全文获取类型
收费全文 | 1815篇 |
免费 | 176篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 29篇 |
技术理论 | 1篇 |
综合类 | 5篇 |
化学工业 | 400篇 |
金属工艺 | 22篇 |
机械仪表 | 32篇 |
建筑科学 | 44篇 |
能源动力 | 54篇 |
轻工业 | 89篇 |
水利工程 | 6篇 |
石油天然气 | 1篇 |
无线电 | 401篇 |
一般工业技术 | 479篇 |
冶金工业 | 133篇 |
原子能技术 | 9篇 |
自动化技术 | 293篇 |
出版年
2023年 | 7篇 |
2022年 | 19篇 |
2021年 | 34篇 |
2020年 | 22篇 |
2019年 | 39篇 |
2018年 | 41篇 |
2017年 | 38篇 |
2016年 | 68篇 |
2015年 | 72篇 |
2014年 | 75篇 |
2013年 | 195篇 |
2012年 | 101篇 |
2011年 | 99篇 |
2010年 | 99篇 |
2009年 | 100篇 |
2008年 | 89篇 |
2007年 | 101篇 |
2006年 | 81篇 |
2005年 | 77篇 |
2004年 | 59篇 |
2003年 | 51篇 |
2002年 | 38篇 |
2001年 | 37篇 |
2000年 | 33篇 |
1999年 | 25篇 |
1998年 | 57篇 |
1997年 | 39篇 |
1996年 | 41篇 |
1995年 | 37篇 |
1994年 | 29篇 |
1993年 | 24篇 |
1992年 | 16篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 18篇 |
1988年 | 7篇 |
1987年 | 11篇 |
1986年 | 13篇 |
1985年 | 16篇 |
1984年 | 13篇 |
1983年 | 5篇 |
1981年 | 6篇 |
1980年 | 7篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 2篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 5篇 |
排序方式: 共有1998条查询结果,搜索用时 15 毫秒
81.
The pulsed laser annealing (PLA) is used to assist nickel silicide transformation for Schottky barrier height reduction and tensile strain enhancement and the effect of different laser power are investigated. In this report, a two-step annealing process which combine the conventional rapid thermal annealing with pulsed laser annealing is proposed to achieve a smooth silicon-rich NiSix interfacial layer on (1 0 0) silicon. With optimized laser energy, a 0.2 eV Schottky barrier height (SBH) modulation is observed from Schottky diode electrical characterization. Furthermore, PLA provides sufficient effective temperature during silicidation which also lead to increased tensile stress of silicide film than the two-step RTA silicide is also investigated. The SBH modulation and tensile stress enhancement benefits of PLA silicidation are considered as an alternative to the conventional rapid thermal annealing for ultra-scaled devices performance enhancement. 相似文献
82.
83.
84.
Abstract Among the parameters that affect photolithography, the most important are exposure and development time which affect the coating photoresist characteristics. This study further researches the relationship between the exposure and development time using a high speed image inspection system, and the relationship between the development time and photoresist depth using a Scanning Probe Microscope (SPM). A partial scan CCD camera and high speed frame capture card were used to obtain the photoresist development processing parameters. The experimental results verified that this imaging system provides an economical and effective method for producing a micro‐photo‐etched product. It is expected that these experiments can also offer some good references useful in the micro electro mechanical industrial field. 相似文献
85.
In semiconductor manufacturing, hot lots are to provide marketing and engineering with extra flexibility regarding delivery lead times, and in turn enhance its competitive advantages against other companies. On the other hand, hot lots are among major sources of disruption of the smoothness of the manufacturing flow. They can lead to a significant increase of cycle time of normal lots, and in turn result in delayed delivery times and serious service deteriorations. Due to the complex nature of semiconductor manufacturing, evaluating the impact of hot lots on the cycle time of normal lots presents major challenges. In this paper, we propose a methodology, called progressive simulation metamodelling (PSM), that allows for an efficient development of the response surface between the cycle time of normal lots and the percentage of hot lots in semiconductor manufacturing. The response surface generated by the proposed PSM is like an easy-to-use analytical model, but with the fidelity of simulation that takes into account all important manufacturing details. The specially-designed mechanisms, including identifying the critical region and sequentially adding design points in the critical region, further grants PSM computational advantages compared to the traditional response surface method. An empirical study conducted in collaboration with a semiconductor company validates the viability of PSM in real settings. 相似文献
86.
