全文获取类型
收费全文 | 644篇 |
免费 | 59篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 1篇 |
综合类 | 21篇 |
化学工业 | 39篇 |
金属工艺 | 6篇 |
机械仪表 | 3篇 |
建筑科学 | 3篇 |
能源动力 | 2篇 |
轻工业 | 586篇 |
石油天然气 | 4篇 |
无线电 | 2篇 |
一般工业技术 | 11篇 |
冶金工业 | 25篇 |
原子能技术 | 1篇 |
自动化技术 | 4篇 |
出版年
2024年 | 3篇 |
2023年 | 14篇 |
2022年 | 28篇 |
2021年 | 29篇 |
2020年 | 30篇 |
2019年 | 37篇 |
2018年 | 28篇 |
2017年 | 20篇 |
2016年 | 18篇 |
2015年 | 29篇 |
2014年 | 38篇 |
2013年 | 39篇 |
2012年 | 54篇 |
2011年 | 50篇 |
2010年 | 21篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 45篇 |
2006年 | 28篇 |
2005年 | 19篇 |
2004年 | 15篇 |
2003年 | 11篇 |
2002年 | 14篇 |
2001年 | 20篇 |
2000年 | 11篇 |
1999年 | 18篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1980年 | 1篇 |
1977年 | 1篇 |
1971年 | 1篇 |
1962年 | 1篇 |
排序方式: 共有708条查询结果,搜索用时 15 毫秒
141.
目的 优化柱前衍生高效液相色谱条件检测功能饮料中牛磺酸的含量。方法 采用配备紫外检测器的高效液相色谱仪,利用C_18反相色谱柱,选择甲醇:乙酸钠=45:55(V:V)为流动相,在流速为0.8 mL/min、标液与衍生试剂比例为1:1(V:V)、衍生时间为1 h时进行检测。结果 在1.0~200μg/mL范围内,牛磺酸的浓度与峰面积呈现良好的线性,标准曲线方程是Y=34182X+14599,r~2=0.9999,优化后的方法回收率在96.83%~100.17%之间,检出限是0.53mg/100g,定量限为1.76mg/100g。结论 本方法高效、准确,适用于能饮料中牛磺酸含量的检测,为日常监管工作提供理论支持。 相似文献
142.
143.
研究了葛根枳椇子植物饮料对小鼠急性酒精性肝损伤的保护作用。采用一次性灌胃50%酒精的方法建立急性酒精性肝损伤模型,检测相关生化指标及肝组织形态,评价葛根枳椇子植物饮料的肝保护作用。与模型组比较,葛根枳椇子植物饮料中剂量组的小鼠血清中谷草转氨酶、谷丙转氨酶、总胆固醇、甘油三酯以及低密度脂蛋白水平显著降低至(19.17±6.22)U/L、(14.81±4.61)U/L、(4.77±0.33)mmol/L、(1.92±0.24)mmol//L、(0.22±0.09)mmol/L,肝脏超氧化物歧化酶、谷胱甘肽过氧化物酶以及还原型谷胱甘肽的活性明显升高,丙二醇含量显著降低至(0.80±0.09)nmol/mg pro。葛根枳椇子植物饮料在一定程度上改善肝组织的病理变化,减轻脂肪变性及炎性细胞浸润。结果表明,葛根枳椇子植物饮料对小鼠急性酒精暴露后的肝组织具有一定的保护作用。 相似文献
144.
Beatriz Maria Curtio Soares Carlos Alberto Rodrigues Anjos Taiane Bonfante Faria Sílvia Tondella Dantas 《Packaging Technology and Science》2016,29(1):65-73
The objectives of this study were to evaluate the characteristics of commercial soft drinks related with the corrosion process of the aluminium packaging and based on that, propose model solutions for future studies of beverage/package interaction and corrosion process of metal packages. Therefore, the pH, acidity, concentration of chlorides and copper in six types of soft drinks were determined, as well as the corrosion potential of the aluminium and the current density corrosion obtained in polarization curves using the beverages as electrolyte. Based on the results obtained, a solution of citric acid (pH = 3) containing chloride (250 mg/kg) and copper ions (250 µg/kg) is proposed. The obtained results are potentially useful for the industry and future studies regarding the interaction process between soft drinks and aluminium cans. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
145.
