全文获取类型
收费全文 | 320篇 |
免费 | 12篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 165篇 |
金属工艺 | 8篇 |
建筑科学 | 5篇 |
矿业工程 | 1篇 |
能源动力 | 27篇 |
轻工业 | 15篇 |
水利工程 | 3篇 |
石油天然气 | 12篇 |
无线电 | 1篇 |
一般工业技术 | 48篇 |
冶金工业 | 26篇 |
原子能技术 | 1篇 |
自动化技术 | 14篇 |
出版年
2023年 | 4篇 |
2022年 | 37篇 |
2021年 | 31篇 |
2020年 | 11篇 |
2019年 | 14篇 |
2018年 | 20篇 |
2017年 | 9篇 |
2016年 | 6篇 |
2015年 | 10篇 |
2014年 | 21篇 |
2013年 | 18篇 |
2012年 | 25篇 |
2011年 | 14篇 |
2010年 | 12篇 |
2009年 | 12篇 |
2008年 | 16篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 2篇 |
1996年 | 3篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1985年 | 1篇 |
排序方式: 共有333条查询结果,搜索用时 31 毫秒
111.
Galina Vladimirovna Kontsevaya Ludmila Alekseevna Gerlinskaya Yury Mikhailovich Moshkin Margarita Vladimirovna Anisimova Aliya Konstantinovna Stanova Tatyana Ivanovna Babochkina Mikhail Pavlovich Moshkin 《International journal of molecular sciences》2021,22(19)
The latest vaccination campaign has actualized the potential impact of antigenic stimuli on reproductive functions. To address this, we mimicked vaccination’s effects by administering keyhole limpet hemocyanin (KLH ) to CD1 male mice and used their sperm for in vitro fertilization (IVF). Two-cell embryos after IVF with spermatozoa from control (C) or KLH-treated (Im) male mice were transferred to surrogate mothers mated with vasectomized control (C) or KLH-treated (Im) male mice, resulting in four experimental groups: C–C, Im–C, C–Im, and Im–Im. The pre-implantation losses were significantly lower in the Im–C group than in the C–Im group. At the same time, the resorption rates reduced markedly in the C–Im compared to the Im–C group. Embryo and placenta weights were significantly higher in the Im–Im group. Although the GM-CSF levels were lower in the amniotic fluid of the gestating surrogate mothers in the Im–Im group, they were strongly correlated with embryo mass. The number–size trade-off was only significant in the Im–Im group. This suggests a positive, cooperative effect of spermatozoa and seminal fluid from immune-primed males on embryo growth and the optimal distribution of surrogate mother maternal resources despite the negative impact of males’ antigenic challenge on the IVF success rate. 相似文献
112.
Andrii Mazur Pavel Grinkevich Radka Chaloupkova Petra Havlickova Barbora Kascakova Michal Kuty Jiri Damborsky Ivana Kuta Smatanova Tatyana Prudnikova 《International journal of molecular sciences》2021,22(21)
Haloalkane dehalogenases (EC 3.8.1.5) play an important role in hydrolytic degradation of halogenated compounds, resulting in a halide ion, a proton, and an alcohol. They are used in biocatalysis, bioremediation, and biosensing of environmental pollutants and also for molecular tagging in cell biology. The method of ancestral sequence reconstruction leads to prediction of sequences of ancestral enzymes allowing their experimental characterization. Based on the sequences of modern haloalkane dehalogenases from the subfamily II, the most common ancestor of thoroughly characterized enzymes LinB from Sphingobium japonicum UT26 and DmbA from Mycobacterium bovis 5033/66 was in silico predicted, recombinantly produced and structurally characterized. The ancestral enzyme AncLinB-DmbA was crystallized using the sitting-drop vapor-diffusion method, yielding rod-like crystals that diffracted X-rays to 1.5 Å resolution. Structural comparison of AncLinB-DmbA with their closely related descendants LinB and DmbA revealed some differences in overall structure and tunnel architecture. Newly prepared AncLinB-DmbA has the highest active site cavity volume and the biggest entrance radius on the main tunnel in comparison to descendant enzymes. Ancestral sequence reconstruction is a powerful technique to study molecular evolution and design robust proteins for enzyme technologies. 相似文献
113.
Technology for the production of new materials based on the heat-resistant powder metallurgy nickel alloy ÉP975 was developed, and the mechanical and tribological properties of these investigated. The formation features of the metallographic structure of the materials was studied. Recommendations for the practical use of the new composites are given. 相似文献
114.
