全文获取类型
收费全文 | 1961篇 |
免费 | 31篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 1993篇 |
出版年
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 21篇 |
2020年 | 14篇 |
2019年 | 12篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 30篇 |
2013年 | 60篇 |
2012年 | 30篇 |
2011年 | 38篇 |
2010年 | 34篇 |
2009年 | 27篇 |
2008年 | 32篇 |
2007年 | 40篇 |
2006年 | 29篇 |
2005年 | 43篇 |
2004年 | 27篇 |
2003年 | 32篇 |
2002年 | 24篇 |
2001年 | 25篇 |
2000年 | 10篇 |
1999年 | 47篇 |
1998年 | 389篇 |
1997年 | 195篇 |
1996年 | 124篇 |
1995年 | 97篇 |
1994年 | 81篇 |
1993年 | 72篇 |
1992年 | 26篇 |
1991年 | 25篇 |
1990年 | 27篇 |
1989年 | 30篇 |
1988年 | 26篇 |
1987年 | 24篇 |
1986年 | 22篇 |
1985年 | 16篇 |
1984年 | 10篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 12篇 |
1979年 | 6篇 |
1978年 | 9篇 |
1977年 | 27篇 |
1976年 | 52篇 |
1975年 | 8篇 |
1974年 | 7篇 |
1965年 | 4篇 |
排序方式: 共有1993条查询结果,搜索用时 15 毫秒
41.
Haiqing?Liu S.?Kay?ObendorfEmail author Michael?J.?Leonard Timothy?J.?Young Michael?J.?Incorvia 《Journal of surfactants and detergents》2005,8(4):311-317
The adsorption of aroma chemicals on cotton fabric was studied relative to the surfactant concentration, surfactant type,
water solubility, and fiber morphology. The adsorption increased with increasing surfactant concentration to a maximum near
the critical micelle concentration, then decreased with further increases in surfactant concentration. The adsorption also
was found to be highly dependent on the fiber surface area and pore structure; dramatic differences were observed between
untreated and mercerized cotton fabric and are believed to be due to morphological differences. Cationic and anionic surfactants
increased the aroma chemical adsorption, which varied with surfactant type, with cetyltrimethylammonium chloride (CTAC)>sodium
dodecyl sulfate (SDS)>H2O. Water solubility also influenced adsorption; in most cases, adsorption increased with water solubility. In addition, adsorption
was also influenced by chemical structure and hydrophobic interactions. The adsorption of aroma chemicals on cotton fabric
can be attributed to the aqueous solution being physically held in capillaries and pore structures within the fibular structure
of cotton fiber and also to molecular interactions among the aroma chemical molecules, surfactants, and cotton substrate. 相似文献
42.
Interpenetrating polymer network (IPN) hydrogels based on poly(ethylene oxide) and poly(methyl methacrylate) were prepared by radical polymerization using 2,2‐dimethyl‐2‐phenylacetophenone and ethylene glycol dimethacrylate as initiators and crosslinkers, respectively. The IPN hydrogels were analyzed for sorption behavior at 25°C and at a relative humidity of 95% using dynamic vapor sorption. The IPN hydrogels exhibited a relatively high equilibrium water content in the range of 13–68%. The state of water in the swollen IPN hydrogels was investigated using differential scanning calorimetry. The free water in the hydrogels increased as the hydrophilic content increased. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 258–262, 2003 相似文献
43.
Garrett BC Dixon DA Camaioni DM Chipman DM Johnson MA Jonah CD Kimmel GA Miller JH Rescigno TN Rossky PJ Xantheas SS Colson SD Laufer AH Ray D Barbara PF Bartels DM Becker KH Bowen KH Bradforth SE Carmichael I Coe JV Corrales LR Cowin JP Dupuis M Eisenthal KB Franz JA Gutowski MS Jordan KD Kay BD Laverne JA Lymar SV Madey TE McCurdy CW Meisel D Mukamel S Nilsson AR Orlando TM Petrik NG Pimblott SM Rustad JR Schenter GK Singer SJ Tokmakoff A Wang LS Wettig C Zwier TS 《Chemical reviews》2005,105(1):355-390
44.
45.