Abstract Two optic fiber sensing systems for temperature and voltage have been developed which utilize the mode‐mode interference of the two orthogonally polarized modes, HEx II and HEy II, in two commencal polarization‐maintaining fibers (bow‐tie and elliptical core fibers). A package of controlled programs in a Macintosh computer, which can record and process all related data automatically, is established for temperature sensing. The signal drifting problem in voltage sensings has been investigated, and the elimination of signal drifting is obtained by the phase tracking with direct current technology The agreement between the sensing results for temperature and dynamic voltage and those predicted by experimental principles is satisfactory, which confirms the validity of the developed sensing systems. 相似文献
87.
A study on the formation of a measurement scale for the environmental quality of Taiwan’s long-term care institutions by the Delphi method 总被引:1,自引:0,他引:1
Yen Ping Hsieh Yen Wen Hsieh Chia Ching Lin Chien Wen Yeh Sing Chiao Chang 《Journal of Housing and the Built Environment》2012,27(2):169-186
This study used a two-round modified Delphi technique with a questionnaire survey in order to reach a consensus for the questionnaire; the survey was conducted from September to December 2009. The six indicators for the environmental quality of long-term care institutions in Taiwan are (1) indoor environmental quality, (2) safety equipment for the prevention and management of disasters occurring in residents?? daily lives, (3) provision for assistive devices for residents?? daily use, (4) provision for privacy and individualized space, (5) provision for comfortable and decorated indoor environments, and (6) provision for social interaction space. The scale included 34 items with an acceptable number of panel members and acceptable construct validity. Panel members all highly approved of Indicators 1, 2, and 6. Although they approved of Indicator 3, they suggested that caregivers at institutions should replace the functions of living assistive devices. They approved of Indicator 5; however, they questioned the method for providing comfortable and decorated environments. They approved of Indicator 4; however, they suggested that private space need not be provided in the living room of the institution. In terms of long-term care institution environments in Taiwan, Indicators 1, 2, and 6 were important for protecting residents?? physical and psychological well-being and improving their social interactions. Indicator 3, although important, could be directly replaced by caregivers. Indicator 5 required more implementation methods, while Indicator 4, the living room of the institution, was considered unnecessary. 相似文献
88.
89.
This work presents large-scale dye-sensitized solar cells and methods for their manufacture. A dye-sensitized solar cell device contains a photosensitive dye adsorbed on a large surface of the anode, and a transparent conductive cathode disposed opposite the anode, wherein platinum nano-catalytic particles adhere to its surface, and an electrolytic solution is sealed between the anode and the transparent conductive cathode. A titania nanotube film was fabricated by thermo-spraying titanium film on 304 stainless-steel substrate. The photo-current conversion efficiency was tested under an AM 1.5 solar simulator. The dye-sensitized solar cell device has a short current density of 8.22 mA cm–2, open voltage of 0.71 V, fill factor of 0.59, and conversion efficiency of 3.4%. The internal impedance of the dye-sensitized solar cell was detected and simulated using an electrical impedance spectra technique with inductance, resistance, and capacitance characteristics. The stainless-steel/titania, titania/electrolyte, electrolyte, and electrolyte/(platinum/indium tin oxide) interfaces were simulated using an resistor–capacitor parallel circuit, and bulk materials such as stainless steel, tin doped indium oxide, and conducting wire were simulated by using a series of resistors and inductance. 相似文献
90.
The thermal conductivity of graphene nanoribbons (GNRs) functionalized by the chemical attachment of methyl and phenyl groups at random positions is calculated using reverse nonequilibrium molecular dynamics. The GNRs exhibit a rapid drop in thermal conductivity with increasing degree of functionalization; a functional group coverage regime of as little as 1.25% of GNR atoms reduces the thermal conductivity by about 50%. The thermal conductivity of nanoribbons with zigzag edges is more sensitive in the degree of functionalization than nanoribbons with armchair edges. The simulation results indicate that the rapid drop in thermal conductivity is a consequence of the higher angular momentum of functional groups, which rotate the unsupported sp3 bonds and thus reduce the phonon mean free paths. 相似文献