全文获取类型
收费全文 | 1537篇 |
免费 | 157篇 |
国内免费 | 18篇 |
专业分类
电工技术 | 12篇 |
综合类 | 45篇 |
化学工业 | 114篇 |
机械仪表 | 17篇 |
建筑科学 | 11篇 |
矿业工程 | 1篇 |
能源动力 | 19篇 |
轻工业 | 1414篇 |
水利工程 | 3篇 |
石油天然气 | 18篇 |
无线电 | 4篇 |
一般工业技术 | 23篇 |
冶金工业 | 3篇 |
原子能技术 | 1篇 |
自动化技术 | 27篇 |
出版年
2024年 | 18篇 |
2023年 | 26篇 |
2022年 | 50篇 |
2021年 | 79篇 |
2020年 | 86篇 |
2019年 | 97篇 |
2018年 | 81篇 |
2017年 | 63篇 |
2016年 | 65篇 |
2015年 | 76篇 |
2014年 | 77篇 |
2013年 | 94篇 |
2012年 | 138篇 |
2011年 | 128篇 |
2010年 | 86篇 |
2009年 | 51篇 |
2008年 | 44篇 |
2007年 | 67篇 |
2006年 | 64篇 |
2005年 | 59篇 |
2004年 | 34篇 |
2003年 | 25篇 |
2002年 | 33篇 |
2001年 | 29篇 |
2000年 | 23篇 |
1999年 | 14篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 6篇 |
1995年 | 11篇 |
1994年 | 11篇 |
1993年 | 11篇 |
1992年 | 14篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1980年 | 3篇 |
1963年 | 1篇 |
排序方式: 共有1712条查询结果,搜索用时 31 毫秒
92.
TERRI R. ROSETT SHERRY L. KENDREGAN YING GAO SHELLY J. SCHMIDT BARBARA P. KLEIN 《Journal of food science》1996,61(5):1099-1104
Low sodium chicken broth with NaCl added to provide Na+ concentrations in typical reduced Na+ soups (144 and 288 mg Na+/240 mL serving) was thickened with commonly used gum, starch, or flour food additives. Xanthan gum suppressed saltiness as the result of ionic binding of Na+, as determined by sensory evaluation and 23Na NMR spectroscopy. Saltiness was affected by added NaCl (p = 0.0001), thickener (p < 0.01), and added NaCl* thickener (p < 0.01), and positively correlated with chicken and overall flavors (p = 0.0001). Cornstarch provided body, no suppression of salt taste, and the greatest salt enhancement of chicken and overall flavors. In complex food systems, temperature and other factors affected Na+ binding as measured by NMR pointing to the need for a new model. 相似文献
93.
Predictive models for growth of Salmonella typhimurium DT104 from low and high initial density on ground chicken with a natural microflora 总被引:1,自引:0,他引:1
Oscar TP 《Food microbiology》2007,24(6):640-651
A single strain (ATCC 700408) of Salmonella typhimurium DT104 was used to investigate and model growth from a low (1.12 log10 mpn g(-1)) and high (3.7 log10 cfu g(-1)) initial density on ground chicken with a natural microflora. Kinetic data for growth of the pathogen on ground chicken were fit to a primary model to determine lag time (lambda), maximum specific growth rate (mu) and maximum population density (Nmax). Secondary models for lambda, mu and Nmax, as a function of temperature (10-40 degrees C), were developed and compared among initial densities. Variation of pathogen growth among replicates (n=4 or 5) was higher at 10-18 degrees C than at 22-40 degrees C and was higher for Nmax than lambda and mu. Prediction problems were observed when secondary models developed with one initial density were used to predict lambda, mu and Nmax from the other initial density, especially at 10-18 degrees C and for Nmax. These results indicated that variation of growth among replicate challenge studies and initial density are important factors to consider when developing predictive models for growth of S. typhimurium DT104 on ground chicken with a natural microflora. 相似文献
94.
目的 了解济南市售生鸡肉中金黄色葡萄球菌污染状况和分离株肠毒素基因携带情况,评估生鸡肉产品对消费者的健康风险。方法 2021年3~11月对济南市主要人口密集区域的部分大型超市、农贸市场、肉制品零售店等流通环节及电商平台进行样品采集,依据GB 4789.10—2016《食品微生物学检验 金黄色葡萄球菌检验》要求对样品进行金黄色葡萄球菌检验;通过聚合酶链式反应(PCR)对分离株进行复核鉴定和5种肠毒素基因(sea、seb、sec、sed、see)的检测;使用Risk ranger风险评估软件评估济南市售生鸡肉中金黄色葡萄球菌对消费者健康的影响。结果 在采集的180份样品中,共55份样品检出金黄色葡萄球菌,其中大型超市、电商平台来源的冷冻鸡制品16份(16/61);农贸市场,肉制品零售店来源的冷冻鸡制品30份(30/60),鲜整鸡9份(9/59)。55株分离株中有9株携带至少一种经典肠毒素基因。半定量风险评估结果提示,济南市售生鸡肉中金黄色葡萄球菌导致消费者罹患食物中毒的风险等级为高风险水平,其中农贸市场、肉制品零售店来源的冷冻鸡制品风险值为53;鲜整鸡风险值为52;大型超市、电商平台来源的冷冻鸡制品风险值为49。结论 济南市市售生鸡肉中金黄色葡萄球菌污染水平较为严重。结合风险评估结果,建议有关部门加强监管力度,规范市售冷冻肉制品的运输和存放条件,降低冷冻鸡制品细菌污染的风险,保障消费者健康。 相似文献
95.
