全文获取类型
收费全文 | 3323篇 |
免费 | 323篇 |
国内免费 | 119篇 |
专业分类
电工技术 | 176篇 |
综合类 | 177篇 |
化学工业 | 725篇 |
金属工艺 | 160篇 |
机械仪表 | 160篇 |
建筑科学 | 204篇 |
矿业工程 | 62篇 |
能源动力 | 81篇 |
轻工业 | 431篇 |
水利工程 | 57篇 |
石油天然气 | 178篇 |
武器工业 | 20篇 |
无线电 | 316篇 |
一般工业技术 | 381篇 |
冶金工业 | 131篇 |
原子能技术 | 21篇 |
自动化技术 | 485篇 |
出版年
2024年 | 16篇 |
2023年 | 57篇 |
2022年 | 155篇 |
2021年 | 250篇 |
2020年 | 150篇 |
2019年 | 112篇 |
2018年 | 142篇 |
2017年 | 151篇 |
2016年 | 128篇 |
2015年 | 168篇 |
2014年 | 225篇 |
2013年 | 223篇 |
2012年 | 255篇 |
2011年 | 262篇 |
2010年 | 241篇 |
2009年 | 203篇 |
2008年 | 191篇 |
2007年 | 172篇 |
2006年 | 147篇 |
2005年 | 111篇 |
2004年 | 83篇 |
2003年 | 64篇 |
2002年 | 38篇 |
2001年 | 46篇 |
2000年 | 38篇 |
1999年 | 25篇 |
1998年 | 19篇 |
1997年 | 20篇 |
1996年 | 13篇 |
1995年 | 15篇 |
1994年 | 10篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1976年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有3765条查询结果,搜索用时 78 毫秒
101.
Yan Huang Honggang Lu Bingnan Wang Wenbo He Hongzhou Dong Lina Sui Zhixing Gan Shuai Ma Beili Pang Lifeng Dong Liyan Yu 《International Journal of Hydrogen Energy》2021,46(5):3530-3538
As a promising catalyst for solar hydrogen production, black phosphorus (BP) has received widespread attention due to variable band gaps, high carrier mobility, and strong light absorption performance. Herein, we use MoS2 as a cocatalyst to synthesize BP/MoS2 catalyst with polycrystalline BP to improve photocatalytic performance under visible light irradiation. A small amount of MoS2 can reduce the recombination of electron-hole pairs in the composite, increase carrier transport efficiency, and then improve photocatalytic performance. As expected, the 10/0.5 ratio of BP/MoS2 catalyst exhibits the highest photocatalytic hydrogen evolution performance with a hydrogen evolution rate of 575.4 μmol h?1 g?1, which is 2.5 times of pure BP. Based on the results above, a simple method is provided to synthesize low-cost black phosphorus-based photocatalysts. 相似文献
102.
Lina Abu-Ghunmi Munawar Badawi Manar Fayyad 《Journal of surfactants and detergents》2014,17(5):833-838
Triton X-100 applications as surfactant raises concern on water and soil environment due to its non-biodegradability and inhibition effect. This paper aims at reviewing Triton X-100 biodegradability and inhibition literature. It shows Triton X-100 is biodegradable by aerobic and anaerobic municipal wastewater sludge and Vibrio cyclitrophicus-sp-Nov organism. Adsorption and biodegradation are mechanisms of Triton removal. Triton inhibits anaerobic sludge organisms and some single aerobic organisms. Inhibition mechanisms are substrate shortage, physiological membrane-damaging and/or alteration in organism cell membrane. Thus Triton X-100 fate in the environment and its sustainable application can be controlled via proper selection of organism type, Triton concentration, and substrate. 相似文献
103.
Emerging techniques for assisting and accelerating food freezing processes: A review of recent research progresses 总被引:1,自引:0,他引:1
Freezing plays an important role in food preservation and the emergence of rapid freezing technologies can be highly beneficial to the food industry. This paper reviews some novel food freezing technologies, including high-pressure freezing (HPF), ultrasound-assisted freezing (UAF), electrically disturbed freezing (EF) and magnetically disturbed freezing (MF), microwave-assisted freezing (MWF), and osmo-dehydro-freezing (ODF). HPF and UAF can initiate ice nucleation rapidly, leading to uniform distribution of ice crystals and the control of their size and shape. Specifically, the former is focused on increasing the degree of supercooling, whereas the latter aims to decrease it. Direct current electric freezing (DC-EF) and alternating current electric freezing (AC-EF) exhibit different effects on ice nucleation. DC-EF can promote ice nucleation and AC-EF has the opposite effect. Furthermore, ODF has been successfully used for freezing various vegetables and fruit. MWF cannot control the nucleation temperature, but can decrease supercooling degree, thus decreasing the size of ice crystals. The heat and mass transfer processes during ODF have been investigated experimentally and modeled mathematically. More studies should be carried out to understand the effects of these technologies on food freezing process. 相似文献
104.
