首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14516篇
  免费   880篇
  国内免费   174篇
电工技术   15篇
技术理论   1篇
综合类   733篇
化学工业   1015篇
金属工艺   14篇
机械仪表   118篇
建筑科学   83篇
矿业工程   11篇
能源动力   57篇
轻工业   11992篇
水利工程   100篇
石油天然气   152篇
无线电   50篇
一般工业技术   893篇
冶金工业   177篇
原子能技术   22篇
自动化技术   137篇
  2024年   173篇
  2023年   421篇
  2022年   553篇
  2021年   790篇
  2020年   833篇
  2019年   774篇
  2018年   702篇
  2017年   630篇
  2016年   670篇
  2015年   620篇
  2014年   812篇
  2013年   1076篇
  2012年   939篇
  2011年   859篇
  2010年   576篇
  2009年   487篇
  2008年   410篇
  2007年   641篇
  2006年   657篇
  2005年   512篇
  2004年   391篇
  2003年   370篇
  2002年   295篇
  2001年   195篇
  2000年   212篇
  1999年   167篇
  1998年   126篇
  1997年   111篇
  1996年   79篇
  1995年   74篇
  1994年   67篇
  1993年   64篇
  1992年   54篇
  1991年   36篇
  1990年   28篇
  1989年   18篇
  1988年   15篇
  1987年   22篇
  1986年   23篇
  1985年   22篇
  1984年   16篇
  1983年   3篇
  1982年   11篇
  1981年   2篇
  1980年   8篇
  1966年   2篇
  1964年   4篇
  1959年   3篇
  1958年   3篇
  1955年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
141.
张南  马春晖  周晓丽  滕蔓 《食品科学》2017,38(3):310-315
21世纪以来食品科学与技术发展迅速,食品科学与情报科学的关系更加紧密,本文应用文献计量学方法通过分析食品科学领域内发表论文的数量与质量,从食品学科竞争力角度出发,对国家和代表机构的学科竞争力进行可视化比较研究。结果表明:2010—2014年Scopus数据库中食品科学学科,中国以17 054篇发文量成为全球第二位大发文国家,但是中国篇均被引次数为4.6次/篇,略低于全球篇均被引次数。虽然我国这些年在发文量上已经取得了不小的成就,但是反映论文质量的篇均被引次数、前10%高被引文献等指标与传统食品科学强国相比,整体上还存在一定的差距。从发文数量与质量等多角度分析得出,中国代表性机构在国际学术中有一定的影响力与知名度,但我国食品科学呈现地区发展不平衡现象。通过观察全球食品学科领域的研究热点及发展趋势,我国在2010—2014年产生了101个具有独特竞争优势(distinctive competencies,DC)的研究方向,这101个DC体现了2010—2014年我国食品科学方向主要的交叉学科竞争优势,为食品科研工作者提供相关参考。  相似文献   
142.
4种防腐剂对副溶血弧菌生物膜形成的抑制作用   总被引:1,自引:0,他引:1  
在确定4种防腐剂壳聚糖、山梨酸钾、脱氢乙酸钠和ε-聚赖氨酸对副溶血弧菌(Vibro parahaemolyticus)的最小抑菌浓度(minimum inhibitory concentration,MIC)的基础上,研究其对副溶血弧菌生物膜的抑制作用。采用结晶紫染色法测生物膜形成量,XTT法测生物膜代谢活性,硫酸-苯酚法测定生物膜中胞外多糖的分泌量。结果表明,壳聚糖的MIC最小,为1.25 mg/m L。4种防腐剂在MIC以及亚抑菌浓度条件下对副溶血弧菌生物膜均有明显的抑制作用,不仅抑制生物膜的形成,而且能显著降低细菌的代谢活性,减少胞外多糖的分泌,其中壳聚糖对副溶血弧菌生物膜的抑制作用最强。  相似文献   
143.
灵菌红素属于天然色素,具有离体抑制肿瘤和癌症细胞增殖、抑制微生物生长以及抗疟疾和免疫抑制等功效,具有潜在的巨大应用价值。缺少急性经口毒性和遗传毒性实验的研究限制了灵菌红素在食品工业领域的应用。本研究依据食品安全国家标准进行了灵菌红素的小鼠急性经口毒性实验、哺乳动物红细胞微核实验、小鼠精子畸形实验和细菌回复突变实验。结果表明,灵菌红素急性经口半数致死剂量LD_(50)10 g/kg(以体质量计),3项遗传毒性实验结果为阴性,灵菌红素对小鼠的急性经口毒性属无毒级,对正常细胞无毒,对动物生殖系统没有毒害。  相似文献   
144.
冯亚净  张志业  李书国 《食品科学》2017,38(16):205-209
基于苯并(a)芘(benzo(a)pyrene,BaP)的电化学氧化还原特征,建立一种快速测定烧烤类食品中BaP含量的电化学分析方法,优化测定条件为乙腈-水(1∶3,V/V)作为溶剂、电解质LiClO_4浓度0.15 mol/L、硫酸浓度0.1 mol/L、富集时间10 min,在此条件下,BaP的氧化峰电流随其浓度的增大而增大,而且浓度在0~100 nmol/L范围内呈线性关系,检测限为0.187 nmol/L(R_(SN)=3)。该方法的稳定性和重复性较好,检测时间短,利用该法对烤羊肉串样品中的BaP进行检测,回收率为96.67%~101.56%,检测结果与高效液相色谱法基本一致,可用于烧烤类食品中BaP的快速检测。  相似文献   
145.
