全文获取类型
收费全文 | 795篇 |
免费 | 29篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 6篇 |
综合类 | 1篇 |
化学工业 | 221篇 |
金属工艺 | 17篇 |
机械仪表 | 11篇 |
建筑科学 | 11篇 |
能源动力 | 36篇 |
轻工业 | 109篇 |
水利工程 | 4篇 |
石油天然气 | 2篇 |
无线电 | 101篇 |
一般工业技术 | 147篇 |
冶金工业 | 79篇 |
原子能技术 | 8篇 |
自动化技术 | 75篇 |
出版年
2024年 | 2篇 |
2023年 | 17篇 |
2022年 | 34篇 |
2021年 | 34篇 |
2020年 | 33篇 |
2019年 | 26篇 |
2018年 | 55篇 |
2017年 | 38篇 |
2016年 | 30篇 |
2015年 | 15篇 |
2014年 | 29篇 |
2013年 | 77篇 |
2012年 | 28篇 |
2011年 | 40篇 |
2010年 | 38篇 |
2009年 | 36篇 |
2008年 | 39篇 |
2007年 | 28篇 |
2006年 | 27篇 |
2005年 | 15篇 |
2004年 | 13篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 7篇 |
2000年 | 4篇 |
1999年 | 6篇 |
1998年 | 27篇 |
1997年 | 27篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有828条查询结果,搜索用时 15 毫秒
21.
Effect of High-Pressure Processing on Physical, Biochemical, and Microbiological Characteristics of Black Tiger Shrimp (Penaeus monodon) 总被引:1,自引:0,他引:1
Barjinder Pal Kaur Neelima Kaushik P. Srinivasa Rao O. P. Chauhan 《Food and Bioprocess Technology》2013,6(6):1390-1400
The effect of high-pressure processing on quality and shelf life of black tiger shrimp was studied. Shrimp was high-pressure processed at selected pressure levels of 100, 270, and 435 MPa for 5 min at room temperature (25?±?2 °C). Changes in physical, biochemical, and microbiological characteristics after processing and during subsequent chilled storage were examined for 35 days. After processing significant (P?<?0.05) increase in moisture content and parallel reduction in protein content was observed. No significant changes were observed in TVB-N and TMA-N levels of shrimp after processing; however, these significantly increased with storage. Whiteness index increased with pressure intensity imparting brighter and mildly cooked appearance. Pressure-induced hardening effect was observed, which showed decreasing trend during storage. The treated samples maintained lower viable counts throughout the storage, thus having better microbial quality than untreated sample. Shelf life was extended to 15 days in shrimp treated at 435 MPa compared with 5 days in untreated sample. Pressure treatment of 435 MPa was found to be most effective in preserving the quality and extending the shelf life of black tiger shrimp. 相似文献
22.
Shima Shayanfar OP Chauhan Stefan Toepfl Volker Heinz 《International Journal of Food Science & Technology》2013,48(6):1289-1295
The combination of pulsed electric fields (PEF) and texturizing and antifreeze agents on quality retention of defrosted potato strips were studied. Potato strips (10 mm thickness, 100 g) were placed in different solutions (1% w/v) of CaCl2, glycerol, trehalose as well as NaCl and sucrose, treated with PEF (0.5 kV cm?1, 100 pulses, 4 Hz). Then, all the samples were soaked in the same solutions for 10 min. After draining, samples were packed into polypropylene pouches and stored at ?18 °C for 12 h. Samples were thawed out at room temperature (20 °C) in 3 h. Untreated controls and PEF treated control samples were also frozen and thawed in similar conditions. To assess the potato strip quality, the thawed samples were analysed for moisture content, weight loss, firmness and colour attributes. The results indicate that PEF treatment by itself is not a suitable pre‐treatment method for frozen potato strips and should be assisted by CaCl2 and trehalose treatment to prevent softening after defrosting. Firmness analyses determined that application of PEF alone results in 2.38 N. However, PEF in combination with CaCl2 and trehalose result in 2.97 N and 2.99 N, respectively, which are both significantly firmer than the samples solely treated with PEF. CaCl2 and trehalose were effective in not only maintaining the structural integrity of the cells, but also retaining colour attributes. The L* value was found to be higher (P < 0.05) in CaCl2 and trehalose treated samples (58.95 and 57.21, respectively), as compared to PEF treated samples (53.97) denoting a darker colour. Application of CaCl2 and trehalsoe in combination with PEF also resulted in significantly less weight loss after thawing. 相似文献
23.
