全文获取类型
收费全文 | 1903篇 |
免费 | 173篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 8篇 |
综合类 | 4篇 |
化学工业 | 858篇 |
金属工艺 | 17篇 |
机械仪表 | 35篇 |
建筑科学 | 47篇 |
矿业工程 | 4篇 |
能源动力 | 40篇 |
轻工业 | 359篇 |
水利工程 | 12篇 |
石油天然气 | 9篇 |
无线电 | 92篇 |
一般工业技术 | 268篇 |
冶金工业 | 71篇 |
原子能技术 | 4篇 |
自动化技术 | 249篇 |
出版年
2024年 | 8篇 |
2023年 | 26篇 |
2022年 | 188篇 |
2021年 | 199篇 |
2020年 | 61篇 |
2019年 | 77篇 |
2018年 | 68篇 |
2017年 | 79篇 |
2016年 | 100篇 |
2015年 | 85篇 |
2014年 | 95篇 |
2013年 | 141篇 |
2012年 | 130篇 |
2011年 | 135篇 |
2010年 | 95篇 |
2009年 | 102篇 |
2008年 | 104篇 |
2007年 | 66篇 |
2006年 | 63篇 |
2005年 | 56篇 |
2004年 | 37篇 |
2003年 | 28篇 |
2002年 | 21篇 |
2001年 | 18篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1996年 | 7篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1980年 | 1篇 |
1978年 | 1篇 |
1976年 | 4篇 |
1967年 | 1篇 |
排序方式: 共有2077条查询结果,搜索用时 15 毫秒
991.
Ronald Vargas Daniela Plana Jorge Mostany Benjamín R. Scharifker 《Electrochimica acta》2010,55(22):6501-6506
Electrochemical oxidation of p-nitrophenol (PNP) and p-methoxyphenol (PMP) at Bi-doped PbO2 electrodes under thin-layer condition was studied by Fourier transform infrared spectroelectrochemistry (FTIR) as a function of electrode potential and the initial concentration of organic compound. The results show that complete mineralization of the organic species was achieved at potentials more positive than 1.4 V vs. SCE and the mineralization process was not determined by the concentration of phenols. From the electric charge transferred during thin-layer controlled potential electrolysis, we found that PNP and PMP electrooxidation follow Langmuir-Hinshelwood kinetics. 相似文献
992.
Jacques Simpore Fatoumata Kabore Frederic Zongo Deleli Dansou Augustin Bere Salvatore Pignatelli Daniela M Biondi Giuseppe Ruberto Salvatore Musumeci 《Nutrition journal》2006,5(1):3
Background
Malnutrition constitutes a public health problem throughout the world and particularly in developing countries. 相似文献993.
Byrne Ruth A.; Kuba Michael J.; Meisel Daniela V.; Griebel Ulrike; Mather Jennifer A. 《Canadian Metallurgical Quarterly》2006,120(3):198
Previous behavioral studies in Octopus vulgaris revealed lateralization of eye use. In this study, the authors expanded the scope to investigate arm preferences. The octopus's generalist hunting lifestyle and the structure of their arms suggest that these animals have no need to designate specific arms for specific tasks. However, octopuses also show behaviors, like exploration, in which only single or small groups of arms are involved. Here the authors show that octopuses had a strong preference for anterior arm use to reach for and explore objects, which points toward a task division between anterior and posterior arms. Four out of 8 subjects also showed a lateral bias. In addition, octopuses had a preference for a specific arm to reach into a T maze to retrieve a food reward. These findings give evidence for limb-specialization in an animal whose 8 arms were believed to be equipotential. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
994.
Daniela Soleri David A. Cleveland 《Food and Foodways: Explorations in the History and Culture of》2007,15(1):107-118
Although cacao is most familiar in industrialized Western societies in the form of a processed solid confection, for most of its history the seeds of Theobroma cacao have been most commonly used as ingredients in beverages. Today, in some of the more traditional communities of Mesoamerica, cacao continues to be used primarily in traditional local beverages. One such beverage is tejate, from the Central Valleys of Oaxaca, Mexico. Tejate is a culturally and socially significant beverage, and because it is made with maize and frequently consumed in some rural households, its nutritional contribution may be meaningful. However, tejate preparation is labor intensive and this, combined with changes in the Central Valleys, is leading to changes in the persistence and geographic distribution of this important form of cacao consumption. 相似文献
995.
Ramona DAmico Roberta Fusco Rosalba Siracusa Daniela Impellizzeri Alessio Filippo Peritore Enrico Gugliandolo Livia Interdonato Andrea Maria Sforza Rosalia Crupi Salvatore Cuzzocrea Tiziana Genovese Marika Cordaro Rosanna Di Paola 《International journal of molecular sciences》2021,22(12)
Fibromyalgia is a chronic condition characterized by persistent widespread pain that significantly reduces quality of life in patients. The purinergic P2X7 receptor (P2X7R) seems to be involved in different pain states and neuroinflammation. The purpose of this study is to investigate the positive effects of P2X7R inhibition by the antagonist Brilliant Blue G (BBG) in a rat model of reserpine-induced fibromyalgia. Sprague–Dawley male rats were injected with 1 mg/kg of reserpine for three consecutive days. Later, animals were administered BBG (50 mg/kg) intraperitoneally for seven days. Reserpine injections induced a significant increase in pain pro-inflammatory mediators as well as a significant increase in neuroinflammation. Chronic pain, in turn, led to depressive-like symptoms and reduced neurogenesis. Blockage of P2X7R by BBG administrations is able to attenuate the behavioral deficits, pain mediators and microglial activation induced by reserpine injection. Additionally, BBG prevents NLRP3 inflammasome activation and consequently the release of active interleukin (IL)-1 and IL-18, involved in the activation of nociceptors. In conclusion, these results suggest that inhibition of P2X7R should be further investigated to develop a potential approach for the management of fibromyalgia. 相似文献
996.