Decomposition of toxic pollutants in landfill leachate by ozone after coagulation treatment 总被引:4,自引:0,他引:4
Poznyak T Bautista GL Chaírez I Córdova RI Ríos LE 《Journal of hazardous materials》2008,152(3):1108-1114
This study deals with evaluation of organic matter from Mexico City waste sanitary landfill leachate of Bordo Poniente (including domestic and industrial) by ozonation after a coagulation treatment with Fe2(SO4)(3) (2.5 g/L at pH 4-5). The content of humic substances after the coagulation treatment decreases up to 70%. Then leachate obtained from a solid with initial COD=1511 mg/L and the pH 8.5 was treated by ozone. The aqueous samples by a UV-vis and HPLC technique were analyzed. The partial identification of the initial composition of the organic matter as well as of intermediates and final products was carried out after the extraction of the initial and ozonated leachate with benzene, chloroform:methanol (2:1) and hexane. Then the extracts with a gas chromatograph with mass detector and FID were analyzed. In the HPLC results we identify malonic and oxalic acids. The initial concentrations of these acids were 19 mg/L and 214 mg/L, respectively. The oxalic acid is formatted and accumulated in ozonation. The obtained results show that the color disappears (visually) at 100% during 5 min of ozonation. The organic substances, extracted with chloroform-methanol, may be destructed during 15 min of ozonation; the organic matter, extracted with benzene, destructs completely by ozone during 5 min, and the organic compounds extracted with hexane have a low ozonation rate. The toxic compounds presented in leachate decompose completely during 15 min of ozonation. The ozonation rate constants for each group of organics (as observed constants) were calculated applying simplified mathematical model and the recurrent least square method using the program MATLAB 6.5. 相似文献
115.
Asiya E. Turgambaeva Galina Zharkova Petr Semyannikov Vladislav V. Krisyuk Tatyana Koretskaya Sergey Trubin Boris Kuchumov Igor Igumenov 《Gold bulletin》2011,44(3):177-184
Thermal properties of oxygen-, phosphorus-, and halogen-free dimethylgold(III) diethyldithiocarbamate complex (CH3)2AuS2CN(C2H5)2 (gold, dimethyl(diethylcarbamodithioato -S,S′)-) having excellent storage stability and the mechanism of its decomposition
to elemental gold were studied. Saturated vapor pressure was found to be ~10−3–10−1 Torr at 50–90°C. Decomposition of the vapor on the surface starts at T = 210°C. The temperature dependence of gas phase composition was studied using the original mass spectrometric technique,
it was established that the decomposition of the compound on the surface in vacuum follows three main pathways. Two of them
result in the formation of elemental gold, saturated C2–C4 alkanes and (1) protonated ligand or (2) methylated ligand. The
third one results in elemental gold and gaseous products: C2–C3 alkylmercaptanes and CH3SCN(C2H5)2. The formation of gold as a sole solid product within the temperature range 210–240°C was confirmed by X-ray photoelectron
spectroscopy analysis. It was shown that the compound exhibits the best combination of volatility, thermal, and storage stability
among volatile organogold complexes and thus it may be a promising precursor for obtaining gold films by chemical vapor deposition. 相似文献
116.
Mikhail A. Matsko Ludmila G. Echevskaya Marina P. Vanina Marina I. Nikolaeva Tatyana B. Mikenas Vladimir A. Zakharov 《应用聚合物科学杂志》2012,126(6):2017-2023
Separation into narrow MWD fractions (liquid–liquid fractionation) and preparative TREF (temperature rising elution fractionation) with subsequent analysis of fractions by GPC, FTIR, and 13C NMR spectroscopy were used to study the comonomer distribution of ethylene/1–hexene copolymers produced over highly active supported titanium‐ and vanadium‐magnesium catalysts (TMC and VMC) and a supported zirconocene catalyst. These catalysts produce PE with different MWD: Mw/Mn values vary from 2.9 for zirconocene catalyst, 4.0 for TMC, and 15 for VMC. 1‐Hexene increases polydispersity to 25 for copolymer produced over VMC and hardly affects MWD of the copolymer produced over TMC and zirconocene catalysts. The most broad short chain branching distribution (SCBD) was found for ethylene/1–hexene copolymers produced over TMC. VMC and supported zirconocene catalyst produce copolymers with uniform profile of SCB content vs. molecular weight in spite of great differences in Mw/Mn values (22 and 2.5 respectively). TREF data showed that majority of copolymer produced over supported zirconocene catalyst was eluted at 70–90°C (about 85 wt %). In the case of VMC copolymer's fractions were eluted in the broad temperature interval (40–100°C). Accordingly, TREF data indicate a more homogeneous SCBD in copolymer, produced over supported zirconocene catalyst. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
117.
