全文获取类型
收费全文 | 450篇 |
免费 | 21篇 |
国内免费 | 15篇 |
专业分类
电工技术 | 11篇 |
综合类 | 17篇 |
化学工业 | 66篇 |
金属工艺 | 15篇 |
机械仪表 | 17篇 |
建筑科学 | 25篇 |
矿业工程 | 5篇 |
能源动力 | 10篇 |
轻工业 | 63篇 |
水利工程 | 4篇 |
石油天然气 | 15篇 |
武器工业 | 3篇 |
无线电 | 37篇 |
一般工业技术 | 42篇 |
冶金工业 | 56篇 |
自动化技术 | 100篇 |
出版年
2023年 | 5篇 |
2022年 | 11篇 |
2021年 | 20篇 |
2020年 | 11篇 |
2019年 | 4篇 |
2018年 | 11篇 |
2017年 | 16篇 |
2016年 | 7篇 |
2015年 | 15篇 |
2014年 | 12篇 |
2013年 | 30篇 |
2012年 | 18篇 |
2011年 | 30篇 |
2010年 | 28篇 |
2009年 | 32篇 |
2008年 | 22篇 |
2007年 | 17篇 |
2006年 | 19篇 |
2005年 | 22篇 |
2004年 | 14篇 |
2003年 | 17篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 8篇 |
1999年 | 13篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 13篇 |
1995年 | 9篇 |
1994年 | 5篇 |
1993年 | 7篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有486条查询结果,搜索用时 15 毫秒
1.
Shmuel Borenstain Gil Bar-Haim Keren Goldshtein Gili Cohen-Taguri 《Color research and application》2020,45(6):1153-1169
Investigation of ink formulation options with the purpose to obtain color-gamut-optimal set of Cyan Magenta and Yellow CMY inks is reported. Implementation of the thickness dependent Kubelka-Munk model on multiple ink layers having different and well-defined thicknesses, provides characteristic absorption and scattering (K, S ) spectra of the ink ingredients. These data enable accurate computation of the reflectance spectrum and thus the L*a*b* color coordinates for any given ink thickness or substrate. Pigment materials investigated are quinacridone as magenta, copper-phthalocyanine as cyan, and arylide yellow. Scaling the peak of the absorption band to the number of molecules per unit area for the specific pigments studied in this article provides the molar extinction coefficients, 1.21 × 104 , 4.7 × 104 , and 3.3 × 104 cm2/millimole respectively, regardless of the different ink formulations used, in accord with Avogadro's principle. Having a set of three pairs of K, S spectra is used to compute the color gamut of any CMY color combination in the L*a*b* space as a function of ink layer thickness and formulation. Using an iterative algorithm, a color-gamut-optimal set of CMY inks is obtained. 相似文献
2.
3.
He Shuilong Chen Keren Xu Enyong Ye Mingsong Wang Yanxue 《Journal of Mechanical Science and Technology》2021,35(10):4329-4341
Journal of Mechanical Science and Technology - This article introduces a rigid-flexible coupling calculation model based on a multi-platform integrated method to analyze and optimize the cab... 相似文献
4.
沥青对水泥沥青砂浆力学性能的影响 总被引:1,自引:0,他引:1
采用微机控制电子万能试验机对水泥沥青砂浆(CA砂浆)进行了应力--应变压缩试验,分析了试验过程中CA砂浆的弹性能和耗散能随沥青含量的变化规律。结果表明:随着沥青含量的增加,CA砂浆的强度逐渐降低,脆性逐渐减弱,象征强度弱化区域的有机物--无机物界面的增多是强度降低的主要原因,沥青含量的增加使CA砂浆内释放的弹性能只有小部分用于缺陷的扩展,加之沥青网络结构的横向约束作用导致脆性逐渐减弱。外力功随应变的增加逐渐增大,随沥青含量的增加逐渐减小;弹性能开始向耗散能转化发生在屈服变形阶段,峰值应力后,弹性能向耗散能的转化速率加快,能量迅速释放。能量释放系数随应变的增加逐渐增大,能量释放加快;能量释放系数随沥青含量的增加逐渐增大,表明CA砂浆的阻尼性能提高,减振作用增强。 相似文献
5.
6.
