全文获取类型
收费全文 | 102篇 |
免费 | 5篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 21篇 |
金属工艺 | 3篇 |
机械仪表 | 11篇 |
建筑科学 | 10篇 |
能源动力 | 3篇 |
轻工业 | 5篇 |
无线电 | 30篇 |
一般工业技术 | 20篇 |
原子能技术 | 1篇 |
自动化技术 | 3篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 3篇 |
2018年 | 3篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 7篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 4篇 |
2009年 | 11篇 |
2008年 | 10篇 |
2007年 | 10篇 |
2006年 | 5篇 |
2005年 | 2篇 |
2004年 | 3篇 |
2003年 | 4篇 |
2002年 | 1篇 |
2001年 | 5篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1997年 | 1篇 |
1995年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有109条查询结果,搜索用时 15 毫秒
1.
John W. Drazin James A. Wollmershauser Heonjune Ryou Mason A. Wolak Edward P. Gorzkowski 《Journal of the American Ceramic Society》2020,103(1):60-69
Pressureless sintering approaches provide a simple avenue to manufacture dense ceramic parts with minimal processing equipment, but current pressureless sintering techniques have yet to demonstrate capabilities of producing dense ceramics while maintaining sub-50 nm grain sizes. Nanocrystalline yttria stablized zirconia ceramics were process from 4 mol% yttria stablized zirconia (4YSZ) nanopowders with a crystallite size of 7.5 nm using dry cold isostatic pressing (CIP) where powders are dried immediately prior to green compact formation and CIP vacuum bagging. It is shown that CIP pressures >75 000 psi (517 MPa) effectively remove pores larger than 100 nm and that pressureless sintering occurs at reduced temperatures for green densities ≥50%. Though the sintering kinetics are shown to be similar to other zirconia nanopowder sintering studies, the small initial crystallize size and reduced sintering temperature allowed densities as high as 97.2%, while retaining a ceramic grain size at or below 40 nm. Produced nanocrystalline 4YSZ ceramics with a grain size of 30.3 nm and a density of 96.3% had Vicker's hardnesses as high as 14.2 GPa and Vicker's indentation fracture resistance of 3.43 MPa·, demonstrating that simple processing approaches can be refined to fabricate nanocrystalline ceramics while maintaining high hardness and indentation fracture resistance. 相似文献
2.
This paper presents a compact and unified hardware architecture implementing SHA-1 and SHA-256 algorithms that is suitable for the mobile trusted module (MTM), which should satisfy small area and low-power condition. The built-in hardware hash engine in a MTM is one of the most important circuit blocks and dominates the performance of the whole platform because it is used as a key primitive to support most MTM commands concerning to the platform integrity and the command authentication. Unlike the general trusted platform module (TPM) for PCs, the MTM, that is to be employed in mobile devices, has very stringent limitations with respect to available power, circuit area, and so on. Therefore, MTM needs the spatially optimized architecture and design method for the construction of a compact SHA hardware. The proposed hardware for unified SHA-1 and SHA-256 component can compute a sequence of 512-bit data blocks and has been implemented into 12,400 gates of 0.25 μm CMOS process. Furthermore, in the processing speed and power consumption, it shows the better performance in comparison with commercial TPM chips and software-only implementation. The highest operation frequency and throughput of the proposed architecture are 137 MHz and 197.6 Mbps, respectively, which satisfy the processing requirement for the mobile application. 相似文献
3.
Nam-In Kim Miad Yarali Mina Moradnia Muhammad Aqib Che-Hao Liao Feras AlQatari Mingtao Nong Xiaohang Li Jae-Hyun Ryou 《Advanced functional materials》2023,33(10):2212538
Extreme environments are often faced in energy, transportation, aerospace, and defense applications and pose a technical challenge in sensing. Piezoelectric sensor based on single-crystalline AlN transducers is developed to address this challenge. The pressure sensor shows high sensitivities of 0.4–0.5 mV per psi up to 900 °C and output voltages from 73.3 to 143.2 mV for input gas pressure range of 50 to 200 psi at 800 °C. The sensitivity and output voltage also exhibit the dependence on temperature due to two origins. A decrease in elastic modulus (Young's modulus) of the diaphragm slightly enhances the sensitivity and the generation of free carriers degrades the voltage output beyond 800 °C, which also matches with theoretical estimation. The performance characteristics of the sensor are also compared with polycrystalline AlN and single-crystalline GaN thin films to investigate the importance of single crystallinity on the piezoelectric effect and bandgap energy-related free carrier generation in piezoelectric devices for high-temperature operation. The operation of the sensor at 900 °C is amongst the highest for pressure sensors and the inherent properties of AlN including chemical and thermal stability and radiation resistance indicate this approach offers a new solution for sensing in extreme environments. 相似文献
4.
