全文获取类型
收费全文 | 2024篇 |
免费 | 101篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 25篇 |
综合类 | 23篇 |
化学工业 | 584篇 |
金属工艺 | 57篇 |
机械仪表 | 43篇 |
建筑科学 | 146篇 |
矿业工程 | 9篇 |
能源动力 | 48篇 |
轻工业 | 229篇 |
水利工程 | 17篇 |
石油天然气 | 2篇 |
无线电 | 118篇 |
一般工业技术 | 362篇 |
冶金工业 | 179篇 |
原子能技术 | 22篇 |
自动化技术 | 262篇 |
出版年
2023年 | 22篇 |
2022年 | 43篇 |
2021年 | 73篇 |
2020年 | 33篇 |
2019年 | 42篇 |
2018年 | 51篇 |
2017年 | 35篇 |
2016年 | 62篇 |
2015年 | 67篇 |
2014年 | 76篇 |
2013年 | 86篇 |
2012年 | 112篇 |
2011年 | 132篇 |
2010年 | 109篇 |
2009年 | 88篇 |
2008年 | 83篇 |
2007年 | 76篇 |
2006年 | 70篇 |
2005年 | 59篇 |
2004年 | 61篇 |
2003年 | 29篇 |
2002年 | 47篇 |
2001年 | 35篇 |
2000年 | 33篇 |
1999年 | 33篇 |
1998年 | 43篇 |
1997年 | 42篇 |
1996年 | 23篇 |
1995年 | 32篇 |
1994年 | 24篇 |
1993年 | 18篇 |
1992年 | 22篇 |
1991年 | 16篇 |
1990年 | 20篇 |
1989年 | 23篇 |
1988年 | 11篇 |
1987年 | 12篇 |
1986年 | 10篇 |
1985年 | 11篇 |
1984年 | 17篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 23篇 |
1977年 | 13篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 21篇 |
1969年 | 12篇 |
1968年 | 10篇 |
排序方式: 共有2126条查询结果,搜索用时 15 毫秒
31.
Georg Sonnek Heinz Reinheckel Karl-Günther Baumgarten 《Advanced Synthesis \u0026amp; Catalysis》1976,318(5):756-760
Aluminium Alkyls with Heteroatoms. II. Preparation of Tris[(3-trimethylsilyl)-propyl]aluminium Tris[(3-trimethylsilyl)-propyl]aluminium is prepared by disproportionation and by an olefine displacement reaction in a circulation process. The reaction way is investigated with the aid of 1H-n.m.r.- and i.r.-spectroscopy. 相似文献
32.
33.
Daniel Lersch Gheorghe Pascovici Benedikt Birkenbach Bart Bruyneel Jürgen Eberth Herbert Hess Peter Reiter Andreas Wiens Heinz Georg Thomas for the AGATA Collaboration 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》2011,640(1):223
34.
35.
Jens Georg Kaufmann Marc P. Y. Desmulliez Yingtao Tian Dennis Price Mike Hughes Nadia Strusevich Chris Bailey Changqing Liu David Hutt 《Microsystem Technologies》2009,15(8):1245-1254
In this paper we propose an agitation method based on megasonic acoustic streaming to overcome the limitations in plating
rate and uniformity of the metal deposits during the electroplating process. Megasonic agitation at a frequency of 1 MHz allows
the reduction of the thickness of the Nernst diffusion layer to less than 600 nm. Two applications that demonstrate the benefits
of megasonic acoustic streaming are presented: the formation of uniform ultra-fine pitch flip-chip bumps and the metallisation
of high aspect ratio microvias. For the latter application, a multi-physics based numerical simulation is implemented to describe
the hydrodynamics introduced by the acoustic waves as they travel inside the deep microvias. 相似文献
36.