Baihui Li Lin Chen Keren Luo Jun Guo Jiankun Wang Luyang Zhang Jing Feng 《Journal of the American Ceramic Society》2022,105(7):4840-4858
A new family of ceramic environmental/thermal barrier coating (E/TBC) materials, that is, ATa2O6 (A = Co, Ni, Mg, Ca), for high-temperature applications, are investigated and reported in this study. We focus on the synthesis and features of crystal structures, and on the mechanical and high-temperature properties. ATa2O6 oxides have an extraordinary phase stability (up to 1300°C), and their thermal expansion coefficients (6.2–7.3 × 10−6 K−1) match those of SiC fiber-enhanced SiC ceramic matrix composites (3–7 × 10−6 K−1). Their low thermal conductivities (min: 1.15 W·m−1·K−1) root in the slow phonon spreading speed and fierce phonon-phonon scattering process, and they will provide exceptional thermal insulation. Moreover, their hardness (5.6–8.8 GPa), toughness (1.4–1.9 MPa·m1/2), and moduli (100–210 GPa) have good comparability with current E/TBCs. We propose the 33CaO-9MgO-13AlO1.5-45SiO2 (CMAS) corrosion mechanisms of ATa2O6 ceramics, and their robust CMAS resistance relies on the phase stability of CaTa2O6 oxides. The excellent high-temperature properties ensure that ATa2O6 can be used as E/TBCs to provide thermal insulation and CMAS corrosion protection. 相似文献
7.
Extraction,Composition and Functional Properties of Pennycress (Thlaspi arvense L.) Press Cake Protein 下载免费PDF全文
Mila P. Hojilla‐Evangelista Gordon W. Selling Mark A. Berhow Roque L. Evangelista 《Journal of the American Oil Chemists' Society》2015,92(6):905-914
This study compared two methods for extracting the protein in pennycress (Thlaspi arvense L.) press cake and determined the composition and functional properties of the protein products. Proteins in pennycress press cake were extracted by using the conventional alkali‐solubilization–acid‐precipitation (AP) method or saline‐based (SE) procedure (0.1 M NaCl at 50 °C). The extraction method has a major influence on the purity and functional properties of press cake protein products. AP had a lower protein yield (23 %) but much higher purity (90 % crude protein) compared with SE (45 % yield, 67 % crude protein). AP protein isolate had high foam capacity (120 ml), high foam stability (96 % foam volume retention) and high emulsion stability (24–35 min), and it was resistant to heat denaturation (3 % loss of solubility at pH 2 and pH 10). On the other hand, SE protein concentrate showed remarkably high solubility (>76 %) between pH 2 and 10 and exceptional emulsifying activity (226–412 m2/g protein), but was more susceptible to heat denaturation at pH 7 and pH 10 (65–78 % loss of solubility). These results strongly demonstrate that higher purity pennycress press cake protein can be produced by either saline extraction or acid precipitation and have functional properties that are desirable for non‐food uses. 相似文献
8.
对国内某催化裂化装置再生斜管的支撑方案进行了分析,详细阐述了支撑方案中支撑碟簧的选型设计,包括计算壳体壁温和两器系统各部分热膨胀值,并对设置碟簧前后的斜管两固定端受力进行了对比:膨胀节前后设置碟簧支撑比未设置时受力减少78%以上.同时也对再生斜管的衬里结构进行了分析,衬里的设置既要考虑到隔热,又要考虑到耐磨,并提出了确保衬里施工质量的措施.再生斜管优化设计后,该装置开车2 a,再生斜管运行良好,未出现振动及局部过热现象. 相似文献
9.
利用傅里叶变换红外光谱仪(FTIR)在线追踪聚乙烯基苄基氯(PVBCl)与N,N,N′,N′-四甲基-1,6-己二胺(TMHDA)的交联反应历程,考察了反应时间与温度对交联程度的影响.实验结果表明,随着反应时间的延长,交联程度先迅速增大,而后趋于平缓直至不变;反应温度越高,交联程度越大.对反应进行动力学的研究计算结果显示,该交联反应的反应级数n=4,表观活化能Ea=97.2kJ/mol. 相似文献
10.
Mila P. Hojilla-Evangelista 《Journal of the American Oil Chemists' Society》2014,91(9):1623-1631
This study evaluated Ultrafiltration–Diafiltration (UFDF) as a means to improve the extractability of wet-milled corn germ protein and determined its effects on the functional properties of the recovered protein product. Wet germ and dried germ proteins were extracted by using 0.1 M NaCl at 50 °C. Major steps in the method were stirring, centrifugation, UFDF and freeze-drying. For dried germ, the UFDF method showed marginal increase in protein extraction efficiency, while that of wet germ remained similar to what we observed for the baseline method (saline extraction with dialysis instead of UFDF). UFDF protein extracts from both germ samples were significantly more soluble than extracts recovered by the baseline method and showed atypical solubility profiles; i.e., the amount of soluble protein was essentially unchanged under acidic, neutral, and alkaline pH. UFDF-dried germ protein was markedly more soluble than UFDF-wet germ protein (80 vs 50 % soluble protein, respectively) between pH 2 and pH 10. Both of these UFDF-germ proteins also had emulsifying capacities and water-holding capacities that were superior to those of proteins extracted by the baseline method, but this favorable effect by UFDF was not observed for emulsion stability, foaming properties, and heat stability. 相似文献