全文获取类型
收费全文 | 1211篇 |
免费 | 62篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 22篇 |
综合类 | 4篇 |
化学工业 | 286篇 |
金属工艺 | 37篇 |
机械仪表 | 50篇 |
建筑科学 | 56篇 |
矿业工程 | 2篇 |
能源动力 | 52篇 |
轻工业 | 206篇 |
水利工程 | 3篇 |
石油天然气 | 20篇 |
无线电 | 85篇 |
一般工业技术 | 170篇 |
冶金工业 | 114篇 |
原子能技术 | 7篇 |
自动化技术 | 169篇 |
出版年
2023年 | 7篇 |
2022年 | 30篇 |
2021年 | 40篇 |
2020年 | 29篇 |
2019年 | 47篇 |
2018年 | 35篇 |
2017年 | 40篇 |
2016年 | 55篇 |
2015年 | 38篇 |
2014年 | 52篇 |
2013年 | 75篇 |
2012年 | 61篇 |
2011年 | 77篇 |
2010年 | 62篇 |
2009年 | 50篇 |
2008年 | 51篇 |
2007年 | 47篇 |
2006年 | 29篇 |
2005年 | 27篇 |
2004年 | 24篇 |
2003年 | 22篇 |
2002年 | 22篇 |
2001年 | 12篇 |
2000年 | 14篇 |
1999年 | 8篇 |
1998年 | 35篇 |
1997年 | 17篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 13篇 |
1993年 | 10篇 |
1992年 | 10篇 |
1991年 | 8篇 |
1990年 | 9篇 |
1989年 | 9篇 |
1988年 | 6篇 |
1987年 | 14篇 |
1986年 | 12篇 |
1985年 | 7篇 |
1984年 | 23篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1980年 | 14篇 |
1979年 | 7篇 |
1978年 | 13篇 |
1977年 | 8篇 |
1976年 | 20篇 |
1975年 | 10篇 |
1972年 | 4篇 |
1969年 | 3篇 |
排序方式: 共有1283条查询结果,搜索用时 15 毫秒
31.
Mustafa Şengül Tuba Erkaya Muhammet Dervişoğlu Oğuz Aydemir Osman Gül 《International Journal of Dairy Technology》2014,67(3):373-383
In the present study, biochemical, chemical and texture changes in Tulum cheeses made using calf rennet and microbial rennets (Aspergillus niger protease and Rhizomucor miehei protease) were compared during ripening for up to 90 days. A total of 15 free fatty acids (FFAs) were detected in the cheese samples. The peroxide values (PV) of the cheeses increased significantly (P < 0.05) during ripening and the cheese made with calf rennet had the highest PV. Proteolysis in the cheeses increased as the ripening time increased. αs1‐casein and β‐casein degradation was higher in cheeses manufactured with R. miehei protease. Cheeses made with calf rennet were significantly (P < 0.05) harder, more adhesive, more cohesive and more resilient than those made with microbial rennet. 相似文献
32.
Omer Said Toker Fatma Tugce Zorlucan Nevzat Konar Orhan Dağlıoğlu Osman Sagdic Dilek Şener 《International Journal of Food Science & Technology》2017,52(3):788-799
Chocolate compound was produced using ball mill refiner, and the effect of agitator shaft speed and refining time on the physical quality parameters (particle size, colour and steady‐state rheology) of compound chocolate was determined using response surface methodology. The shaft speed and refining time range were selected between 40–60 r.p.m. and 10–30 min, respectively. Determination coefficient of the models established for particle size, Newtonian viscosity and colour parameters (brightness, chroma and hue angle) were found to be very close to unity. Increasing shaft speed and time induced a reduction in particle size and an increase in viscosity of the samples. Temperature sweep test was also performed, and the obtained data were successfully fitted to Arrhenius equation to calculate the corresponding parameters representing temperature dependency of the compounds. The results highlighted that the establishment of such models can provide essential information in terms of optimisation of production processes regarding usage purpose of the compound chocolate. 相似文献
33.
S. F. Siddiqi Fasih Ahmad M. S. Siddiqi S. M. Osman G. R. Fenwick 《Journal of the American Oil Chemists' Society》1984,61(4):798-800
The seeds ofVernonia volkameriaefolia contain 20% oil and are a good source of epoxidized triglycerides. The vernolic acid (cis-12, 13-epoxy-cis-9, 10-octadecenoic acid) content of the oil was 63.5%. The structure of this compound was established by chemical and physical
methods, including a study of the mass spectral fragmentation of the parent compound and its derivatives. 相似文献
34.
