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1.
对超重力场条件下Cu熔体中的氧化夹杂进行受力分析,建立夹杂颗粒沿超重力方向上的运动速度与运动距离方程,并通过理论计算分析重力系数、夹杂物特性(尺寸、种类、含量)以及熔体温度对夹杂物在超重力场中运动行为的影响。计算结果表明,超重力场能强化Cu熔体中氧化夹杂的定向分离过程,其中重力系数、夹杂物尺寸、夹杂与熔体之间密度差(固液密度差)对夹杂颗粒运动行为影响较大。较大的重力系数、夹杂物尺寸以及固液密度差均有利于夹杂物的上浮去除。  相似文献   
2.
The extraction of raw materials is associated with energy input and CO2 emissions. What is obvious for extraction from mining, however, also applies to recycling. Mostly, recycling is preferred for reasons of climate protection or because of the geological scarcity of raw materials, which is controversially discussed. While in mining, the declining ore grade is a driver for the energy demand, in case of recycling it is the dissipation of materials into products or waste. As concentration decreases, the effort required also increases disproportionately. The “closing the loop” metaphor of Circular Economy is therefore inappropriate in its stricter meaning. It is rather about optimizing the overall system and finding the optimal recycling rate. However, first, it must be clarified what the political goals for Circular Economy are.  相似文献   
3.
The synthesized novel metal oxides YxCeyRuzO4 (x = 1.5, y = 0.84, z = 0.04) which was produced by the sol-gel method was used as a support for Cu active metal on the surface of a microchannel plate reactor in the methanol steam reforming (MSR) process. The prepared catalysts were characterized by X-ray powder diffraction (XRD), BET surface area analysis (SBET), energy-dispersive X-ray analysis (EDX), field-emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), temperature-programmed desorption (NH3-TPD), and temperature-programmed reduction (H2-TPR). High methanol conversion (99.5%) and H2 selectivity (98.7%) and low CO selectivity (1.4%) were achieved for Cu/YxCeyRuzO4 coated microchannel reactor at 250 °C. FE-SEM images and TGA curve of the spent catalyst displayed no coke formation on the surface of the catalyst after 32 h on stream at 300 °C. The low reduction temperature of Cu, high BET surface area, and high pore volume of the catalyst are considered imperative factors that cause a better dispersion of copper on the Y1.5Ce0.84Ru0.04O4 support.  相似文献   
4.
《Ceramics International》2022,48(16):22699-22711
An integrated experimental and thermodynamic modeling study of the phase equilibria in the ‘CuO0.5’-MgO-SiO2 system in equilibrium with liquid Cu metal has been undertaken to better understand the reactions between MgO-based refractories and liquid slag in copper converting and refining processes. New experimental phase equilibria data at 1250–1680 °C were obtained for this system using a high-temperature equilibration of synthetic mixtures with predetermined compositions in silica ampoules or magnesia crucibles, a rapid quenching technique, and electron probe X-ray microanalysis of the equilibrated phase compositions. The system has been shown to contain primary phase fields of cristobalite (SiO2), tridymite (SiO2), pyroxene/protoenstatite (MgSiO3), olivine/forsterite (Mg2SiO4), periclase (MgO), and cuprite (Cu2O). Three regions of 2-liquid immiscibility were found—two in the high-silica range of compositions above the cristobalite primary phase field (close to ‘CuO0.5’-SiO2 and MgO–SiO2 binaries) and one in the low-SiO2, high-‘CuO0.5’ compositional region above the periclase and olivine phase fields. The results obtained in this study indicate that silica in high-copper refining slags likely led to olivine and pyroxene phase formation, increased solubility of MgO in liquid slag, and decline in the performance of MgO-based refractories. New experimental data were used in the development of a thermodynamic database describing this pseudo-ternary system.  相似文献   
5.
Bimetallic catalysts have been investigated as the most efficient materials to accelerate the chemical transformations at the anode in Direct Ethanol Fuel Cells. A comparative study is presented here to synthesize Ni–Cu bimetallic nanoparticles for the ethanol oxidation reaction on three conducting polymers: poly-ortho-phenylenediamine, poly-meta-phenylenediamine, and poly-para-phenylenediamine. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Electrochemical Impedance Spectroscopy (EIS) were used to analyze the modified electrodes. A series of bimetallic Ni–Cu nanoparticles with tunable ratios were successfully synthesized by simply changing the concentrations of Nickel and Copper. It has been confirmed that the best Ni/Cu molar ratio was 25% in the aspect of catalytic performance. The electrocatalyst exhibited an excellent catalytic activity with an anodic current of 70.5 mA cm?2 at the lowest onset potential of 0.39 V with impressive stability. Ni4Cu1/PpPD should be considered as a good alternative to noble metal anode catalyst.  相似文献   
6.
