全文获取类型
收费全文 | 217篇 |
免费 | 11篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 5篇 |
综合类 | 2篇 |
化学工业 | 22篇 |
金属工艺 | 3篇 |
机械仪表 | 1篇 |
建筑科学 | 76篇 |
矿业工程 | 2篇 |
能源动力 | 31篇 |
轻工业 | 12篇 |
水利工程 | 10篇 |
石油天然气 | 39篇 |
无线电 | 3篇 |
一般工业技术 | 7篇 |
冶金工业 | 7篇 |
自动化技术 | 9篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 9篇 |
2020年 | 6篇 |
2019年 | 7篇 |
2018年 | 6篇 |
2017年 | 11篇 |
2016年 | 14篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 25篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 3篇 |
2007年 | 5篇 |
2006年 | 7篇 |
2005年 | 5篇 |
2004年 | 10篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 11篇 |
1995年 | 4篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
1985年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有229条查询结果,搜索用时 0 毫秒
31.
Sand Control Measures and Sand Drift Fences 总被引:1,自引:0,他引:1
Sand drift and sand dune movements are typical logistic problems facing civilian and industrial cities in arid and semiarid countries like Saudi Arabia. Some of these countries are considered active when it comes to sand drift and sand dune movement, due to the high annual sand drift rate. Urban cities have extensive facilities in the middle of these active areas that require good protection and innovative solutions?to this problem. This paper briefly reviews sand movement control measures and highlights sand drift fence design guidelines for the first time. 相似文献
32.
The factors used in this model are financial stability, experience, references, past performance, current work load, staff availability, manpower resources, company organization, office location, experience in geographic location of project, quality performance, failure to complete contracts, procurement experience, safety consciousness and claim attitude. 相似文献
33.
The study reports from a survey, in Saudi Arabia, of the use of applications software by knowledge workers. Results indicate that user productivity is positively related to satisfaction and negatively to alienation. Knowledge workers in Saudi Arabia generally use low-end applications software. Expert Systems and 4 GL's are rarely used in a micro-environmnet. Informal knowledge sources are more significantly correlated with higher proficiency and productivity of knowledge workers than are the formal sources. Computer periodicals are an important information source for successful users. Younger knowledge workers are more productive than the older ones. Sharing with others has a negative effect on productivity. Implications of the use of applications software by knowledge workers in developing countries are discussed. 相似文献
34.
35.
36.
Natural coarse and fine aggregates which accumulated along six selected wadis in the region of Makkah were assessed both
qualitatively and quantitatively. The six wadis were Numan, Al-Yamanyah, Al-Shamyah, Hwarah, Alaf and Faydah. More than 440
aggregate samples were collected and their physical, mechanical and chemical properties determined. Petrographic studies on
the gravel samples were undertaken to characterise the aggregate types. The results were compared with ASTM and British Standard
specifications. The aggregates were generally within the acceptable limits for use in concrete although there were the relatively
high values of chloride, sulphate and total dissolved salts in the fine aggregates in Wadis Alaf, Hwarah and Faydah. Nine
fine aggregate samples representing upstream, midstream and downstream deposits from these saline wadis were washed in distilled
waters after which the aggregates were within the acceptable limits for structural concrete. There were indications of material
which could cause alkali-silica in the coarse aggregate at Wadi Faydah. The study proved reserves of 12.5 million m3 of coarse aggregate and 23 million m3 of fine aggregate.
Received: 27 May 1998 · Accepted: 18 February 1999 相似文献
37.
In this work, the weather conditions and wind power in the eastern part of Saudi Arabia over a period of 36 years (1961–1996) are studied and modelled. The study involves temperature, relative humidity, fog, wind speed, wind power and dust storms. A regression analysis is carried out by using the linear regression technique to model the weather parameters. The models developed can be used in any study related to weather and its effect on the environment and energy. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
38.
39.
DEPOSITIONAL AND DIAGENETIC BARRIERS,BAFFLES AND CONDUITS: PERMIAN – CARBONIFEROUS UNAYZAH RESERVOIR,NUAYYIM FIELD,CENTRAL SAUDI ARABIA 下载免费PDF全文
K. Al‐Ramadan S.G. Franks S. Al‐Shammari A. Rees A. Koeshidayatullah S. Abu‐Khamsin 《Journal of Petroleum Geology》2017,40(1):85-103
The Unayzah Formation is one of the most important Palaeozoic reservoir systems in Saudi Arabia. In the Nuayyim field, Central Saudi Arabia, it produces light, sweet crude oil and consists of three main reservoir units, in descending stratigraphic order: Unayzah A, B and C. These reservoir units include a wide range of depositional facies deposited under a variety of climatic conditions, from high‐latitude glacio‐fluvial to more temperate playa/lacustrine, floodplain and braided‐fluvial to hot‐arid aeolian environments. Together with the diagenetic changes superimposed on the various depositional facies, this has produced complex reservoir heterogeneity. The effects of this diagenetic and sedimentologic complexity on reservoir quality and compartmentalization are the subject of this paper. Approximately 816 ft of core and 611 core plug samples were examined from three wells which penetrate, completely or in part, the Unayzah reservoir. We combine petrographic and scanning electron microscope analysis with porosity and permeability data and calculated pore throat dimensions to identify fluid conduits, barriers and baffles to fluid flow. A rock classification scheme is proposed which takes into account whether the pore‐level control on fluid flow is due to depositional or diagenetic processes and the composition of depositional or diagenetic phases within the pores. Distinguishing depositional versus diagenetic controls on fluid flow is important for predicting the three‐dimensional geometry of conduits, barriers and baffles, and a priori knowledge of potential reactions between injected fluids and reservoir rocks is important for designing enhanced oil recovery fluids. In the three wells studied, it appears that the Unayzah reservoir is compartmentalized vertically due to the occurrence of diagenetic and depositional barriers and baffles. There is insufficient data to assess the lateral or areal extent of the barriers, baffles and fluid conduits, but the understanding of pore‐level controls on reservoir quality and the rock classification schemes introduced here will provide a starting point for future studies. These studies should combine well logs, seismic and engineering data with data presented here to assist mapping conduits, barriers and baffles across the field. The proposed classification schemes may also prove to be useful for assessing reservoirs in other fields both within Saudi Arabia and elsewhere. 相似文献
40.
沙特B区块高效破岩钻井技术 总被引:1,自引:1,他引:0
沙特B区块为典型的高温高压低孔低渗砂岩储层,平均机械钻速2.25 m/h,平均钻井周期250 d。为了提高机械钻速,缩短钻井周期,进行了沙特B区块高效破岩技术研究与应用。根据建立的沙特B区块岩石可钻性剖面,以岩石可钻性为基础,不同类型钻头的现场实钻效果为依据,与钻头厂家共同研究优选出了该区块不同地层的钻头推荐方案;参照沙特B区块地层的可钻性,根据螺杆钻具和涡轮钻具工作特征参数,优选出了适用于该区块的螺杆钻具和涡轮钻具。现场应用表明,沙特B区块采用优选出的钻头推荐方案“螺杆钻具+PDC钻头”和“涡轮钻具+孕镶金刚石钻头”复合钻井方式可以实现高效破岩,使该区块平均机械钻速提高46.8%,钻井周期缩短23.3%。 相似文献