Jamal Mustafa M. S. Ahmad A. Rauf S. M. Osman 《Journal of the American Oil Chemists' Society》1984,61(3):555-558
Methyl 4-oxo-trans-2-octadecenoate (II), when treated with excess hydrazoic acid in the presence of BF3-etherate, produced 66% methyl 5-aza-nonadec-trans-2-enoate (4,5-d)-tetrazole (III), 10% methyl 5-aza-nonadec-4-oxo-trans-2-enoate (IV) and 7% pentadecamide (V). Individual products were characterized by spectral and elemental methods. 相似文献
35.
Hasan Yalcin Ismet ?zt��rk Eray Tuluk?u Osman Sa?dic 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2011,6(2):197-202
Sar? 85 (Linum usitatissimum L.) linseed variety was used in this study. Linseed was cultivated at 2008 (LS-08) and 2009 (LS-09) without fertilizer. In addition, at 2009 diammonium phosphate [(NH4)2HPO4] and ammonium nitrate (NH4NO3) were applied (LSF-09). The linseeds were analyzed for protein, ash and oil contents and fatty acid compositions. There were differences among harvesting years for oil, protein and ash contents of the seeds. The greater oil and protein contents were obtained during LS-08 compared with LS-09. There were no significant difference in protein and ash content between LS-09 and LSF-09 while a significant difference was observed in oil content. Seed protein, oil and ash contents were significantly affected by the harvesting year, but only oil content was affected by the fertilizer treatment. There are significant differences in palmitic, stearic, oleic, ??-linolenic and arachidic acid between LS-08 and LS-09. While palmitic, stearic, oleic acid decreased, ??-linolenic and arachidic acid increased during 2009 harvesting year. LSF-09 has the highest amount of ??-linolenic acid. The fertilizing treatment seems to have an increasing effect on the amount of ??-linolenic acid, while it has a decreasing effect on the oleic acid content. 相似文献
36.
Tornuk F Cankurt H Ozturk I Sagdic O Bayram O Yetim H 《International journal of food microbiology》2011,148(1):30-35
In the present study, inhibitory effects of the hydrosols of thyme, black cumin, sage, rosemary and bay leaf were investigated against Salmonella Typhimurium and Escherichia coli O157:H7 inoculated to apple and carrots (at the ratio of 5.81 and 5.81 log cfu/g for S. Typhimurium, and 5.90 and 5.70 log cfu/g for E. coli O157:H7 on to apple and carrot, respectively). After the inoculation of S. Typhimurium or E. coli O157:H7, shredded apple and carrot samples were washed with the hydrosols and sterile tap water (as control) for 0, 20, 40 and 60 min. While the sterile tap water was ineffective in reducing (P > 0.05) S. Typhimurium and E. coli O157:H7, 20 min hydrosol treatment caused a significant (P < 0.05) reduction compared to the control group. On the other hand, thyme and rosemary hydrosol treatments for 20 min produced a reduction of 1.42 and 1.33 log cfu/g respectively in the E. coli O157:H7 population on apples. Additional reductions were not always observed with increasing treatment time. Moreover, thyme hydrosol showed the highest antibacterial effect on both S. Typhimurium and E. coli O157:H7 counts. Inhibitory effect of thyme hydrosol on S. Typhimurium was higher than that for E. coli O157:H7. Bay leaf hydrosol treatments for 60 min reduced significantly (P < 0.05) E. coli O157:H7 population on apple and carrot samples. In conclusion, it was shown that plant hydrosols, especially thyme hydrosol, could be used as a convenient sanitizing agent during the washing of fresh-cut fruits and vegetables. 相似文献
37.
Fatma Osman Ibnouf 《Food Security》2011,3(2):215-231
This paper investigates the role of women in achieving household food security in the Western Region of Sudan, an area much
affected by the impacts of drought and civil conflicts. The study is based on a quantitative survey and qualitative focus
group discussions, supported by personal observations made during fieldwork. Additionally, the study draws upon secondary
data that is publicly available. Results demonstrate that women play a major role in producing and providing food for their
households in this high-risk climate and conflict area, while men are more likely to migrate seasonally and even permanently.
In addition, women are responsible for food preparation, processing, and food preservation and are wholly responsible for
attending to household garden plots. They therefore contribute more to household food security than men, though this contribution
is not recognized in official statistics. The study findings indicate that the main problems women face as food producers
and providers are a lack of access to the full package of improved production methods (improved seeds, fertilizers, modern
farming methods, credit services, pesticides, appropriate technologies, and marketing facilities), in addition to gender disparities
and gender-biased traditions. The impacts of natural crises and civil conflicts are gendered and therefore the responses to
these crises must be gender responsive. Holistic and strategic policies and plans that take gender issues into account are
thus needed in order to achieve food security. 相似文献
38.
