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21.
Atherosclerosis and nonalcoholic fatty liver disease are leading causes of morbidity and mortality in the Western countries. The renin–angiotensin system (RAS) with its two main opposing effectors, i.e., angiotensin II (Ang II) and Ang-(1–7), is widely recognized as a major regulator of cardiovascular function and body metabolic processes. Angiotensin-converting enzyme 2 (ACE2) by breaking-down Ang II forms Ang-(1–7) and thus favors Ang-(1–7) actions. Therefore, the aim of our study was to comprehensively evaluate the influence of prolonged treatment with ACE2 activator, diminazene aceturate (DIZE) on the development of atherosclerotic lesions and hepatic steatosis in apoE−/− mice fed a high-fat diet (HFD). We have shown that DIZE stabilized atherosclerotic lesions and attenuated hepatic steatosis in apoE−/− mice fed an HFD. Such effects were associated with decreased total macrophages content and increased α-smooth muscle actin levels in atherosclerotic plaques. Moreover, DIZE changed polarization of macrophages towards increased amount of anti-inflammatory M2 macrophages in the atherosclerotic lesions. Interestingly, the anti-steatotic action of DIZE in the liver was related to the elevated levels of HDL in the plasma, decreased levels of triglycerides, and increased biosynthesis and concentration of taurine in the liver of apoE−/− mice. However, exact molecular mechanisms of both anti-atherosclerotic and anti-steatotic actions of DIZE require further investigations.  相似文献   
22.
A comprehensive investigation to determine the initiation power of detonators containing as a base charge the novel explosives: dihydroxylammonium 5,5′‐bis(tetrazolate‐1N‐oxide) – TKX‐50, dihydroxylammonium 5,5′‐bis(3‐nitro‐1,2,4‐triazolate‐1N‐oxide) – MAD‐X1, pentaerythritol tetranitrocarbamate – PETNC and 3,3′‐diamino‐4,4′‐azoxyfurazan – DAAF in comparison with RDX, HMX and PETN was undertaken. In order to estimate the initiation power of the detonators, the underwater initiating capability test was used. The total energy as a sum of the primary shock wave energy and the bubble gas energy was determined for each of these explosives, by measuring the overpressure of the shock waves generated in water. Moreover, the complete synthesis for novel explosives is presented. The thermal behavior of the explosives was investigated using DSC (differential scanning calorimetry). The gas phase absolute molar enthalpies at 298 K and 105 Pa were calculated theoretically using the modified complete basis set method (CBS‐4M; M referring to the use of minimal population localization) with the Gaussian 09 software. Gas phase standard molar enthalpies of formation (ΔHf°(g)) at 298 K were computed using the atomization energy method. Standard molar enthalpies of formation (▵H(s)°) were calculated using ΔHf°(g) and the standard molar enthalpies of sublimation by applying Trouton’s rule. The Chapman‐Jouguet (CJ) characteristics based on calculated ▵H(s)° values were computed using the EXPLO5 V6.01 thermochemical computer code. For the calculations the theoretical maximum densities and densities obtained during the experiments presented in this work were used.  相似文献   
23.
Sorption is a suitable method for the removal of all contaminants in the ionic form, also including heavy metal ions in the presence of complexing agents from different systems. The aim of this study was a comparison of Cu(II), Ni(II), and Pb(II) sorption in the presence of a complexing agent of a new generation on the strongly basic anion exchangers Amberjet 4200, Amberjet 4600, and Purolite A 520E under different chemical conditions. In the investigation, methylglycinediacetic acid (MGDA), patented by BASF The Chemical Company (Germany) and marketed under the brand name Trilon M, was used. It is a strong complexing agent, readily biodegradable in compliance with Organization for Economic Co-operation and Development (OECD) standards. It was found that the sorption efficiency of strongly basic anion exchangers varied, depending on the metal ions concentration, the pH, the contact time, the temperature, and the properties of anion exchangers, that is, their forms. From the determined breakthrough curves, the distribution coefficients and the ion exchange capacities were calculated. Besides, two different kinetic behaviors were tested for the investigated systems. The experimental data fitted using the Langmuir, Freundlich, and Elovich sorption models, were applied to describe the equilibrium isotherms and determine the isotherm constants. The variations of thermodynamic functions were also calculated.  相似文献   
24.
Untreated and thermally annealed platinum carbon (PtC) composites obtained by ion beam induced deposition (IBID) are physically and electrochemically characterized as novel patternable electrode materials. Energy dispersive X-ray spectroscopy (EDX) and Raman spectroscopy reveal that annealing in ambient atmosphere and at temperatures above 400 °C substantially reduces the amount of carbon within the deposited material. Raman spectra also show that at elevated temperatures carbon rearranges into a more structured graphitic-like phase. Atomic force microscopy (AFM) reveals that after the annealing procedure the surface structure appears more corrugated, while the dimensions of granular surface features decreases. Furthermore, it is shown that electrodes based on annealed PtC material show an improved heterogeneous electron transfer rate for the oxidation of potassium hexacyanoferrate(II) trihydrate by almost three orders of magnitude, whereas the reduction of hexaammineruthenium(III) trichloride proceeds at similar rates for both treated and untreated electrodes. The rate of electrochemical oxidation of H2O2, which is influenced by the composition of the electrode surface, is also improved at thermally annealed electrodes. Finally, cyclic voltammetry in sulfuric acid shows an increase in surficial platinum concentration after annealing of the material.  相似文献   
25.
