全文获取类型
收费全文 | 1639篇 |
免费 | 87篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 19篇 |
综合类 | 12篇 |
化学工业 | 566篇 |
金属工艺 | 36篇 |
机械仪表 | 41篇 |
建筑科学 | 130篇 |
矿业工程 | 2篇 |
能源动力 | 48篇 |
轻工业 | 137篇 |
水利工程 | 3篇 |
石油天然气 | 3篇 |
无线电 | 108篇 |
一般工业技术 | 309篇 |
冶金工业 | 72篇 |
原子能技术 | 20篇 |
自动化技术 | 226篇 |
出版年
2023年 | 19篇 |
2022年 | 33篇 |
2021年 | 41篇 |
2020年 | 25篇 |
2019年 | 39篇 |
2018年 | 37篇 |
2017年 | 30篇 |
2016年 | 57篇 |
2015年 | 65篇 |
2014年 | 63篇 |
2013年 | 75篇 |
2012年 | 79篇 |
2011年 | 132篇 |
2010年 | 94篇 |
2009年 | 97篇 |
2008年 | 74篇 |
2007年 | 85篇 |
2006年 | 55篇 |
2005年 | 64篇 |
2004年 | 53篇 |
2003年 | 44篇 |
2002年 | 41篇 |
2001年 | 21篇 |
2000年 | 23篇 |
1999年 | 31篇 |
1998年 | 30篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 19篇 |
1994年 | 13篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 25篇 |
1990年 | 17篇 |
1989年 | 13篇 |
1988年 | 14篇 |
1987年 | 10篇 |
1986年 | 15篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1979年 | 6篇 |
1978年 | 7篇 |
1977年 | 8篇 |
1976年 | 11篇 |
1975年 | 10篇 |
1972年 | 6篇 |
1970年 | 6篇 |
1969年 | 10篇 |
排序方式: 共有1732条查询结果,搜索用时 0 毫秒
41.
Filip Tintchev Uwe Kuhlmann Hainer Wackerbarth Stefan Töpfl Volker Heinz Dietrich Knorr Peter Hildebrandt 《Food chemistry》2009
Non-thermal food preservation technology is based on the application of high pressures up to 600 MPa. Here we report a resonance Raman (RR) spectroscopic analysis of smoked salmon meat after high pressure processing. High quality spectra, which can be obtained even from packed salmon without spectral interference of the packing foil, allow determining pressure-dependent irreversible changes of the main RR-active components of salmon meat, astaxanthin and myoglobin/haemoglobin. High pressure-treatment causes a decrease of the relative RR intensities of astaxanthin as probed with 514 nm excitation which is in line with a slight attenuation of the originally intense red colour of the salmon meat. 413-nm excited RR spectra indicate a heterogeneous broadening of astaxanthin bands accompanied by the formation of deoxy-myoglobin or deoxy-haemoglobin. The results suggest that pressure-treatment facilitates the oxidative degradation of astaxanthin coupled to the reduction of metmyoglobin (methaemoglobin). 相似文献
42.
Uwe Matuschczyk Herbert Reil 《中华纸业》2005,26(4):31-32
对比了QualiFlex Q型,QualiFlex QX型、QualiFlex QV型三种聚胺酯材料靴套的性能,从而说明独特的QualiFlex靴套性能,使纸幅横幅水分的均匀性得到改善,纸幅出压榨干度得以维持恒定. 相似文献
43.