Lactic acid bacteria profiles and tyramine and tryptamine contents of Turkish tulum cheeses 总被引:1,自引:0,他引:1
Zubeyde??nerEmail author Osman?Sa?di? Bedia??im?ek 《European Food Research and Technology》2004,219(5):455-459
Tulum cheese, commonly produced in Turkey, is a traditional Turkish dairy product made from raw milk. In this research, 20 samples of tulum cheese were purchased from different markets in Isparta and Ankara (Turkey) and the populations of lactic acid bacteria (LAB) and contents of biogenic amines of Turkish tulum cheeses were investigated. The mean counts of LAB (as log10 cfu/g) were 7.22±0.67 on MRS agar, 6.93±1.77 on M17 agar, 7.28±0.72 on APT agar and 5.98±2.20 on ADA agar. Isolates of LAB obtained from 20 tulum cheeses were characterised as lactobacilli (48.5%), enterococci (32.7%), lactococci (15.8%) and streptococci (3.0%). Lactobacillus paracasei ssp. paracasei, Lactobacillus bifermentans and Enterococcus faecium predominated among the LAB in the samples of tulum cheeses; these organisms represented 30.2% of the isolates. As amino acids, tyrosine and tryptophan were determined in tulum cheeses. Tyramine and tryptamine, biogenic amines, were found at 0.00–329.00 and 0.32–40.44 mg/kg, respectively. 相似文献
39.
Ruxangul Jamal Ahmat Ali Li Zhang Yakupjan Osman Adalet Rahman Tursun Abdiryim 《Polymer Composites》2015,36(9):1597-1605
Poly(3′,4′‐ethylenedioxy‐2,2′:5′,2″‐terthiophene)/ZnO(poly(TET)/ZnO) composites with the ratio of poly(TET) and nano‐ZnO from 3:1 to 1:3 were synthesized by hand grinding and ball milling methods, respectively. The photocatalytic activities of the composites were examined through the degradation processes of methylene blue (MB) solution under UV light irradiation, and the possible mechanism for the photocatalytic activity enhancement by synergetic effects between nano‐ZnO and poly(TET) was proposed. The results showed that the strong interactions between the poly(TET) and nano‐ZnO occurred in the case of ball milling method. The results also proved that the crystallinity of ZnO was not disturbed in both of methods, and the nano‐ZnO was uniformly distributed in polymer matrix in the case of ball milling method. The comparative studies showed that the addition of the nano‐ZnO could enhance the photocatalytic activities of the composites. The highest degradation efficiency (100%) at 3 h under UV light irradiation occurred in the case of poly(TET)/ZnO(1:1) synthesized by ball milling method. Furthermore, the nanocompsosite displayed higher photocatalytic activity than nano‐ZnO, which was due to the holes (h+) transferring from the valence band of ZnO to the polymer backbone and the adsorption of MB molecules in polymer matrix via π–π conjugation between MB and aromatic regions of the poly(TET). POLYM. COMPOS., 36:1597–1605, 2015. © 2014 Society of Plastics Engineers 相似文献
40.
Nadia Abu Samra Herbert F. Jelinek Habiba Alsafar Farah Asghar Muhieddine Seoud Shahad M. Hussein Hisham M. Mubarak Siddiq Anwar Mashal Memon Nariman Afify Ridda Manzoor Zahrah Al-Homedi Wael Osman 《International journal of molecular sciences》2022,23(7)
One of the most common complications during pregnancy is gestational diabetes mellitus (GDM), hyperglycemia that occurs for the first time during pregnancy. The condition is multifactorial, caused by an interaction between genetic, epigenetic, and environmental factors. However, the underlying mechanisms responsible for its pathogenesis remain elusive. Moreover, in contrast to several common metabolic disorders, molecular research in GDM is lagging. It is important to recognize that GDM is still commonly diagnosed during the second trimester of pregnancy using the oral glucose tolerance test (OGGT), at a time when both a fetal and maternal pathophysiology is already present, demonstrating the increased blood glucose levels associated with exacerbated insulin resistance. Therefore, early detection of metabolic changes and associated epigenetic and genetic factors that can lead to an improved prediction of adverse pregnancy outcomes and future cardio-metabolic pathologies in GDM women and their children is imperative. Several genomic and epigenetic approaches have been used to identify the genes, genetic variants, metabolic pathways, and epigenetic modifications involved in GDM to determine its etiology. In this article, we explore these factors as well as how their functional effects may contribute to immediate and future pathologies in women with GDM and their offspring from birth to adulthood. We also discuss how these approaches contribute to the changes in different molecular pathways that contribute to the GDM pathogenesis, with a special focus on the development of insulin resistance. 相似文献