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91.
HARUHIKO SATO SHIN SAITO SHOTA MIZUNO KOICHI AKAHANE HIRONAGA UCHIDA 《Electrical Engineering in Japan》2017,198(3):27-33
The spin‐dependent scattering of conduction electron in metallic magnetic multilayers was investigated to reveal the optical properties which corresponded to the magnetization state. From the measurement of magnetorefractive effect in antiferro‐magnetically exchange coupled Co/Ru multilayers, it was found that (1) the transmittance varied around 1% at wavelength of 1550 nm during the parallel/antiparallel spin alignment changes, (2) as a result of number of repetition and Co thickness for the multilayers, transmittance difference between the parallel and antiparallel spin alignment states had trade‐off relationship with the magnitude of transmittance, and (3) asymmetric Co/Ru/Co stacking structure brought different interlayer exchange coupling fields in each layer, which resulted in magnetic field sensitive transmittance. 相似文献
92.
Structure, corrosion, and hardness properties of Ti/Al multilayers coated on NdFeB by magnetron sputtering 总被引:2,自引:0,他引:2
Ti/Al multilayers deposited on sintered NdFeB magnets by direct current magnetron sputtering with ion-beam assistance were studied in this report. Ti layers with a hexagonal close packed structure were obtained in the Ti/Al multilayers. The columnar structure growth of Al layers was successfully interrupted by the intercalated Ti layers. The Ti/Al multilayers showed more compact and uniform surfaces than the Al single layer. The corrosion current densities of the sintered NdFeB magnets coated with Ti/Al multilayers were much lower than that of the Al single layer. The Ti/Al multilayers also presented improved hardness. 相似文献
93.
《Materials Science & Technology》2013,29(7):1213-1221
AbstractThis paper is focused on the microstructure modelling and evaluation of effective elastic properties of three-dimensional multiphase and multilayer braided composite. Regarding the multiscale characteristics of the composite, the microstructure modelling is carried out sequentially from fibre to tow scale. The geometrical configuration of the microstructure is first analysed, and mathematical relations among different geometrical parameters are derived on each scale. Second, effective elastic properties are obtained based on the sequential homogenisation from fibre to tow scale. A strain energy based method is proposed to evaluate effective elastic properties with specific boundary conditions imposed on the microstructure. Numerical results obtained by the proposed method and the microstructure model show a good agreement with the results measured experimentally. 相似文献
94.
多层模板支撑体系设计的几点思考 总被引:1,自引:0,他引:1
目前,多层模板支撑体系的设计方法并不完善。本文根据在进行多层模板支撑体系设计中遇到的问题,提出了几点思考:多层模板支撑荷载分配问题、水平荷载如何分配、抗冲切计算、施工人员及设备荷载标准值等。以期引起工程人员的注意,从而减少安全隐患。 相似文献
95.
计算、分析了多层PCB内埋平面电阻的特性,并将其应用于一种多层射频板威尔金森功分器的设计,研究并分析了平面电阻尺寸对该功分器射频性能的影响。 相似文献
96.
Hyun-Ju Choi Jong-Un Woo Hyun-Gyu Hwang Dae-Su Kim Mohan Sanghadasa Sahn Nahm 《Journal of the European Ceramic Society》2021,41(4):2559-2567
Li2O/B2O3-added Ba1-xSrxTiO3 (B1-xSxT) ceramics, where 0.2 ≤ x ≤ 0.35, were well densified at 920 °C with pure perovskite structure. The dielectric constant, tunability, and figure of merit (FOM) of B1-xSxT ceramics increased with x because of the decreasing Curie temperature (TC). The specimen with x = 0.35, whose TC was close to room temperature, exhibited a large tunability of 27.4 % and FOM of 110 at 10 kV/cm. A compositionally graded multilayer (CGML), which was sintered at 920 °C, was fabricated using B1-xSxT thick films to produce a temperature-stable tunable capacitor, and it evinced a dense microstructure and a continuous interface between the B1-xSxT thick film and the Ag electrode. This CGML capacitor showed a large tunability (51 %) and FOM (150) at 20 kV/cm. It also exhibited stable tunability (17–28 % at 10 kV/cm) at temperatures between 30–90 °C. Therefore, the B1-xSxT CGML capacitor is a suitable candidate for temperature-stable tunable capacitors. 相似文献
97.
