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1.
Chemical fluxes of Asian rivers into oceans bear different regional variations. Three zones are characteristic of distinct dissolved sediment loads and yields and ionic concentration.Rivers into oceans in China play an important role in Asia because of their different chemical fluxes, among which those draining the Loess Plateau have high ionic concentration, low water discharges and dissolved sediment loads and yields.Climate, vegetation, soil and strata lithology, chemical weathering intensity and tectonic activity dominate chemical fluxes of Asian rivers into oceans, and different factors have different effects on the chemical fluxes of separate regional rivers. Rising of the Tibet Plateau also exerts an important influence on chemical compositions of rivers originating from it. 相似文献
2.
烟台市污水处理深海排放工程设计方案研究与选择 总被引:2,自引:0,他引:2
沿海城市污水处理深海排放工程在我国起步较晚,烟台市污水处理深海排放工程我国目前规模最大的同类工程,且已进入施工阶段,本文详细阐述了该工程及水工设计方案,在我国城市污水2深海排放工程领域作了积极有益的探索。 相似文献
3.
从国库集中收付改革的内容、要求,地质勘查单位的现状出发,探讨了国库集中收付改革与深化地质勘查单位改革之间存在的问题,指出国库集中收付制度虽然能够使事业单位的财政收支得到有效监管,但因地质勘查单位具有事业与企业的双重职能,现行的国库集中收付制度不利于地勘单位的深化改革。为有效解决这一矛盾.提出了在国库单一账户体系外,建立地质勘查单位改革性基本账户的建议。 相似文献
4.
5.
区位进入理论与企业集团的国际化扩张——以海尔集团为例 总被引:5,自引:1,他引:5
中国企业集团是改革开放以后出现的大型企业组织 ,在经济全球化的背景下 ,研究其国际化扩张具有重大现实意义。本文在详细介绍Hayter的国际企业区位进入理论的基础上 ,以海尔集团为例 ,分析了企业集团的国际化扩张过程 ;其次 ,分析了海尔集团所具有的进入优势以及所面临的空间进入壁垒。海尔集团所具有的进入优势有管理与文化优势、技术创新优势、产品质量优势、营销优势 ,但还面临着心理距离、企业规模小以及东道国政策的限制等空间壁垒。最后 ,提出了有关企业集团国际化扩张的一些对策。 相似文献
6.
7.
加入WTO后中国旅行社的生存与发展 总被引:1,自引:3,他引:1
中国入世后,旅游市场的进一步开放将有利于引进先进的经营管理经验,进一步发展中国得天独厚的旅游资源和劳动力优势。同时,伴随着服务贸易总协定(CATS)在各成员国的实施与经济全球化,中国旅行社的生存与发展将面临机遇和挑战。中国旅行社应勇敢面对挑战,从以下几个方面提高竞争力:(1)树立战略发展思想;(2)树立战略管理思想;(3)化危机为商机,积极成为网介者;(4)界定企业发展方向,发展产品核心功能;(5)迎合消费者需求与创新需求;(6)组建集团化旅行社;(7)实行跨国际化经营,参加国际竞争;(8)加强对外宣传。 相似文献
8.
Based on hydrometric data and extensive investigations on water-extracting projects, this paper presents a preliminary study on water discharge changes between Datong and Xuliujing during dry season. The natural hydrological processes and human factors that influence the water discharge are analyzed with the help of GIS method. The investigations indicate that the water-extracting projects downstream from Datong to Xuliujing had amounted to 64 in number by the end of 2000, with a water-extracting capacity up to 4,626 m3/s averaged in a tidal cycle. The water extraction from the Changjiang River has become the most important factor influencing the water discharge downstream Datong during dry season. The potential magnitude in water discharge changes are estimated based on historical records of water extraction and a water balance model. The computational results were calibrated with the actual data. The future trend in changes of water discharge into the sea during dry season was discussed by taking into consideration of newly built hydro-engineering projects. The water extraction downstream Datong in dry season before 2000 had a great influence on discharges into the sea in the extremely dry year like 1978-1979. It produced a net decrease of more than 490 m3/s in monthly mean discharges from the Changjiang into the sea. It is expected that the water extraction will continually increase in the coming decades, especially in dry years, when the net decrease in monthly mean water discharge will increase to more than 1000 m3/s and will give a far-reaching effect on the changes of water discharge from the Changjiang into the sea. 相似文献
9.
从市场的角度介绍国内外气象科技服务的现状,分析我国气象科技服务存在的问题和面临的形势,提出应对策略和建议。 相似文献
10.
In this paper we study the infiltration of DNAPL in a porous medium containing a single low-permeable lens. Our aim is to
determine whether or not DNAPL infiltrates into the lens. A key role is played by the capillary pressure: DNAPL cannot infiltrate
into the lens unless the capillary pressure exceeds the entry pressure of the lens. In the model this is reflected by an interface
condition, the extended capillary pressure condition. To derive analytical approximations we first consider a steady-state
DNAPL plume in a homogeneous medium. This results in an estimate of the DNAPL plume width as a function of depth, and an asymptotic
solution for small saturations. Assuming that the extent of the lens is much larger than the width of the unperturbed DNAPL
plume in the homogeneous medium, we derive an explicit criterion for DNAPL infiltration into the lens in terms of a critical
inflow rate. A numerical algorithm is presented in which the extended capillary pressure condition is incorporated. The numerical
and analytical results show good qualitative agreement.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献