全文获取类型
收费全文 | 340篇 |
免费 | 39篇 |
国内免费 | 1篇 |
学科分类
工业技术 | 380篇 |
出版年
2023年 | 6篇 |
2022年 | 2篇 |
2021年 | 12篇 |
2020年 | 4篇 |
2019年 | 15篇 |
2018年 | 14篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 18篇 |
2012年 | 32篇 |
2011年 | 38篇 |
2010年 | 39篇 |
2009年 | 33篇 |
2008年 | 27篇 |
2007年 | 14篇 |
2006年 | 14篇 |
2005年 | 14篇 |
2004年 | 8篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 5篇 |
1998年 | 6篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1991年 | 1篇 |
排序方式: 共有380条查询结果,搜索用时 359 毫秒
21.
Joung Soo Kim Yong-Sun Yi Oh Chul Kwon Mi-Ae Kim Hong Pyo Kim 《Metals and Materials International》2008,14(3):341-346
Nickel-based iron-chromium alloys are used as steam generator (SG) tubing materials in nuclear power plants (NPPs) but experience
intergranular stress corrosion cracking (IGSCC) and lead stress corrosion cracking (PbSCC) due to the harsh operating conditions
of NPPs. In order to improve the integrity of SGs, many studies have sought suitable inhibitors for IGSCC, while those for
PbSCC have been sought to a limited extent. In this study, the performance of nickel boride (NiB) as an inhibitor for PbSCC
was evaluated. Nickel boride has been shown to be a good inhibitor for IGSCC of Alloy (or Inconel) 600 in a caustic aqueous
solution containing no lead (Pb). No significant SCC was observed to occur in Alloy 600 tested in pure water under the slow
strain rate test (SSRT) condition in this study. A mixed mode of IGSCC and TGSCC, however, occurred relatively easily in Alloy
600 tested in pure water containing lead oxide (PbO) at 315 °C. The susceptibility of Alloy 600 to SCC decreased with the
addition of NiB, implying that NiB can be used as an inhibitor for PbSCC in Pb-contaminated water. 相似文献
22.
Min Jung Kang Youn Hee Kim Gun Pyo Park Mi Sun Han Woo Nyon Kim Sang Do Park 《Journal of Materials Science》2010,45(19):5412-5419
The effects of liquid-type nucleating silane additives on the cell structure, mechanical strength, and thermal insulating
properties of the polyisocyanurate (PIR) foams have been studied. The PIR foams synthesized with hexamethyldisilazane (HMDS)
as a silane additive showed the smaller average cell size and lower thermal conductivity than those of the PIR foams prepared
with the hexamethyldisiloxane, dimethoxydimethylsilane, and hexadecyltrimethoxysilane. When HMDS was added, average cell size
of the PIR foam was becoming smaller due to lower surface tension of the polyol solution, thereby the nucleation rate and
number of bubbles produced were increased and then the cell size becomes smaller. The additives likely act as nucleating agents
during the formation of PIR foams. The smaller cell size appears to be one of the major reasons for the improvement of thermal
insulation properties and mechanical properties of the PIR foams. From the results of cell size, thermal conductivity, and
mechanical strength of the PIR foams, it is suggested that the HMDS may be the efficient liquid-type additive for the reduction
of cell size and improvement of the thermal insulation property of the PIR foams. 相似文献
23.
Chang Hoon Kim Chun Pyo Hong Soonhak Kwon 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2005,13(4):476-483
In this paper, an efficient digit-serial systolic array is proposed for multiplication in finite field GF(2/sup m/) using the standard basis representation. From the least significant bit first multiplication algorithm, we obtain a new dependence graph and design an efficient digit-serial systolic multiplier. If input data come in continuously, the proposed array can produce multiplication results at a rate of one every /spl lceil/m/L/spl rceil/ clock cycles, where L is the selected digit size. Analysis shows that the computational delay time of the proposed architecture is significantly less than the previously proposed digit-serial systolic multiplier. Furthermore, since the new architecture has the features of regularity, modularity, and unidirectional data flow, it is well suited to VLSI implementation. 相似文献
24.
25.
