全文获取类型
| 收费全文 | 739篇 |
| 免费 | 54篇 |
| 国内免费 | 32篇 |
专业分类
| 电工技术 | 3篇 |
| 综合类 | 36篇 |
| 化学工业 | 150篇 |
| 金属工艺 | 5篇 |
| 机械仪表 | 42篇 |
| 建筑科学 | 48篇 |
| 矿业工程 | 1篇 |
| 能源动力 | 14篇 |
| 轻工业 | 398篇 |
| 水利工程 | 17篇 |
| 石油天然气 | 16篇 |
| 无线电 | 12篇 |
| 一般工业技术 | 38篇 |
| 冶金工业 | 4篇 |
| 原子能技术 | 1篇 |
| 自动化技术 | 40篇 |
出版年
| 2025年 | 3篇 |
| 2024年 | 38篇 |
| 2023年 | 26篇 |
| 2022年 | 43篇 |
| 2021年 | 61篇 |
| 2020年 | 43篇 |
| 2019年 | 39篇 |
| 2018年 | 35篇 |
| 2017年 | 31篇 |
| 2016年 | 36篇 |
| 2015年 | 26篇 |
| 2014年 | 31篇 |
| 2013年 | 48篇 |
| 2012年 | 34篇 |
| 2011年 | 46篇 |
| 2010年 | 29篇 |
| 2009年 | 22篇 |
| 2008年 | 22篇 |
| 2007年 | 31篇 |
| 2006年 | 33篇 |
| 2005年 | 20篇 |
| 2004年 | 21篇 |
| 2003年 | 13篇 |
| 2002年 | 16篇 |
| 2001年 | 12篇 |
| 2000年 | 11篇 |
| 1999年 | 11篇 |
| 1998年 | 10篇 |
| 1997年 | 6篇 |
| 1996年 | 5篇 |
| 1995年 | 3篇 |
| 1994年 | 3篇 |
| 1993年 | 4篇 |
| 1992年 | 1篇 |
| 1991年 | 2篇 |
| 1990年 | 4篇 |
| 1989年 | 3篇 |
| 1986年 | 1篇 |
| 1985年 | 1篇 |
| 1977年 | 1篇 |
排序方式： 共有825条查询结果，搜索用时 15 毫秒
41.
42.
Ting Wang Qun-Li Lei Ming Wang Guoying Deng Le Yang Xijian Liu Chunlin Li Qi Wang Zhihua Liu Jianwu Wang Zequn Cui Kevin Goldio Utama Ran Ni Xiaodong Chen 《Advanced materials (Deerfield Beach, Fla.)》2020,32(22):2000991
Epidermal bioelectronics that can monitor human health status non-invasively and in real time are core to wearable healthcare equipment. Achieving mechanically tolerant surface bioreactions that convert biochemical information to detectable signals is crucial for obtaining high sensing fidelity. In this work, by combining simulations and experiments, a typical epidermal biosensor system is investigated based on a redox enzyme cascade reaction (RECR) comprising glucose oxidase/lactate oxidase enzymes and Prussian blue nanoparticles. Simulations reveal that strain-induced change in surface reactant flux is the key to the performance drop in traditional flat bioelectrodes. In contrast, wavy bioelectrodes capable of curvature adaptation maintain the reactant flux under strain, which preserves sensing fidelity. This rationale is experimentally proven by bioelectrodes with flat/wavy geometry under both static strain and dynamic stretching. When exposed to 50% strain, the signal fluctuations for wavy bioelectrodes are only 7.0% (4.9%) in detecting glucose (lactate), which are significantly lower than the 40.3% (51.8%) in flat bioelectrodes. Based on this wavy bioelectrode, a stable human epidermal metabolite biosensor insensitive to human gestures is further demonstrated. This mechanically tolerant biosensor based on adaptive curvature engineering provides a reliable bio/chemical-information monitoring platform for soft healthcare bioelectronics. 相似文献
43.
