全文获取类型
收费全文 | 1039篇 |
免费 | 37篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 16篇 |
综合类 | 3篇 |
化学工业 | 237篇 |
金属工艺 | 22篇 |
机械仪表 | 40篇 |
建筑科学 | 28篇 |
能源动力 | 44篇 |
轻工业 | 93篇 |
水利工程 | 4篇 |
石油天然气 | 19篇 |
无线电 | 110篇 |
一般工业技术 | 221篇 |
冶金工业 | 37篇 |
原子能技术 | 2篇 |
自动化技术 | 203篇 |
出版年
2024年 | 6篇 |
2023年 | 15篇 |
2022年 | 46篇 |
2021年 | 56篇 |
2020年 | 35篇 |
2019年 | 40篇 |
2018年 | 35篇 |
2017年 | 38篇 |
2016年 | 30篇 |
2015年 | 34篇 |
2014年 | 29篇 |
2013年 | 78篇 |
2012年 | 57篇 |
2011年 | 82篇 |
2010年 | 54篇 |
2009年 | 56篇 |
2008年 | 46篇 |
2007年 | 31篇 |
2006年 | 38篇 |
2005年 | 23篇 |
2004年 | 30篇 |
2003年 | 18篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 12篇 |
1999年 | 8篇 |
1998年 | 17篇 |
1997年 | 15篇 |
1996年 | 10篇 |
1995年 | 9篇 |
1994年 | 8篇 |
1993年 | 10篇 |
1992年 | 8篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 15篇 |
1988年 | 8篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 2篇 |
1976年 | 3篇 |
1974年 | 3篇 |
1972年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
排序方式: 共有1079条查询结果,搜索用时 0 毫秒
31.
The wood carbonization in Tunisia consists essentially of traditional activity using charcoaling stacks and pits characterized by high atmospheric pollution and poor energy conversion. Indeed, 70% of the initial mass of anhydrous wood are found in the vapor as aerosols, polluting and toxic gases and complex condensable organic compounds that can cause a substantial pollution of air, ground and water. Several processes of treatment and energy valorization of such effluents were proposed, but the incineration remains at present the most promising technique of depollution. The results show that the incineration, at about 1000°C, of wood carbonization smokes allows the destruction of 99% of the mass of pollutants except CO2 and the reduction of polluting gas emission. The possible valorization of the smoke’s energy in the exit of the incinerator enhances the thermal efficiency of the process. 相似文献
32.
Ingudam Shakuntala Samir Das Sandeep Ghatak Rajkumari Sanjukta Kekungu-U Puro 《Food Biotechnology》2019,33(3):237-250
Listeria monocytogenes is a pathogenic microorganism infects man mostly through food. A total of 1615 samples of foods of animal origin and water were collected from retail meat shops of North-Eastern India and processed. Sixty-three (3.9%) samples were positive for L. monocytogenes. Animal origin foods showing the highest prevalence was chevon (9.8%) followed by beef (8.9%), chicken (8.5%), pork (2.8%) and milk (1.8%). The prevalence rate in water from retail meat shops was 10%. Recovered L. monocytogenes were distributed into 3 serogroups, of which 74.6% fit in to 1/2a, 3a serogroup, 17.5% to 1/2b, 3b and 7.9 % to 4b, 4d, 4e serogroups. Thirty-five isolates out of 63 possessed all the tested four virulence genes. RAPD- and ERIC -PCR based analyses jointly revealed a discriminative genetic profile for the L. monocytogenes. On the whole, the occurrence of L. monocytogenes in foods of animal origin of North Eastern India displays public health hazard. 相似文献
33.
Jasmin Kuhn Philipp M. Klein Nader Al Danaf Joel Z. Nordin Sren Reinhard Dominik M. Loy Miriam Hhn Samir El Andaloussi Don C. Lamb Ernst Wagner Yoshitsugu Aoki Taavi Lehto Ulrich Lchelt 《Advanced functional materials》2019,29(48)
Phosphorodiamidate morpholino oligomers (PMOs) are oligonucleotide analogs that can be used for therapeutic modulation of pre‐mRNA splicing. Similar to other classes of nucleic acid‐based therapeutics, PMOs require delivery systems for efficient transport to the intracellular target sites. Here, artificial peptides based on the oligo(ethylenamino) acid succinyl‐tetraethylenpentamine (Stp), hydrophobic modifications, and an azide group are presented, which are used for strain‐promoted azide‐alkyne cycloaddition conjugation with splice‐switching PMOs. By systematically varying the lead structure and formulation, it is determined that the type of contained fatty acid and supramolecular assembly have a critical impact on the delivery efficacy. A compound containing linolenic acid with three cis double bonds exhibits the highest splice‐switching activity and significantly increases functional protein expression in pLuc/705 reporter cells in vitro and after local administration in vivo. Structural and mechanistic studies reveal that the lipopeptide PMO conjugates form nanoparticles, which accelerate cellular uptake and that the content of unsaturated fatty acids enhances endosomal escape. In an in vitro Duchenne muscular dystrophy exon skipping model using H2K‐mdx52 dystrophic skeletal myotubes, the highly potent PMO conjugates mediate significant splice‐switching at very low nanomolar concentrations. The presented aminoethylene‐lipopeptides are thus a promising platform for the generation of PMO‐therapeutics with a favorable activity/toxicity profile. 相似文献
34.
