全文获取类型
收费全文 | 81395篇 |
免费 | 15417篇 |
国内免费 | 10174篇 |
专业分类
电工技术 | 9743篇 |
技术理论 | 1篇 |
综合类 | 10403篇 |
化学工业 | 2470篇 |
金属工艺 | 1788篇 |
机械仪表 | 6156篇 |
建筑科学 | 2208篇 |
矿业工程 | 1281篇 |
能源动力 | 1814篇 |
轻工业 | 3395篇 |
水利工程 | 2202篇 |
石油天然气 | 1235篇 |
武器工业 | 1415篇 |
无线电 | 13052篇 |
一般工业技术 | 5321篇 |
冶金工业 | 680篇 |
原子能技术 | 321篇 |
自动化技术 | 43501篇 |
出版年
2024年 | 266篇 |
2023年 | 1644篇 |
2022年 | 2924篇 |
2021年 | 3274篇 |
2020年 | 3575篇 |
2019年 | 3029篇 |
2018年 | 2853篇 |
2017年 | 3329篇 |
2016年 | 3763篇 |
2015年 | 4511篇 |
2014年 | 5723篇 |
2013年 | 5735篇 |
2012年 | 7013篇 |
2011年 | 7272篇 |
2010年 | 5830篇 |
2009年 | 6054篇 |
2008年 | 6205篇 |
2007年 | 6854篇 |
2006年 | 5484篇 |
2005年 | 4398篇 |
2004年 | 3577篇 |
2003年 | 2829篇 |
2002年 | 2142篇 |
2001年 | 1737篇 |
2000年 | 1409篇 |
1999年 | 1115篇 |
1998年 | 884篇 |
1997年 | 690篇 |
1996年 | 574篇 |
1995年 | 420篇 |
1994年 | 376篇 |
1993年 | 288篇 |
1992年 | 287篇 |
1991年 | 154篇 |
1990年 | 171篇 |
1989年 | 117篇 |
1988年 | 96篇 |
1987年 | 48篇 |
1986年 | 52篇 |
1985年 | 47篇 |
1984年 | 46篇 |
1983年 | 38篇 |
1982年 | 36篇 |
1981年 | 15篇 |
1980年 | 27篇 |
1979年 | 11篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1975年 | 11篇 |
1959年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
In recent years, artificial intelligence (AI) is being increasingly utilised in disaster management activities. The public is engaged with AI in various ways in these activities. For instance, crowdsourcing applications developed for disaster management to handle the tasks of collecting data through social media platforms, and increasing disaster awareness through serious gaming applications. Nonetheless, there are limited empirical investigations and understanding on public perceptions concerning AI for disaster management. Bridging this knowledge gap is the justification for this paper. The methodological approach adopted involved: Initially, collecting data through an online survey from residents (n = 605) of three major Australian cities; Then, analysis of the data using statistical modelling. The analysis results revealed that: (a) Younger generations have a greater appreciation of opportunities created by AI-driven applications for disaster management; (b) People with tertiary education have a greater understanding of the benefits of AI in managing the pre- and post-disaster phases, and; (c) Public sector administrative and safety workers, who play a vital role in managing disasters, place a greater value on the contributions by AI in disaster management. The study advocates relevant authorities to consider public perceptions in their efforts in integrating AI in disaster management. 相似文献
4.
5.
6.
Kang Luan Meijin He Bojie Xu Pengwei Wang Jiajia Zhou Binbin Hu Lei Jiang Huan Liu 《Advanced functional materials》2021,31(26):2010634
In nature, the feathers of the goose Anser cygnoides domesticus stay superhydrophobic over a long term, thought as the main reason for keeping the surface clean. However, contaminants, especially those that are oleophilic or trapped within textures, cannot be removed off the superhydrophobic feathers spontaneously. Here, a different self-cleaning strategy based on superhydrophilic feathers is revealed that is imparted by self-coating of the amphiphilic saliva, which enables removing away low-surface-tension and/or small-size contaminants by forming directional water sheeting depending on their unique anisotropic microstructures. Particularly, the surface superhydrophilicity is switchable to superhydrophobicity upon exposure to air for maintaining a clean surface for a long time, which is further enhanced by coating with self-secreted preening oil. By alternate switching between a transient superhydrophilicity and a long-term stable superhydrophobicity, the goose feathers exhibit an integrated smart self-cleaning strategy, which is also shared by other aquatic birds. An attractive point is the re-entrant structure of the feathers, which facilitates not only liquid spreading on superhydrophilic feathers, but also long-term stability of the cleaned surface by shedding water droplets off the superhydrophobicity feathers. Thus, artificial self-cleaning microtextures are developed. The result renews the common knowledge on the self-cleaning of aquatic bird feathers, offering inspiration for developing bioinspired self-cleaning microtextures and coatings. 相似文献
7.
8.
基于GA-BP的汽车风振噪声声品质预测模型 总被引:1,自引:1,他引:0
目前对于汽车风振噪声的优化研究主要以声压级(Sound pressure level,SPL)作为单一评价指标,既不能全面反映噪声的物理属性,也无法考虑人耳对噪声的主观认知过程。为准确评价风振噪声,引入声品质,运用大涡模拟(Large eddy simulation,LES)对风振噪声进行数值仿真,根据实车道路试验判断仿真的准确性;对仿真结果进行声品质客观评价与主观评价,综合声品质客观评价参数与声品质主观评价试验结果建立BP神经网络预测模型;利用遗传算法(Genetic algorithm,GA),进一步对BP神经网络的结构参数进行优化,建立GA-BP声品质预测模型。研究结果表明,GA-BP声品质预测模型在训练速度和预测精度上都优于BP神经网络预测模型。预测模型基于声品质主客观评价结果,其预测值可以代替传统的声压级评价指标,为风振噪声提供更为准确合理的评价。 相似文献
9.
10.
Referring to the total surface existing in wheat dough, gluten–starch interfaces are a major component. However, their impact on dough rheology is largely unclear. Common viewpoints, based on starch surface modifications or reconstitution experiments, failed to show unambiguous relations of interface characteristics and dough rheology. Observing hybrid artificial dough systems with defined particle surface functionalization gives a new perspective. Since surface functionalization standardizes particle–polymer interfaces, the impact on rheology becomes clearly transferable and thus, contributes to a better understanding of gluten–starch interfaces. Based on this perspective, the effect of particle/starch surface functionality is discussed in relation to the rheological properties of natural wheat dough and modified gluten–starch systems. A competitive relation of starch and gluten for intermolecular interactions with the network-forming polymer becomes apparent during network development by adsorption phenomena. This gluten–starch adhesiveness delays the beginning of non-linearity under large deformations, thus contributing to a high deformability of dough. Consequently, starch surface functionality affects the mechanical properties, starting from network formation and ending with the thermal fixation of structure. 相似文献