Hee‐Kyoung Son Hye‐Won Shin Eun‐Seok Jang Byoung‐Seok Moon Choong Hwan Lee Jae‐Joon Lee 《Food Science & Nutrition》2020,8(3):1562-1574
The aim of this study was to compare whether gochujang products prepared using giant embryo rice koji (rice gochujang, RG) and wheat koji (wheat gochujang, WG) have anti‐obesity effects on rats fed a high‐fat diet (HFD), who served as a model for obesity. The nutritional composition of RG and WG including proximate constituents, amino acid and fatty acid compositions were investigated. Consequently, the secondary fermented metabolites were analyzed in RG and WG by ultrahigh‐performance liquid chromatography and mass spectrometry. Rats were fed a HFD containing 10% RG powder (HFD‐RG) or 10% WG powder (HFD‐WG) for 8 weeks. Body weight gain, weights of liver, epididymal, retroperitoneal, perirenal, and total white fat pads, and levels of serum triglyceride (TG), total cholesterol, low‐density lipoprotein cholesterol, and leptin were lower in all gochujang groups than in the HFD group. Furthermore, RG and WG treatment decreased the hepatic TG content and lipid accumulation and significantly reduced the size of epididymal adipocytes. These effects are probably mediated through inhibition of hepatic fatty acid synthase, acetyl CoA carboxylase, malic enzyme, and adipose tissue lipoprotein lipase activities. The anti‐obesity effect was slightly greater in the HFD‐RG group than in the HFD‐WG group. This effect may be attributed to secondary metabolites, such as capsaicin, genistein, daidzein, soyasaponin, and lysophosphatidylcholines, contained in gochujang prepared using giant embryo rice or wheat koji. 相似文献
44.
目的 以导视系统为载体赋予川西林盘农耕文化新意境,是展现农耕文化的一种有效形式。以成都市郫都区林盘农耕文化导视系统设计为模型,以乡村发展复兴为契机推进农耕文化与乡村产业革新相融合,打造突显川西林盘特色的导视系统。方法 结合设计符号学理论,从元素符号的语义、语用、语境、语构四个维度,剖析川西林盘导视系统设计方法,以造型元素、色彩、材质肌理等客体对象解构导视系统符号化体系;同时与“境-景-人-物”四维体系相结合构建川西林盘导视系统。结果 表达林盘农耕文化外延造型及内涵意识,借助导视系统唤起川西农耕文化审美范式记忆,建立具有农耕文化特征符号的导视系统设计方法。结论 保护与传承川西农耕文化特色,提升川西林盘整体文化形象,拓展现代乡村导视系统设计思路。 相似文献
45.
Tremendous advances in crop biotechnology related to the availability of molecular tools and methods developed for transformation and regeneration of specific plant species have been observed. As a consequence, the interest in plant molecular farming aimed at producing the desired therapeutic proteins has significantly increased. Since the middle of the 1980s, recombinant pharmaceuticals have transformed the treatment of many serious diseases and nowadays are used in all branches of medicine. The available systems of the synthesis include wild-type or modified mammalian cells, plants or plant cell cultures, insects, yeast, fungi, or bacteria. Undeniable benefits such as well-characterised breeding conditions, safety, and relatively low costs of production make plants an attractive yet competitive platform for biopharmaceutical production. Some of the vegetable plants that have edible tubers, fruits, leaves, or seeds may be desirable as inexpensive bioreactors because these organs can provide edible vaccines and thus omit the purification step of the final product. Some crucial facts in the development of plant-made pharmaceuticals are presented here in brief. Although crop systems do not require more strictly dedicated optimization of methodologies at any stages of the of biopharmaceutical production process, here we recall the complete framework of such a project, along with theoretical background. Thus, a brief review of the advantages and disadvantages of different systems, the principles for the selection of cis elements for the expression cassettes, and available methods of plant transformation, through to the protein recovery and purification stage, are all presented here. We also outline the achievements in the production of biopharmaceuticals in economically important crop plants and provide examples of their clinical trials and commercialization. 相似文献
46.
Krishna Somaletha Chandran John Humphries Jason Q.D. Goodger Ian E. Woodrow 《International journal of molecular sciences》2022,23(6)
Flavonoids are ubiquitous polyphenolic compounds in plants, long recognised for their health-promoting properties in humans. Methylated flavonoids have received increasing attention due to the potential of methylation to enhance medicinal efficacy. Recently, Eucalyptus species with high levels of the O-methylated flavanone pinostrobin have been identified. Pinostrobin has potential commercial value due to its numerous pharmacological and functional food benefits. Little is known about the identity or mode of action of the enzymes involved in methylating flavanones. This study aimed to identify and characterise the methyltransferase(s) involved in the regiospecific methylation of pinostrobin in Eucalyptus and thereby add to our limited understanding of flavanone biosynthesis in plants. RNA-seq analysis of leaf tips enabled the isolation of a gene encoding a flavanone 7-O-methyltransferase (EnOMT1) in Eucalyptus. Biochemical characterisation of its in vitro activity revealed a range of substrates upon which EnOMT1 acts in a regiospecific manner. Comparison to a homologous sequence from a Eucalyptus species lacking O-methylated flavonoids identified critical catalytic amino acid residues within EnOMT1 responsible for its activity. This detailed molecular characterisation identified a methyltransferase responsible for chemical ornamentation of the core flavanone structure of pinocembrin and helps shed light on the mechanism of flavanone biosynthesis in Eucalyptus. 相似文献
47.