Xiuhua Li Thomas JV Higgins Wayne L Bryden 《Journal of the science of food and agriculture》2006,86(12):1900-1907
The nutritive value of transgenic peas expressing an α‐amylase inhibitor (α‐Ai1) was evaluated with broiler chickens. The effects of feeding transgenic peas on the development of visceral organs associated with digestion and nutrient absorption were also examined. The chemical composition of the conventional and the transgenic peas used in this study were similar. In the two feeding trials, that were conducted normal and transgenic peas were incorporated into a maize–soybean diet at concentrations up to 500 g kg?1. The diets were balanced to contain similar levels of apparent metabolisable energy (AME) and amino acids. In the first trial, the birds were fed the diets from 3 to 17 days post‐hatching and with levels of transgenic peas at 250 g kg?1 or greater there was a significant reduction in body weight but an increase in feed intake resulting in deceased feed conversion efficiency. In the second trial, in which the birds were fed diets containing 300 g kg?1 transgenic peas until 40 days of age, growth performance was significantly reduced. It was also demonstrated that the ileal starch digestibility coefficient (0.80 vs 0.42) was significantly reduced in the birds fed transgenic peas. Determination of AME and ileal digestibility of amino acids in 5‐week‐old broilers demonstrated a significant reduction in AME (12.12 vs 5.08 MJ kg?1 DM) in the birds fed the transgenic peas. The AME value recorded for transgenic peas reflected the lower starch digestibility of this line. Ileal digestion of protein and amino acids was unaffected by treatment. Expression of α‐Ai1 in peas did not appear to affect bird health or the utilisation of dietary protein. However, the significant reduction in ileal digestion of starch in transgenic peas does reduce the utility of this feedstuff in monogastric diets where efficient energy utilisation is required. Copyright © 2006 Society of Chemical Industry 相似文献
96.
热反应对鸡肉味香味料挥发性成分影响初探 总被引:2,自引:0,他引:2
用同时蒸馏提取技术对由半胱氨酸、硫胺素、味精、葡萄糖、I +C、甘氨酸、丙氨酸组成的经热反应产生的鸡肉味香味料的挥发性成分进行了分离和浓缩 ,所得到的浓缩物用GC MS技术定量分析 ,共鉴定出 40余种化合物 ,并计算出它们的含量。其中 ,重要的肉味化合物如 2 甲基 3 呋喃硫醇、二 (2 甲基 3 呋喃基 )二硫、(2 甲基 3 呋喃基 ) (2 甲基 4,5 二氢 3 呋喃基 )二硫、二 (2 甲基 4,5 二氢 3 呋喃基 )二硫、呋喃、噻吩等被鉴定出来 ,并对其感觉特性及形成途径进行了简略说明 相似文献
97.
98.
利用超滤分级、凝胶过滤色谱法和反相-高效液相色谱法对武定鸡肉中鲜味肽进行分离纯化,结合感官评价追踪鲜味最强烈的组分,以纳升高效液相色谱-串联质谱联用技术与固相合成法对鲜味肽进行鉴定和合成,进一步分析鲜味肽的序列来源及其呈味特征。结果表明:从武定鸡肉中分离鉴定出8 条多肽,分子质量范围为365.20~1 735.92 Da,其中LDF、FVT和DLAGRDLTDYLMKIL这3 条肽段具有明显的鲜味活性,阈值在0.062~0.250 mg/mL之间,是武定鸡肉鲜味的关键组分。 相似文献
99.
以鸡肉肽为基础,本实验构建了8组反应体系对鸡肉肽在美拉德反应中生成肉味化合物的贡献进行了研究。结果发现,鸡肉肽在美拉德反应中主要贡献呈坚果香、烤香的吡嗪类物质(增加量14744.1μg/L),进一步贡献体系的肉味。另外,对添加了游离氨基酸Cys的肽美拉德反应体系的研究发现,鸡肉肽可以大幅度促进Cys-木糖体系中含硫气味活性化合物如噻吩类和呋喃硫醇类物质的生成。而鸡肉肽-Leu-木糖体系中吡嗪的生成量大于Leu-糖与肽-糖体系两者之和,进一步说明添加Leu对鸡肉肽-木糖体系中吡嗪的生成具有促进作用。最后,构建不同p H值体系进行反应,结果发现,较低p H值(5.0)对鸡肉肽参与美拉德反应吡嗪的生成具有抑制作用。结合不挥发物的定量分析最终得出,主要分布在200-500u的鸡肉肽在美拉德反应中在较高p H下对食品肉味的形成具有重要的贡献。 相似文献
100.
从四川豆豉、鸡精等着眼,论述了复合调味品的类型、特点、营养及开发、研制状况。认为复合调味品是生产企业新的竞争主题,有着广阔的发展前景。 相似文献