全文获取类型
收费全文 | 1529篇 |
免费 | 71篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 32篇 |
综合类 | 4篇 |
化学工业 | 324篇 |
金属工艺 | 87篇 |
机械仪表 | 174篇 |
建筑科学 | 11篇 |
能源动力 | 33篇 |
轻工业 | 124篇 |
水利工程 | 1篇 |
无线电 | 196篇 |
一般工业技术 | 274篇 |
冶金工业 | 167篇 |
原子能技术 | 34篇 |
自动化技术 | 146篇 |
出版年
2023年 | 14篇 |
2022年 | 9篇 |
2021年 | 46篇 |
2020年 | 20篇 |
2019年 | 32篇 |
2018年 | 31篇 |
2017年 | 48篇 |
2016年 | 44篇 |
2015年 | 24篇 |
2014年 | 44篇 |
2013年 | 85篇 |
2012年 | 93篇 |
2011年 | 95篇 |
2010年 | 59篇 |
2009年 | 70篇 |
2008年 | 71篇 |
2007年 | 60篇 |
2006年 | 71篇 |
2005年 | 58篇 |
2004年 | 41篇 |
2003年 | 51篇 |
2002年 | 51篇 |
2001年 | 33篇 |
2000年 | 46篇 |
1999年 | 44篇 |
1998年 | 64篇 |
1997年 | 49篇 |
1996年 | 55篇 |
1995年 | 27篇 |
1994年 | 26篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 9篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 10篇 |
1987年 | 20篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 8篇 |
1983年 | 4篇 |
1982年 | 6篇 |
1981年 | 5篇 |
1980年 | 4篇 |
1979年 | 4篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1968年 | 3篇 |
排序方式: 共有1607条查询结果,搜索用时 15 毫秒
51.
Sensory and Physicochemical Studies of Thermally Micronized Chickpea (Cicer arietinum) and Green Lentil (Lens culinaris) Flours as Binders in Low‐Fat Beef Burgers 下载免费PDF全文
Shiva Shariati‐Ievari Donna Ryland Andrea Edel Tiffany Nicholson Miyoung Suh Michel Aliani 《Journal of food science》2016,81(5):S1230-S1242
Pulses are known to be nutritious foods but are susceptible to oxidation due to the reaction of lipoxygenase (LOX) with linolenic and linoleic acids which can lead to off flavors caused by the formation of volatile organic compounds (VOCs). Infrared micronization at 130 and 150 °C was investigated as a heat treatment to determine its effect on LOX activity and VOCs of chickpea and green lentil flour. The pulse flours were added to low‐fat beef burgers at 6% and measured for consumer acceptability and physicochemical properties. Micronization at 130 °C significantly decreased LOX activity for both flours. The lentil flour micronized at 150 °C showed a further significant decrease in LOX activity similar to that of the chickpea flour at 150 °C. The lowering of VOCs was accomplished more successfully with micronization at 130 °C for chickpea flour while micronization at 150 °C for the green lentil flour was more effective. Micronization minimally affected the characteristic fatty acid content in each flour but significantly increased omega‐3 and n‐6 fatty acids at 150 °C in burgers with lentil and chickpea flours, respectively. Burgers with green lentil flour micronized at 130 and 150 °C, and chickpea flour micronized at 150 °C were positively associated with acceptability. Micronization did not affect the shear force and cooking losses of the burgers made with both flours. Formulation of low‐fat beef burgers containing 6% micronized gluten‐free binder made from lentil and chickpea flour is possible based on favorable results for physicochemical properties and consumer acceptability. 相似文献
52.
To prepare self-emulsificable urethane acrylate resin, PEG-modified urethane acrylates (PMUA), containing polyoxyethylene chains as a terminal hydrophilic group and urethane acrylate anionomers (UAA) incorporated dimethylolpropionic acid (DMPA) as a pendant hydrophilic one were synthesized. For PMUA emulsions, the reaction molar ratio of PEG to 2-hydroxyethyl methacrylate (2-HEMA) significantly influenced the viscosity and droplet size of the emulsion and tensile strength of cured films. These emulsions were stable to pH change and the addition of electrolyte, but coagulated around 60°C. In the case of UAA, emulsions, however, were very stable to elevated temperatures and coagulated in adding even a little bit of electrolyte. For soap-free emulsions of the mixture of PMUA and UAA, emulsion stabilities of these mixtures against temperature, pH change, the addition of electrolyte, and the rate of shear and freeze–thaw increased synergetically. Additionally, the tensile strength of cured films was also improved. © 1996 John Wiley & Sons, Inc. 相似文献
53.
A new processing system for the extrusion of microcellular polymer sheets is presented. Specifically, the detailed design of a shaping and cell growth control system is discussed in the context of an overall extrusion system design with particular emphasis on the system level functional requirements of cell nucleation, cell growth, and shaping. The principle of the basic extrusion system design is to shape a nucleated polymer/gas solution flow under pressure and accurate temperature control. In this way, the initial cell growth is controlled so as to prevent degradation of the nucleated cell density during shaping. Two foaming die designs for satisfying the initial shaping and cell growth requirements are presented. Critical experiments are then presented which verified the concept of shaping a nucleated polymer/gas solution. Moreover, these experiments demonstrated the feasibility of the overall microcellular polymer sheet extrusion system design. 相似文献
54.
