全文获取类型
收费全文 | 248篇 |
免费 | 16篇 |
专业分类
化学工业 | 80篇 |
金属工艺 | 3篇 |
机械仪表 | 1篇 |
建筑科学 | 2篇 |
能源动力 | 18篇 |
轻工业 | 47篇 |
水利工程 | 2篇 |
石油天然气 | 2篇 |
无线电 | 16篇 |
一般工业技术 | 66篇 |
冶金工业 | 5篇 |
原子能技术 | 3篇 |
自动化技术 | 19篇 |
出版年
2023年 | 15篇 |
2022年 | 22篇 |
2021年 | 18篇 |
2020年 | 14篇 |
2019年 | 8篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 11篇 |
2015年 | 14篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 5篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 5篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 1篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1989年 | 3篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有264条查询结果,搜索用时 437 毫秒
131.
132.
We report herein that copolymers containing glycidyl methacrylate (GMA) with acrylonitrile (AN) units were synthesized by free radical solution polymerization technique using benzoyl peroxide as a free radical initiator and 1,4‐dioxane as a solvent at 70°C. The copolymerization behavior was studied in different composition with the mole fractions of GMA ranging from 0.20 to 0.80 in the feed and under 10% copolymer conversion. The copolymers were characterized by Fourier transform infrared spectroscopy, gel permeation chromatography, and scanning electron microscopy techniques. The thermogravimetric analysis of the copolymers suggest an overall decrease in the thermal stability of the copolymer with decreasing content of GMA in the copolymers. Thermal decomposition activation energies are calculated by the Ozawa method. The copolymer composition was determined by the application of elemental analysis method. The monomer reactivity ratios were estimated by the application of conventional linearization methods, such as Kelen–Tudos (K‐T), Fineman–Ross (F‐R) methods, and a nonlinear error in variable model (RREVM) method using a computer program, and all results were discussed and compared with the literature. 相似文献
133.
Hilal Yılmaz Celebioglu Deniz Cekmecelioglu Muhammet Dervisoglu Talip Kahyaoglu 《International Journal of Food Science & Technology》2012,47(12):2597-2605
Hemicellulose is a valuable component of agro‐food industrial wastes and used in various areas such as drug manufacture and food industry for encapsulation and emulsification. In this study, effects of raw material type, particle size, and extraction conditions (alkaline concentration, temperature, time) and methods (direct alkaline extraction, alkaline extraction after component removal and acidic extraction method) on hemicellulose yields were investigated. Sugar beet pulp and corn wastes were used as raw material. The alkaline method resulted in 40.2% pure extracts, while the acidic method gave only 27.4% purity in the same extraction conditions. The optimal extraction conditions were found as 30 °C temperature, 10% alkali (NaOH) and 24 h time (64.3%). It was also observed that removal of constituents such as fat, protein, starch and soluble sugar increased the purity of hemicellulose from 40.2% to 58.2% at the same conditions. The results indicated that using both low alkaline concentration and low temperature allows to recover higher‐quality extracts. 相似文献
134.
Hilal Anwer Mustafa Al-Wesabi Fahd N. Hamza Manar Ahmed Medani Mohammed Mahmood Khalid Mahzari Mohammad 《Pattern Analysis & Applications》2022,25(1):47-62
Pattern Analysis and Applications - Due to the rapid increase in exchange of text information via internet network, the security and the reliability of the digital content has become a major... 相似文献
135.
Hilal Zeynep Sahin Mehtap Celik Seda Kotay 《Food Additives and Contaminants: Part B: Surveillance Communications》2016,9(2):152-158
This study aims to detect aflatoxins (AFs) in dairy cow feed, milk and milk products using a high-performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) method. All the validation parameters met the method performance criteria of the European Union. The samples comprised 76 dairy cow feeds and 205 milk and milk products (including yoghurt and yoghurt-based beverage, ayran). AFs were present in 26.3% of the feed samples. Two feed samples exceeded the maximum limit (ML) of 5 µg kg?1 for AFB1 as established by the EU. Nineteen milk samples (21.1%) contained aflatoxin M1 (AFM1) of which three exceeded the EU ML of 0.05 µg l?1. In addition, only two yoghurt samples and one ayran sample contained AFM1, but the levels were lower than the EU ML. 相似文献
136.
This study revealed the effect of cam setting and number of yarn ply on air permeability and bursting strength of weft-knitted fabrics from glass yarn. Change in cam setting from loose to tight level increased fiber content, and stitch-density; while it decreased loop length. Fabrics with 3-ply yarn exhibited higher fiber content; lower stitch-density; and longer loop length than fabrics with 2-ply yarn. Cam setting showed more pronounced effect on physical properties of fabric than number of yarn ply. Fabrics knitted via tight cam setting level exhibited less air permeability, and higher bursting strength than fabrics knitted via loose cam setting. Fabrics from 3-ply yarn showed less air permeability and higher bursting strength than fabrics from 2-ply yarn. Loop length, wale density, and fiber content were determined as the most effective physical properties on permeability and bursting strength. A negative correlation was detected between air permeability and bursting strength. 相似文献
137.