Sungeun Lee Hakmin Lee Jaehyeon Kim Ji Hoon Kim Eun Mei Gao Yoonjeong Lee Miryeong Yoo Trang H. T. Trinh Jieun Kim Chul Young Kim Chongsuk Ryou 《International journal of molecular sciences》2023,24(1)
Prion diseases are neurodegenerative disorders in humans and animals for which no therapies are currently available. Here, we report that Curcuma phaeocaulis Valeton (Zingiberaceae) (CpV) extract was partly effective in decreasing prion aggregation and propagation in both in vitro and in vivo models. CpV extract inhibited self-aggregation of recombinant prion protein (PrP) in a test tube assay and decreased the accumulation of scrapie PrP (PrPSc) in ScN2a cells, a cultured neuroblastoma cell line with chronic prion infection, in a concentration-dependent manner. CpV extract also modified the course of the disease in mice inoculated with mouse-adapted scrapie prions, completely preventing the onset of prion disease in three of eight mice. Biochemical and neuropathological analyses revealed a statistically significant reduction in PrPSc accumulation, spongiosis, astrogliosis, and microglia activation in the brains of mice that avoided disease onset. Furthermore, PrPSc accumulation in the spleen of mice was also reduced. CpV extract precluded prion infection in cultured cells as demonstrated by the modified standard scrapie cell assay. This study suggests that CpV extract could contribute to investigating the modulation of prion propagation. 相似文献
5.
Ha Taewook Kang Yerim Kim Nam Seok Park So Hee Lee Sang Han Kim Dong Kyu Ryou Hong Sun 《Journal of Mechanical Science and Technology》2021,35(1):407-415
Journal of Mechanical Science and Technology - The cooling effect of oil cooling method on electric vehicle motors with hairpin winding is analyzed. A 160 kW motor being developed by a commercial... 相似文献
6.
Sung Kun Hyuk Shin Hyun Ju Baek Dabin Ryou Hong Sun 《Journal of Mechanical Science and Technology》2017,31(8):4029-4034
Journal of Mechanical Science and Technology - The major function of smoke control system is to prevent smoke from penetrating to vertical shaft or stairwell by pressurizing vestibule where is... 相似文献
7.
Theodore Chung Jae Limb Jae-Hyun Ryou Wonseok Lee Peng Li Dongwon Yoo Xue-Bing Zhang Shyh-Chiang Shen Russell D. Dupuis David Keogh Peter Asbeck Ben Chukung Milton Feng Dimitri Zakharov Zusanne Lilienthal-Weber 《Journal of Electronic Materials》2006,35(4):695-700
The design and growth of GaN/InGaN heterojunction bipolar transistors (HBTs) by metalorganic chemical vapor deposition (MOCVD)
are studied. Atomic-force microscopy (AFM) images of p+InGaN base layers (∼100 nm) deposited under various growth conditions indicate that the optimal growth temperature is limited
to the range between 810 and 830°C due to a trade-off between surface roughness and indium incorporation. At these temperatures,
the growth pressure must be kept above 300 Torr in order to keep surface pit density under control. An InGaN graded-composition
emitter is adopted in order to reduce the number of V-shaped defects, which appear at the interface between GaN emitter and
InGaN base and render an abrupt emitter-base heterojunction nearly impossible. However, the device performance is severely
limited by the high p-type base contact resistance due to surface etching damage, which resulted from the emitter mesa etch. 相似文献
8.
The mechanical performance of woven composites was analyzed focusing on their nonlinear and rate dependent asymmetric/anisotropic deformation behavior. Three key characteristics were identified which are indispensable for realistically simulating the mechanical performance of woven composites: the asymmetric material behavior between tension and compression, its anisotropic and nonlinear evolution and rate dependency. To include all three characteristics into the nonlinear finite element analysis for woven composites, a phenomenological constitutive equation was developed based on an elasto-viscoplastic theory using the modified Drucker–Prager yield criterion and, in particular, developing the anisotropic nonlinear hardening law. A characterization method using both uniaxial tensile and compressive tests at different strain rates was proposed to determine the material properties for the constitutive equation. Then, the developed constitutive equation was incorporated into a finite element code and was validated by comparing the finite element simulation of the three points bending test with experiments. 相似文献
9.
Dongwon Yoo Limb J. Jae-Hyun Ryou Yun Zhang Shyh-Chiang Shen Dupuis R.D. Hanser D. Preble E. Evans K. 《Photonics Technology Letters, IEEE》2007,19(17):1313-1315
AlxGa1-xN (x=0.05) ultraviolet (UV) avalanche photodiodes grown on a GaN substrate are reported. The epitaxial structure was grown by metal-organic chemical vapor deposition on a free-standing bulk GaN substrate having low dislocation density. The growth conditions for AlxGa1-xN epitaxial layers on GaN substrates were optimized to achieve improved crystalline and structural quality. With UV illumination at lambda~250 nm, devices with mesa diameters of ~30 mum achieve stable maximum optical gains of ~50 at a reverse bias voltage of ~87 V. 相似文献
10.