In the current study, we investigated the biotransformation of monosodium glutamate (MSG) to gamma-aminobutyric acid (GABA) by the growing and resting cells from an isolated bacterial strain, Lactobacillus brevis. This strain is a high GABA-producing strain that was identified and isolated from natural kimchi. We gathered the experiment results by design of response surface methodology (RSM) for optimum condition for GABA production and results indicated the optimum culture temperature (35°C) and culture time (58 h). Using resting cells from the same culture batch in the substrate-containing buffer, approximately 3.98 g/l of GABA was produced at a conversion rate of 65.6%. GABA-treated mice showed significantly increased sleep duration compared to that of a control group (p < 0.05) in the pentobarbital-induced sleep test using a hypnotic dose. These results suggest that biotransformed GABA could potentially be used a novel nutraceutical supplement for sleep. 相似文献
55.
Young Cheol Ryu Tae Gun Kim Guem-Seok Seo Jin Hwan Park Cha Soo Suh Seong-Soo Park Seong-Soo Hong Gun Dae Lee 《Journal of Industrial and Engineering Chemistry》2008,14(2):213-218
The TiO2/substrate pearlescent pigments were prepared by the hydrolysis of TiOCl2 on the substrate followed by a calcinations process. The natural mica (muscovite), synthetic mica (fluorophlogopite) and -alumina flake were selected as the substrates for pearlescent pigments. The effect of substrate on the anatase to rutile (A–R) phase transformation of TiO2 was studied. The A–R phase transformation of TiO2 during the preparation of pearlescent pigments and their proportion in the TiO2 layer have been analyzed by XRD measurements. The phase compositions of TiO2 layer in each pearlescent pigment are quite different depending on the substrates. The TiO2 layer deposited on -alumina has higher rutile fraction than those on the natural and synthetic mica. The XPS analysis showed that the cations originally present in the substrates diffused into the TiO2 layer. The TiO2 layer deposited on -alumina contains Al, while those on the natural and synthetic mica substrates contain Si and K in addition to Al. The metal cations diffusing from the substrate into TiO2 layer might retard the A–R phase transformation of TiO2. The suppressing effect on the A–R transformation of TiO2 by mixed cations seems to be much stronger than that of single cation, resulting in relatively higher rutile fraction in the case of TiO2 layer deposited on -alumina. 相似文献
56.
57.
58.
Hye-Ju Jung Ji-Sook Hong Jeong-Kwon Suh 《Korean Journal of Chemical Engineering》2011,28(9):1882-1888
This study aimed to find a way to remove organic pollutants, phenol and humic acid in aqueous solutions using TiO2 spherical activated carbon (Ti-SPAC). The Ti-SPAC was manufactured by resin ion-exchange and a heating process. This method was very effective not only in creating TiO2 on the surface of the supports evenly, but also in making activated carbon that has highly-developed micro pores. To estimate whether Ti-SPAC has the proper features as a photocatalyst and adsorbent, it was examined in detail by X-ray patterns, SEM image, EDXS, BET, EPMA. The results proved that Ti-SPAC is a very useful material for treating wastewater by photocatalysis and absorption. 相似文献
59.
Suh K.S. Damon D. Tanaka J. 《Dielectrics and Electrical Insulation, IEEE Transactions on》1995,2(1):1-11
Measurements of thermally stimulated currents were made on ionomer/polyethylene blends. The objective of this work was to study space charge formation in these materials. Two ionomers were compared; both ionomers contained methacrylic acid, neutralized by zinc in one and by sodium in the other. A large current peak centered near 60°C was observed in all blends and associated with the motion of space charges injected into the blends during poling. All blends accumulated large negative space charge concentrations. The approach to the equilibrium space charge distribution (negative and spatially uniform in all blends) is much more rapid in the blends containing the sodium ionomer than in the blends containing the zinc ionomer 相似文献
60.
Suh K.S. Hyung Jae Lee Dai Soo Lee Chang Gyun Kang 《Dielectrics and Electrical Insulation, IEEE Transactions on》1995,2(3):460-466
The formation of space charge in polycarbonate (PC)/poly (styrene-co-acrylonitrile) (SAN) blends containing poly (ϵ-caprolactone) (PCL) as a compatibilizer for improving the miscibility, has been studied by measuring spatial charge distributions. It is found that the miscibility of PC/SAN blends is improved as the PCL content increases. The amount of charge accumulated in the blends decreases when the PCL content increases to 15% by weight and then increases when the PCL content is >15% wt. The decrease of charge at the PCL content <15% wt was attributed to the combined effects of changes in conductivities and the molecular interactions at the domain interfaces. The increase of charge at the PCL content >15% wt was attributed to the trapping of charge at the amorphous and crystalline phases of PC and PCL 相似文献