Maria Giovanna Parisi Annalisa Grimaldi Nicol Baranzini Claudia La Corte Mariano Dara Daniela Parrinello Matteo Cammarata 《International journal of molecular sciences》2021,22(11)
Given the anatomical simplicity and the extraordinary ability to regenerate missing parts of the body, Cnidaria represent an excellent model for the study of the mechanisms regulating regenerative processes. They possess the mesoglea, an amorphous and practically acellular extracellular matrix (ECM) located between the epidermis and the gastrodermis of the body and tentacles and consists of the same molecules present in the ECM of vertebrates, such as collagen, laminin, fibronectin and proteoglycans. This feature makes cnidarians anthozoans valid models for understanding the ECM role during regenerative processes. Indeed, it is now clear that its role in animal tissues is not just tissue support, but instead plays a key role during wound healing and tissue regeneration. This study aims to explore regenerative events after tentacle amputation in the Mediterranean anemone Anemonia viridis, focusing in detail on the reorganization of the ECM mesoglea. In this context, both enzymatic, biometric and histological experiments reveal how this gelatinous connective layer plays a fundamental role in the correct restoration of the original structures by modifying its consistency and stiffness. Indeed, through the deposition of collagen I, it might act as a scaffold and as a guide for the reconstruction of missing tissues and parts, such as amputated tentacles. 相似文献
997.
Segmented biopolyurethanes for medical applications 总被引:1,自引:0,他引:1
Doina Macocinschi Daniela Filip Stelian Vlad Mariana Cristea Maria Butnaru 《Journal of materials science. Materials in medicine》2009,20(8):1659-1668
Polyurethanes are one of the most popular groups of biomaterials applied for medical devices. Their segmented block copolymeric
character endows them a wide range of versatility in terms of tailoring their physical properties, blood and tissue compatibility.
Polyester- and polyether-urethanes have been modified with hydroxypropyl cellulose aiming the change of their surface and
bulk characteristics to confer them biomaterial qualities. In this respect, dynamic contact angle measurements, dynamic mechanical
analyses accompanied by mechanical testing have been done. Platelet adhesion test has been carried out in vitro and the use
of hydroxypropyl cellulose in the polyurethane matrix reduces the platelet adhesion and therefore recommends them as candidates
for biocompatible materials. 相似文献
998.
We wish for robots to manipulate objects and move flexibly in three-dimensional spaces. We describe a robot that can move on a web of surfaces oriented around arbitrary directions in three-space and a set of control algorithms that implements motion in three-dimensions. The robot can manipulate objects in three dimensions while moving, by using the same set of physical resources and control algorithms. This robot is an inchworm-like robot with a simple, modular, and flexible design. Finally, we discuss our experiments. 相似文献
999.
This review presents the major animal models usually used for the study of the pathological processes related to insulin-dependent diabetes mellitus (IDDM), non-insulin-dependent diabetes mellitus (NIDDM) and to the main diabetic complications. These models can be observed spontaneously or can be obtained by selective cross-breeding or toxic exposure (chemical or viral), as well as genetically induced. They reproduce some aspects of the human pathology without combining them all in a single model. Consequently, a pertinent pharmacological approach may compare the results obtained with several models. The examination of the recent results obtained with transgenesis does not allow these animal models to replace more classical ones but they may constitute a future challenge for gene therapy despite the multifactorial aspect of diabetic disease. 相似文献
1000.
Roberta Zuntini Elena Bonora Laura Maria Pradella Laura Benedetta Amato Michele Vidone Sara De Fanti Irene Catucci Laura Cortesi Veronica Medici Simona Ferrari Giuseppe Gasparre Paolo Peterlongo Marco Sazzini Daniela Turchetti 《International journal of molecular sciences》2021,22(11)
The NBN gene has been included in breast cancer (BC) multigene panels based on early studies suggesting an increased BC risk for carriers, though not confirmed by recent research. To evaluate the impact of NBN analysis, we assessed the results of NBN sequencing in 116 BRCA-negative BC patients and reviewed the literature. Three patients (2.6%) carried potentially relevant variants: two, apparently unrelated, carried the frameshift variant c.156_157delTT and another one the c.628G>T variant. The latter was subsequently found in 4/1390 (0.3%) BC cases and 8/1580 (0.5%) controls in an independent sample, which, together with in silico predictions, provided evidence against its pathogenicity. Conversely, the rare c.156_157delTT variant was absent in the case-control set; moreover, a 50% reduction of NBN expression was demonstrated in one carrier. However, in one family it failed to co-segregate with BC, while the other carrier was found to harbor also a probably pathogenic TP53 variant that may explain her phenotype. Therefore, the c.156_157delTT, although functionally deleterious, was not supported as a cancer-predisposing defect. Pathogenic/likely pathogenic NBN variants were detected by multigene panels in 31/12314 (0.25%) patients included in 15 studies. The risk of misinterpretation of such findings is substantial and supports the exclusion of NBN from multigene panels. 相似文献