Jiao Xin Tingyu You Xiangfu Jiang Dongdong Fu Jiarong Wang Wei Jiang Xiaowen Feng Jiagen Wen Yan Huang Chengmu Hu 《International journal of molecular sciences》2022,23(14)
Acetaminophen (APAP) is a widely used antipyretic analgesic which can lead to acute liver failure after overdoses. Chronic alcoholic fatty liver disease (AFLD) appears to enhance the risk and severity of APAP-induced liver injury, and the level of angiotensin II (Ang II) increased sharply at the same time. However, the underlying mechanisms remain unclear. Caveolin-1 (CAV1) has been proven to have a protective effect on AFLD. This study aimed to examine whether CAV1 can protect the APAP-induced hepatotoxicity of AFLD by affecting Ang II or its related targets. In vivo, the AFLD model was established according to the chronic-plus-binge ethanol model. Liver injury and hepatic lipid accumulation level were determined. The levels of Angiotensin converting enzyme 2 (ACE2), Ang II, CAV1, and other relevant proteins were evaluated by western blotting. In vitro, L02 cells were treated with alcohol and oleic acid mixture and APAP. CAV1 and ACE2 expression was downregulated in APAP-treated AFLD mice compared to APAP-treated mice. The overexpression of CAV1 in mice and L02 cells alleviated APAP-induced hepatotoxicity in AFLD and downregulated Ang II, p-EGFR/EGFR and P-ERK/ERK expression. Immunofluorescence experiments revealed interactions between CAV1, Ang II, and EGFR. The application of losartan (an Ang II receptor antagonist) and PD98059 (an ERK1/2 inhibitor) alleviated APAP-induced hepatotoxicity in AFLD. In conclusion, our findings verified that CAV1 alleviates APAP-aggravated hepatotoxicity in AFLD by downregulating the Ang II /EGFR/ERK axis, which could be a novel therapeutic target for its prevention or treatment. 相似文献
146.
147.
148.
Janko Kaliterna Ruud A. Weusthuis Juan I. Castrillo Johannes P. Van Dijken Jack T. Pronk 《Yeast (Chichester, England)》1995,11(4):317-325
The facultatively fermentative yeast Candida utilis exhibits the Kluyver effect for maltose: this disaccharide is respired and assimilated but, in contrast to glucose, it cannot be fermented. To study the mechanism of the Kluyver effect, metabolic responses of C. utilis to a transition from aerobic, sugar-limited growth to oxygen-limited conditions were studied in chemostat cultures. Unexpectedly, the initial response of maltose-grown cultures to oxygen limitation was very similar to that of glucose-grown cultures. In both cases, alcoholic fermentation occurred after a lag phase of 1 h, during which glycerol, pyruvate and D-lactate were the main fermentation products. After ca. 10 h the behaviour of the maltose- and glucose-grown cultures diverged: ethanol disappeared from the maltose-grown cultures, whereas fermentation continued in steady-state, oxygen-limited cultures grown on glucose. The disappearance of alcoholic fermentation in oxygen-limited chemostat cultures growing on maltose was not due to a repression of the synthesis of pyruvate decarboxylase and alcohol dehydrogenase. The results demonstrate that the Kluyver effect for maltose in C. utilis does not reflect an intrinsic inability of this yeast to ferment maltose, but is caused by a regulatory phenomenon that affects a key enzyme in maltose metabolism, probably the maltose carrier. The observed kinetics indicate that this regulation occurs at the level of enzyme synthesis rather than via modification of existing enzyme activity. 相似文献
149.
A simple and rapid (15min) spectrophotometric method for the determination of subpercentage ethanol in beverages is based on the colour reaction between ethanol and Ce(IV). Other alcohols and reducing substances interfere, but may be minimized by distilling the alkali and mercuric chloride treated sample. Calibration was linear up to 0.78% v/v, with r.s.d. of 5.0% at the ethanol level of 0.34% v/v. the ethanol contents of a number of non-alcoholic beverages and beer samples were determined and compared with results from AOAC and gas chromatographic methods. 相似文献
150.
采用高效液相色谱法测定五味子籽压榨油中的五味子醇甲、五味子甲素和五味子乙素,结果显示其含量分别为2.518%、0.577%和2.736%.五味子籽压榨油对小鼠的半数致死量(LD50)为10.8g/kg,30d小鼠喂养试验的血液生化指标均在正常范围内,表明五味子籽压榨油的毒性较低.通过建立小鼠酒精性肝损伤模型,并分别给予小鼠不同量的五味子籽压榨油以研究其对小鼠酒精肝损伤的保护作用,结果表明高剂量组与模型组呈显著性差异,证明五味子籽压榨油具有一定的肝保护作用. 相似文献