Lesa Lorenzen Huber Kalpana Shankar Kelly Caine Kay Connelly L. Jean Camp Beth Ann Walker 《International journal of human-computer interaction》2013,29(7):441-455
In-home technologies can support older adults' activities of daily living, provide physical safety and security, and connect elders to family and friends. They facilitate aging in place while reducing caregiver burden. One of older adults' primary concerns about in-home technologies is their potential to reduce human contact, particularly from cherished caregivers. In this exploratory in situ study, we provided an ecosystem of networked monitoring technologies to six older adults and their caregivers. We analyzed the amount and content of communication between them. The amount of noncomputer-mediated communication did not decrease through the 6-week study. The content of communication coalesced into four themes: communication about the technologies, communication facilitated by technologies, intrusiveness of technologies, and fun and playfulness with the technologies. Results suggest that in-home technologies, designed with sensitivity to older adults' primary motivations, have the potential to shape and tailor important relationships in later life. 相似文献
46.
The purpose of this study was to examine individual differences in the effectiveness of learning objects in secondary school classrooms. Specifically, gender, age, grade, subject area, and computer comfort (self-efficacy) were examined in 850 students. Effectiveness was measured in terms of student attitude (learning, quality, and engagement) and student performance. No gender differences were observed between males and females with respect to student attitudes or performance. Age was significantly correlated with student attitudes and performance, however correlation coefficients were small. Grade 12 students were more positive about learning objects and performed better than grade 9 and 10 students. Science students had significantly more positive attitudes and performed better than mathematics students. Finally, students who were more comfortable about computers, appreciated learning objects more than their less confident peers, however performance was unaffected. 相似文献
47.
Recent research of complex networks has significantly contributed to the understanding how networks can be classified according
to its topological characteristics. However, transport networks attracted less attention although their importance to economy
and daily life. In this work the development of the Swiss road and railway network during the years 1950–2000 is investigated.
The main difference between many of the recently studied complex networks and transport networks is the spatial structure.
Therefore, some of the well-established complex network measures may not be applied directly to characterise transport networks
but need to be adapted to fulfil the requirements of spatial networks. Additionally, new approaches to cover basic network
characteristics such as local network densities are applied. The focus of the interest hereby is always not only to classify
the transport network but also to provide the basis for further applications such as vulnerability analysis or network development.
It could be showed that the proposed measures are able to characterise the growth of the Swiss road network. To proof the
use of local density measures to explain the robustness of a network however needs further research.
相似文献
Kay W. AxhausenEmail: |
48.
Andreas Goralczyk Sofya Savicheva Ramin Montazeri Simona Fine Fadoua Mayoussi Pang Zhu Kay Steffen Frederik Kotz-Helmer Dorothea Helmer Bastian E. Rapp 《Advanced Engineering Materials》2023,25(8):2201314
Superhydrophobic coatings are widely applicable, e.g., as self-cleaning surfaces or water–oil separation membranes, yet their wider usage is impeded due to costs of fabrication, size, or substrate limitation. Spray-coating is a versatile coating procedures and might offer a good solution for the fabrication of these superhydrophobic coatings, due to the fact that coatings can be fabricated on various materials in a simple, fast, and inexpensive manner. Most procedures rely on hybrid coatings of hydrophobized nanoparticles and a polymeric matrix, which have several drawbacks including the easy loss of nanoparticles and difficult waste handling. Here, the fabrication of the superhydrophobic material, called Fluoropor, for the first time, by spray-coating on various substrates including metals, tissues, concrete, and glass is presented. It is fabricated by spray-coating a mixture of a highly fluorinated monomer blended with porogens followed by photopolymerization. The superhydrophobicity of the material relies on the porous structure on the micro-/nanoscale across the bulk material and does not require any nanoparticles. Excellent self-cleaning ability of these coatings, resistance against thermal and abrasive impact, and their application as oil–water separation membranes are shown. This versatile applicability is highly promising for real-world application as self-cleaning coatings or oil–water separating membranes. 相似文献
49.
The aim of this paper is to show how information theoretic measures can be used to analyse and interpret the results of psychophysical experiments designed to search for conditions under which information from one source modulates the transmission of information from another source. We therefore use measures of mutual and conditional information to analyse systems with two inputs. The information transmitted by such a system can be split into three components depending on whether it is shared between the two inputs or is specific to each. We are concerned here with distinguishing systems that use one input to modulate transmission of information about the other from systems that simply add both inputs, and show how the three components provide evidence for distinguishing between additive and modulatory effects. We also report numerical simulations of the sampling biasses and variances of these measures as a function of the sample size and propose minimum sample sizes that should be used to overcome the bias. 相似文献