M. Faber Frank Jst Reiner Manstetten Georg MüllerFürstenberger 《Advanced Synthesis \u0026amp; Catalysis》1996,338(1):497-505
Joint Production and Environmental Policy: A Case Study for the Chlorine and Sulphuric Acid Industry The chemical industry is a key sector of industrialised economy. Thus, environmental policy with a focus on the chemical industry is likely to affect the economy as a whole. In this article we show, that environmental regulation of the chemical industry has major consequences for other production sectors. Two major problem areas of the chemical industry are considered: the chlorine industry and the sulphur industry. While the chlorine industry can cope with environmental legislation by process and product innovation without a substantial impact on other sectors, this is not the case with the sulphur industry. The production of its key product, sulphuric acid, utilises joint products of other sectors as inputs. The chemical industry offers these sectors the possibility to dispose of their unwanted by-products. Environmental policy, directed towards a reduction of sulphuric acid is likely to cause a waste disposal problem in sectors which manufacture sulphur or sulphur dioxide as by-products. Solving environmental problems within the chemical industry therefore creates new problems in other sectors. 相似文献
37.
Rokas Lukosevicius Simonas Juzenas Violeta Salteniene Ugne Kulokiene Justina Arstikyte Georg Hemmrich-Stanisak Andre Franke Alexander Link Paulius Ruzgys Saulius Satkauskas Henrikas Pauzas Tadas Latkauskas Gediminas Kiudelis Francesc Balaguer Juozas Kupcinskas Jurgita Skieceviciene 《International journal of molecular sciences》2022,23(4)
Regulatory changes occurring early in colorectal cancer development remain poorly investigated. Since the majority of cases develop from polyps in the adenoma-carcinoma transition, a search of early molecular features, such as aberrations in miRNA expression occurring prior to cancer development, would enable identification of potentially causal, rather than consequential, candidates in the progression of polyp to cancer. In the current study, by employing small RNA-seq profiling of colon biopsy samples, we described differentially expressed miRNAs and their isoforms in the adenoma-carcinoma transition. Analysis of healthy-adenoma-carcinoma sequence in an independent validation group enabled us to identify early deregulated miRNAs including hsa-miR-1246 and hsa-miR-215-5p, the expressions of which are, respectively, gradually increasing and decreasing. Loss-of-function experiments revealed that inhibition of hsa-miR-1246 lead to reduced cell viability, colony formation, and migration rate, thereby indicating an oncogenic effect of this miRNA in vitro. Subsequent western blot and luciferase reporter assay provided evidence of hsa-miR-1246 being involved in the regulation of target AXIN2 and CFTR genes’ expression. To conclude, the present study revealed possible involvement of hsa-miR-1246 in early colorectal cancer development and regulation of tumor suppressors AXIN2 and CFTR. 相似文献
38.
Fine temperature control is essential in homeothermic animals. Both hyper- and hypothermia can have deleterious effects. Multiple, efficient and partly redundant mechanisms of adjusting the body temperature to the value set by the internal thermostat exist. The neural circuitry of temperature control and the neurotransmitters involved are reviewed. The GABAergic inhibitory output from the brain thermostat in the preoptic area POA to subaltern neural circuitry of temperature control (Nucleus Raphe Dorsalis and Nucleus Raphe Pallidus) is a function of the balance between the (opposite) effects mediated by the transient receptor potential receptor TRPM2 and EP3 prostaglandin receptors. Activation of TRPM2-expressing neurons in POA favors hypothermia, while inhibition has the opposite effect. Conversely, EP3 receptors induce elevation in body temperature. Activation of EP3-expressing neurons in POA results in hyperthermia, while inhibition has the opposite effect. Agonists at TRPM2 and/or antagonists at EP3 could be beneficial in hyperthermia control. Activity of the neural circuitry of temperature control is modulated by a variety of 5-HT receptors. Based on the theoretical model presented the “ideal” antidote against serotonin syndrome hyperthermia appears to be an antagonist at the 5-HT receptor subtypes 2, 4 and 6 and an agonist at the receptor subtypes 1, 3 and 7. Very broadly speaking, such a profile translates in a sympatholytic effect. While a compound with such an ideal profile is presently not available, better matches than the conventional antidote cyproheptadine (used off-label in severe serotonin syndrome cases) appear to be possible and need to be identified. 相似文献
39.
Hinkel Georg Goldschmidt Thomas Burger Erik Reussner Ralf 《Software and Systems Modeling》2019,18(1):129-155
Software and Systems Modeling - Model-driven engineering (MDE) has proved to be a useful approach to cope with today’s ever-growing complexity in the development of software systems;... 相似文献
40.
Software and Systems Modeling - Despite good results in several industrial projects, model-driven engineering (MDE) has not been widely adopted in industry. Although MDE has existed for more than a... 相似文献