全文获取类型
收费全文 | 237篇 |
免费 | 21篇 |
国内免费 | 1篇 |
专业分类
综合类 | 5篇 |
化学工业 | 135篇 |
机械仪表 | 4篇 |
建筑科学 | 2篇 |
能源动力 | 2篇 |
轻工业 | 108篇 |
一般工业技术 | 1篇 |
冶金工业 | 2篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 14篇 |
2021年 | 10篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 3篇 |
2016年 | 4篇 |
2015年 | 7篇 |
2014年 | 10篇 |
2013年 | 4篇 |
2012年 | 9篇 |
2011年 | 15篇 |
2010年 | 4篇 |
2009年 | 6篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 1篇 |
2005年 | 4篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 8篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 8篇 |
1998年 | 9篇 |
1997年 | 12篇 |
1996年 | 4篇 |
1995年 | 13篇 |
1994年 | 5篇 |
1993年 | 11篇 |
1992年 | 15篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 2篇 |
排序方式: 共有259条查询结果,搜索用时 15 毫秒
81.
Shirom Arie; Melamed Samuel; Berliner Shlomo; Shapira Itzhak 《Canadian Metallurgical Quarterly》2009,28(6):649
Objective: The authors hypothesized that high-pleasure low-arousal (HPLA) would predict a subsequent decrease of low-density lipoprotein cholesterol (LDL-C) and triglycerides (TRI), as well as a subsequent increase of high-density lipoprotein cholesterol (HDL-C). The authors also hypothesized that high-pleasure high-arousal (HPHA) would have the opposite effects on these blood lipids, predicting a subsequent increase of LDL-C and TRI, and a decrease of HDL-C. Design: Participants were 990 male and 595 female apparently healthy employees who underwent a routine periodic health examination at two points in time, Time 1 (T1) and Time 2 (T2), about 24 months apart. Data were analyzed separately for the men and women, and the authors controlled for possible confounders shown in past research to be implicated with hyperlipidemia. Main Outcome Measures: HPHA and HPLA were assessed based on the Job-Related Affective Well-Being Scale, while LDL-C, TRI, and HDL-C were assessed based on fasting blood samples. Results: For the men, support for our hypotheses was found relative to HDL-C and TRI. The authors did not find support for our hypotheses for thee women. Conclusion: Our findings suggest that for men, the two types of positive affects may have opposite physiological consequences with respect to subsequent changes in blood lipid levels. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
82.
Viscosity prediction for fatty systems 总被引:5,自引:4,他引:1
Juliana Rabelo Eduardo Batista Fl vio W. Cavaleri Antonio J. A. Meirelles 《Journal of the American Oil Chemists' Society》2000,77(12):1255-1262
Viscosity data have been measured as a function of temperature for two pure polyunsaturated fatty compounds (linoleic acid
and trilinolein), for two multicomponent fatty systems, for a commercial-grade oleic acid (approximately 80% pure), and for
canola oil. The measurements were performed in Cannon Fenske glass capillary kinematic viscometers. The contents of a large
data bank, containing viscosity data for saturated, monousaturated, and polyunsaturated pure fatty substances, were correlated
by an equation based on the number of carbon atoms and double bonds. By using this equation for pure compounds and the UNIMOD
group contribution method for mixtures, the viscosity data for model fatty systems, commercial oleic acid, and canola oil
were predicted. The good results obtained in the present work indicate that this approach can be a valuable tool for designing
or evaluating chemical process equipment for the oil industry. 相似文献
83.
