全文获取类型
收费全文 | 3247篇 |
免费 | 192篇 |
国内免费 | 20篇 |
专业分类
电工技术 | 65篇 |
综合类 | 15篇 |
化学工业 | 961篇 |
金属工艺 | 66篇 |
机械仪表 | 134篇 |
建筑科学 | 112篇 |
矿业工程 | 3篇 |
能源动力 | 231篇 |
轻工业 | 380篇 |
水利工程 | 46篇 |
石油天然气 | 33篇 |
无线电 | 284篇 |
一般工业技术 | 509篇 |
冶金工业 | 77篇 |
原子能技术 | 12篇 |
自动化技术 | 531篇 |
出版年
2024年 | 14篇 |
2023年 | 81篇 |
2022年 | 152篇 |
2021年 | 235篇 |
2020年 | 178篇 |
2019年 | 193篇 |
2018年 | 247篇 |
2017年 | 229篇 |
2016年 | 226篇 |
2015年 | 150篇 |
2014年 | 223篇 |
2013年 | 366篇 |
2012年 | 260篇 |
2011年 | 243篇 |
2010年 | 146篇 |
2009年 | 113篇 |
2008年 | 67篇 |
2007年 | 50篇 |
2006年 | 44篇 |
2005年 | 31篇 |
2004年 | 28篇 |
2003年 | 27篇 |
2002年 | 14篇 |
2001年 | 21篇 |
2000年 | 16篇 |
1999年 | 10篇 |
1998年 | 18篇 |
1997年 | 9篇 |
1996年 | 11篇 |
1995年 | 11篇 |
1994年 | 15篇 |
1993年 | 5篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 6篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1977年 | 2篇 |
排序方式: 共有3459条查询结果,搜索用时 0 毫秒
81.
The effects of hydrocolloids in rice–wheat flour were studied. Hydrocolloids at 0%, 0.3%, 0.6% and 1% w/w (flour basis) and guar (G), Lepidium sativum seed (L) and guar-L. sativum seed (GL) gum were tested as additives to the rice/flour in various combinations. The quality parameters for the experiment were assessed with farinography, extensography, amylography and texture profile analysis. The evaluation of dough rheology showed that water absorption, dough development time, dough stability and viscosity all increased with the addition of hydrocolloids alone or in a combination. It was demonstrated that G1L1 promoted the highest effect. The mixing tolerance index and gelatinization temperature decreased with an increased hydrocolloid concentration. Extensibility value for the dough that incorporated guar and L. sativum seed gum increased with increasing hydrocolloid concentration from 0.3% to 0.6% and then decreased at 1%. The water activity of all bread didn't have significant differences with increasing hydrocolloids concentration but this parameter 24 decreased during storage. Firmness decreased with increasing hydrocolloid concentration and increased with increasing storage time. The sensory evaluation by a consumer panel gave the higher score for overall acceptability to G0.3L0.3 and G0.3L0.6 samples. The results also showed that G1L1, G1L0.6 and G0.6L1 samples had high specific volume and porosity. 相似文献
82.
The effect of chitosan–gelatin coating and film on the rancidity development in rainbow trout (Oncorhynchus mykiss) fillets during refrigerated storage (4 ± 1 °C) was examined over a period of 16 days. Composite and bilayer coated and film wrapped fish samples were analysed periodically for microbiological (total viable count, psychrotrophic count) and chemical (TVB-N, POV, TBARS, FFA) characteristics. The results indicated that chitosan–gelatin coating and film retained their good quality characteristics and extend the shelf life of fish samples during refrigerated storage .The coating was better than the film in reducing lipid oxidation of fillets, but there was no significant difference between them in control of bacterial contamination. 相似文献
83.
Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 总被引:4,自引:0,他引:4
The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups. 相似文献
84.
Shih Yeh Lim Mohd Sokhini Abdul Mutalib Sui Kiat Chang 《International Journal of Food Properties》2018,21(1):2428-2451
There is a growing concern over the food safety issue related to increased incidence of cooking oil adulteration with recycled cooking oil (RCO). The objective of this study was to detect fresh palm olein (FPO) adulteration with RCO using fatty acid composition (FAC) and Fourier-transform infrared spectroscopy (FTIR) spectral analyses combined with chemometrics. RCO prepared in the laboratory was mixed with FPO in the proportion ranged from 1% to 50% (v/v) to obtain the adulterated oil samples (AO). FACs for FPO, RCO, and AO were determined using gas chromatography equipped with a flame ionization detector (GC-FID). The compositions of most fatty acids in RCO lied within the normal ranges of Codex standard, except for C8:0, C10:0, C11:0, C15:0, trans C18:1, and polyunsaturated fatty acids (PUFAs), C20:5. PUFAs showed a consistent decreasing trend with increasing magnitude of change with respect to increasing adulteration level and thus might be a good indicator for detecting FPO adulteration with RCO. The evaluation parameters (coefficient of determination, root mean standard error) of the FTIR-partial least square (PLS) model of palm oil adulteration with recycled oil are R2 = 0.995 and 3.25, respectively. For FTIR spectral analysis, the distinct variations in spectral regions and aberrations in characteristic bands between FPO and RCO were observed. The optimized PLS calibration model developed from normal spectral of the combined region at 3602–3398, 3016–2642, and 1845–650 cm?1 overpredict the adulteration level. On the other hand, the discriminant analysis classification model was able to classify the FPO and AO into two distinct groups. Improvement of the principles of combined techniques in authenticating AO from fresh oil is beneficial as a guideline to detect adulteration in cooking oil. 相似文献
85.