Nawaf N. Hamadneh Waqar A. Khan Waqar Ashraf Samer H. Atawneh Ilyas Khan Bandar N. Hamadneh 《计算机、材料和连续体(英文)》2021,66(3):2787-2796
In this study, we have proposed an artificial neural network (ANN) model to estimate and forecast the number of confirmed and recovered cases of COVID-19 in the upcoming days until September 17, 2020. The proposed model is based on the existing data (training data) published in the Saudi Arabia Coronavirus disease (COVID-19) situation—Demographics. The Prey-Predator algorithm is employed for the training. Multilayer perceptron neural network (MLPNN) is used in this study. To improve the performance of MLPNN, we determined the parameters of MLPNN using the prey-predator algorithm (PPA). The proposed model is called the MLPNN–PPA. The performance of the proposed model has been analyzed by the root mean squared error (RMSE) function, and correlation coefficient (R). Furthermore, we tested the proposed model using other existing data recorded in Saudi Arabia (testing data). It is demonstrated that the MLPNN-PPA model has the highest performance in predicting the number of infected and recovering in Saudi Arabia. The results reveal that the number of infected persons will increase in the coming days and become a minimum of 9789. The number of recoveries will be 2000 to 4000 per day. 相似文献
98.
Donghai Ding Lihua Lv Guoqing Xiao Jiyuan Luo Changkun Lei Yun Ren Shoulei Yang Pan Yang Xing Hou 《International Journal of Applied Ceramic Technology》2020,17(2):645-656
The paper investigated the effects of different amounts (0%, 3%, 6%, 9%) of in situ multilayer graphene/MgAl2O4 composite powders on the slag resistance, thermal shock resistance, and oxidation resistance of low-carbon MgO-C refractories. Comparing with commercial MgAl2O4, the MgAl2O4 in in situ multilayer graphene/MgAl2O4 composite powders has higher lattice strain of crystal, which can trap more Mn and Fe ions, resulting in the better slag resistance. The oxidation decarbonation layer of MgO-C specimen with 3% composite powders is 9.71 mm, which is lower than not only the specimen with other contents but also specimen containing carbon black/MgAl2O4 powders. Moreover, the residual strength ratio of the specimen C/MA-3 was 47.47%, which is 28.5% and 8.08% higher than specimens with no additive and with carbon black/MgAl2O4 powders, respectively. Both improving thermal shock and oxidation resistance properties are related with the unique nano structure, multilayer graphene in situ formed between MgAl2O4 grains, of added composite powders. The former is due to higher strain energy consumed by multi-deflection of cracks inside the multilayer graphene/MgAl2O4 composite powders. And the latter is due to the higher energy of oxidation activation of multilayer graphene/MgAl2O4 composite powders due to effective protection of multilayer graphene by MgAl2O4. 相似文献
99.
Polyelectrolyte bilayers, which consist of poly-l-lysine (PLL) and hyaluronic acid (HA) were simulated with lipid membranes at different temperatures and ion concentrations. Starting with the sequential deposition of PLL and HA above the membrane surface, PLL and HA become completely mixed, leading to the formation of stable bilayers. PLL/HA bilayers are thicker at higher salt concentration because of weakened electrostatic interactions between PLLs and membrane lipids, in agreement with experiments. This salt effect decreases as PLL size increases. Also, bilayers become thinner at higher temperature because of the increased surface area of membrane. In particular, regardless of temperature and salt concentration, larger PLLs induce thicker bilayers, although larger PLLs have lower diffusivities than do smaller ones. Bilayers with larger PLLs show larger vacancy (more water) inside the bilayer, indicating that larger PLLs are less densely stacked on membrane surface than do smaller ones and thus form the thicker bilayer. These findings show the lower diffusivity of larger polyelectrolytes, which supports the experimental observation regarding the restricted diffusion of large polymers, and also imply the dependence of bilayer thickness on the polymer size. 相似文献
100.
Cheng Huang 《热应力杂志》2016,39(12):1471-1482
The multilayer ferroelectric actuator (MFA) with electrodes is an important smart structure and it has found wide application in engineering. Under the applied electric–elastic loads, the local stress concentration will be intensified near the tips of electrodes, and it finally may lead to the failure of the MFA. On the other hand, the temperature-dependent behavior of ferroelectrics results in the novel evolutions of local stresses and microstructure in the MFA under different temperature environments. In this work, the different temperature-induced nonlinear behavior and electroelastic field concentration around the electrode tip in the MFA is studied based on a phase-field approach containing the time-dependent Ginzburg–Landau equation. Using three-dimensional nonlinear finite element method, the temperature-induced domain switching behavior of the MFA and the evolution of the local stress near the electrode tips are simulated under different loadings and temperatures. It is found that the maximum tensile stress ahead of the electrode tip increases as the temperature increases from room temperature to a critical temperature. However, over the critical temperature, the stress decreases significantly due to the ferroelectric–paraelectric phase transition, which implies that by optimizing the environmental temperature, the local stress concentrations can be controlled. 相似文献