Eunhye Choi Hye-Eun Jo Kee Hyuk Sohn Tae-Young Kang Bumsik Kim Kang Pyo Lee Jung Sook Han Suyong Lee Sanghoon Ko 《Food science and biotechnology》2016,25(4):1053-1058
The effects of steaming time (6, 8, and 10 min), freezing storage period, and re-steaming for thawing on the textural properties of non-glutinous rice cakes (baekseolgi) were investigated. As the steaming time increased, the rice cakes softened. In particular, the sample that was steamed for 10 min showed lower hardness than those steamed for shorter periods. A short period of steaming was insufficient for water bound to the surface of the starch granules to penetrate the granules in the dough. During the re-steaming process of the frozen non-glutinous rice cake samples, the retrogradation of starch and water syneresis contributed to the increased hardness of non-glutinous rice cakes. 相似文献
26.
A new method for the fast extraction of microcystins RR and LR in cyanobacterium was developed using supercritical CO2. The microcystins were successfully extracted with aqueous methanol modified supercritical fluid (90% CO2, 9.0% methanol, 1.0% water). The method developed here has several advantages over solid-phase extraction sample preparation for the analysis of microcystins. Sample handling steps are minimized, thus reducing possible losses of analytes and saving analysis time. No organic solvent extractions are involved in this method, and no cleanup steps are employed. 相似文献
27.
An aerosol dynamics equation for the below-cloud scavenging process considering phoretic and electric charging effects in addition to the conventional mechanisms (the Brownian diffusion, interception, and impaction) is developed by using the moment method. Then, the dynamics of particle size distribution by the below-cloud scavenging process is calculated by using the developed equation and verified with the measurement data. The calculated particle size distribution changes are quite small compared to the measured changes. The calculated removal rate is smaller by 10?2–10?3 than the measured data when only the conventional mechanisms are considered. With the extended mechanisms, the scavenging coefficient increases upto 20 times, mainly for the particle size range of 0.1 μm<dp<3.0 μm. However, the difference between the calculated and measured scavenging coefficient is still large, especially, for dp<0.1 μm. Other possible scavenging mechanisms that might affect the below-cloud scavenging process such as coagulation and condensational growth of hygroscopic particles, turbulence, and updraft into cloud are discussed. It is recommended that further studies on wet scavenging process are needed. 相似文献
28.
Woo-Seok JeongJin-Wook Lee Soonil JungJae Ho Yun Nam-Gyu Park 《Solar Energy Materials & Solar Cells》2011,95(12):3419-3423
A tandem solar cell is constructed by series connection of a semi-transparent dye-sensitized solar cell (DSSC) as a top cell and a Cu(In, Ga)Se2 (CIGS) solar cell as a bottom cell, where the isolated DSSC and CIGS cells show the conversion efficiency of 8.27% and 11.71%, respectively. The DSSC/CIGS tandem cell exhibits the improved conversion efficiency of 12.35% with photocurrent density of 14.1 mA/cm2, open-circuit voltage of 1.435 V and fill factor of 0.61. External quantum efficiency (EQE) of the tandem cell is investigated under DC and AC modes. EQE of the isolated DSSC and CIGS cell can be measured by either DC mode or AC mode, whereas EQE for the tandem cell is detected only under AC mode with bias light. Bias light intensity is found to play the crucial role in determining the precise EQE of the tandem cell. At the given chopping frequency as low as 10 Hz, the measured EQE at bias light corresponding to 1 sun intensity is consistent with the simulated EQE data. 相似文献
29.
Sung Gyu Pyo 《Metals and Materials International》2010,16(2):293-297
When a dip test in buffered oxide etching chemicals is combined with narrow contact pattern, the test can be used as a simple barrier evaluation method, especially for predicting of IPVD (Ionized Physical Vapor Deposition) extendibility. In spite of the excellent coverage of IPVD TaNx films the structural defect at the corner of the pattern could be the root cause of device degradation. The use of extremely thin IPVD TaNx film of around 20 Å was limited by the contact of less than 0.2 μm and an AR (Aspect Ratio) value greater than 4:1. 相似文献
30.
In this letter, we propose a novel design scheme for an optimal non‐uniform planar array geometry in view of maximum side‐lobe reduction. This is implemented by a thinned array using a genetic algorithm. We show that the proposed method can maintain a low side‐lobe level without pattern distortion during beam steering. 相似文献