全文获取类型
收费全文 | 589篇 |
免费 | 37篇 |
国内免费 | 70篇 |
专业分类
电工技术 | 5篇 |
综合类 | 23篇 |
化学工业 | 127篇 |
金属工艺 | 168篇 |
机械仪表 | 17篇 |
建筑科学 | 17篇 |
矿业工程 | 13篇 |
能源动力 | 5篇 |
轻工业 | 181篇 |
水利工程 | 3篇 |
石油天然气 | 13篇 |
武器工业 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 72篇 |
冶金工业 | 23篇 |
原子能技术 | 4篇 |
自动化技术 | 8篇 |
出版年
2024年 | 1篇 |
2023年 | 21篇 |
2022年 | 15篇 |
2021年 | 23篇 |
2020年 | 21篇 |
2019年 | 25篇 |
2018年 | 17篇 |
2017年 | 22篇 |
2016年 | 23篇 |
2015年 | 22篇 |
2014年 | 25篇 |
2013年 | 25篇 |
2012年 | 35篇 |
2011年 | 45篇 |
2010年 | 38篇 |
2009年 | 31篇 |
2008年 | 24篇 |
2007年 | 45篇 |
2006年 | 30篇 |
2005年 | 28篇 |
2004年 | 30篇 |
2003年 | 23篇 |
2002年 | 35篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1997年 | 11篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 2篇 |
1992年 | 4篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1975年 | 2篇 |
1951年 | 1篇 |
排序方式: 共有696条查询结果,搜索用时 28 毫秒
81.
82.
Ja-Young Jung Shin-Bok Lee Ho-Young Lee Young-Chang Joo Young-Bae Park 《Journal of Electronic Materials》2008,37(8):1111-1118
Anodic dissolution characteristics and electrochemical migration (ECM) behavior of Sn-3.0Ag-0.5Cu solder in NaCl and Na2SO4 solutions were investigated using anodic polarization tests and water drop tests (WDT). The ECM lifetime of Sn-3.0Ag-0.5Cu
solder in NaCl solution (42.4 s) was longer than that in Na2SO4 solution (34.8 s). The pitting potential of Sn-3.0Ag-0.5Cu solder in NaCl solution (135 mV, SCE) was higher than that in
Na2SO4 solution (−367 mV, SCE). The passivity film (SnO2) formed on Sn-3.0Ag-0.5Cu solder during WDTs in NaCl solution was thicker than that formed in Na2SO4 solution. Therefore, the longer ECM lifetime of Sn-3.0Ag-0.5Cu solder in NaCl solution than in Na2SO4 solution can be attributed to the higher pitting potential in the NaCl solution, which is ascribed to the formation of a
thicker passivity film (SnO2) in the former. It was confirmed that microelements such as Ag and Cu do not take part in ECM because they form chemically
stable intermetallic compounds with Sn. We believe that Sn is the only element that contributes to ECM, and dissolution of
Sn at the anode is possibly the rate-determining step of ECM of Sn-3.0Ag-0.5Cu solder. 相似文献
83.
Modifications of fruit quality, in response to a long-term salt stress of four months, were studied in two strawberry cultivars differing in their sensitivity to salinity. The sensitive cv. Elsanta and the less sensitive cv. Korona were treated during two vegetation seasons with 0, 40 or 80 mmol NaCl/l in the nutrient solution. While mean fruit weight decreased, dry matter and contents of total soluble carbohydrates, as well as sweetness index of fruits, remained constant. Salt stress in both cultivars increased the antioxidant capacity, antioxidants pools (ascorbic acid, anthocyanins, superoxide dismutase) and selected minerals such as Na+, Cl−, K+, N, P and Zn2+, as well as lipid peroxidation. Furthermore, salt stress increased the contents of free and essential amino acids, especially in cv. Elsanta. The more tolerant cv. Korona was characterized by an increase of reduced glutathione and a better fruit taste. In salt-stressed fruits of cv. Elsanta, taste was significantly impaired. 相似文献
84.
目的研究3种冷却方式和不同NaCl浓度对冷鲜猪肉匀浆物凝胶特性的影响。方法以冷鲜猪肉为原料,分析测定不同冷却方式和NaCl浓度对猪肉匀浆物蛋白质溶解度、凝胶脱水率,凝胶持水力、凝胶强度和凝胶硬度的影响。结果 NaCl浓度为0.42mol/L时,常规冷却的猪肉匀浆物蛋白质溶解度为18.25mg/m L、凝胶持水力为49.66%、凝胶强度为40.65 g、硬度为52.38 g,均大于快速冷却和浸没冷却; NaCl浓度为0.60 mol/L时,快速冷却的猪肉匀浆物蛋白质溶解度为20.74mg/m L、凝胶强度72.27g、凝胶持水力为74.02%,均大于常规冷却和浸没冷却。结论在较高的NaCl浓度(0.60mol/L)下,快速冷却的猪肉匀浆物凝胶特性相对较好;在较低的NaCl浓度(0.42 mol/L)下,常规冷却的猪肉匀浆物凝胶特性相对较好。 相似文献
85.
