全文获取类型
收费全文 | 3480篇 |
免费 | 315篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 3797篇 |
出版年
2024年 | 15篇 |
2023年 | 50篇 |
2022年 | 54篇 |
2021年 | 183篇 |
2020年 | 114篇 |
2019年 | 118篇 |
2018年 | 175篇 |
2017年 | 166篇 |
2016年 | 174篇 |
2015年 | 115篇 |
2014年 | 176篇 |
2013年 | 303篇 |
2012年 | 239篇 |
2011年 | 255篇 |
2010年 | 190篇 |
2009年 | 189篇 |
2008年 | 174篇 |
2007年 | 143篇 |
2006年 | 117篇 |
2005年 | 79篇 |
2004年 | 63篇 |
2003年 | 69篇 |
2002年 | 71篇 |
2001年 | 45篇 |
2000年 | 38篇 |
1999年 | 33篇 |
1998年 | 92篇 |
1997年 | 63篇 |
1996年 | 36篇 |
1995年 | 37篇 |
1994年 | 28篇 |
1993年 | 32篇 |
1992年 | 15篇 |
1991年 | 18篇 |
1990年 | 8篇 |
1989年 | 14篇 |
1988年 | 11篇 |
1986年 | 8篇 |
1985年 | 15篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 7篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1969年 | 2篇 |
排序方式: 共有3797条查询结果,搜索用时 15 毫秒
1.
Lopes Elio Jordan Kataria Shaolin Keshav Shashank Ikram Sumaiya Thaseen Ghalib Muhammad Rukunuddin Shankar Achyut Krichen Moez 《Wireless Networks》2022,28(7):3111-3125
Wireless Networks - In centralized video streaming platforms, the platform owner, rather than the content producer, controls most of the content uploaded on the centralized video... 相似文献
2.
3.
Camila C. Lopes Wagner A. Pinheiro Daniel Navarro da Rocha José G. Neves Américo Bortolazzo Correr José R.M. Ferreira Rafael M. Barbosa Jefferson R.F. Soares Jheison L. Santos Marcelo H. Prado da Silva 《Ceramics International》2021,47(6):7653-7665
The repair of bone fractures is a clinical challenge for patients with impaired healing, such as osteoporosis. Currently, different strategies have been developed to design new biomaterials, enhancing their interactions with biological systems and conducting the cellular behavior in the desired direction to help fracture healing. In the present work, hydroxyapatite-graphene oxide (HA-GO) nanocomposites were produced and the morphological and physicochemical influences of the addition of 0.5 wt%, 1.0 wt% and 1.5 wt% of GO to HA were observed. FEG-SEM and TEM analyses of HA-GO nanocomposites showed HA nanoparticles adhered to the surface of the GO sheets, suggesting an effective method to form nanostructured graphene-based biomaterials. As confirmation, physicochemical analyses by Raman, FTIR and TGA demonstrated a strong affinity between HA and GO, according to the increase of concentration from 0.5 wt% to 1.5 wt% GO in the HA-GO nanocomposites. Also, in order to evaluate the HA-GO nanocomposites behavior under biological microenvironment, in vitro bioactivity and indirect cytotoxicity tests were performed. FEG-SEM analyses confirmed the positive results for the bioactivity properties of HA-GO nanocomposite and indirect cytotoxicity demonstrated that even with a decrease in the hDPSCs viability and proliferation, when increasing to 1.5 wt% of GO concentration, high level of cell viability was exhibited by HA-GO nanocomposites. These biological results suggested the 0.5 wt% HA-GO nanocomposite as a potential bioactive bone graft and a promising biomaterial for bone tissue regeneration, when compared to the pure HA. 相似文献
4.
Dr. Francesca Ferlenghi Dr. Michele Mari Prof. Gabriella Gobbi Dr. Gian Marco Elisi Prof. Marco Mor Prof. Silvia Rivara Prof. Federica Vacondio Dr. Silvia Bartolucci Prof. Annalida Bedini Dr. Fabiola Fanini Prof. Gilberto Spadoni 《ChemMedChem》2021,16(19):3071-3082
The MT2-selective melatonin receptor ligand UCM765 (N-(2-((3-methoxyphenyl)(phenyl)amino)ethyl)acetamide), showed interesting sleep inducing, analgesic and anxiolytic properties in rodents, but suffers from low water solubility and modest metabolic stability. To overcome these limitations, different strategies were investigated, including modification of metabolically liable sites, introduction of hydrophilic substituents and design of more basic derivatives. Thermodynamic solubility, microsomal stability and lipophilicity of new compounds were experimentally evaluated, together with their MT1 and MT2 binding affinities. Introduction of a m-hydroxymethyl substituent on the phenyl ring of UCM765 and replacement of the replacement of the N,N-diphenyl-amino scaffold with a N-methyl-N-phenyl-amino one led to highly soluble compounds with good microsomal stability and receptor binding affinity. Docking studies into the receptor crystal structure provided a rationale for their binding affinity. Pharmacokinetic characterization in rats highlighted higher plasma concentrations for the N-methyl-N-phenyl-amino derivative, consistent with its improved microsomal stability and makes this compound worthy of consideration for further pharmacological investigation. 相似文献
5.
P. Carrasqueira H. Rocha J. M. Dias T. Ventura B. C. Ferreira M. C. Lopes 《International Transactions in Operational Research》2023,30(1):206-223
Radiation therapy is a technology-driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head-and-neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high-quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques. 相似文献
6.
Lipase production by solid‐state fermentation of olive pomace in tray‐type and pressurized bioreactors 下载免费PDF全文
7.
Dr. Kristina Goncharenko Dr. Michele Mari Dr. Yves P. Auberson Brieuc Matagne 《ChemMedChem》2020,15(24):2359-2362
The European Federation for Medicinal Chemistry (EFMC) created the Young Scientists Network (YSN) to support early-career medicinal chemists and chemical biologists. By doing this, it addressed the rapid changes taking place in the scientific community and in our society, such as the rise of social media, the evolution of the gender balance in the scientific population, and educational needs. Creating the YSN was also a way to ensure that the next generation of scientists would contribute to shaping EFMC's strategy, while recognizing and addressing their needs. The YSN was set up as a very dynamic concept, and has now developed to the point where its impact is evident. The activities it promotes complement EFMC's community support and scientific opportunities, rejuvenating the Federation and preparing it for the future. It also provides opportunities for many brilliant young scientists, who do not hesitate to invest time and energy in supporting our community and shaping their own future. 相似文献
8.
9.
10.
Ariana de Souza Soares Afonso Mota Ramos Érica Nascif Rufino Vieira Ellen Silva Lago Vanzela Patrícia Martins de Oliveira Daniele de Almeida Paula 《International Journal of Food Science & Technology》2018,53(9):2229-2238
The goal of this research was to evaluate the use of vacuum impregnation (VI) and soaking techniques (ST) in the application of edible coatings of chitosan and chitosan + lauric acid to minimally processed pumpkins (MPP). The vacuum impregnation method led to greater component incorporation (5.9% and 1.75%, respectively) in the pumpkins when compared to soaking and consequently the formation of more uniform, thicker coatings (25.6 and 22.3 μm, respectively). However, VI caused greater changes in pH, acidity, colour and firmness. Relating to water content and carotenoid content, noncoated pumpkins presented greater losses during the storage period, regardless of impregnation method. The pumpkins with edible coatings, regardless of method, presented lower numbers of psychrotrophic micro‐organisms and coliforms during the storage period. Therefore, soaking was considered the best method for the application of chitosan‐based edible coatings to minimally processed pumpkins, as it led to smaller changes in the properties of the product. 相似文献