绿化黄河工程土地资源促进沿黄生态环境建设     

孙玉民  许曰坤  刘丕建 《山东国土资源》2006,22(10):50-51

1998年以来，国家加大对防洪工程建设投入的同时，也对工程环境保护和建设提出了更高的要求，防洪工程绿化建设已纳入了全国生态环境建设和城市总体规划，是生态建设和经济可持续发展的战略布置。它不仅可保持工程的完整，提高工程的防护性能，为抢险提供丰富的物料，而且绿化黄河沿岸，对改善生态环境，美化黄河景点，建立沿黄景观带，发展旅游观光业具有非常现实而且深远的意义，同时也是将黄河堤防建设成为防洪保安线、抢险交通线、生态景观线的重大举措。  相似文献   

Protective effect of topically applied polypeptide from Chlamys farreri against ultraviolet radiation-induced chronic skin damage in guinea pig     

Chi Mingliang  Cao Pengli  Yu Guoying  Zhu Li  Wang Yuejun  Wang Chunbo 《中国海洋湖沼学报》2003,21(4):319-323

Polypeptide fromChlamys farreri (PCF), a topical polypeptide isolated fromChlamys farreri, was used in this experiment aimed to investigate the photoprotective effect of PCF against chronic skin damage induced by ultraviolet A (UVA) and ultraviolet B (UVB) radiation. The chronic ultraviolet-irradiated guinea pig model was established, and visible changes in the skin including wrinkling, sagging and erythema were observed. Malondialdehyde (MDA) and antioxidant enzymes including superoxide dismutase (SOD) and glutathione peroxidase (GSH-px) in the dorsal skin were determined using biochemical methods. The results showed: (1) PCF (5 % and 20%) could greatly protect the dorsal skin of guinea pig against wrinkling, sagging and erythema induced by UV radiation in a concentration-dependent manner. (2) PCF could reduce MDA formation in the dorsal skin caused by UV irradiation, while increasing the activities of SOD and GSH-px. (3) The differences among the PCF groups and UV model group were significant (P<0.05,P<0.01). These results indicated that topical application, of PCF provided broad solar UV spectrum photoprotection; and that the antioxidant property of PCF might play a role in photoprotection. Project No. 39970638 supported by the NSFC, and the Science and Technology Bureau of Qingdao (No. 2001-28-50).  相似文献   

    

A. S. Belyakov  V. S. Lavrov  A. V. Nikolaev  L. L. Khudzinskii 《Doklady Earth Sciences》2006,407(2):258

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胶东“玲珑-焦家式”金矿资源潜力与找矿   总被引：1，自引：1，他引：0  

李士先  王建收 《山东国土资源》2006,22(12):36-41

“玲珑焦家式”金矿的成岩成矿,从新太古代至中生代存在着继承性的成因关系,成矿具有长期性、多源性特点,但中生代燕山早期岩浆活动是主导成矿因素。区域化探成果显示胶东金矿直接矿源岩———郭家岭花岗岩金的丰度比原始矿源岩———早前寒武纪变质沉积岩系及侵入岩系金的丰度低1/2。郭家岭花岗岩面积在2 km2以上岩体定量估计金亏损总量与胶东金矿总量预测的资源量相当,从一个侧面展现了胶东金矿资源的潜力。望儿山金矿的找矿实践展示,焦家式金矿在1 000 m以下尚有巨大潜力,整个胶东金矿产区在3 000 m以上的资源潜力应在5000 t以上。  相似文献   

差分法周跳探测与修复方法改进     

郑作亚  程宗颐  黄珹 《中国科学院上海天文台年刊》2004,(1)

在目前常用的周跳探测与修复方法基础上 ,提出了首先将观测资料按照观测历元不连续分成若干小弧段 ,然后利用差分法进行周跳探测 ,根据差分后周跳放大的特性判断周跳和野值 ,并确定其位置利用宽带组合和电离层组合的方法解算周跳大小。通过实例验证了其有效性。  相似文献   

Application of Grain Size Analysis to Study Sedimentary Environment of Sand Dune in the Vicinity of Tumen River     

Feng Ma  Li Liu  Lin Cao 《东北亚地学研究》2003,(1)

