全文获取类型
收费全文 | 380篇 |
免费 | 24篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 5篇 |
综合类 | 5篇 |
化学工业 | 103篇 |
金属工艺 | 9篇 |
机械仪表 | 15篇 |
建筑科学 | 11篇 |
矿业工程 | 1篇 |
能源动力 | 29篇 |
轻工业 | 38篇 |
水利工程 | 6篇 |
石油天然气 | 6篇 |
无线电 | 32篇 |
一般工业技术 | 81篇 |
冶金工业 | 18篇 |
自动化技术 | 48篇 |
出版年
2023年 | 6篇 |
2022年 | 9篇 |
2021年 | 21篇 |
2020年 | 18篇 |
2019年 | 31篇 |
2018年 | 34篇 |
2017年 | 19篇 |
2016年 | 23篇 |
2015年 | 14篇 |
2014年 | 29篇 |
2013年 | 39篇 |
2012年 | 32篇 |
2011年 | 21篇 |
2010年 | 19篇 |
2009年 | 10篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 4篇 |
2004年 | 6篇 |
2003年 | 2篇 |
2002年 | 5篇 |
2001年 | 2篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1995年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
1985年 | 1篇 |
1979年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有407条查询结果,搜索用时 15 毫秒
31.
32.
Yoojin Jung Paul T. Imhoff Don C. Augenstein Ramin Yazdani 《Canadian Metallurgical Quarterly》2009,135(3):138-146
Gas collection systems of various designs have been used to control landfill gas emissions, which can be problematic, particularly before installation of final landfill covers. In this work, an innovative gas collection system that includes a permeable layer near the top surface of landfills was evaluated for enhancing capture of landfill gas and reducing fugitive methane emissions. A computational model that accounts for advective and diffusive fluxes of multiple gas components was used to evaluate the efficiency of this new design for intermediate landfill covers. The utility of the high-permeability gas-conductive layer was illustrated for several conditions of interest including varying refuse permeability, varying degrees of permeability anisotropy, and temporal atmospheric pressure changes. Simulations showed that the permeable layer decreased methane emissions by 43% when the horizontal to vertical permeability ratio for refuse was kh/kv = 3 and the domain average kh = 3×10?12?m2, while reductions in methane emissions decreased to 17% for the same anisotropy but with kh = 10?11?m2. With this design, barometric pressure changes did not significantly affect oxygen intrusion or methane emission rates. 相似文献
33.
Mandeep M. Sahani Tarek M. Daoud Ramin Sam Jerry Andrews Yuk Lun Cheng Carl M. Kjellstrand Todd S. Ing 《Hemodialysis international. International Symposium on Home Hemodialysis》2001,5(1):92-96
An aggressive dialysis in a grossly azotemic patient, especially one with severe metabolic acidosis, can lead to dialysis disequilibrium syndrome (DDS). Mild forms present as nausea, vomiting, restlessness, and headache. Severe manifestations include seizures, obtundation, coma, and even death. This clinical picture is caused by cerebral edema induced by one or more of the following mechanisms:
- 相似文献
34.
Majid Aryafar Ramin Raiszadeh Alireza Shalbafzadeh 《Journal of Materials Science》2010,45(11):3041-3051
The possibility of the bonding of the two layers of a double oxide film defect when held in liquid A356 Al alloy was investigated.
The defect was modelled experimentally by maintaining two aluminium oxide layers in contact with each other and the atmosphere
trapped between them in the A356 liquid alloy for varying lengths of time of between 30 s and 48 h. Any changes in the composition
and morphology of these layers were studied by SEM, EDX and XRD. The results showed that the two layers of a double oxide
film defect might bond to each other by two different mechanisms, one during the transformation of Al2O3 to MgAl2O4 spinel in relatively short holding times, which would cause the layers to bond at several points and the other during the
gradual transformation of spinel to MgO in longer times, which would cause strong bonding between the layers. It was shown
that any bonding can take place essentially only after the oxygen and nitrogen of the atmosphere within the defect are consumed. 相似文献
35.