Lina R. Nih Elias Sideris S. Thomas Carmichael Tatiana Segura 《Advanced materials (Deerfield Beach, Fla.)》2017,29(32)
With the number of deaths due to stroke decreasing, more individuals are forced to live with crippling disability resulting from the stroke. To date, no therapeutics exist after the first 4.5 h after the stroke onset, aside from rest and physical therapy. Following stroke, a large influx of astrocytes and microglia releasing proinflammatory cytokines leads to dramatic inflammation and glial scar formation, affecting brain tissue's ability to repair itself. Pathological conditions, such as a stroke, trigger neural progenitor cells (NPCs) proliferation and migration toward the damaged site. However, these progenitors are often found far from the cavity or the peri‐infarct tissue. Poststroke tissue remodeling results in a compartmentalized cavity that can directly accept a therapeutic material injection. Here, this paper shows that the injection of a porous hyaluronic acid hydrogel into the stroke cavity significantly reduces the inflammatory response following stroke while increasing peri‐infarct vascularization compared to nonporous hydrogel controls and stroke only controls. In addition, it is shown that the injection of this material impacts NPCs proliferation and migration at the subventricular zone niche and results, for the first time, in NPC migration into the stroke site. 相似文献
105.
Electronic Commerce Research - With the innovation of information technology and the rise of the Internet economy, cross-border e-commerce has grown up to be an important means and strategy for... 相似文献
106.
<正>为集中资源优势,打造顶级期刊,助力学科行业发展,《园林》学刊编辑部与同济大学建筑与城市规划学院景观学系于2022年起正式联合办刊。2022年1月4日,《园林》学刊同济大学编辑部揭牌仪式暨学刊发展交流会在同济大学建筑与城市规划学院C1会议室顺利举行。 相似文献
107.
Yüksel Korkmaz Behrus Puladi Kerstin Galler Peer W. Kmmerer Agnes Schrder Lina Glz Tim Sparwasser Wilhelm Bloch Andreas Friebe James Deschner 《International journal of molecular sciences》2021,22(2)
Nitric oxide (NO) binds to soluble guanylyl cyclase (sGC), activates it in a reduced oxidized heme iron state, and generates cyclic Guanosine Monophosphate (cGMP), which results in vasodilatation and inhibition of osteoclast activity. In inflammation, sGC is oxidized and becomes insensitive to NO. NO- and heme-independent activation of sGC requires protein expression of the α1- and β1-subunits. Inflammation of the periodontium induces the resorption of cementum by cementoclasts and the resorption of the alveolar bone by osteoclasts, which can lead to tooth loss. As the presence of sGC in cementoclasts is unknown, we investigated the α1- and β1-subunits of sGC in cementoclasts of healthy and inflamed human periodontium using double immunostaining for CD68 and cathepsin K and compared the findings with those of osteoclasts from the same sections. In comparison to cementoclasts in the healthy periodontium, cementoclasts under inflammatory conditions showed a decreased staining intensity for both α1- and β1-subunits of sGC, indicating reduced protein expression of these subunits. Therefore, pharmacological activation of sGC in inflamed periodontal tissues in an NO- and heme-independent manner could be considered as a new treatment strategy to inhibit cementum resorption. 相似文献
108.
Yanshun Xu Lina He Wenshui Xia Qixing Jiang Fang Yang Pei Gao Bin Wang 《International Journal of Food Science & Technology》2019,54(3):723-733
To accelerate fermentation and improve quality of fermented fish, the impact of fermentation at elevated temperature on physicochemical, microbiological and flavour characteristics, as well as biogenic amines (BAs) accumulation of low-salt fermented fish was investigated. Results showed that increasing temperature at later stage significantly promoted the growth of lactic acid bacteria, retarded the reduction of yeast and increased the titratable acidity, while staphylococci and enterobacteriaceae were inhibited to higher extent when fermented at elevated temperature. BAs contents in samples fermented at 30 °C during later stage were lower than those in the group fermented at 25 °C for 28 days, and the lowest values were observed in the sample initially fermented at 25 °C for 10 days followed by fermentation at 30 °C for 18 days. Furthermore, fermentation at elevated temperature at later stage favoured the formation of desired volatile flavour compounds. Results suggested that fermentation at elevated temperature at later stage could reduce BAs accumulation and enhance quality attributes of low-salt fermented fish. 相似文献
109.
水闸作为水利工程中最重要的基础建筑设施,具有资源调配、防洪、灌溉等功能。本文介绍了如何加强水利工程安全管理的方法,希望为水利工程建设做出贡献。 相似文献
110.
A. F. D’ Intino B. de Caprariis M. L. Santarelli N. Verdone A. Chianese 《Frontiers of Chemical Science and Engineering》2014,8(2):156-160
In this work, Mg2+ doped hydroxyapatite (Mg-HAP) nanoparticles were produced by a reactionprecipitation process by using a spinning disc reactor (SDR) at high rotational speed. The production process of these nanoparticles consisted of the neutralization reaction between two aqueous solutions of calcium chloride and ammonia orthophosphate at room temperature. By operating at pH = 10, a high purity Mg-HAP nanoparticles were obtained. In particular, they were 51 nm in average size when the two reagents were fed over the disc symmetrically at 3 cm from the disc center and a rotational speed of the disc reactor equal to 1400 r/min was adopted. 相似文献