35.
L. Nrgaard M.T. Hahn L.B. Knudsen I.A. Farhat S.B. Engelsen 《International Dairy Journal》2005,15(12):1261-1270
The use of near-infrared (NIR) and Fourier transform Raman spectroscopy for quantification of crystalline lactose content in whey permeate powder was investigated using chemometric methods. Sample sets consisting of binary mixtures of crystalline (50.0–98.0%) and amorphous lactose and process whey permeate samples with different amounts of crystalline lactose (75.0–95.5%) added were analyzed. The best results for quantification of crystallinity were obtained by partial least squares (PLS) regression on NIR data in five selected intervals in the range 1100–2498 nm. Data analysis on the total sample set of 35 samples yielded a prediction error (root mean square error of cross validation) of 0.627%. The corresponding result for Raman spectroscopy in the range 3500–100 cm−1 was 1.62%. Interval-PLS regression was used for the selection of relevant spectral intervals as well as for improving the spectral interpretation. Alternating regression was used to show that the amorphous lactose preparation contained only a negligible amount of crystalline lactose. 相似文献
36.
Samir Ananou Margarita Garriga Anna Jofré Teresa Aymerich Antonio Gálvez Mercedes Maqueda Manuel Martínez-Bueno Eva Valdivia 《Meat science》2010
The single and combined effects of enterocin AS-48 and high hydrostatic pressure (HHP) on Listeria monocytogenes, Salmonellaenterica, and Staphylococcus aureus was investigated in fuet (a low acid fermented sausage) during ripening and storage at 7 °C or at room temperature. AS-48 (148 AU g−1) caused a drastic 5.5 log cfu g−1 decrease in L. monocytogenes (P < 0.001) and a significant (P < 0.01) inhibition (1.79 logs) for Salmonella at the end of ripening (10 d). After pressurization (400 MPa) and storage Listeria counts remained below 5 cfu g−1 in all fuets containing AS-48 (pressurized or not). HHP alone had no anti-Listeria effect. HHP treatment significantly reduced Salmonella counts, with lowest levels in pressurized fuets with AS-48. S. aureus showed similar growth for all treatments and storage conditions. These results indicate that AS-48 can be applied alone to control L. monocytogenes and combined with HHP treatment to control Salmonella in fuets. 相似文献
37.
Amandine Carrër Jean‐Daniel Brion Mouad Alami Samir Messaoudi 《Advanced Synthesis \u0026amp; Catalysis》2014,356(18):3821-3830
A straightforward assisted tandem palladium(II)‐ and palladium(0)‐catalyzed direct C‐3 and N‐4 arylation of quinoxalin‐2(1 H)‐ones with boronic acids and aryl halides in water as safe and cheap solvent is reported. This environmentally friendly catalytic protocol is compatible with a wide range of functional groups and allows construction of various biologically important quinoxalin‐2(1 H)‐one backbones.
38.
Sodium alginate was graft-copolymerized with ethyl acrylate using ceric ammonium nitrate as an initiator. In order to optimize the conditions for grafting, the concentrations of nitric acid, initiator and monomer together with temperature, time and amount of substrate were varied. The kinetic scheme of free radical graft copolymerization has been proposed and the equations relating the values of rate of polymerization, rate of graft copolymerization and rate of homopolymerization are also suggested. The experimental results agree very well with the proposed kinetic scheme. 相似文献
39.
Pierrick Paillot Wissam Farhat Frédéric Becquart Ruben Vera Corinne Jegat Mohamed Taha 《应用聚合物科学杂志》2019,136(30):47799
The use of silver as an antimicrobial agent has exhibited great interest in recent years. In this research, poly(ethylene-co-vinyl alcohol) (EVOH)–silver acetate-based antimicrobial materials were prepared at high temperature by reactive extrusion. Silver acetates were used without pretreatment. The thermal reaction of silver acetates in the material and their effect on the thermal and mechanical properties of the polymer were investigated as a function of their concentration. The dispersed silver acetate salts within the EVOH matrix have displayed a significant thermal reaction. This reaction of metallic salts was partial when the extrusion temperature was fixed at 190 °C and completed at 230 °C. The antimicrobial agents also had significant effects on the properties of the matrix. Reductions of glass temperature and storage modulus were observed by the analyses. All the variations were dependent on both the concentration of silver acetate and the extrusion parameters. The antimicrobial activity was studied and demonstrated a promising potential to create an antimicrobial material in a one-step solvent free extrusion method. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47799. 相似文献