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71.
72.
Material removal and surface damage of Ti3SiC2 ceramic during electrical discharge machining (EDM) were investigated. Melting and decomposition were found to be the main material removal mechanisms during the machining process. Material removal rate was enhanced acceleratively with increasing discharge current, ie, working voltage, ui, but increased deceleratively with pulse duration, te. Microcracks in the surface and loose grains in the subsurface resulted from thermal shock were confirmed, and the surface damage in Ti3SiC2 ceramic led to a degradation of both strength and reliability. 相似文献
73.
Hu P.J.-H. Tsang-Hsiang Cheng Chin-Ping Wei Chun-Hui Yu Chan A.L.F. Hue-Yu Wang 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2007,37(4):481-492
Drug-related problems, particularly those that result from sub- or overtherapeutic doses of high-alert medications, have become a growing concern in clinical medicine. In this paper, we use a model-tree-based regression technique (namely, M5) and support vector machine (SVM) for regression to develop learning-based systems for predicting the adequacy of a vancomycin regimen. We empirically evaluate each system's accuracy in predicting patients' peak and trough concentrations in different clinical scenarios characterized by renal functions and regimen types. Our data consist of 1099 clinical cases that were collected from a major tertiary medical center in southern Taiwan. We also examine the use of bagging for enhancing the prediction power of the respective systems and include in our evaluation a salient one-compartment model for performance benchmark purposes. Overall, our evaluation results suggest that both M5 and SVM are significantly more accurate than the benchmark one-compartment model in predicting patients' peak and trough concentrations across all investigated clinical scenarios. M5 appears to benefit considerably from bagging, which has a positive but seemingly smaller effect on SVM. Taken together, our findings indicate supervised learning techniques that are capable of effectively supporting clinicians' use of vancomycin or similar high-alert drugs in their patient care and management. 相似文献
74.
针对W9Cr3M04V轧制成品材低倍碳化物剥落的形成原因分析,得出一次碳化物颗粒粗大、在1/4D至中心区域聚集是导致低倍热酸浸试验碳化物剥落的主因;由此进行冶炼过程中注速(锭形)、浇注温度选择对比工艺试验,得出在原有冶炼+轧制的工艺基础上选用2.2t锭、降低浇注温度(1489℃)能有效改善一次碳化物颗粒大小和聚集程度,进而有效降低低倍碳化物剥落倾向。 相似文献
75.
对转炉炼钢实现低铁耗和高碳低磷工艺进行了分析,介绍了南钢公司转炉炼钢实践低铁耗条件下高碳低磷工艺的具体应用措施。 相似文献
76.
77.
This paper addresses the application of Genetic Programming (GP) to the synthesis of multicomponent product nonsharp distillation
sequences. Combined with the domain knowledge of chemical engineering, some evolutionary factors are improved, and a set of
special encoding method and solving strategy is proposed to deal with this kind of problem. The system structural variable
is optimized by GP and the continuous variable is optimized by the simulated annealing algorithm simultaneously. Because GP
has an automatic searching function, the optimal solution can be found including distillation, splitting, blending and bypassing
operations automatically without any superstructures of nonsharp distillation sequences. Three illustrative examples are presented
to demonstrate the effective computational strategies. 相似文献
78.
钢纤维聚合物混凝土抗压本构关系 总被引:2,自引:0,他引:2
钢纤维聚合物混凝土是由聚合物混凝土基体和钢纤维共同组成的纤维增强复合材料,它的力学行为不仅依赖于聚合物混凝土基体的行为,而且与钢纤维的掺量、分散特征以及钢纤维的几何尺寸有关,本文将基于损伤力学原理研究在不同纤维掺量下的钢纤维聚合物混凝土的全程压力-应变曲线及其本构模型。 相似文献
79.
A thin film of poly(l-serine) was prepared via electropolymerization for the determination of trace levels of estradiol. In pH 5.0 phosphate buffer,
l-serine was oxidized during the cyclic potential sweeps between −0.60 and 2.0 V, forming a thin film at the electrode surface.
The electrochemical behavior of estradiol was investigated. The oxidation peak potential of estradiol shifts negatively at
the poly(l-serine) film-coated glassy carbon electrode (GCE) compared with that at the bare GCE. Otherwise, the oxidation peak current
greatly increases at the poly(l-serine) film-modified GCE. These phenomena suggest that the poly(l-serine) film exhibits catalytic activity towards the electrochemical oxidation of estradiol. Based on this, a sensitive,
rapid and simple electrochemical method was proposed for the determination of estradiol. The limit of detection is evaluated
to be 2.0 × 10−8 mol L−1. Finally, this method was successfully used to determine estradiol in blood serum. 相似文献
80.
In this work, microcrystalline cellulose (MCC) was activated with ultrasonic waves. The influences of ultrasonic treatment on the changes of supramolecular structures and morphology structure were studied by WAXS and SEM. The accessibility of the MCC was characterized by water retention value (WRV) and specific surficial area. The influence of ultrasonic treatment on the reactivity of MCC was investigated through the reaction of MCC being oxidized into 2,3‐diadehyde cellulose (DAC) by periodate sodium. The mechanism of the reactivity change of ultrasonically treated MCC was examined. The results showed that the degree of crystallinity of MCC decreased and the degree of polymerization showed little change after treatment with ultrasonic waves. The morphologial variation of the treated MCC was significant when compared with the untreated MCC, which contribute to the improvement of accessibility. The aldehyde content of DAC prepared from ultrasonically treated MCC was improved from 64.19 to 85.00%, indicating that the regioselective oxidation reactivity of MCC was significantly improved. The aldehyde content was found to first increase with time of ultrasonic treatment to a point, and then decrease as time progressed. In addition, the aldehyde content was found to increase with an increase in ultrasonic power. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献