Mamo Di Lella Riccardo Ramin 《变频器世界》2008,(11):106-107
当我们谈论效率时,我们主要指的是电力效率。然而,这种用法并不是效率一次本身的完整含义。在电力电子应用巾,工程师在开发新产品过程中的追求的主要目标是以最大限度地发挥不同类型的效率,如电效率和热效率,以及优化谐波失真和产品整体的尺寸。 相似文献
36.
Ramin Halavati Saeed Bagheri Shouraki 《Soft Computing - A Fusion of Foundations, Methodologies and Applications》2009,13(6):565-575
Artificial Immune System algorithms use antibodies that fully specify the solution of an optimization, learning, or pattern
recognition problem. By being restricted to fully specified antibodies, an AIS algorithm cannot make use of schemata or classes
of partial solutions, while sub solutions can help a lot in faster emergence of a totally good solution in many problems.
To exploit schemata in artificial immune systems, this paper presents a novel algorithm that combines traditional artificial
immune systems and symbiotic combination operator. The algorithm starts searching with partially specified antibodies and
gradually builds more and more specified solutions till it finds complete answers. The algorithm is compared with CLONALG
algorithm on several multimodal function optimization and combinatorial optimization problems and it is shown that it is faster
than CLONALG on most problems and can find solutions in problems that CLONALG totally fails. 相似文献
37.
38.
Wireless Networks - In a wireless sensor network, one of the most important constraints on sensor nodes is their power source, which is a battery. Sensor nodes carry a limited and generally... 相似文献
39.
Yuko ShimodaM. Ekram Azim Gurbir PerharMaryam Ramin Melissa A. KenneySomayeh Sadraddini Alex GudimovGeorge B. Arhonditsis 《Journal of Great Lakes research》2011,37(1):173-193
Climatic change is recognized as an important factor capable of influencing the structural properties of aquatic ecosystems. Lake ecosystems are particularly sensitive to climate change. Several long time-series studies have shown close coupling between climate, lake thermal properties and individual organism physiology, population abundance, community structure, and food-web structure. Understanding the complex interplay between climate, hydrological variability, and ecosystem structure and functioning is essential to inform water resources risk assessment and fisheries management. The purpose of this paper is to present the current understanding of climate-induced changes on lake ecosystem phenology. We first review the ability of climate to modulate the interactions among lake hydrodynamics, chemical factors, and food-web structure in several north temperate deep lakes (e.g., Lake Washington, Lake Tahoe, Lake Constance, Lake Geneva, Lake Baikal, and Lake Zurich). Our aim is to assess long-term trends in the physical (e.g., temperature, timing of stratification, and duration of ice cover), chemical (e.g., nutrient concentrations), and biological (e.g., timing of the spring bloom, phytoplankton composition, and zooplankton abundance) characteristics of the lakes and to examine the signature of local weather conditions (e.g., air temperature and rainfall) and large-scale climatic variability (e.g., ENSO and PDO) on the lake physics, chemistry and biology. We also conducted modeling experiments to quantify the relative effect of climate change and nutrient loading on lake phenology. These modeling experiments focused on the relative changes to the major causal associations underlying plankton dynamics during the spring bloom and the summer stratified period. To further understand the importance of climate change on lakes, we propose two complementary directions of future research. First, additional research is needed to elucidate the wide array of in-lake processes that are likely to be affected by the climate change. Second, it is essential to examine the heterogeneity in responses among different water bodies. The rationale of this approach and its significance for dealing with the uncertainty that the climate signals cascade through lake ecosystems and shape abiotic variability and/or biotic responses have been recently advocated by several other synthesis papers. 相似文献
40.
Sükran Cakli Latif Taskaya Duygu Kisla Ufuk Çelik Can Altinel Ataman Asli Cadun Berna Kilinc Ramin Haji Maleki 《European Food Research and Technology》2005,220(5-6):526-530
Abstract Production of fish fingers was achieved by using fish species such as sardine (Sardina pilchardus, Walbaum, 1792), whiting (Merlangius merlangus, Linnaeus, 1758) and pike perch (Sander lucioperca, Linnaeus, 1758). Quality changes of battered fish patties during a period of 8 months at –18 °C were investigated. According to the results of microbiological and chemical analysis, fish fingers were found to be within acceptable limits during frozen storage for 8 months. However, sensory analysis showed that, at the end of the frozen storage, fish fingers made from sardine could not be consumed because of rancidity. 相似文献