药食同源中药抗衰老研究进展   总被引:4,自引:0,他引:4  
"药食同源"即"医食同源,药食同根",药食同源中药兼具了丰富的营养价值和药用价值。近年来,对药食同源中药进行抗衰老研究的报道越来越多,药食同源中药所具有的抗衰老活性也逐渐被人们所认知,因此将其开发成抗衰老药物具有广阔的发展前景。本文以药食同源中药为研究对象,通过其抗氧化活性以及已报道药食同源中药抗衰老研究的文献数量,筛选出可以用作抗衰老研究的中药;同时,以衰老机制为基础,对药食同源中药的研究进行综述,并对其今后的研究方向进行展望。  相似文献   
146.
路磊  徐媛媛  杨娇  任珊 《食品科学》2021,42(11):356-364
实施食品安全战略、推进食品安全治理体系和治理能力现代化需要完备的食品学科知识和大量的专业人才进行支撑.食品安全问题的复杂性和特殊性决定了食品安全治理工作需要复合型的食品学科人才,高校作为学科建设和人才培养的主阵地,应发挥基础性、先导性作用,完善院校课程设置,加强食品学科建设和人才培养.本文对国内外食品学科及相关专业的人...  相似文献   
147.
Hydroxycinnamic acids (HCAs) are a major class of phenolic acids with the characteristic phenylpropanoid C6-C3 backbone. Its typically conjugated status with plant cell wall components and liberation by limited enzymes might be the reason for its neglect by researchers compared to flavonoid-type polyphenols. The polyphenol–gut microbiota interactions and their impact on human health have captured the interest of researchers recently. In addition, there has been a significant progress over the past few years in understanding the gut microbiota-modulating effect of HCA using animal model studies. This review discusses the metabolism of HCA in the digestive tract, HCA–gut microbiota interactions, and its link to colorectal cancer, inflammatory bowel diseases, mental-cognitive impairments, nonalcoholic liver disease, and obesity. The effects of food matrix and processing technologies on HCA bioavailability and HCA–gut microbiota interactions, and HCA safety concerns are also featured in this review. This paper has provided an in-depth insight on HCA–gut microbiota relationship and identified the current literature gaps for future research.  相似文献   
148.
Proteins displayed on the cell surface of lactic acid bacteria (LAB) perform diverse and important biochemical roles. Among these, the cell-envelope proteinases (CEPs) are one of the most widely studied and most exploited for biotechnological applications. CEPs are important players in the proteolytic system of LAB, because they are required by LAB to degrade proteins in the growth media into peptides and/or amino acids required for the nitrogen nutrition of LAB. The most important area of application of CEPs is therefore in protein hydrolysis, especially in dairy products. Also, the physical location of CEPs (i.e., being cell-envelope anchored) allows for relatively easy downstream processing (e.g., extraction) of CEPs. This review describes the biochemical features and organization of CEPs and how this fits them for the purpose of protein hydrolysis. It begins with a focus on the genetic organization and expression of CEPs. The catalytic behavior and cleavage specificities of CEPs from various LAB are also discussed. Following this, the extraction and purification of most CEPs reported to date is described. The industrial applications of CEPs in food technology, health promotion, as well as in the growing area of water purification are discussed. Techniques for improving the production and catalytic efficiency of CEPs are also given an important place in this review.  相似文献   
149.
Aflatoxins represent a global public health and economic concern as they are responsible for significant adverse health and economic issues affecting consumers and farmers worldwide. Produced by fungal species from the Aspergillus genus, aflatoxins are a toxic, mutagenic, and carcinogenic group of fungal metabolites that routinely contaminate food and agricultural products. Climate and diet are essential factors in the aflatoxin contamination of food and subsequent human exposure process. Countri es with warmer climates and staple foods that are aflatoxin-susceptible shoulder a substantial portion of the global aflatoxins burden. Enactment of regulations, prevention of pre- and postharvest contamination, decontamination, and detoxification have been used to prevent human dietary exposure to aflatoxin. Exploiting their chemical and structural properties, means are devised to detect and quantify aflatoxin presence in foods. Herein, recent developments in several important aspects impacting aflatoxin contamination of the food supply, including: fungal producers of the toxin, occurrence in food, worldwide regulations, detection methods, preventive strategies, and removal and degradation methods were reviewed and presented. In conclusion, aflatoxin continues to be a major food safety problem, especially in developing countries where regulatory limits do not exist or are not adequately enforced. Finally, knowledge gaps and current challenges in each discussed aspect were identified, and new solutions were proposed.  相似文献   
150.
Pore-forming toxins (PFTs) are water-soluble molecules that have been identified as the most crucial virulence factors during bacterial pathogenesis. PFTs disrupt the host cell membrane to internalize or to deliver other bacterial or virulence factors for establishing infections. Disruption of the host cell membrane by PFTs can lead to uncontrollable exchanges between the extracellular and the intracellular matrix, thereby disturbing the cellular homeostasis. Recent studies have provided insights into the molecular mechanism of PFTs during pathogenesis. Evidence also suggests the activation of several signal transduction pathways in the host cell on recognition of PFTs. Additionally, numerous distinctive host defense mechanisms as well as membrane repair mechanisms have been reported; however, studies reveal that PFTs aid in host immune evasion of the bacteria through numerous pathways. PFTs have been primarily associated with foodborne pathogens. Infection and death from diseases by consuming contaminated food are a constant threat to public health worldwide, affecting socioeconomic development. Moreover, the emergence of new foodborne pathogens has led to the rise of bacterial antimicrobial resistance affecting the population. Hence, this review focuses on the role of PFTs secreted by foodborne pathogens. The review highlights the molecular mechanism of foodborne bacterial PFTs, assisting bacterial survival from the host immune responses and understanding the downstream mechanism in the activation of various signaling pathways in the host upon PFT recognition. PFT research is a remarkable and an important field for exploring novel and broad applications of antimicrobial compounds as therapeutics.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号