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131.
针对当前化纤市场的情况,通过对目前流行的差别化产品的分析比较,结合本企业的实际情况,选择了产品开发的方式,并提出了产品开发的一些建议。 相似文献
132.
根据近十年的工作实践,分析了T51-200/ZK型金属离子注入机弗里曼离子源失效机理,着重讨论了以MoCl_5为工作物质时的灯丝中毒现象。结合作者的工作经验,提出了减少灯丝中毒现象的一些具体措施。 相似文献
133.
Electron holographic observation for biological specimens: electron holography of bio-specimens 总被引:1,自引:0,他引:1
Electron holography has been applied to the observation of biological filaments. The technique has some advantages over conventional imaging for observing weak-phase objects such as small unstained biological structures. To avoid artificial structural transformation of the sample owing to the interaction with the supporting film, a holey carbon film was used to support the filaments. A tobacco mosaic virus bridged over a hole was observed as a cylindrical shape; the contrast distribution across the filament represents its actual shape, which is difficult to obtain with conventional transmission electron microscopy. A number of technical limitations which at present prevent high-resolution structure analysis of biological macromolecules by electron holography are discussed in this report. 相似文献
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135.
The time‐dependent bending recovery of human hair fibers was investigated for a variety of relative humidities and aging times. The data were analyzed on the basis of a viscoelastic filament/matrix model and the Denby‐equation, containing the parameter K as the ratio of the elastic bending rigidities of the matrix and the filaments and the Kohlrausch‐Williams‐Watts (KWW) function as relaxation function. The first stage of the analysis ascertained that the recovery curves shift with aging time on the time scale with the expected aging rate of μ ≈ 1. The second stage showed that the shape factor of the KWW function exhibits a mean value across the aging and humidity range of m = 0.28, which is close to the “universal” value of 1/3. On this basis, it was found that virtually no change occurs for the modulus ratio for low water contents up to about 10%, being constant at K0= 6 .1, while linearly decreasing beyond this threshold. The reduced, characteristic relaxation time drops on the log‐time scale from logτr(0) = 0.47 for the dry fiber linearly with water content, covering about two thirds of a decade for 0–20% water content. With the pronounced humidity dependence of the parameters, hair shows what is termed hydro‐rheologically complex (HRC) in analogy to thermo‐rheologically complex behavior. Using the HRC approach, the dynamical mechanical performance of hair (1 Hz) was calculated for a range of water contents and aging times and found to be in good general agreement with experimental data. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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137.
飞机着滑灯由于亮度高、工作电压高、寿命短而不同于普通照明白炽灯。使用针对普通白炽灯灯丝设计而开发的软件对着滑灯灯丝进行设计时,设计误差超过20%。在白炽灯灯丝设计理论基础之上,采用线性回归方法给出了着滑灯灯丝参数的计算公式。经过实际测试,设计精度在8%之内。 相似文献
138.
20μm的不锈钢长丝与25 tex的竹浆/丝光羊毛(50/50)股线经过并线加捻设计开发出5种不锈钢长丝含量不同的纱线,设计并试织了不锈钢长丝质量分数分别为11%、15%、17%、22%、26%的5种2/2斜纹组织织物。测试和分析了这5种织物的防辐射性能、厚度、面密度、透气性、悬垂性、刺痒感、汽蒸收缩性、折皱回复性。结果表明:开发的5种织物均具有良好的防电磁辐射性能,且随着不锈钢长丝含量增加,织物的防辐射性能提高,厚度、面密度、刺痒分值逐渐增大,透气性、悬垂性、折皱回复性降低,汽蒸收缩性先降低后保持不变。 相似文献
139.
为调整微钻表面金刚石薄膜的晶粒尺寸和粗糙度以满足PCB板钻孔的工况要求,调节氩气和氢气流量比,采用热丝化学气相沉积法,以甲烷、氢气及氩气为气源在硅基体上沉积出一系列金刚石薄膜。利用拉曼光谱仪、X射线衍射仪(XRD)、扫描电子显微镜(SEM)及原子力显微镜(AFM),分别表征不同氩气流量下制备的金刚石薄膜的碳价键结构、晶面取向、晶粒尺寸和表面粗糙度。结果表明:随着氩气流量增大,金刚石薄膜中的石墨含量呈升高趋势,薄膜趋向(111)晶面择优生长,晶粒尺寸从微米级(1. 27μm)细化至纳米级,薄膜粗糙度先升高后降低,最低为65 nm。研究表明,存在最优的氩气流量使得制备的薄膜具有适宜的结构特点,如碳价键含量高、(111)晶面取向度高、晶粒尺寸小和粗糙度低,可满足PCB板超细钻孔的要求。 相似文献
140.
In this study, filaments comprising natural silk fibroin microparticles (NSFP) and biomedical polyurethane (BPU) were prepared via wet-spinning as a reusable-controlled drug-delivery system. The rheological properties of the spinning solution were studied to examine the effect of NSFP on the BPU/NSFP filament formation. The influences of NSFP content and spinning conditions on the morphology, molecular interactions, mechanical properties, and swelling performance of BPU/NSFP filaments were also investigated. The morphology and mechanical property studies showed that NSPF and BPU exhibit good compatibility. The capacity of the BPU/NSFP filaments as drug loading carriers and drug release behavior were studied by spectroscopy. The presence of NSFP in the drug controlled system increase the drug loading amount and enhance the drug release time. This paper presents a well-designed manufacturing method for preparing BPU/NSFP filaments with good controlled drug delivery. 相似文献