖面Ｐ波、Ｓ波的联合解释，得到沿剖面不同地质单元隆起区与裂陷区、震源区与非震区的速度和波速比结构．鲁西隆起和太行、山西隆起为较均匀的成层构造，地壳厚度分别为３２ｋｍ和４０－４３ｋｍ，波速比为１．７４．中段裂陷区构造变化较大，地壳厚度约３０－３３ｋｍ，波速比为１．７５－１．７７．邢台地震区上地壳下部和中地壳出现高波速比１．７７的异常，与裂陷区东的１．７３形成明显的差异．由此推测，地震的发生不仅与震源区的构造有关，更主要是与震源区岩石的性质有关。  相似文献   

工程VSP技术在三峡坝区中的应用   总被引：2，自引：0，他引：2       下载免费PDF全文

张双喜  刘永华  李江风 《地球物理学报》1996,39(Z1):316-325

通过对长江三峡枢纽工程坝区白岩尖１井的工程ＶＳＰ测试，在采用四分量采集、双子波监控和复杂波场的波形识别等技术的基础上，提出反映岩石特性的多种动弹模量，综合解释井口周围复杂的花岗岩岩体内部风化带分布和裂隙及岩脉充填分布．  相似文献   

中国地表感热的气候计算及其分布          下载免费PDF全文

高庆先  翁笃鸣 《大气科学学报》1996,19(2):238-244

讨论了我国地表感热的气候计算问题,提出以鲍文比法为基础的感热气候计算式,并据此计算出全国215站月、年平均感热通量密度,进而分析了其在全国的时空分布特点。  相似文献   

COMPREHENSIVE PLANNING FOR WATER RESOURCES EXPLOITATION AND WATER POLLUTION CONTROL FOR CHANGLI COUNTY-A CASE STUDY FOR SMALL TOWNS OF CHINA     

Cheng Tianwen  Mou Haisheng 《地理学报(英文版)》1996,(3)

I.EnvironmeotaICharacterishcsofChangliCountyChangliCoLmtyislocatedinthenortheastermendoftheNorthChinaPlain,nexttoBohaiSeaontheeastandthesouthemendofYanshanMountainsontl1enortl1.Luani1emverWhichrunsthroughthecouotyforn1sthewestemandsouthemboundaryoftitiscoastalcounty.ThenorthempartofthecoUnyishillywithaverageheigltrrangingfrom5oto5Oom,andmostportionintheeastemandsouflempartislocatedonthealluvialplainofLuani1eandYirunarivers,inclilungfromnorthwesttosoutieastwiil1heighrangingfrom2to3m.Tl1…  相似文献   

Material flow analysis for an industry—A case study in packaging     

Kevin Sandgren 《Natural Resources Research》1996,5(4):235-247

The basic materials used in packaging are glass, metals (primarily aluminum and steel), an ever-growing range of plastics, paper and paperboard, wood, textiles for bags, and miscellaneous other materials (such as glues, inks, and other supplies). They are fabricated into rigid, semirigid, or flexible containers. The most common forms of these containers include cans, drums, bottles, cartons, boxes, bags, pouches, and wraps. Packaging products are, for the most part, low cost, bulky products that are manufactured close to their customers. There is virtually no import or export of packaging products. A material flow analysis can be developed that looks at all inputs to an industrial sector, inventories the losses in processing, and tracks the fate of the material after its useful life. An example is presented that identifies the material inputs to the packaging industry, and addresses the ultimate fate of the materials used.Correspondence should be directed to Earle B. Amey, U.S. Geological Survey, National Center 983, Reston, Virginia 20192.  相似文献   

岩石受力状态对弹性波传播速度影响的初步研究   总被引：2，自引：0，他引：2  

刘盛东  杨玉岷 《中国煤田地质》1996,8(3):48-51

岩石所受的三向应力状态对其弹性波传播性质有一定的影响，此认识为所做的以泥质砂岩、泥岩和硅质胶结的坚硬砂岩为试样的实验所证实。为保证岩石中存在微隙，对部分试样还作了高温预热处理。实验结果表明，泥质砂岩和泥岩的Ｖ＿ｐ／Ｖ＿ｓ值几乎保持不变，但坚硬砂岩的Ｖ＿ｐ／Ｖ＿ｓ值曲线却在应力达破坏荷载的９０％左右时出现下凹现象，经热处理的硬砂岩的这一下凹现象则更突出。  相似文献   

等高活篱笆试验研究的若干问题^*   总被引：4，自引：0，他引：4  

李秀彬  施迅 《地理研究》1996,15(1):66-72

本文讨论了等高活篱笆技术在设计、管理和效益分析等方面的原则与方法,指出应结合当地的自然条件和社会经济需求,围绕一两种主要功用来应用这种坡地持续利用技术。植物种类选择和篱笆的管理应以篱笆植物的属性、篱笆的形成及农林复合系统中各组分的和谐关系为依据。活篱笆改善生态的功能、社会经济效益宜采用费用-效益分析的方法进行评价。  相似文献   

ANALYSIS OF SOIL EROSION CHARACTERISTICS AND SEDIMENT SOURCES FOR THE YANTZE THREE GORGES REGION     

SHI Deming  YANG Yansheng  LU Xixi  and LIANG Ying 《国际泥沙研究》1992,(2)

In this paper the researches made in 1981-1990 have identified that the annual soil loss in the Three Gorges region is 157 million t. and the annual incoming sediment load of the Three Gorges reservoir is 40 million t. Soil erosion increases with the destruction of vegetative cover and its subsequent evolution. The annual amounts of sediment erosion for forest land, shrub land, grassland and farmland make up respectively 6.19%, 10.76%, 23.05% and 60% of the total erosion of the Three Gorges region; the quantities of incoming sediment load to the Yangtze River from the above four types of land account for 5.95%, 12.42%, 35.46% and 46.1 % of the total amount of sediment transported to the reservoir. The farmland of offers the main source of sediment. Gravitational erosion produces more bed loads, which will present serious threat to the Three Gorges Project if entering the reservoir. Resettlement of people to the upper parts of the mountainous areas for agricultural production will increase the sediment yield of the Three Gorges region by 10-20 million t and increase the incoming sediment of the Yangtze River by 50-60 million t. Consequently, it is necessary to make a realistic assessment of the soil erosion in the Three Gorges region.  相似文献