Zhaojuan Shi Lili Cao Shengmei Kang Shaotong Jiang Min Pang 《International Journal of Food Science & Technology》2022,57(4):2003-2014
Camellia oil (CO) and medium chain triglycerides (MCTs), characterised by different carbon chain lengths, were gelled using beeswax (BW), candelilla wax (CLW) and carnauba wax (CRW). Critical concentrations, oil-binding capacity (OBC), textural parameters, thermal properties, microscopic properties and infrared spectra were used to evaluate their differences. The carbon chain length of oil sources showed different results for the critical concentration of the three wax-based gel oils at 25 °C, and the oleogel of MCT and CLW exhibited a minimum value (1%). The oleogels formed from CO and waxes with wax esters as the main components (BW and CRW) exhibit significantly lower OBC and textural value than the oleogels made from MCT with BW and CRW. Meanwhile, this is corroborated with the thermal behaviour and crystal morphology, and distribution of the oleogels. However, no differences in crystal types and generation of new functional groups were observed by X-ray diffraction and Fourier-transform infrared spectrometer, suggesting that the differences in the properties of wax-based oleogels with different carbon chain lengths are attributed to the interactions between the waxes and the oil sources (physical interaction). 相似文献
84.
Pawel Niemiec Tomasz Nowak Tomasz Iwanicki Sylwia Gorczynska-Kosiorz Anna Balcerzyk Jolanta Krauze Wladyslaw Grzeszczak Maria Wiecha Iwona Zak 《International journal of molecular sciences》2015,16(6):13203-13216
Single nucleotide polymorphisms (SNPs) of the USF1 gene (upstream stimulatory factor 1) influence plasma lipid levels. This study aims to determine whether USF1 SNPs interact with traditional risk factors of atherosclerosis to increase coronary artery disease (CAD) risk. In the present study serum lipid levels and USF1 gene polymorphisms (rs2516839 and rs3737787) were determined in 470 subjects: 235 patients with premature CAD and 235 controls. A trend of increasing triglycerides (TG) levels in relation to the C allele dose of rs2516839 SNP was observed. The synergistic effect of cigarette smoking and C allele carrier state on CAD risk was also found (SIM = 2.69, p = 0.015). TG levels differentiated significantly particular genotypes in smokers (1.53 mmol/L for TT, 1.80 mmol/L for CT and 2.27 mmol/L for CC subjects). In contrast, these differences were not observed in the non-smokers subgroup (1.57 mmol/L for TT, 1.46 mmol/L for CT and 1.49 mmol/L for CC subjects). In conclusion, the rs2516839 polymorphism may modulate serum triglyceride levels in response to cigarette smoking. Carriers of the C allele seem to be particularly at risk of CAD, when exposed to cigarette smoking. 相似文献
85.
86.
Novel quaternary ammonium salts derived from triglycerides and their application in skin and hair products 总被引:1,自引:0,他引:1
An investigation has been carried out into the synthesis of quaternary ammonium salts of triglycerides. The aim of this work was to produce such compounds without breaking the triglyceride skeleton. The reaction of chloracetyl chloride with the triglyceride of ricinoleic acid which is the major constituent (88–90%) of castor oil gave an intermediate derivative with pendant chloro groups. Quaternization with stearyl dimethylamine gave a 98% yield of a quaternary ammonium salt containing three quaternary groups per molecule. This reaction sequence overcame the steric hindrance problems encountered in unsuccessful attempts to quaternize halogen groups attached directly to the main chain. Using the same procedure, a quaternary salt was prepared from castor oil.
In skin care studies this quaternary was used at a low level in a moisturizing lotion. Subjective assessment of the ease of application of the test lotion versus control was significantly in favour of the test. Viscoelastic measurements of the skin were made using two techniques before and after application of the lotion. Both showed an advantage to the test lotion. No difference between the test and control lotions was found when sebum levels and transepidermal water loss measurements were measured. A C-12 quaternary synthesized from dimethyl-dodecylamine exhibited antimicrobial activity. An aqueous dispersion of the C-18 quaternary when applied to bleached hair in order to improve combing, gave excellent results showing superiority to four other commercially available quaternary ammonium salts. 相似文献
In skin care studies this quaternary was used at a low level in a moisturizing lotion. Subjective assessment of the ease of application of the test lotion versus control was significantly in favour of the test. Viscoelastic measurements of the skin were made using two techniques before and after application of the lotion. Both showed an advantage to the test lotion. No difference between the test and control lotions was found when sebum levels and transepidermal water loss measurements were measured. A C-12 quaternary synthesized from dimethyl-dodecylamine exhibited antimicrobial activity. An aqueous dispersion of the C-18 quaternary when applied to bleached hair in order to improve combing, gave excellent results showing superiority to four other commercially available quaternary ammonium salts. 相似文献
87.
