全文获取类型
收费全文 | 94篇 |
免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 15篇 |
金属工艺 | 3篇 |
机械仪表 | 3篇 |
能源动力 | 1篇 |
轻工业 | 6篇 |
无线电 | 4篇 |
一般工业技术 | 55篇 |
冶金工业 | 7篇 |
自动化技术 | 2篇 |
出版年
2022年 | 4篇 |
2021年 | 3篇 |
2020年 | 1篇 |
2018年 | 1篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 3篇 |
2012年 | 1篇 |
2011年 | 4篇 |
2010年 | 2篇 |
2009年 | 1篇 |
2008年 | 3篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
1996年 | 1篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 3篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1973年 | 3篇 |
1972年 | 2篇 |
1971年 | 2篇 |
1970年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有97条查询结果,搜索用时 11 毫秒
11.
The effect of previous long-term loading on the strength of 1Cr18Ni9Ti steel at 20, 500, 650, 800, and 950° C was investigated. 相似文献
12.
Kousi P Remoundaki E Hatzikioseyian A Battaglia-Brunet F Joulian C Kousteni V Tsezos M 《Journal of hazardous materials》2011,189(3):677-684
A batch upflow fixed-bed sulphate-reducing bioreactor has been set up and monitored for the treatment of synthetic solutions containing divalent iron (100mg/L and 200mg/L), zinc (100mg/L and 200mg/L), copper (100mg/L and 200mg/L), nickel (100mg/L and 200mg/L) and sulphate (1700 mg/L and 2130 mg/L) at initial pH 3-3.5, using ethanol as the sole electron donor. The reactor has been operated at the theoretical stoichiometric ethanol/sulphate ratio. Complete oxidation of ethanol has been achieved through complete oxidation of the intermediately, microbially produced acetate. This is mainly attributed to the presence of Desulfobacter postgatei species which dominated the sulphate-reducing community in the reactor. The reduction of sulphate was limited to about 85%. Quantitative precipitation of the soluble metal ions has been achieved. XRD and SEM-EDS analyses performed on samples of the produced sludge showed poorly crystalline phases of marcasite, covellite and wurtzite as well as several mixed metal sulphides. 相似文献
13.
E. J. Pavlina A. M. Meier P. Monteleone J. D. Weigner 《Journal of Materials Science》2007,42(2):705-713
Existing multi-layer devices using lead-based piezoelectric ceramics utilize an internal electrode that does not bond the
ceramic layers. Improvements in device performance and processing could be gained if the electrode also acted as a bond between
the ceramic layers. In the current work, the feasibility of brazing lead zirconate titanate (PZT) in ambient conditions utilizing
silver-based alloys containing low melting temperature metal oxides was investigated. Wettability, joint fracture strength,
and microstructural analyses were conducted for various PZT/silver–metal oxide systems. The metal oxide additions included
copper (II) oxide, vanadium pentoxide, lead (II) oxide, and eutectic lead oxide-titanium (IV) oxide. The silver–copper oxide
(Ag–CuO) system demonstrated the most potential; exhibiting an apparent contact angle of approximately 64° and an average
braze joint fracture strength that was approximately 62% of the monolithic PZT strength. In addition, no significant reaction
product formation was observed at the silver/PZT interface. However, a preliminary investigation of multi-layer devices electroded
with Ag–CuO alloys indicated a decrease in the resistivity of the brazed PZT by several orders of magnitude. 相似文献
14.
15.
16.
Yu Cheng Pavlina Vechtova Zoltan Fussy Jan Sterba Zuzana Linhartov Marek Rodina Vladimíra Tu
kov David Gela Azin Mohagheghi Samarin Ievgen Lebeda Miaomiao Xin Songpei Zhang Deepali Rahi Otomar Linhart 《International journal of molecular sciences》2021,22(11)
The purpose of the current study was to analyze phenotypic and functional characteristics of common carp (Cyprinus carpio) spermatozoa during in vitro aging and to investigate whether global DNA methylation is affected by sperm aging. Milt was collected from five individual males, stored in vitro on ice in a refrigerator for up to 96 h post stripping (HPS) and used to fertilize eggs with intervals of 1, 24 and 96 h. Computer-assisted sperm analysis and a S3e Cell Sorter was employed to determine the spermatozoa phenotypic characteristics (motility, velocity, concentration and viability). In addition, pH and osmolality of the seminal fluid and the capacity of the spermatozoa to fertilize, hatching rate and health of the resulting embryos were examined at different aging times. Whole-genome bisulfite sequencing was used to compare the global and gene-specific DNA methylation in fresh and aged spermatozoa. The results demonstrated that spermatozoa aging in common carp significantly affects their performance and thus the success of artificial fertilization. The methylation level at the cytosine-phosphate-guanine (CpG) sites increased significantly with 24 HPS spermatozoa compared to the fresh group at 1 HPS and then decreased significantly at 96 HPS. A more detailed investigation of gene specific differences in the DNA methylation was hindered by incomplete annotation of the C. carpio genome in the public databases. 相似文献
17.
