全文获取类型
收费全文 | 1667篇 |
免费 | 100篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 24篇 |
综合类 | 8篇 |
化学工业 | 625篇 |
金属工艺 | 35篇 |
机械仪表 | 21篇 |
建筑科学 | 47篇 |
矿业工程 | 4篇 |
能源动力 | 43篇 |
轻工业 | 310篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 84篇 |
一般工业技术 | 240篇 |
冶金工业 | 108篇 |
原子能技术 | 8篇 |
自动化技术 | 206篇 |
出版年
2024年 | 4篇 |
2023年 | 31篇 |
2022年 | 139篇 |
2021年 | 198篇 |
2020年 | 48篇 |
2019年 | 51篇 |
2018年 | 64篇 |
2017年 | 53篇 |
2016年 | 53篇 |
2015年 | 53篇 |
2014年 | 75篇 |
2013年 | 102篇 |
2012年 | 88篇 |
2011年 | 103篇 |
2010年 | 79篇 |
2009年 | 79篇 |
2008年 | 85篇 |
2007年 | 52篇 |
2006年 | 40篇 |
2005年 | 26篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 32篇 |
2001年 | 14篇 |
2000年 | 17篇 |
1999年 | 8篇 |
1998年 | 31篇 |
1997年 | 27篇 |
1996年 | 29篇 |
1995年 | 18篇 |
1994年 | 21篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 7篇 |
1990年 | 3篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 2篇 |
1982年 | 7篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有1770条查询结果,搜索用时 15 毫秒
101.
Monika Choudhary Jasvinder Kaur Sangha Kiran Grover 《Journal of the American Oil Chemists' Society》2014,91(2):179-206
The Indian dietary pattern has undergone major changes over the past 40 years. Many of these changes involve modification in dietary intake of fats and oils. In developing countries like India, vegetable oils are replacing animal fats because of the cost and health concerns. A wide range of vegetable oils are available in the market but the choice of healthy cooking oil has been a controversial subject since ideas keep on changing as new evidence accumulates. One of the factors holding back the increased use of value-added healthy oils in India is that most potential consumers are genuinely not aware of their health benefits. Edible oil consumption is primarily a community-driven phenomenon in India. The purpose of this paper is to highlight the current scenario of edible oils in India, their composition, health benefits, food applications, stability issues and future aspects as buying the right oil for health has become of great importance. 相似文献
102.
103.
104.
Fabian Heinemann Meike Gummich Manfred Radmacher Monika Fritz 《Materials science & engineering. C, Materials for biological applications》2011,31(2):99-105
Mineral growth in nacre and other CaCO3-containing biominerals is controlled by biopolymers. Water-soluble proteins were extracted from nacre of the sea snail Haliotis laevigata by dissolving the mineral phase with 6% acetic acid. The influence of this protein mixture on CaCO3 precipitation rates was investigated at different concentrations. A well-established assay for measuring the pH-value during CaCO3 precipitation with and without protein additives was extended by calculating maximum precipitation rates from the pH-values. It could be shown that precipitation rates are greatly influenced by the mixtures of water-soluble nacre proteins. At very low protein concentrations (0.02 μg/ml) a rate enhancement in comparison to the pure supersaturated calcium carbonate solution by a factor of 1.4 was observed. At higher protein concentrations, a strong inhibitory effect occurred, with total inhibition at concentrations of 1.0 μg/ml and higher. Two unspecific proteins (bovine serum albumin and lysozyme) showed little or no modification of precipitation rates. In vivo, the function of the strong inhibition of CaCO3 precipitation by nacre proteins at higher concentrations is presumably to prevent uncontrolled crystallization in the extrapallial fluid. The rate-enhancing capability of proteins at low concentrations may be explained by the presence of acidic and/or hydrophilic moieties. 相似文献
105.
Ann Heylighen Monika Rychtáriková Gerrit Vermeir 《Universal Access in the Information Society》2010,9(3):283-292
Inclusive design aims at objects and environments that are accessible, usable and comfortable for all people throughout their
entire lifespan. In architecture, this aim is usually associated with physical accessibility. Yet acoustic qualities may considerably
impact usability and comfort as well, especially in spaces for listening. This case study explores the notion of acoustic
comfort for all in the context of university education. One auditorium, situated in a historic building and subject to renovation
in the near future, is studied in detail: acoustic obstacles are identified in collaboration with user/experts and are measured
in situ; specific interventions are proposed in consultation with building professionals, technicians and conservation specialists
and are tested using dedicated acoustic simulation software. The study draws attention to the importance of acoustic comfort
for all and offers a first view of which solutions are possible and desirable and how these can be obtained. 相似文献
106.
