全文获取类型
收费全文 | 321篇 |
免费 | 36篇 |
专业分类
电工技术 | 2篇 |
综合类 | 1篇 |
化学工业 | 108篇 |
金属工艺 | 9篇 |
机械仪表 | 4篇 |
建筑科学 | 14篇 |
矿业工程 | 5篇 |
能源动力 | 8篇 |
轻工业 | 37篇 |
水利工程 | 1篇 |
石油天然气 | 4篇 |
无线电 | 49篇 |
一般工业技术 | 41篇 |
冶金工业 | 32篇 |
原子能技术 | 1篇 |
自动化技术 | 41篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2022年 | 23篇 |
2021年 | 29篇 |
2020年 | 17篇 |
2019年 | 9篇 |
2018年 | 27篇 |
2017年 | 13篇 |
2016年 | 19篇 |
2015年 | 14篇 |
2014年 | 9篇 |
2013年 | 20篇 |
2012年 | 15篇 |
2011年 | 19篇 |
2010年 | 16篇 |
2009年 | 16篇 |
2008年 | 16篇 |
2007年 | 8篇 |
2006年 | 15篇 |
2005年 | 4篇 |
2004年 | 8篇 |
2003年 | 12篇 |
2002年 | 5篇 |
2001年 | 3篇 |
1999年 | 3篇 |
1998年 | 4篇 |
1997年 | 2篇 |
1996年 | 5篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1983年 | 1篇 |
1981年 | 2篇 |
1976年 | 1篇 |
1972年 | 1篇 |
1967年 | 1篇 |
排序方式: 共有357条查询结果,搜索用时 15 毫秒
81.
Kruse Natalie Hawkins Caleb López Dina L. Johnson Kelly 《Mine Water and the Environment》2019,38(4):718-734
Mine Water and the Environment - The East Branch of Raccoon Creek, Ohio is highly impacted by pre-regulation coal mining and contains 10 steel slag leach beds that passively treat the low pH, and... 相似文献
82.
83.
84.
Site‐Specific Labelling of Native Mammalian Proteins for Single‐Molecule FRET Measurements 下载免费PDF全文
Alexander Gust Dr. Leonhard Jakob Daniela M. Zeitler Dr. Astrid Bruckmann Kevin Kramm Dr. Sarah Willkomm Prof. Dr. Philip Tinnefeld Prof. Dr. Gunter Meister Prof. Dr. Dina Grohmann 《Chembiochem : a European journal of chemical biology》2018,19(8):780-783
Human cells are complex entities in which molecular recognition and selection are critical for cellular processes often driven by structural changes and dynamic interactions. Biomolecules appear in different chemical states, and modifications, such as phosphorylation, affect their function. Hence, using proteins in their chemically native state in biochemical and biophysical assays is essential. Single‐molecule FRET measurements allow exploration of the structure, function and dynamics of biomolecules but cannot be fully exploited for the human proteome, as a method for the site‐specific coupling of organic dyes into native, non‐recombinant mammalian proteins is lacking. We address this issue showing the site‐specific engineering of fluorescent dyes into human proteins on the basis of bioorthogonal reactions. We show the applicability of the method to study functional and post‐translationally modified proteins on the single‐molecule level, among them the hitherto inaccessible human Argonaute 2. 相似文献
85.
Lithium‐Ion Batteries: Making Ultrafast High‐Capacity Anodes for Lithium‐Ion Batteries via Antimony Doping of Nanosized Tin Oxide/Graphene Composites (Adv. Funct. Mater. 23/2018) 下载免费PDF全文
86.
Nikita M. Kuznetsov Vitaliy G. Shevchenko Dina Yu. Stolyarova Sergei A. Ozerin Sergey I. Belousov Sergei N. Chvalun 《应用聚合物科学杂志》2018,135(32)
The dielectric characteristics of various modified montmorillonites suspensions in polydimethylsiloxane were investigated. Such materials are promising candidates as electrorheological fluids. The effect of small water content and temperature change in the dielectric spectra of suspensions was studied. The electrical conductivity of suspensions rises with filler concentration. Conductivity also increases with frequency for all samples by 5–6 orders of magnitude. The frequency dependence of permittivity changes significantly with temperature and strongly depends on the type of modifier. The positions of relaxation transitions peaks observed in dielectric loss curves substantially depend on the type of filler and water content. Dielectric loss peaks shift to higher frequencies with temperature. Relaxation mechanism is related to filler and described by capacitor model. Based on X‐ray data a model of relaxation transitions is proposed. Also, the activation energy of dielectric relaxation is estimated. The activation energy is independent of filler concentration but is determined by the structural features of fillers in polymer medium. The prospects of dielectric spectroscopy for analyzing the layered nanosilicates structure in polymer solution are demonstrated. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46614. 相似文献
87.
