全文获取类型
收费全文 | 11700篇 |
免费 | 1431篇 |
国内免费 | 266篇 |
专业分类
电工技术 | 147篇 |
综合类 | 801篇 |
化学工业 | 2514篇 |
金属工艺 | 668篇 |
机械仪表 | 505篇 |
建筑科学 | 1062篇 |
矿业工程 | 141篇 |
能源动力 | 367篇 |
轻工业 | 3701篇 |
水利工程 | 75篇 |
石油天然气 | 204篇 |
武器工业 | 158篇 |
无线电 | 474篇 |
一般工业技术 | 1855篇 |
冶金工业 | 290篇 |
原子能技术 | 88篇 |
自动化技术 | 347篇 |
出版年
2024年 | 67篇 |
2023年 | 239篇 |
2022年 | 332篇 |
2021年 | 464篇 |
2020年 | 437篇 |
2019年 | 433篇 |
2018年 | 462篇 |
2017年 | 458篇 |
2016年 | 438篇 |
2015年 | 473篇 |
2014年 | 687篇 |
2013年 | 720篇 |
2012年 | 903篇 |
2011年 | 928篇 |
2010年 | 617篇 |
2009年 | 591篇 |
2008年 | 543篇 |
2007年 | 656篇 |
2006年 | 664篇 |
2005年 | 499篇 |
2004年 | 358篇 |
2003年 | 410篇 |
2002年 | 327篇 |
2001年 | 295篇 |
2000年 | 253篇 |
1999年 | 193篇 |
1998年 | 197篇 |
1997年 | 137篇 |
1996年 | 113篇 |
1995年 | 102篇 |
1994年 | 84篇 |
1993年 | 53篇 |
1992年 | 65篇 |
1991年 | 47篇 |
1990年 | 51篇 |
1989年 | 26篇 |
1988年 | 22篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 5篇 |
1983年 | 3篇 |
1982年 | 4篇 |
1981年 | 2篇 |
1980年 | 5篇 |
1976年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
《Journal of the European Ceramic Society》2020,40(5):2151-2162
Anorthite-based highly porous membranes were successfully produced using calcined oyster shell to enhance the pore network. The calcined oyster shells produce CaO responsible for the crystallisation of gehlenite and anorthite at relatively low temperature. While the crystallisation produced nano and meso size of intergranular pores, vitrification of feldspar is responsible for development of the capillary porosities. The increasing sintering temperature from 1200 °C to 1300 °C implies the increase in average pores radius from 1.2 μm to 14.3 μm due to the formation of spherical pores from vitrification. The combination of different class of porosities in the matrices results in the interconnection with improvement of the permeability of the porous network. Porosity, permeability and chemical stability were improved with 20 wt.% of calcined oyster shell addition allowing the possible development of high strength porous network which is promising for the membranes support and other applications including liquid separation as well as liquid filtration where high pressure is used. 相似文献
6.
Qi Yang Qilong Wu Yang Liu Shuiping Luo Xiaotong Wu Xixia Zhao Haiyuan Zou Baihua Long Wen Chen Yujia Liao Lanxi Li Pei Kang Shen Lele Duan Zewei Quan 《Advanced materials (Deerfield Beach, Fla.)》2020,32(36):2002822
Engineering novel Sn-based bimetallic materials could provide intriguing catalytic properties to boost the electrochemical CO2 reduction. Herein, the first synthesis of homogeneous Sn1−xBix alloy nanoparticles (x up to 0.20) with native Bi-doped amorphous SnOx shells for efficient CO2 reduction is reported. The Bi-SnOx nanoshells boost the production of formate with high Faradaic efficiencies (>90%) over a wide potential window (−0.67 to −0.92 V vs RHE) with low overpotentials, outperforming current tin oxide catalysts. The state-of-the-art Bi-SnOx nanoshells derived from Sn0.80Bi0.20 alloy nanoparticles exhibit a great partial current density of 74.6 mA cm−2 and high Faradaic efficiency of 95.8%. The detailed electrocatalytic analyses and corresponding density functional theory calculations simultaneously reveal that the incorporation of Bi atoms into Sn species facilitates formate production by suppressing the formation of H2 and CO. 相似文献
7.
Thermoresponsive behavior and rheology of SiO2–hyaluronic acid/poly(N‐isopropylacrylamide) (NaHA/PNIPAm) core–shell structured microparticles
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
8.
Sergey Bombin Mitchell LeFebvre Jennifer Sherwood Yaolin Xu Yuping Bao Katrina M. Ramonell 《International journal of molecular sciences》2015,16(10):24174-24193
Increasing use of iron oxide nanoparticles in medicine and environmental remediation has led to concerns regarding exposure of these nanoparticles to the public. However, limited studies are available to evaluate their effects on the environment, in particular on plants and food crops. Here, we investigated the effects of positive (PC) and negative (NC) charged iron oxide (Fe2O3) nanoparticles (IONPs) on the physiology and reproductive capacity of Arabidopsis thaliana at concentrations of 3 and 25 mg/L. The 3 mg/L treated plants did not show evident effects on seeding and root length. However, the 25 mg/L treatment resulted in reduced seedling (positive-20% and negative-3.6%) and root (positive-48% and negative-negligible) length. Interestingly, treatment with polyethylenimine (PEI; IONP-PC coating) also resulted in reduced root length (39%) but no change was observed with polyacrylic acid (PAA; IONP-NC coating) treatment alone. However, treatment with IONPs at 3 mg/L did lead to an almost 5% increase in aborted pollen, a 2%–6% reduction in pollen viability and up to an 11% reduction in seed yield depending on the number of treatments. Interestingly, the treated plants did not show any observable phenotypic changes in overall size or general plant structure, indicating that environmental nanoparticle contamination could go dangerously unnoticed. 相似文献
9.
Ramesh Shruthy Stephen Jancy Radhakrishnan Preetha 《International Journal of Food Science & Technology》2021,56(8):3991-3999
In this study, the cellulose nanoparticles (CNP) isolated from potato peel were used for reinforcement of polyvinyl alcohol (PVA)-based active packaging film. The above film was used to pack the raw prawns (Penaeus monodon) at −20 °C, and the colour change, protein content, TVB-N, TMA and microbial analysis were done at regular interval for prawns stored in CNP-PVA active packaging film. A significant difference was observed in the quality of prawns stored in potato CNP-PVA film compared with prawns packed and stored in polyethylene film. The newly designed active packaging with CNP and fennel seed oil enhanced the shelf life of prawns up to two months for both HOSO (head on shell on) prawn and PD (peeled and deveined) prawn. Hence, the study recommends the potato peel CNP-PVA film with fennel seed oil as better choice to extend the shelf life of the prawns during storage compared with polyethylene packaging. 相似文献
10.