The dunes in estuary of Tumen River in China lie to the area between the Jiushaping and Fangchuan in the left bank of Tumen River (Fig.1). The dis-tance is about 15～20 km between the dunes and the coast. It ranges from China to D. P. R. Korea and Russia. The range of the height of dunes is about 15～20 m and the width is 100～200 m. By the re-connaissance, we protracted 9 section planes of the dunes and collected 40 sand samples of the dunes, and identified the sedimentary environment …  相似文献   

CPLD技术及其在现代时统中的应用     

杨蕾  胡永辉 《时间频率学报》2003,26(1):40-47

对CPLD(复杂可编程逻辑器件)技术的基本特征和发展趋势作了简要介绍,揭示了该技术在现代数字系统中的重要地位及作用.利用CPLD对时统设备IRIG-B码产生器进行集成,其实验结果表明,集成了的B码产生器不但简单、可靠,而且便于调试,克服了以往硬件电路复杂的缺点.  相似文献   

Quantifying hydrogen‐deuterium exchange of meteoritic dicarboxylic acids during aqueous extraction     

Megan FULLER  Yongsong HUANG 《Meteoritics & planetary science》2003,38(3):357-363

Abstract— Hydrogen isotope ratios of organic compounds in carbonaceous chondrites provide critical information about their origins and evolutionary history. However, because many of these compounds are obtained by aqueous extraction, the degree of hydrogen‐deuterium (H/D) exchange that occurs during the process needs to be quantitatively evaluated. This study uses compound‐specific hydrogen isotopic analysis to quantify the H/D exchange during aqueous extraction. Three common meteoritic dicarboxylic acids (succinic, glutaric, and 2‐methyl glutaric acids) were refluxed under conditions simulating the extraction process. Changes in δD values of the dicarboxylic acids were measured following the reflux experiments. A pseudo‐first order rate law was used to model the H/D exchange rates which were then used to calculate the isotope exchange resulting from aqueous extraction. The degree of H/D exchange varies as a result of differences in molecular structure, the alkalinity of the extraction solution and presence/absence of meteorite powder. However, our model indicates that succinic, glutaric, and 2‐methyl glutaric acids with a δD of 1800%***_o would experience isotope changes of 38_o, 10_o, and 6_o, respectively during the extraction process. Therefore, the overall change in δD values of the dicarboxylic acids during the aqueous extraction process is negligible. We also demonstrate that H/D exchange occurs on the chiral α‐carbon in 2‐methyl glutaric acid. The results suggest that the racemic mixture of 2‐methyl glutaric acid in the Tagish Lake meteorite could result from post‐synthesis aqueous alteration. The approach employed in this study can also be used to quantify H/D exchange for other important meteoritic compounds such as amino acids.  相似文献   

Characters of the Pco2 and CO2 Flux in the East China Sea in Autumn     

纪雷  崔鹤  辛淑平  王军  张龙军  陆贤昆 《中国海洋湖沼学报》2003,21(2):180-186

Pco2 of air and seawater samples from the East China Sea(ECS) were measured in situ in autumn, 1994,Ocean currents,terrestrial fluviation,biological activities,etc.,Pco2 char-acters in air and seawater were investigated,CO2 flux and its character in the East China Sea are discussed on the basis of the Pco2 profiles of air and seawater,It was clear that the nearshore was the source of CO2;and tht the oulter sea area was the sink of CO2; and that the shelf area of the EXS is a net sink for atmospheric CO2 in autumn.  相似文献   

Geological environment conflicts of Kunming Basin and its urban sustainable development     

Jianhua FAN Bingfei SHI 《东北亚地学研究》2006,9(2):217-219

Kunming Basin locates middle of Yunnan altiplano and has a particularity in geography,topographic and geological environment.With the urban dilation quickly,add the reason of the unreasonable city layout,conflicts between environment and urban resources consumption become shrill increasingly.It is human being activities that lead to vulnerability and depravation of geological environment in local.Take a few examples on geological environment to expatiate relationship between urban construction and geological environment carrying capacity,and find a way how to make a better plan for urban sustainable development to achieve new balance between man and nature in local.  相似文献