《Ceramics International》2021,47(22):31319-31328
Manufacturing lightweight aggregate (LWA) at high temperature is an effective way to immobilize heavy metals in solid waste. This work investigated the performance and solidification mechanism of LWA prepared from copper contaminated soil. The volume expansion of LWA could reach a maximum of 28%, and its lowest density accounted of 1.5 g/cm3, which met the standard requirements. Optical microscope and micro-CT test illustrated that the addition of Cu leaded to obvious phase separation in LWA. The Cu leaching result of LWA first increased and then dropped with the temperature. The XRD test found that the main formation phase of Cu in LWA were t-CuFe2O4 and amorphous phase that they had different acid resistance ability. XPS revealed that the main cause of the agglomeration of liquid phase in LWA was the chain broken reaction between Cu and Si–O tetrahedron. SEM-EDS results showed that the distribution of Cu and Si had a strong correlation, which meant that Cu mostly formed amorphous phase. This work showed the uniqueness of Cu in the high temperature immobilization and pointed out the best immobilization target phase.  相似文献   
7.
The production of hydrogen, a favourable alternative to an unsustainable fossil fuel remains as a significant hurdle with the pertaining challenge in the design of proficient, highly productive and sustainable electrocatalyst for both oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, the dysprosium (Dy) doped copper oxide (Cu1-xDyxO) nanoparticles were synthesized via solution combustion technique and utilized as a non-noble metal based bi-functional electrocatalyst for overall water splitting. Due to the improved surface to volume ratio and conductivity, the optimized Cu1-xDyxO (x = 0.01, 0.02) electrocatalysts exhibited impressive HER and OER performance respectively in 1 M KOH delivering a current density of 10 mAcm?2 at a potential of ?0.18 V vs RHE for HER and 1.53 V vs RHE for OER. Moreover, the Dy doped CuO electrocatalyst used as a bi-functional catalyst for overall water splitting achieved a potential of 1.56 V at a current density 10 mAcm?2 and relatively high current density of 66 mAcm?2 at a peak potential of 2 V. A long term stability of 24 h was achieved for a cell voltage of 2.2 V at a constant current density of 30 mAcm?2 with only 10% of the initial current loss. This showcases the accumulative opportunity of dysprosium as a dopant in CuO nanoparticles for fabricating a highly effective and low-cost bi-functional electrocatalyst for overall water splitting.  相似文献   
8.
细炻砖作为仿古砖的一个重要组成部分一直在家庭装修中被广泛应用。在细炻砖的生产过程中,铜锈在浅色版面中容易显露出来,占总缺陷的比例比较大,也降低了产品的品质。本文用XRF对原材料和坯体配方进行了定性分析,用SEM对铜锈进行了表面形貌分析,用EDS对铜锈进行了元素分析。结果表明,铜锈主要是原料中的有色金属杂质引起。通过加强浆料的过筛,降低浆料的细度可以有效减少铜锈的产生。  相似文献   
9.
Effect of chemical composition of Mg-xCu based alloys (x = 9.94–58.00 wt %) modified by KCl upon their hydrogen storage performance was studied. Kinetic curves and pressure-concentration isotherms were measured in the ranges up to 60 bar and 388 °C, respectively. It was observed that desorption rate dc/dt is not significantly influenced by the composition. Unknown Cu-rich phase was detected that has shown a catalytic effect on desorption from a mixture with other phases. Activation energy of hydrogen desorption decreased with increasing x from 180 kJ/mol down to 98 kJ/mol. Average hydride dissociation enthalpy, ΔH, for the lowest plateau was 75 kJ/mol which is equal to literature value for pure Mg. Slightly lover average value, 67 kJ/mol was obtained for the second plateau and ΔH for the third one decreased from 70 kJ/mol for the lowest to 49 kJ/mol for the highest x.  相似文献   
10.
This study describes the synthesis and characterization of Cu-doped ZnO nanorods (NRs) by an electrochemical method in the presence of two different Cu precursor (Cu+2 and Cu+) in order to improve photocurrent generation. Analyses of the resulting materials by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV–Vis and electrochemical photocurrent (ECP) spectroscopy confirm the formation of well-aligned ZnO Würtzite nanostructures in the form of hexagonal rods. For both doping source with a concentration of up to 0.5%, the following changes were observed: a distortion of the ZnO morphology, an increase in transmittance to 96% for ZnO doped with Cu+2, and a reduction of the energy gap from 3.36 eV to 3.06 and 3.02 eV for ZnO doped with Cu+2 and Cu+, respectively. From photoelectrochemical tests, the photo-current density was improved up to 0.05 mA cm-2 in the presence of Cu doping, which is twelve times superior to that of undoped ZnO nanorods, which means that the incorporation of Cu+2 or Cu + significantly improves the separation efficiency of photogenerated electron-hole pairs. These results can be considered promising for optoelectronic and photocatalysis applications.  相似文献   
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