Tatyana V. Sukhareva 《Journal of Superconductivity and Novel Magnetism》2013,26(5):2021-2025
The objective of the work is to establish the contribution of superconductive granules and grain boundaries (weak links) in magnetoresistance ρ value of YBa2Cu3O7?δ granular high-temperature superconductor (HTS) at T<T c. The current-voltage characteristics (CVCs) $E(j)_{H_{\mathrm{ext}} = \mathrm{const}}$ of YBa2Cu3O6.95 ceramic samples were measured in H ext (0≤H ext≤≈500 Oe) magnetic fields. The CVCs $E(j)_{H_{\mathrm{trap}} = \mathrm{const}}$ of the samples magnetized in H treat magnetic fields were measured at H ext=0. Based on the CVCs, $\rho(j)_{H_{\mathrm{ext}} = \mathrm{const}}$ , ρ(H ext) j=const and $\rho(j)_{H_{\mathrm{treat}} = \mathrm{const}}$ dependences were reestablished. The comparative analysis of $\rho(j)_{H_{\mathrm{ext}} = \mathrm{const}}$ and ρ(H ext) j=const dependences indicates the magnetic field redistribution between grain boundaries and superconductive granules influence on transport and galvanomagnetic properties of granular HTS. The superconductive grain magnetoresistance ρ g was established to be significantly lower than ρ J value of Josephson medium. 相似文献
118.
Tatyana V. Laurinavichene Kestutis S. Laurinavichius Anatoly A. Tsygankov 《International Journal of Hydrogen Energy》2014
Purple non-sulfur bacteria Rhodobacter sphaeroides N7 was integrated into the heterotrophic starch-hydrolyzing consortium containing Clostridium butyricum as the main component. The resulting light-dependent consortium with Bchl ∼9 μg/ml was maintained during 12 months of regular transfers. The protein content in this consortium was four-fold higher compared to the heterotrophic consortium, suggesting that purple bacteria became its important component. Under illumination, the starch hydrolysis by the light-dependent consortium (as opposed to heterotrophic consortium) resulted in the absence of VFAs, hydrogen production being quite similar and residual hexose higher. Fermentation of glucose (unlike to starch) by the light-dependent consortium or Rb. sphaeroides alone resulted in ∼3 fold increase of hydrogen production compared to the heterotrophic consortium. Apparently, hydrolysis of starch to hexose was the bottleneck in H2 photoproduction by the light-dependent consortium. Availability of residual hexose after photofermentation of starch/glucose by the light-dependent consortium or Rb. sphaeroides is discussed. 相似文献
119.
Tatyana V. Bandos Álvaro Montero Esther Fernández Juan Luis G. Santander José María Isidro Jezabel Pérez Pedro J. Fernández de Córdoba Javier F. Urchueguía 《Geothermics》2009
A solution to the three-dimensional finite line-source (FLS) model for borehole heat exchangers (BHEs) that takes into account the prevailing geothermal gradient and allows arbitrary ground surface temperature changes is presented. Analytical expressions for the average ground temperature are derived by integrating the exact solution over the line-source depth. A self-consistent procedure to evaluate the in situ thermal response test (TRT) data is outlined. The effective thermal conductivity and the effective borehole thermal resistance can be determined by fitting the TRT data to the time-series expansion obtained for the average temperature. 相似文献
120.
Laura Matuschik Vladimir Riabov Christina Schmuttermaier Tatyana Sevastyanova Christel Weiss Harald Klüter Julia Kzhyshkowska 《International journal of molecular sciences》2022,23(3)
Hyperglycemia, a hallmark of diabetes, can induce inflammatory programming of macrophages. The macrophage scavenger receptor CD163 internalizes and degrades hemoglobin-haptoglobin (Hb-Hp) complexes built due to intravascular hemolysis. Clinical studies have demonstrated a correlation between impaired scavenging of Hb-Hp complexes via CD163 and diabetic vascular complications. Our aim was to identify whether hyperglycemia is able to amplify inflammation via Hb-Hp complex interactions with the immune system. M(IFNγ), M(IL-4), and control M0 macrophages were differentiated out of primary human monocytes in normo- (5 mM) and hyperglycemic (25 mM) conditions. CD163 gene expression was decreased 5.53 times in M(IFNγ) with a further decrease of 1.99 times in hyperglycemia. Hyperglycemia suppressed CD163 surface expression in M(IFNγ) (1.43 times). Flow cytometry demonstrated no impairment of Hb-Hp uptake in hyperglycemia. However, hyperglycemia induced an inflammatory response of M(IFNγ) to Hb-Hp1-1 and Hb-Hp2-2 uptake with different dynamics. Hb-Hp1-1 uptake stimulated IL-6 release (3.03 times) after 6 h but suppressed secretion (5.78 times) after 24 h. Contrarily, Hb-Hp2-2 uptake did not affect IL-6 release after 6h but increased secretion after 24 h (3.06 times). Our data show that hyperglycemia induces an inflammatory response of innate immune cells to Hb-Hp1-1 and Hb-Hp2-2 uptake, converting the silent Hb-Hp complex clearance that prevents vascular damage into an inflammatory process, hereby increasing the susceptibility of diabetic patients to vascular complications. 相似文献