Gray cotton fabric shows hydrophobic characteristics due to presence of non-cellulosic impurities in outermost layers of cotton fiber. In the present study, atmospheric pressure plasma treatment for the removal of the non-cellulosic impurities from gray cotton fabric is investigated. Gray cotton fabric is treated with air dielectric barrier discharge at different time interval, and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Different species formed in plasma are identified using optical emission spectroscopy. The results clearly show that the plasma treatment improves wettability of gray cotton which is due to the removal of non-cellulosic impurities and due to the formation of polar carboxylate group. Removal of wax after plasma treatment is clearly reflected in ATR-FTIR spectra as disappearance of symmetric and asymmetric stretching of alkyl group at 2852.24 and 2917.81?cm?1. Further, ATR-FTIR spectroscopy provides a fast and satisfactory assessment of removal of impurities from cotton surface when untreated and plasma-treated cotton fabric is exposed to HCl vapor and subsequently spectra are collected. We observed a strong carboxyl peak is induced at 1749?cm?1 in case of untreated cotton. While for plasma-treated cotton fabrics substantial variation in the intensity of 1641 and 1749?cm?1 peak is observed with increase in plasma treatment time. The morphological changes observed by SEM are in accordance with ATR-FTIR results. The results are compared with conventionally (alkaline scouring) treated cotton fabric. The study reveals that atmospheric pressure plasma has potential to become dry and environment friendly process to improve wettability of gray cotton fabric. 相似文献
24.
2-Acetyl-1-pyrroline: A key aroma component of aromatic rice and other food products 总被引:1,自引:0,他引:1
2-Acetyl-1-pyrroline is an aroma compound that gives aromatic rice its characteristic flavor. This compound either is present naturally in various food sources or is generated during certain processing methods, as reported in a number of studies. This review focuses on several sources of 2-acetyl-1-pyrroline, including aromatic rice, and the factors, including chemical and genetic parameters, affecting the formation of 2-acetyl-1-pyrroline. Extensive work has been conducted on the agricultural parameters, postharvest processing, storage, and cooking methods, influencing the concentrations of 2-acetyl-1-pyrroline in different food commodities. This article is an attempt to emphasize the importance of this compound in the food industry as a major aroma compound. 相似文献
25.
26.
Priti Tagde Agnieszka Najda Kalpana Nagpal Giriraj T. Kulkarni Muddaser Shah Obaid Ullah Sebastian Balant Md. Habibur Rahman 《International journal of molecular sciences》2022,23(5)
Breast cancer is one of the most common types of cancer among women globally. It is caused by mutations in the estrogen/progesterone receptors and conventional treatment methods are commonly utilized. About 70–80 percent of individuals with the early-stage non-metastatic disease may be cured. Conventional treatment is far less than the optimal ratio, as demonstrated through the high mortality rate of women with this cancer. However, conventional treatment methods like surgery, radiotherapy, and chemotherapy are not as effective as expected and lead to concerns about low bioavailability, low cellular uptake, emerging resistance, and adverse toxicities. A nanomedicine-based approach is a promising alternative for breast cancer treatment. The present era is witnessing rapid advancements in nanomedicine as a platform for investigating novel therapeutic applications and modern intelligent healthcare management strategies. This paper focuses on nanomedicine-based therapeutic interventions that are becoming more widely accepted for improving treatment effectiveness and reducing undesired side effects in breast cancer patients. By evaluating the state-of-the-art tools and taking the challenges involved into consideration, various aspects of the proposed nano-enabled therapeutic approaches have been discussed in this review. 相似文献
27.