Luqman Jameel Rather Shahid-ul-Islam Mohd Shabbir Mohd Nadeem Bukhari Mohd Ali Khan 《Journal of Natural Fibers》2018,15(4):611-623
This study was undertaken to propose an alternative use of Adhatoda vasica leaves extract as a potential source of natural dye for the coloration of woolen yarn/fibers. Premordanting technique was adopted with double metal salt combinations of ferrous sulfate, stannous chloride, and potassium aluminum sulfate and double biomordant combinations of gallnut, pomegranate, and babool, to achieve dyed textile materials of acceptable colorimetric and fastness properties. Sixty-three sober and elegant shades were developed on wool by varying the nature and the concentration of mordants involved in the combinations. The hue of color developed was found to be in yellow-red coordinate of color space diagram. All the dyed samples presented excellent color strength (K/S) values and highest values were found in case of gallnut + pomegranate peel extract (PPE) combination. Biomordants produced altogether different behavior in comparison to metal mordants in the development of ecofriendly shades of different hue and tune. Majority of the dyed samples showed excellent fastness properties with respect to light, washing, and rubbing which confirmed the possibility of using A. vasica leaves extract as an effective yellow natural dye. 相似文献
86.
Comparison of in vivo toxicity,antioxidant and immunomodulatory activities of coconut,nipah and pineapple juice vinegars 下载免费PDF全文
87.
Fetemeh Zendeboodi Asgar Farahnaky Mohammad Mahdi Gholian 《Journal of texture studies》2019,50(6):465-473
Ultrasound has been used for cold gelation of κ‐carrageenan hydrocolloid. In this work, the effect of ultrasound conditions such as power (50–150 W) and time (20–240 s) of sonication has been investigated. The application of ultrasound to hydrocolloid dispersion caused an increase in water solubility. The texture profile analysis test was used in order to evaluate the mechanical properties of gels. Textural parameters of κ‐carrageenan gels, enhanced with increasing sonication time and power up to a certain level (usually 2.5 min) and longer sonication times had negative effects. In addition, intrinsic viscosities of sonicated specimens were measured to investigate the molecular characteristics of all samples. An increase in the process time and power reduced the intrinsic viscosity. The microstructural observation by scanning electron microscope determined that applying power ultrasound on κ‐carrageenan dispersions influenced the formation of gel networks significantly. 相似文献
88.
89.
Shima Jafarzadeh Mehrdad Forough Vahid Javan Kouzegaran Masoumeh Zargar Farhad Garavand Maryam Azizi-Lalabadi Mehdi Abdollahi Seid Mahdi Jafari 《Comprehensive Reviews in Food Science and Food Safety》2023,22(4):2850-2886
Non-biodegradability and disposal problems are the major challenges associated with synthetic plastic packaging. This review article discusses a new generation of biodegradable active and smart packaging based on porous nanomaterials (PNMs), which maintains the quality and freshness of food products while meeting biodegradability requirements. PNMs have recently gained significant attention in the field of food packaging due to their large surface area, peculiar structures, functional flexibility, and thermal stability. We present for the first time the recently published literature on the incorporation of various PNMs into renewable materials to develop advanced, environmentally friendly, and high-quality packaging technology. Various emerging packaging technologies are discussed in this review, along with their advantages and disadvantages. Moreover, it provides general information about PNMs, their characterization, and fabrication methods. It also briefly describes the effects of different PNMs on the functionality of biopolymeric films. Furthermore, we examined how smart packaging loaded with PNMs can improve food shelf life and reduce food waste. The results indicate that PNMs play a critical role in improving the antimicrobial, thermal, physicochemical, and mechanical properties of natural packaging materials. These tailor-made materials can simultaneously extend the shelf life of food while reducing plastic usage and food waste. 相似文献
90.
Shahida Anusha Siddiqui Ito Fernando Yuniar Rizky Saraswati Teguh Rahayu Iskandar Azmy Harahap Qifa Yao Andrey Nagdalian Andrey Blinov Mohd Asif Shah 《Comprehensive Reviews in Food Science and Food Safety》2023,22(5):3647-3684
Global food production is anticipated to rise along with the growth of the global population. As a result, creative solutions must be devised to ensure that everyone has access to nutritious, affordable, and safe food. Consequently, including insects in diets has the potential to improve global food and nutrition security. This paper aims to share recent findings by covering edible termites as the main aspect, from their consumption record until consumer acceptance. A total of 53 termite species are reported as edible ones and distributed in 6 biogeographic realms. Generally, termites have a nutrient composition that is suitable for human consumption, and cooked termites are a better dietary choice than their raw counterparts. Besides, increasing customer interest in eating termite-based food can be achieved by making it more palatable and tastier through various cooking processes, that is, boiling, frying, grilling, roasting, smoking, and sun-drying. Moreover, edible termites can also be used as a new source of medication by exhibiting antimicrobial activity. Regarding their advantages, it is strongly encouraged to implement a seminatural rearing system to sustain the supply of edible termites. Overall, this paper makes it evident that termites are an important natural resource for food or medicine. Hence, the long-term objective is to stimulate scientific inquiry into the potential of edible insects as an answer to the problem of global food security. 相似文献