Mohamed M. Soumanou Uwe T. Bornscheuer Rolf D. Schmid 《Journal of the American Oil Chemists' Society》1998,75(6):703-710
Structured triacylglycerides with medium-chain fatty acids (caprylic acid) in sn1- and sn3-positions and a long-chain unsaturated fatty acid (oleic or linoleic acid) in the sn2-position of glycerol (MLM) were synthesized by lipase catalysis in a two-step process. First, pure 2-monoacylglycerides
(2-MG) were synthesized by alcoholysis of triacylglycerides (triolein, trilinolein, or peanut oil) in organic solvents with
1,3-regiospecific lipases (from Rhizomucor miehei, Rhizopus delemar, and Rhizopus javanicus). The 2-MG were purified by crystallization and obtained in up to 71.8% yield. These 2-MG were esterified in a second reaction
with caprylic acid in n-hexane to form almost pure MLM. For 2-MG obtained from peanut oil, the final product contained more than 90% caprylic acid
in the sn1- and sn3-positions, whereas the sn2-position was composed of 98.5% unsaturated long-chain fatty acids. Reaction conditions for both steps were optimized with
respect to source and immobilization of lipase, water activity, and solvent. 相似文献
44.
Stephan Bose-O'Reilly Gustav Drasch Saulo Rodrigues-Filho Beate Lettmeier Alexandra Maydl Uwe Siebert 《The Science of the total environment》2010,408(4):713-1000
Small scale miners use mercury to extract gold from ore in many countries. An environmental and health assessment was performed in Indonesia in two regions, Galangan in Central Kalimantan and Talawaan in Northern Sulawesi. The environmental assessment showed severe mercury contamination of the sediments, and increased mercury levels in local fish. For the health investigation 281 volunteers were recruited and examined by a standardized questionnaire, a neurological examination and neuro-psychological tests. A medical score was used consisting of significant factors of mercury intoxication. Mercury exposed workers showed typical symptoms of mercury intoxication, such as movement disorders (ataxia, tremor, dysdiadochokinesia, etc.). Blood, urine and hair samples were taken from any participant and analyzed for mercury. The mercury concentration in the biomonitors was high, partly extreme high in the working population, increased in the population living in the same habitat and low in the control group. By a standard protocol which includes a combination of threshold values of mercury in the biomonitors and a medical sum score the diagnosis of chronic mercury intoxication was made for highly burdened workers (amalgam smelters) in 55% in Sulawesi and in 62% in Kalimantan. Less exposed mineral processors and the general population in the mining areas were also intoxicated to a high percentage. 相似文献
45.
Stefano Panebianco Klara Berg Jean-Christophe David Mohamed Eid Uwe Filges Friedrich Gröschel Arnaud Guertin Alexander Yu Konobeyev Christian Latgé Sébastien Lemaire Sylvie Leray Alain Letourneau Markus Lüthy Franco Michel-Sendis Selene Scazzi Gediminas Stankunas Nicolas Thiollière Leonhard Tobler Luca Zanini 《Annals of Nuclear Energy》2009
The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment. 相似文献
46.
47.
Minds and Machines - In this paper, we show that reproducibility is a severe problem that concerns simulation models. The reproducibility problem challenges the concept of numerical solution and... 相似文献
48.
49.
50.
Williams CC Thang SH Hantke T Vogel U Seeberger PH Tsanaktsidis J Lepenies B 《ChemMedChem》2012,7(2):281-291
A series of well‐defined polymer–drug conjugates were prepared in order to modify the physical properties of a known cytotoxic drug, 7‐ethyl‐10‐hydroxycamptothecin (SN‐38), the active metabolite of irinotecan (CPT‐11). Reversible addition–fragmentation chain transfer (RAFT) polymerisation was used to covalently and site‐specifically append a defined N‐(2‐hydroxypropyl)methacrylamide (HPMA) polymer to SN‐38 using a graft‐from process. These poly‐HPMA–SN‐38 conjugates displayed excellent aqueous solubility and stability, whilst retaining the cytotoxic activity of the parent SN‐38. In vitro co‐culture assays containing both cancer and noncancer cell lines demonstrated the specificity of RAFT‐derived poly‐HPMA–SN‐38 conjugates for cancerous cells. The concept of post‐optimisation modification of small‐molecule drugs through a graft‐from polymer conjugation method is introduced. 相似文献