Plants have various self-defense mechanisms against biotic attacks, involving both physical and chemical barriers. Physical barriers include spines, trichomes, and cuticle layers, whereas chemical barriers include secondary metabolites (SMs) and volatile organic compounds (VOCs). Complex interactions between plants and herbivores occur. Plant responses to insect herbivory begin with the perception of physical stimuli, chemical compounds (orally secreted by insects and herbivore-induced VOCs) during feeding. Plant cell membranes then generate ion fluxes that create differences in plasma membrane potential (Vm), which provokes the initiation of signal transduction, the activation of various hormones (e.g., jasmonic acid, salicylic acid, and ethylene), and the release of VOCs and SMs. This review of recent studies of plant–herbivore–infection interactions focuses on early and late plant responses, including physical barriers, signal transduction, SM production as well as epigenetic regulation, and phytohormone responses. 相似文献
48.
49.
Ali Alipour Najmi Elchin Jafariyeh-Yazdi Mojgan Hadian Jos Hermans Prof. Rainer Bischoff Prof. Jun Yue Prof. Alexander Dömling Prof. Arne Wittstock Dr. Hjalmar P. Permentier 《ChemMedChem》2022,17(11):e202200040
A novel method for the selective catalytic N-dealkylation of drug molecules on a nanoporous gold (NPG) catalyst producing valuable N-dealkylated metabolites and intermediates is described. Drug metabolites are important chemical entities at every stage of drug discovery and development, from exploratory discovery to clinical development, providing the safety profiles and the ADME (adsorption, distribution, metabolism, and elimination) of new drug candidates. Synthesis was carried out in aqueous solution at 80 °C using air (oxygen source) as oxidant, in single step with good isolated yields. Different examples examined in this study showed that aerobic catalytic N-dealkylation of drug molecules on NPG has a broad scope supporting N-deethylation, N-deisopropylation and N-demethylation, converting either 3° amines to 2° amines, or 2° amines to 1° amines. 相似文献
50.
近年来,非传染性慢性疾病的发病率迅速上升,已成为一个全球性的问题。过度食用简单的加工碳水化合物食品被认为是导致年轻人和老年人罹患非传染性慢性疾病的主要原因之一。全谷物米是碳水化合物、膳食纤维的重要来源,富含维生素、矿物质和抗氧化剂。然而,糙米的适口性是其在长期以白米消费为主的人群中被接受的关键因素。在初始阶段,我们成功培育出了水稻品种,其全谷物米芳香、柔软且白米具有较高的铁锌密度和中血糖指数（GI）。最成功的品种是独特的具有较软质构的黑紫色稻米,名为紫莓香米（Riceberry）,富含蓝莓花青素等营养物质的稻米。针对富含膳食纤维、高抗氧化活性的稻米产品研发一直是学术界、实体部门和中小企业极为活跃的领域,目前共有关于紫莓香米相关的39项专利申请（18项已授权专利）、12项国际出版物、以及18 700个与紫莓香米有关的YouTube视频。从2017年开始,紫莓香米已超越泰国Hom茉莉香米（Thai Hommali Rice）成为最受欢迎的产品开发选择原料,已有超过200种作为乳制品替代品、配菜、主餐食品、热饮料、烘焙食品和早餐麦片等的商业化食品和非食品产品。在第二阶段,我们成功地培育出了名为Pink+4的低血糖指数水稻品种,该品种具有对骤发洪水、水稻白叶枯病、稻瘟病和破坏性褐飞虱的首选抗性,适用于有机水稻生产。以紫色紫莓香米为原料的低GI米粉创新产品已成为功能性配料和功能性食品的下一个发展趋势。这些健康的稻米产品在全球具有较好的发展潜力,可以作为健康食品、无麸质、富含纤维、复杂碳水化合物和可持续有机农业的营养密集型产品。 相似文献