Cho Z. H. Hong K. S. Ra J. B. Lee S. Y. Hilal S. K. Correll J. 《IEEE transactions on nuclear science》1981,28(1):94-98
A new sampling scheme applicable to the circular ring geometry positron camera is described. The new scheme employs Dichotomic-Ring (two half rings) with linearmotion which allows parallel or fan mode sampling with any desired degree of sampling interval. The parallel and fan data sets obtained by dichotomic motion provide d/4 and d/2 samplings where d is the detector to detector spacing. Computer simulations were made which confirmed the expected performances and results are compared with other conventional schemes such as wobbling and d/2 angular motion sampling schemes for a ring geometry positron camera. 相似文献
138.
Dogan HB Kuleasan H Cakir I Halkman AK 《International journal of food microbiology》2003,87(1-2):29-34
To improve enrichment and isolation of Escherichia coli O157:H7, this study evaluated increased incubation temperature and cefixime-tellurite (CT) on five strains of each of the following bacteria, E. coli, Hafnia alvei, Enterobacter spp., Citrobacter freundii and E. coli O157:H7, and two strains of E. coli O157:nH7. These were grown in pure culture in LST broth with varying cefixime-tellurite concentrations. A range of incubation temperatures from 37 to 46 degrees C was investigated for the inhibition of cohabitant microorganisms. Minced beef, spiked with E. coli O157:H7 and cohabitant microorganisms was investigated. Increased incubation temperature (42 degrees C) and treatment with half of the prescribed amount of cefixime-tellurite by BAM for SMAC agar in enrichment step were the most effective in selectively growing E. coli O157:H7. The results show that E. coli O157:H7 is more resistant to these two conditions than the other cohabitant bacteria. 相似文献
139.
Chafekar SM Malda H Merkx M Meijer EW Viertl D Lashuel HA Baas F Scheper W 《Chembiochem : a European journal of chemical biology》2007,8(15):1857-1864
The key pathogenic event in the onset of Alzheimer's disease (AD) is the aggregation of beta-amyloid (Abeta) peptides into toxic aggregates. Molecules that interfere with this process might act as therapeutic agents for the treatment of AD. The amino acid residues 16-20 (KLVFF) are known to be essential for the aggregation of Abeta. In this study, we have used a first-generation dendrimer as a scaffold for the multivalent display of the KLVFF peptide. The effect of four KLVFF peptides attached to the dendrimer (K(4)) on Abeta aggregation was compared to the effect of monomeric KLVFF (K(1)). Our data show that K(4) very effectively inhibits the aggregation of low-molecular-weight and protofibrillar Abeta(1-42) into fibrils, in a concentration-dependent manner, and much more potently than K(1). Moreover, we show that K(4) can lead to the disassembly of existing aggregates. Our data lead us to propose that conjugates that bear multiple copies of KLVFF might be useful as therapeutic agents for the treatment of Alzheimer's disease. 相似文献
140.
Hilal Gurler Yi Yu Jacqueline Choi Andre A. Kajdacsy-Balla Maria V. Barbolina 《International journal of molecular sciences》2015,16(2):3419-3433
Epithelial ovarian carcinoma is the deadliest gynecologic malignancy. One reason underlying treatment failure is resistance to paclitaxel. Expression of the microtubule associated protein tau has recently been proposed as a predictor of response to paclitaxel in ovarian carcinoma patients. Expression of tau was probed using immunohistochemistry in 312 specimens of primary, and 40 specimens of metastatic, ovarian carcinoma. Serous epithelial ovarian carcinoma cell line models were used to determine the expression of tau by Western blot and immunofluorescence staining. Subcellular fractionation and Western blot were employed to examine nuclear and cytoplasmic localization of tau. Gene silencing and clonogenic assays were used to evaluate paclitaxel response. Tau was expressed in 44% of all tested cases. Among the primary serous epithelial ovarian carcinoma cases, 46% were tau-positive. Among the metastatic serous epithelial ovarian carcinomas, 63% were tau-positive. Cell culture experiments demonstrated that tau was expressed in multiple isoforms. Three-dimensional collagen I matrix culture conditions resulted in up-regulation of tau protein. Silencing of tau with specific siRNAs in a combination with three-dimensional culture conditions led to a significant decrease of the clonogenic ability of cells treated with paclitaxel. The data suggest that reduction of tau expression may sensitize ovarian carcinoma to the paclitaxel treatment. 相似文献