Monika Haros Nils-Gunnar Carlsson Annette Almgren Marie Larsson-Alminger Ann-Sofie Sandberg Thomas Andlid 《International journal of food microbiology》2009,135(1):7-14
The growing awareness of the relationship between diet and health has led to an increasing demand for food products that support health above and beyond providing basic nutrition. Probiotics are live organisms present in foods, which yield health benefits related to their interactions with the gastrointestinal tract. Phytases are a subgroup of phosphatases that catalyse the desphosphorylation of phytate, which reduces its negative impact on mineral bioavailability, and generates lower inositol phosphates. The aims of this investigation were to (i) study the ability of the probiotic candidate Bifidobacterium pseudocatenulatum to degrade phytate in synthetic medium, to (ii) identify the lower inositol phosphates generated, to (iii) study its survival under conditions mimicking gastrointestinal passage and finally to (iv) assess adhesion of the bacteria to Caco-2 cells. The first steps of InsP6 degradation by B. pseudocatenulatum phytate-degrading enzyme/s were preferentially initiated at the DL-6-position and 5-position of the myo-inositol ring. It suggests that the main InsP6 degradation pathway by B. pseudocatenulatum by sequential removal of phosphate groups was D/L-Ins(1,2,3,4,5)P5 or D/L-Ins(1,2,3,4,6)P5; D/L-Ins(1,2,3,4)P4; to finally Ins(1,2,3)P3 and D/L-Ins(1,2,4)P3/D/L-Ins(1,3,4)P3. This human strain also showed a notable tolerance to bile as well as a selective adhesion capacity (adhesion to control surfaces was zero), to human intestinal Caco-2 cells comparable to the commercial probiotic B. lactis. The phytate-degrading activity constitutes a novel metabolic trait which could contribute to the improvement of mineral absorption in the intestine as a nutritional probiotic feature with potential trophic effect in human gut. 相似文献
107.
A new strategy to improve alkyd/acrylic compatibilization in waterborne hybrid dispersions 总被引:3,自引:0,他引:3
Monika Goikoetxea 《Polymer》2010,51(23):5313-5317
Grafting of alkyd resin to the acrylic polymer is needed to fully exploit the possibilities of these hybrids; but in the current technology, grafting is accompanied by an important reduction of the unsaturated groups of the alkyds, which adversely affects the curing of the film and its properties. A novel strategy that overcomes these limitations is presented. The strategy is based on the use of alkyd resin functionalized with methacrylic groups, that substantially improved the incorporation of the resin to the growing acrylic polymer chain, and the polymer particle homogeneity, without decreasing the degree of unsaturation in the alkyd resin. 相似文献
108.
Michele Leonardi Urszula Skomra Monika Agacka Anna Stochmal Katarzyna E. Ambryszewska Wieslaw Oleszek Guido Flamini Luisa Pistelli 《International Journal of Food Science & Technology》2013,48(8):1770-1774
Polish cultivars of hop (Humulus lupulus L.) are well known as aroma and bitter raw material in the brewing industry. To characterise four popular Polish hop cultivars, Lubelski (Lublin), Marynka, Sybilla and Iunga (also known as Junga), the essential oil profiles were determined by gas chromatography/flame ionisation detector (GC‐FID) and gas chromatography/chemical ionisation mass spectrometry (GC‐CIMS) and the alpha/beta acids amounts by high‐performance liquid chromatography/diode array detector (HPLC‐DAD) analysis. In addition, the multivariate statistical analysis of the volatile profiles was performed. The results obtained evidenced qualitative and quantitative differences between the four cultivars studied and the foreign hops described in the literature. Lubelski and Iunga showed the typical chemical profile of the fine‐aroma and high‐alpha cultivars, respectively. In Marynka and Sybilla, the average amounts of alpha acids were similar to the bitter hops, but with a volatile profile characteristics of the fine‐aroma and aroma cultivars respectively. 相似文献
109.
Redox-active films have been generated via electrochemical reduction in a solution containing palladium(II) acetate and [C60]fullerene, or derivatives of C60. The C60 derivatives include piperazine (piperazine-C60), pyrrolidine (CH3-pyr-C60), and a pyrrolidine salt, [(CH3)2-pyr-C60]+ attached to the fullerene unit. In these films, fullerene moieties are covalently bonded to palladium atoms to form a polymeric network. The polymer yields involving the piperazine and pyrrolidine derivatives of C60 are significantly lower than the yield of the C60/Pd film. The CH3-pyr-C60/Pd and [(CH3)2-pyr-C60]+/Pd films are electrochemically active in the negative potential region due to the reduction of the fullerene moiety. Reduction of the CH3-pyr-C60/Pd film is accompanied by the transport of supporting electrolyte cations from the solution into the film. In the first reduction step of the [(CH3)2-pyr-C60]+/Pd film, both cations and anions of the supporting electrolyte are involved. The piperazine-C60/Pd film exhibits electrochemical activity at both negative and positive potentials. In the negative potential region, reduction of the fullerene cage takes place. Oxidation of the piperazine moiety is responsible for the observed current in the positive potential range. Here, the oxidation process of this polymer is significantly influenced by the presence of metallic palladium particles in the film. 相似文献
110.
The aim of this article is to present results of an experimental campaign performed on a full-scale facility provided with a double-skin façade. The behaviour of this architectural concept is tested under controlled climatic conditions. A summer case is scrutinised under different configurations: variation of the airflow through the double-skin façade and different angle of the solar shading device. This paper describes the experimental conditions, as well the test facility and the tested façade element. The results show the temperatures of the test cell and the façade and how they depend on the climatic conditions and the sun-shading device blade angles. One objective of this research was to measure and provide extensive data set detailing air and surface temperatures on the double-skin façade, together with airflow rates and air velocities. The experiments are fully described so that the results can be used for the validation of numerical models dealing with ventilated double-skin façades with venetian sun-shading device. 相似文献