Kevin Harvey Zhidong Xu Candace Walker Thomas Pavlina Sheila McGrath Gary Zaloga Rafat Siddiqui 《Lipids》2014,49(8):777-793
Lipid emulsions are made by mixing vegetable and/or fish oils with egg yolk and contain different types and amounts of fatty acids and sterols. This study assessed the effects of oral diet, soybean oil (SO)-, fish oil (FO)-, a mixture of olive and soybean oil (OOSO)-, and a mixture of fish, olive, coconut, and soybean oil (FOCS)-based emulsions on plasma triacylglycerols and plasma and tissue fatty acid and sterol content following acute and chronic intravenous administration in the guinea pig. Upon acute administration, peak triacylglycerols were highest with SO and lowest with OOSO. Upon chronic administration, the plasma triglyceride levels did not increase in any group over that of the controls. Fatty acid levels varied greatly between organs of animals on the control diets and organs of animals following acute or chronic lipid administration. Squalene levels increased in plasma following acute administration of OOSO, but plasma squalene levels were similar to control in all emulsion groups following chronic administration. Total plasma phytosterol levels were increased in the SO, OOSO, and FOCS groups following both acute and chronic infusions, whereas phytosterols were not increased following FO infusion. Total phytosterol levels were higher in liver, lung, kidney and adipose tissue following SO and OOSO. Levels were not increased in tissues after FO and FOCS infusion. These results indicate that fatty acid and sterol contents vary greatly among organs and that no one tissue reflects the fatty acid or sterol composition of other tissues, suggesting that different organs regulate these compounds differently. 相似文献
18.
19.
In this paper an approach for resource management for Heterogeneous Networks (HetNets) based on the dynamic association of users in sets is proposed. The approach is based on the consideration that in a telecommunication network every access point has the property of limited performance, capacity and service potential. Through the definition of two generalized parameters of the servicing cell a characteristic model of the servicing properties of a HetNet access point is developed. An optimization task is defined for a resource management approach with the goal of “providing user service with the required quality of Service while minimizing servicing costs”. The task is solved via the introduction of a modified ADD/DROP heuristic algorithm. A comparison with two other heuristic algorithms is performed showing some of the advantages of the proposed algorithm such as its low computational complexity, fast convergence and effectiveness of the heuristic procedure. A sample application for transmission power control is presented. 相似文献
20.
Zhidong Xu Kevin A. Harvey Thomas M. Pavlina Gary P. Zaloga Rafat A. Siddiqui 《European Journal of Lipid Science and Technology》2015,117(1):15-22
Parenteral lipid emulsions, which are made of oils from plant and fish sources, contain different types of tocopherols and tocotrienols (vitamin E homologs). The amount and types of vitamin E homologs in various lipid emulsions vary considerably and are not completely known. The objective of this analysis was to develop a quantitative method to determine levels of all vitamin E homologs in various lipid emulsions. An HPLC system was used to measure vitamin E homologs using a Pinnacle DB Silica normal phase column and an isocratic, n‐hexane:1,4 dioxane (98:2) mobile phase. An optimized protocol was used to report vitamin E homolog concentrations in soybean oil‐based (Intralipid®, Ivelip®, Lipofundin® N, Liposyn® III, and Liposyn® II), medium‐ and long‐chain fatty acid‐based (Lipofundin® , MCT and Structolipid®), olive oil‐based (ClinOleic® ), and fish oil‐based (Omegaven®) and mixture of these oils‐based (SMOFlipid®, Lipidem®) commercial parenteral lipid emulsions. Total content of all vitamin E homologs varied greatly between different emulsions, ranging from 57.9 to 383.9 µg/mL. Tocopherols (α, β, γ, δ) were the predominant vitamin E homologs for all emulsions, with tocotrienol content < 0.3%. In all of the soybean emulsions, except for Lipofundin® N, the predominant vitamin E homolog was γ‐tocopherol, which ranged from 57–156 µg/mL. ClinOleic® predominantly contained α‐tocopherol (32 µg/mL), whereas α‐tocopherol content in Omegaven® was higher than most of the other lipid emulsions (230 µg/mL). Practical applications: The information on the types and quantity of vitamin E homologs in various lipid emulsions will be extremely useful to physicians and healthcare personnel in selecting appropriate lipid emulsions that are exclusively used in patients with inadequate gastrointestinal function, including hospitalized and critically ill patients. Some emulsions may require vitamin E supplementation in order to meet minimal human requirements. Vitamin E homologs (tocopherols and tocotrienols) contain a chromanol ring and a hydrophobic side chain. 相似文献