Stabilization of foams and emulsions by mixtures of surface active food-grade particles and proteins
Surface active biopolymers such as proteins can form films with particularly high interfacial elasticities and viscosities and these molecules are widely exploited as foaming and emulsifying agents in foods. Solid particles of the correct size and wetting characteristics can also be extremely effective stabilizers of foams and emulsions, although the underlying mechanism of stabilization is somewhat different. Relatively little is known about what happens when both surface active polymers and surface active particles are present together. This work presents recent findings on the effects of mixtures of proteins plus novel food-compatible surface active particles. The proteins include caseins and whey proteins. The surface active particles prepared include cellulose + ethyl cellulose complexes, hydrophobically-modified starch granule particles and stable (non-spreading) protein-stabilized oil droplets. Interfacial shear rheology of adsorbed films was measured via a biconical bob apparatus and interfacial dilatational rheology was measured via a Langmuir trough type apparatus. The corresponding stability of bubbles to coalescence and disproportionation was assessed in separate experiments. Stability of oil-in-water emulsions was assessed via measurement of particle size distributions as function of time and visual assessment of the tendency to creaming and oiling off. In general, it is shown that the surface active particles on their own exhibit much lower measures of interfacial elasticity and viscosity than the proteins, but in combination with the proteins they appear to enhance the interfacial viscoelasticity considerably, with concomitant increases in bubble and emulsion droplet stability. There is little evidence of attractive interactions between the particles and the proteins, so a possible explanation of the increased stability is that the proteins increase the accumulation of particles at the interface, giving rise to increased jamming of particles at the interface. 相似文献
28.
Mechanical and thermal properties of wood fibers reinforced poly(lactic acid)/thermoplasticized starch composites 下载免费PDF全文
Thermoplasticized starch (TPS) filled poly(lactic acid) (PLA) blends are usually found to have low mechanical properties due to poor properties of TPS and inadequate adhesion between the TPS and PLA. The purpose of this study was to investigate the reinforcing effect of wood fibers (WF) on the mechanical properties of TPS/PLA blends. In order to improve the compatibility of wood with TPS/PLA blends, maleic anhydride grafted PLA (MA‐g‐PLA) copolymer was synthesized and used. TPS, TPS/PLA blends, and WF reinforced TPS/PLA composites were prepared by twin‐screw extrusion and injection molded. Scanning electron microscope and crystallinity studies indicated thermoplasticity in starch. WF at two different weight proportions, that is, 20% and 40% with respect to TPS content were taken and MA‐g‐PLA at 10% to the total weight was chosen to study the effect on mechanical properties. At 20% WF and 10% MA‐g‐PLA, the tensile strength exhibited 86% improvement and flexural strength exhibited about 106% improvement over TPS/PLA blends. Increasing WF content to 40% further enhanced tensile strength by 128% and flexural strength by 180% with respect to TPS/PLA blends. Thermal behavior of blends and composites was analyzed using dynamic mechanical analysis and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46118. 相似文献
29.
Bubble temperatures at 95 kPa over the entire composition range are measured for the five binary systems formed by 1,2-dimethylbenzene with 2-propanol, 1-butanol, 2-butanol, 2- methylpropan-1-ol, and 2-methylpropan- 2-ol. A Swietoslawski - type ebulliometer was used for the measurements. The composition versus temperature measurements are well represented by the Wilson model. 相似文献
30.
Isothermal titration calorimetry (ITC) was used to identify the optimal timolol:functional monomer ratio for preparing soft contact lenses (SCLs) able to sustain drug release. ITC profiles revealed that each timolol molecule required six to eight acrylic acid (AAc) monomers to saturate the binding and that these ratios could be the most suitable for creating imprinted cavities. Various poly(hydroxyethyl methacrylate‐co‐AAc) hydrogels 0.2 and 0.9 mm thick were prepared with timolol:AAc molar ratios ranging from 1 : 6 to 1 : 32 and also in the absence of timolol. The hydrogels were reloaded with timolol by immersion in 0.04, 0.06, 0.08, and 0.10 mM drug solutions. Both imprinted and nonimprinted hydrogels showed a high affinity for the drug because of the presence of AAc. Nevertheless, the 1 : 6 and 1 : 8 imprinted hydrogels loaded less timolol but sustained the release better than the other hydrogels. These differences were explained in terms of the different arrangement of the functional monomers along the network. The imprinting effect was more noticeable in the case of the thinnest hydrogels, where the contribution of the diffusion path to the release rate was smaller. The results obtained prove the interest of ITC for the rational design of drug‐imprinted networks to be used as medicated SCLs. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献