利用脂肪酶催化中链甘油三酯(MCT)与核桃油发生酯交换反应,利用分子蒸馏脱除产物中的游离脂肪酸(FAA),再用乙醇萃取MCT制备高含量中长链甘油三酯(MLCT)的结构脂产品。对酶催化酯交换反应条件进行优化,对乙醇萃取条件进行优化,并对结构脂产品的脂肪酸组成及分布进行测定。结果表明:最佳酯交换反应条件为以Novozym 435为催化用酶,加酶量10%、MCT与核桃油摩尔比2∶1、反应温度55℃、反应时间9 h,在此条件下反应并通过分子蒸馏脱除FAA后所得产品的MLCT含量为76.2%,MCT含量为14.3%,长链甘油三酯(LCT)含量为9.5%;最佳乙醇萃取条件为乙醇体积分数85%、底物(分子蒸馏脱除游离脂肪酸后产物)与乙醇溶液的比例1∶3,在最佳条件下所得产品的MLCT含量为85.4%,MCT含量为3.7%,LCT含量为10.8%,产品得率为80.8%。制备的产品中MLCT含量高,富含亚油酸与亚麻酸,其含量比值为5.8,可作为消化系统缺陷患者补充必需脂肪酸的油脂来源。 相似文献
88.
本文研究了在超临界CO2状态下酶法酯化合成长短链脂肪酸甘油三酯的工艺条件,选用脂肪酶Lipozyme RM IM,以酯化率为参考指标,通过单因素试验考察了反应压力、反应温度、反应时间、体系水分添加量、酶用量和底物摩尔比对酯化率的影响,再通过响应面对工艺条件进行优化,结果为:反应压力11MPa、反应温度56℃、反应时间15h、体系水分添加量2.5%、酶用量4%、底物摩尔比3:1。并在此最佳工艺条件下进行酯交换试验,测得产品的酯化率为65.3%,且此法制得的甘油三酯热量值较普通葵花油降低了大约50%。 相似文献
89.
J. A. Segura M. L. Herrera M. C. Añón 《Journal of the American Oil Chemists' Society》1990,67(12):989-992
The effect of storage temperature on the consistency of commercial margarine was analyzed by viscometry, differential scanning
calorimetry (DSC), microscopy at low temperature and X-ray diffraction. The results obtained show that samples harden at 13°C
and soften at 4°C. The greater strength of samples was apparently associated with crystals of higher melting points. Recrystallization
takes place during storage leading to more stable solid solutions with higher melting points. 相似文献
90.
利用脂肪酶控制马尾松酸性亚硫酸盐浆树脂的沉积 总被引:4,自引:0,他引:4
马尾松酸性亚硫酸盐浆是一种易产生树脂障碍的纸浆.本文利用 三种来源的脂肪酶对马尾松酸性亚硫酸盐浆进行了生物处理.Vibromixer 沉积实验表明,马尾松酸性亚硫酸盐浆经脂肪酶处理后树脂的沉积量明 显降低.利用来自 Camlicla lipolytica的脂肪酶对纸浆生物处理的结果也 表明,脂肪酶生物处理可以降低马尾松酸性亚硫酸盐浆树脂的R_N值(树 脂中的中性组分占中性组分与弱酸性组分之和的百分比).例如,脂肪酶 用量为 5U/g绝干浆时,纸浆中树脂的R_N值由初绍的 21.2%降为16.8%,大 多数甘油三酸酯发生水解.提出的R_N值是评价脂肪酶生物控制效果的有 效方法. 相似文献