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71.
湿法浸取硫酸镍工艺研究中,净化提纯工艺采取了蒸发浓缩浸液、分步沉淀杂质的技术方案。中试表明,采用此种工艺生产效率很低,还导致生产流水线上的设备匹配性差。为此,作者提出了二次浸取的技术方案。实验室及中试试验表明:采用二次浸取工艺替代蒸发浓缩工艺,行之有效。 相似文献
72.
73.
Quaternary Climate and Environment in the Lop Nur, Xinjiang 总被引:4,自引:0,他引:4
WANG Mill PU Qingyu Geological Society of Chin Baiwanzhuang Rd. Beijing LIU Chenglin CHEN YongzhiInstitute of Mineral Deposits Chinese Academy of Geological Sciences Baiwanzhuang Rd. Beijing 《《地质学报》英文版》2000,74(2):273-278
Since the middle Early Pleistocene (1.20 Ma B.P.), the desert steppe climate and environment have predominated in the Lop Nur area, Xinjiang, characterized by warm humid epochs interrupted by dry cold intervals. The grain-size and magnetic susceptibility curves record 30 climatic oscillations, each with a ca. 40 ka cycle, in the area since 1.2 Ma B.P., which reflects the controlling effects exerted by the astronomic factor on the environment. The Quaternary sedimentary environment in the Lop Nur gradually changed from a fresh lake through a brackish lake to a saline lake, showing a spiral evolution, and finally it evolved into a playa. 相似文献
74.
Technology 《国土资源导刊(湖南)》2007,(11)
青岛266071潜艇;;定深旋回;;控制定深等速直航潜艇操方向舵后将逐渐进入并保持圆周运动,要实现潜艇定深旋回,可同时操纵尾升降舵、首升降舵或者首尾升降舵配合操舵。通过仿真分析各种操纵方案的优劣,得到实现定深旋回的最佳控制方式。Modeling and analysis on the control of submarine's certain depth and gyration motionCHEN Jun-feng, TIAN Wei,CHE Meng-hu (Navy Submarine Academy, Qingdao 266071, China)Submarine will go into and keep the states of circular motion under the contro 相似文献
75.
回顾了体系地震动力分析的历史过程,并对地震动力分析的传统理论方法、近似方法和现代计算技术从新的角度加以阐述,同时给出体系地震动力分析的应用前景,以促进经典的传统理论方法、近似方法和现代计算技术的综合和在实际工程中的应用,形成系统而完整的地震动力分析体系。 相似文献
76.
Water samples were collected in 120 stations in the Bohai Sea of China to analyze the distribution of dissolved nutrients and assess the degree of eutrophication in August 2002. The result shows that the average concentration of DIN increased and the PO4-P concentration sharply decreased compared to the previous data of corresponding period. The high concentrations of DIN and PO4-P occurred in coastal waters, especially in the bays and some river estuaries, while the high concentrations of SiO3-Si in the surface and middle depth occurred in the central area of the Bohai Sea. The average ratio of DIN/ PO4-P was much higher than the Redfield Ratio (16:1). Apparently, PO4-P was one of the limiting nutrient for phytoplankton growing in the sea. The average concentrations of DON and DOP were higher than their inorganic forms. The results of eutrophication assessment show that 22.1% of all stations were classified as violating the concentration levels of the National Seawater Quality Standard (GB 3097-1997) for DIN and only 3.9% for PO4-P. The average eutrophication index in the overall area was 0.21±0.22 and the high values occurred in Bohai Bay, Liaodong Bay and near the Yellow River estuary. This means that the state of eutrophication was generally mesotrophic in the Bohai Sea, but relatively worse in the bays, especially some river estuaries. 相似文献
77.
The de-eutrophication abilities and characteristics of Ulva pertusa, a marine green alga, were investigated in Qingdao Yihai Hatchery Center from spring to summer in 2005 by analyzing the dynamic changes in NH+4, NOˉ3, NO2ˉ as well as the total dissolved inorganic nitrogen (DIN). The results show that the effluent wastewater produced by fish aquaculture had typical eutrophication levels with an average of 34.3 μmol L-1 DIN. This level far exceeded the level IV quality of the national seawater standard and c... 相似文献
78.
山东省国土资源厅测绘行业管理处 《山东国土资源》2009,25(5)
国务院、山东省政府于2007年9月和2008年7月分别下发了《关于加强测绘工作的意见》和《关于进一步加强测绘工作的意见》(以下简称《意见》),要求进一步加强测绘工作。2009年山东省国土资源厅测绘行业管理处的总体工作思路是:以邓小平理论和“三个代表”重要思想为指导,深入学习实践科学发展观, 相似文献
79.
Aref M.O.AL-JABALI Abdo S.AL-MAQTARY Hussein AL-AKHALI Mohammed HAZAEA Fadel AL-AGHBARI 《东北亚地学研究》2009,(1)
According to topography of Yemen,most areas and villages are located at obligated crest,toe of mountain and under cliffs.Therefore Al-Huwayshah consisting of Tawilah sandstone group is characterized by steep slope reach to 90° in some areas.This area is affected by strong tectonic movements and faults that occurred during the geological epochs.This effect enhances to find out fractures and joints as well as the rocks become brittle and ready to slide depending on the position of area.And there are some frac... 相似文献
80.
HUANG Yulong WANG Pujun CHEN Shuming .College of Earth Sciences Jilin University Changchun China.Daqing Oilfield Corporation PetroChina Daqing Heilongjiang China 《东北亚地学研究》2009,12(2):64-79
About forty productive oil/gas fields hosted in volcanic reservoirs have been found since 1957 in fourteen basins of China. They can be simply subdivided into two groups, the east and the west. Reservoir volcanic rocks of the east group are predominantly composed of Late Jurassic to Early Cretaceous rhyolite and Tertiary basalt, preferred being considered as rift type volcanics developed in the circum-Pacific tectonic regime. Those of the west are Permo-Carboniferous intermediate/basic volcanic rocks, being island-arc type ones developed in paleo-Asian Ocean tectonic regime. 相似文献