In this article, synthesis and properties of novel dimethacrylic resin (ISETDMA) based on human friendly, biobased isosorbide was described. Its potential as a possible diluting monomer for medical applications, mainly dental restorative systems was assessed. The resin was obtained in two‐step synthesis including ethoxylation of isosorbide and subsequent methacrylation with methacryloyl chloride. 1HNMR, FTIR, and electrospray ionization mass spectroscopy (ESI‐MS) techniques were used to identify products. ISETDMA as well as composition with 2,2‐bis[4‐(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]propane were polymerized using UV initiator IRGACURE 651. Double bond conversion, polymerization shrinkage, water sorption, and sol fraction of resulting polymers were determined. Selected mechanical (flexural strength and modulus, Brinell hardness) and thermomechanical (dynamic mechanical analysis) properties were also investigated. Triethylene glycol dimethacrylate and 2,2‐bis(4‐(2‐methacryloxyethyl‐1‐oxy)phenyl)propane based homopolymers and copolymers were prepared as reference for comparison of particular properties. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2514–2522, 2013  相似文献   
26.
Arborescent polyoxyethylene of high molar mass (2×105 g/mol) and narrow molar mass distribution was synthesized in a three-stage process. In the first stage a triblock copolymer of ethylene oxide (central block, DP ca. 90) and 2,3-epoxypropanol-1 (short flanking blocks, DP ca. 5) was synthesized. The potassium alcoholate derived from this copolymer was used to initiate the polymerization of ethylene oxide and the subsequent addition of protected glycidol (1-etoxyethyl glycidyl ether). After deprotection the short polyglycidol blocks were used as branching units for the next generation. Repeated step by step process leads to the ‘pom-pom like’ branched polyoxyethylene macromolecules enriched with the reactive hydroxyl groups in the outer shell. The branched structure of the obtained polymers was evidenced by the size exclusion chromatography and NMR spectroscopy.  相似文献   
27.
以ZSM-5分子筛为模板担载金属镍(Ni/ZSM-5)为催化剂,在不同质量分数Ni和温度下进行气相化学沉积过程得到氢气和纳米碳质材料(碳纳米管、纳米炭纤维)。氢气和纳米碳质材料的产率随Ni质量分数增加和反应温度升高而显著地增加,但当Ni含量为8%时产率却减小。纳米碳质材料的形貌与反应温度密切相关。在较高温度下可沉积出碳纳米管,在较低温度下则可得到纳米炭纤维。随着反应时间的延长Ni/ZSM-5的催化活性降低。  相似文献   
28.
Exact, contact-free and non-destructive, optical analysis of semiconducting layers, are advantageous for thin film solar cell applications. A non-numerical theoretical model has been developed to extract approximation-free optical and electrical data from UV/Vis/NIR spectra. Special focus has been set on single layers; an adequate single-layer model is provided. Complex parameter evaluation is possible.This exact data acquisition model provides deeper insights in the process-parameter dependencies of pulsed direct current and radio frequency sputtered, opaque tin-sulphide thin films upon glass substrates. They have been analysed with respect to space-time dependencies of the sputter process. Therefore, sputter-depositions have been examined, referring to positions upon the substrate, r, target-substrate distances, dTarSub, and sputter durations, tSp. Theoretical sputter-concepts were proved and enhanced. Results were compared with those of the well-known Keradec/Swanepoel model. The necessity of taking both spectra—transmission and reflection spectra—into account has been shown.A non-contact, optical conductivity measurement possibility by use of UV/Vis/NIR spectroscopy has been provided. Optically evaluated conductivities, σL, were compared with electrically taken values, by use of a four-tip measurement system.  相似文献   
29.
This paper presents a new microwave device - a non-radiative dielectric (NRD) waveguide with a dielectric pseudochiral Ω-slab - the Ω-NRD waveguide. A rigorous full-wave analysis is presented and the modal equations for the longitudinal-section magnetic (LSM) and longitudinal-section electric (LSE) modes are derived. The dispersion curves and operational diagrams for the first hybrid LSM modes are presented. The effect of the pseudochiral Ω-medium is discussed. New interesting modal features are revealed, showing that the propagation characteristics may differ considerably from the common isotropic case  相似文献   
30.
Benign and malignant tumors of papilla Vateri are rare diagnoses in the endoscopic practice. Sixteen patients with benign and 22 cases of malignant tumors are presented. In all of them endoscopic cholangiopancreatography with or without papillotomy followed by biopsy and operation in 13 cases was performed. Biopsy confirmed the endoscopy in 71%. Adenomyosis, supposed by endoscopy was proved by repeated histology in only 2/9 cases although invasive component of the tumor was found in 3/9 patients at operation underlying precancerous nature of this entity. Among 5 cases of villous adenoma one developed malignant alterations during 4 years of follow-up. Biopsy was not more effective after papillotomy than without it, and 5-7 days of delay for recovery of thermic lesion did not ameliorate success rate of histology. For malignant diseases surgical therapy should be considered if staging of tumor and general condition of the patient permits. In unresectable cases endoscopic palliation (papillotomy or polypectomy with or without drainage) can increase survival. In patients with benign tumors operative endoscopy followed by regular ultra-sonography and endoscopy seems to be necessary.  相似文献   
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