Vishvas Haridas Kshirsagar Ashok M. Kanthe Dina Simunic 《Wireless Personal Communications》2018,100(2):311-320
The mobile ad hoc network (MANET) is communication network of a mobile node without any prior infrastructure of communication. The network does not have any static support; it dynamically creates the network as per requirement by using available mobile nodes. This network has a challenging security problem. The security issue mainly contains a denial of service attacks like packet drop attack, black-hole attack, gray-hole attack, etc. The mobile ad-hoc network is an open environment so the working is based on mutual trust between mobile nodes. The MANETs are vulnerable to packet drop attack in which packets travel through the different node. The network while communicating, the node drops the packet, but it is not attracting the neighboring nodes to drop the packets. This proposed algorithm works with existing routing protocol. The concept of trusted list is used for secure communication path. The trusted list along with trust values show how many times node was participated in the communication. It differentiates between altruism and selfishness in MANET with the help of energy level of mobile components. The trust and energy models are used for security and for the differentiation between altruism and selfishness respectively. 相似文献
88.
Dina K. Gaynullina Olga S. Tarasova Anastasia A. Shvetsova Anna A. Borzykh Rudolf Schubert 《International journal of molecular sciences》2022,23(11)
The activity of many vasomotor signaling pathways strongly depends on extracellular/intracellular pH. Nitric oxide (NO) is one of the most important vasodilators produced by the endothelium. In this review, we present evidence that in most vascular beds of mature mammalian organisms metabolic or respiratory acidosis increases functional endothelial NO-synthase (eNOS) activity, despite the observation that direct effects of low pH on eNOS enzymatic activity are inhibitory. This can be explained by the fact that acidosis increases the activity of signaling pathways that positively regulate eNOS activity. The role of NO in the regulation of vascular tone is greater in early postnatal ontogenesis compared to adulthood. Importantly, in early postnatal ontogenesis acidosis also augments functional eNOS activity and its contribution to the regulation of arterial contractility. Therefore, the effect of acidosis on total peripheral resistance in neonates may be stronger than in adults and can be one of the reasons for an undesirable decrease in blood pressure during neonatal asphyxia. The latter, however, should be proven in future studies. 相似文献
89.
Danyang Wang Simone Hildorf Elissavet Ntemou Linn Salto Mamsen Lihua Dong Susanne Elisabeth Pors Jens Fedder Erik Clasen-Linde Dina Cortes Jrgen Thorup Claus Yding Andersen 《International journal of molecular sciences》2022,23(14)
Organotypic culture of human fetal testis has achieved fertilization-competent spermatids followed by blastocysts development. This study focuses on whether the organotypic culture of testicular tissue from infant boys with cryptorchidism could support the development of spermatogonia and somatic cells. Frozen-thawed tissues were cultured in two different media, with or without retinoic acid (RA), for 60 days and evaluated by tissue morphology and immunostaining using germ and somatic cell markers. During the 60-day culture, spermatocytes stained by boule-like RNA-binding protein (BOLL) were induced in biopsies cultured with RA. Increased AR expression (p < 0.001) and decreased AMH expression (p < 0.001) in Sertoli cells indicated advancement of Sertoli cell maturity. An increased number of SOX9-positive Sertoli cells (p < 0.05) was observed, while the percentage of tubules with spermatogonia was reduced (p < 0.001). More tubules with alpha-smooth muscle actin (ACTA, peritubular myoid cells (PTMCs) marker) were observed in an RA-absent medium (p = 0.02). CYP17A1/STAR-positive Leydig cells demonstrated sustained steroidogenic function. Our culture conditions support the initiation of spermatocytes and enhanced maturation of Sertoli cells and PTMCs within infant testicular tissues. This study may be a basis for future studies focusing on maintaining and increasing the number of spermatogonia and identifying different factors and hormones, further advancing in vitro spermatogenesis. 相似文献
90.
Dina Alramadhani Anfal S. Aljahdali Osheiza Abdulmalik B. Daniel Pierce Martin K. Safo 《International journal of molecular sciences》2022,23(13)
Sickle cell disease (SCD) is a genetic disorder that affects millions of individuals worldwide. Chronic anemia, hemolysis, and vasculopathy are associated with SCD, and their role has been well characterized. These symptoms stem from hemoglobin (Hb) polymerization, which is the primary event in the molecular pathogenesis of SCD and contributes to erythrocyte or red blood cell (RBC) sickling, stiffness, and vaso-occlusion. The disease is caused by a mutation at the sixth position of the β-globin gene, coding for sickle Hb (HbS) instead of normal adult Hb (HbA), which under hypoxic conditions polymerizes into rigid fibers to distort the shapes of the RBCs. Only a few therapies are available, with the universal effectiveness of recently approved therapies still being monitored. In this review, we first focus on how sickle RBCs have altered metabolism and then highlight how this understanding reveals potential targets involved in the pathogenesis of the disease, which can be leveraged to create novel therapeutics for SCD. 相似文献