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41.
Both integrating sphere reflectometry (ISR) as well as laser polarimetry have their advantages and limitations in their ability to determine the normal spectral emissivity of metallic samples. Laser polarimetry has been used for years to obtain normal spectral emissivity measurements on pulse-heated materials. The method is based on the Fresnel equations, which describe reflection and refraction at an ideally smooth interface between two isotropic media. However, polarimetry is frequently used with surfaces that clearly deviate from this ideal condition. Questions arise with respect to the applicability of the simple Fresnel equations to non-specular surfaces. On the other hand, reflectometry utilizing integrating spheres provides a measurement of the hemispherical spectral reflectance, from which the normal spectral emissivity can be derived. ISR provides data on spectral-normal-hemispherical reflectance and, hence, normal spectral emissivity for a variety of surfaces. However, the resulting errors are minimal when both the sample and the reference have a similar bidirectional reflectance distribution function (BRDF). In an effort to explore the limits of polarimetry in terms of surface roughness, room temperature measurements on the same samples with various degrees of roughness were performed using both ISR and a laser polarimeter. In this paper the two methods are briefly described and the results of the comparison are discussed. 相似文献
42.
球罐球壳板的划线与切割 总被引:1,自引:0,他引:1
球壳板划线与切割的精度直接影响着球罐现场组装质量,本文论述了采用三维坐标系下解析几何的方法计算球壳板上切割点与检查点的划线尺寸,并利用划线尺寸进行划线,通过分析原切割模具存在的缺点,重新设计计算了切割模具,提高了球壳板划线与切割的精度 相似文献
43.
Yue Wang Yangyu Li Wei Guo Xiao Yang Jiameng Qu Mang Gao Shuting Chen Jiangru Dong Qing Li Tiejie Wang 《International journal of molecular sciences》2022,23(22)
To clarify the differences in the clinical application scope of Chrysanthemum morifolium flower (CMF) and Chrysanthemum indicum flower (CIF), two herbs of similar origin, an integrated strategy of network pharmacology, molecular pharmacology, and metabolomics was employed, with a view to investigating the commonalities and dissimilarities in chemical components, efficacy and mechanisms of action. Initial HPLC-Q-TOF-MS analysis revealed that CMF and CIF had different flavonoid constituents. The biological processes underlying the therapeutic effects of CMF and CIF on liver-fire hyperactivity syndrome of hypertension (LFHSH) were predicted to be related to inflammatory response, fatty acid production, and other pathways based on network pharmacology analysis. ELISA, molecular docking, Western blot, and metabolomics techniques showed similar effects of CMF and CIF in lowering blood pressure, resistance to tissue, organ and functional damage, and dyslipidemia. However, distinct effects were found in the regulation of inflammatory response, PI3K-Akt and NF-κB signaling pathways, lipid anabolism, renin-angiotensin system, and metabolic abnormalities. The comparable efficacies of CMF and CIF, despite having distinct mechanisms of action, may be attributed to the integration and counteraction of their different regulating capabilities on the above anti-LFHSH mechanisms. This study offers a vital platform for assessment of differential and precise applications of herbs of close origin with similar but slightly different medicinal properties, and provides a research strategy for bridging Chinese medicine and modern precision medicine. 相似文献
44.
As a commercial high-grade cut flower, the marketability of herbaceous peony (Paeonia lactiflora Pall.) is limited by its short vase life in water. Si (silicon) is an alternative to improve the postharvest life of cut flowers. However, the effects of the combined application of Si and preservatives on the postharvest performance of cut peony flowers are unknown. In this study, the effects of a Si application and a preservative alone and collegial on the longevity of the vase life, water loss, antioxidant defense system, and stock carbohydrates level of cut flowers of three peony cultivars were investigated. It was observed that Si effectively prolonged the vase life, while the preservative alone, to a lesser extent, but markedly induced an early flowering and a greater flower diameter (flower open degree). The simultaneous use of Si and the preservatives not only showed larger flowers, but also improved the postharvest performance as characterized by an extended vase life and delayed the water loss. In addition, the Si supplementation dramatically intensified the antioxidant defense system (ameliorated antioxidant enzymes and alleviated ROS accumulation) in petals but did not increase the stock carbohydrates (starch and soluble sugars) levels, as compared to the treatment with the preservative alone. We show that a Si supplementation to a preservative is highly recommended for a large-scale use to promote the postharvest performance and competitiveness of marketed cut flowers. 相似文献
45.
二进神经网络中汉明球的逻辑意义及一般判别方法 总被引:3,自引:0,他引:3
剖析二进神经元的逻辑意义对二进神经网络的规则提取是十分重要的,在布尔空间中,汉明球是一种线性可分的空间结构,如何从汉明球中提取出具有清晰逻辑意义的规则是二进神经网络研究的一个问题,通过对MofN规则表达形式的扩展,分析了汉明球的逻辑意义,提出了表达汉明球逻辑意义的LEM规则和GEM规则方法,并且讨论了汉明球和汉明补球的等价性,另一个重要的结果是证明了二进神经元和汉明球等价的充要条件,从而建立了判别汉明球的一般方法。 相似文献
46.
47.
塑料花专用树脂的结构与性能 总被引:1,自引:0,他引:1
分析了低密度聚乙烯(LDPE)塑料花专用树脂868—000的结构性能,发现长链支化度低、相对分子质量分布窄是导致其性能欠佳的主要原因。改性实验结果表明,添加质量分数为15%的改性母粒后,可将868—000的耐应力开裂时间从4min提高到28min。低温脆化温度从-7℃降低到-20℃,并有效地改善了产品的柔软性和黏接性能。 相似文献
48.
构造绿色云数据中心的两个主要目标是低能量消耗与物理资源利用效率的充分利用,为此需要采用虚拟机分配策略来完成优化。本文提出了基于改进花授粉算法的虚拟机分配策略(Flower pollination algorithm based virtual machine allocation, FPA-VMA)。FPA-VMA中一朵花或一个配子就对应于虚拟机映射到物理主机分配优化问题中的一个解;并且描述了云数据中心云客户端的资源请求模型和多维物理资源的能量消耗模型。FPA-VMA在花授粉的动态切换概率阶段的策略可以平衡全局最优解搜索和局部最优解搜索之间的切换,同时改善资源分配的全局收敛能力。真实的虚拟机数据的访问测试结果标明:FPA-VMA比常见的虚拟机分配优化策略有更低的能量消耗和更高的物理资源利用效率。 相似文献
49.
球形解码(Sphere Decoding, SD)是多输入多输出系统(MIMO)系统中一种非常高效的解码算法.它的初始搜索半径对算法的计算复杂度有很大的影响.提出一种名为 IR-ZF-OSUC的初始搜索半径确定方法.它利用了SD内嵌的QR分解结果来得到初始半径.相比其他类似方法,因半径更为接近最优值,且无需专门的处理步骤,使SD具有更低的计算复杂度.仿真表明,使用IR-ZF-OSUC来确定初始半径的SD相比基于其他策略的SD,在很宽的SNR范围内具有最低的计算复杂度. 相似文献
50.