The electrochemical preparation of NaClO has been widely used for the production of industrial disinfectant. To reduce the cost of electrode preparation using the brushing method, this paper introduces a method for the electrodeposition for RuO2/Ti and RuO2‐IrO2/Ti preparation and NaCl solution electrolysis. The deposition of Ir improves the uniformity and stability of the RuO2/Ti electrode. The optimum preparation conditions and additive concentrations were investigated in detail through the orthogonal experiment. By adjusting the electroplating time, temperature and voltage, the electrode with a high content of available chlorine was synthesized successfully. The physicochemical properties of the as‐prepared RuO2/Ti and RuO2‐IrO2/Ti were determined by XRD, SEM‐EDS, and XPS, and the electrochemical performance and lifetime of the RuO2/Ti and RuO2‐IrO2/Ti was verified via an electrochemical workstation. Uniform and stable RuO2/TiO2 and RuO2‐IrO2/TiO2 were synthesized successfully for the electrolysis of the NaCl solution. 相似文献
86.
低钠条件下肌原纤维蛋白(myofibrillar protein,MP)作为乳化剂制备的乳液稳定性差,本实验采用高强度超声波(high intensity ultrasound,HIU)(频率20 kHz、功率450 W)对低钠条件下(0.15 mol/L NaCl)MP进行不同时间(0、3、6、9、12 min)处理,测定处理后MP乳液乳化活性指数(emulsifying activity index,EAI)、乳液稳定性指数(emulsion stability index,ESI)、Turbiscan稳定性指数(turbiscan stability index,TSI)和平均粒径等,并进行微观结构观察和流变性分析等,研究低钠条件下超声处理对鸡肉MP乳化特性及其乳液稳定性和流变性能的影响。结果表明:与对照组相比,随着超声处理时间延长,MP的EAI和ESI显著增加(P<0.05),MP制备乳液的TSI和粒径随着超声处理时间的延长明显减小,且乳液液滴分布均匀,乳液Zeta-电位的绝对值显著增加(P<0.05)。乳液的流变学特性分析结果表明超声波明显提高了MP乳液的黏弹性。MP乳液的油-水界面张力分析结果显示超声处理有效增强了MP的移动性,使界面张力迅速降低,同时超声处理显著增加了MP乳液吸附蛋白相对含量(P<0.05),这表明超声处理MP有助于稳定乳液。通过冷场扫描电子显微镜观察进一步证实了超声处理12 min MP制备的乳液液滴体积最小。综上,超声波能够有效提高低钠条件下MP的乳液稳定性,本实验可为超声处理在减盐乳化型肉制品中的应用提供理论参考。 相似文献
87.
研究了不同浓度(0.2mol/L和0.6mol/L)NaCl和pH(6.0和6.5)对肉糜中脂肪微粒表面蛋白吸收量、乳化稳定性、凝胶硬度和微观结构的影响。研究结果表明,高浓度(0.6mol/L)NaCl能够显著提高肉糜中脂肪微粒表面蛋白吸收量和单位界面膜蛋白吸收量,有效地改善肉糜乳化稳定性、凝胶硬度和微观结构等指标(P〈0.05)。但在相同浓度(0.2mol/L和0.6mol/L)NaCl条件下,较大pH(6.0和6.5)对脂肪微粒表面蛋白吸收量、单位界面膜蛋白吸收量、乳化稳定性、凝胶硬度和微观结构等指标无作用效果(P〉0.05).因此.本实验认为0.6mol/L NaCl(pH6.0和6.5)的提取条件下能够充分剪切肌肉蛋白和脂肪,肉糜乳化性能好. 相似文献
88.
Glenn J.T. Leighton Paul M. Jones Quentin Lonne Robert A. Dorey Fabien Giuliano 《Journal of the European Ceramic Society》2018,38(10):3483-3488
Using thick and thin films instead of bulk functional materials presents tremendous advantages in the field of flexible electronics and component miniaturization. Here, a low-cost method to grow and release large-area, microscale thickness, freestanding, functional, ceramic foils is reported. It uses evaporation of sodium chloride to silicon wafer substrates as sacrificial layers, upon which functional lead titanate zirconate ceramic films are grown at 710?°C maximum temperature to validate the method. The freestanding, functional foils are then released by dissolution of the sacrificial sodium chloride in water and have the potential to be integrated into low-thermal stability printed circuits and flexible substrates. The optimization of the sodium chloride layer surface quality and bonding strength with the underlying wafer is achieved thanks to pre-annealing treatment. 相似文献
89.
90.
Hubby Izzuddin Shigenari Hayashi Suzue Yoneda Takashi Kogin Eiji Ishikawa Manabu Noguchi 《工业材料与腐蚀》2020,71(9):1488-1499
The effect of Mo on the corrosion behavior of Ni20Cr–xMo alloys in an oxidizing chlorine-containing atmosphere using air mixed with the salt-vapor mixture of NaCl–KCl–CaCl2 at 570°C was investigated. The results revealed that the corrosion performance of the Ni20Cr alloys in the oxidizing chlorine atmosphere was improved by Mo addition of up to 3 wt%. The Mo-free alloy formed a potassium chromate during corrosion as a result of the reaction between the Cr2O3 scale and KCl vapor. The chromate formation increased the chlorine potential at the scale surface and induced the breakdown of the protective Cr2O3 scale, resulting in internal chromium chloride precipitates and a Cr-depleted zone. In contrast, the presence of Mo resulted in the formation of a NiO scale, which did not react with the salt vapors and, therefore, prevented the formation of chromates. The beneficial effect of Mo on the high-temperature chlorination of Ni–Cr alloys in salt-vapor-containing atmospheres was ascribed to the suppression of chlorine generation due to NiO scale formation. 相似文献