全文获取类型
收费全文 | 515篇 |
免费 | 9篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 15篇 |
化学工业 | 129篇 |
金属工艺 | 14篇 |
机械仪表 | 5篇 |
建筑科学 | 15篇 |
能源动力 | 17篇 |
轻工业 | 31篇 |
水利工程 | 2篇 |
无线电 | 59篇 |
一般工业技术 | 78篇 |
冶金工业 | 135篇 |
原子能技术 | 9篇 |
自动化技术 | 17篇 |
出版年
2023年 | 1篇 |
2022年 | 7篇 |
2021年 | 13篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 9篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 7篇 |
2014年 | 18篇 |
2013年 | 19篇 |
2012年 | 14篇 |
2011年 | 20篇 |
2010年 | 20篇 |
2009年 | 17篇 |
2008年 | 10篇 |
2007年 | 12篇 |
2006年 | 10篇 |
2005年 | 11篇 |
2004年 | 10篇 |
2003年 | 19篇 |
2002年 | 7篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 12篇 |
1998年 | 45篇 |
1997年 | 35篇 |
1996年 | 17篇 |
1995年 | 19篇 |
1994年 | 14篇 |
1993年 | 16篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 10篇 |
1986年 | 9篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1982年 | 6篇 |
1981年 | 7篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1973年 | 2篇 |
1972年 | 1篇 |
1970年 | 2篇 |
排序方式: 共有526条查询结果,搜索用时 0 毫秒
521.
K. Matsuki Y. Kimura K. Sakaguchi A. Kizaki A.A. Giwelli 《International Journal of Rock Mechanics and Mining Sciences》2010,47(3):436-449
The effect of shear displacement inclined relative to macroscopic water flow on the hydraulic conductivity of a rock fracture was estimated, using synthetic fractures that reproduce a tensile fracture in granite. The results showed that the hydraulic aperture normalized by the mean aperture increased with the angle between the directions of shear displacement and macroscopic water flow, according to a sinusoidal function of twice the angle. Formulae were established to estimate the hydraulic aperture of the fracture as a function of the mean aperture, the standard deviation of the initial aperture, the shear displacement, and the angle between the shear displacement and macroscopic water flow, based on results obtained in both this work and previous work, but neglecting scale effects. By assuming the mechanical properties of the fracture based on experimental results for granite, but neglecting scale effects, the hydraulic conductivity of the fracture with an arbitrary direction under a given state of stress (σ1=29 MPa, σ2=25 MPa and σ3=13.5 MPa) was estimated for macroscopic water flow in the directions of both σ1 and σ2. When the contour map of the transmissivity of the fracture is plotted on a stereonet of the normal direction of the fracture in the principal axes of stress, there is a ridge (line of the local maximum) of transmissivity in the circumferential direction, and the inclination angle of the ridge from the σ3-axis decreases with shear displacement, since shear dilation increases with both a decrease in normal stress and an increase in shear displacement. Furthermore, for the condition of stress given in this study, the transmissivity for macroscopic water flow in the direction of σ1 is maximum for a fracture with a normal direction within the σ2–σ3 plane, while that in the direction of σ2 is maximum for a fracture with a normal direction within the σ1–σ3 plane. 相似文献
522.
Hitomi Terada Yurika Saitoh Kiyokazu Kametani Masahiko Sakaguchi Takeharu Sakamoto Akio Kamijo Nobuo Terada 《Microscopy research and technique》2019,82(3):244-249
The high‐pressure freezing (HPF) technique is known to cryofix water‐containing materials with little ice‐crystal formation in deep depths compared with other freezing techniques. In this study, HPF for anesthetized living Drosophila was performed by placing them directly on the carrier of the HPF unit and exposing them to light. Frozen Drosophila were freeze substituted, and their compound eyes were examined by transmission electron microscopy. The ultrastructures of ommatidia composed of photoreceptor cells were well preserved. The location of the cytoplasmic organelles inside the photoreceptor cells was observed. In some photoreceptor cells in ommatidia of the light‐exposed Drosphila, the cytoplasmic small granules were localized nearer the base of rhabdomeres, compared with those of the nonlight‐exposed Drosophila. Thus, HPF with the direct insertion of living Drosophila under light exposure into the HPF machine enabled us to examine changes to functional structures of photoreceptor cells that occur within seconds. 相似文献
523.
K. Matsuki E. Q. Wang K. Sakaguchi K. Okumura 《International Journal of Rock Mechanics and Mining Sciences》2001,38(5):436
Time-dependent closure of a fracture with rough surfaces subjected to stepwise normal stress was considered theoretically by viscoelastic modeling of rock. A formula for the relationship between constant normal stress and time-dependent closure as a function of time was derived based on the aperture distributions of a fracture and the relaxation modulus YE′(t) of rock. Theoretical consideration showed that the ultimate closure of a fracture under constant normal stress can be estimated from the normal stress–elastic closure curve by using the values of the relaxation modulus at t=0 and ∞, and that the ultimate time-dependent closure is independent of the normal stress if the elastic closure is linear with the logarithm of the normal stress. Experiments and a Monte Carlo simulation on time-dependent closure under constant normal stress were conducted for a hydraulic fracture created in granite in the laboratory to provide the verification of the theory. The results obtained in the experiments showed that the ultimate time-dependent closure of a hydraulic fracture was almost independent of the normal stress when the elastic closure was linear with the logarithm of the normal stress. A Monte Carlo simulation on time-dependent closure of a fracture under constant normal stress showed that time-dependent closure of a fracture for which the elastic closure is linear with the logarithm of the normal stress does not depend on the normal stress because the increase in contact area during time-dependent closure increases with the normal stress. 相似文献
524.
Pablo Vergara Deependra Kumar Sakthivel Srinivasan Iyo Koyanagi Toshie Naoi Sima Singh Masanori Sakaguchi 《International journal of molecular sciences》2021,22(6)
The mammalian hippocampal dentate gyrus is a unique memory circuit in which a subset of neurons is continuously generated throughout the lifespan. Previous studies have shown that the dentate gyrus neuronal population can hold fear memory traces (i.e., engrams) and that adult-born neurons (ABNs) support this process. However, it is unclear whether ABNs themselves hold fear memory traces. Therefore, we analyzed ABN activity at a population level across a fear conditioning paradigm. We found that fear learning did not recruit a distinct ABN population. In sharp contrast, a completely different ABN population was recruited during fear memory retrieval. We further provide evidence that ABN population activity remaps over time during the consolidation period. These results suggest that ABNs support the establishment of a fear memory trace in a different manner to directly holding the memory. Moreover, this activity remapping process in ABNs may support the segregation of memories formed at different times. These results provide new insight into the role of adult neurogenesis in the mammalian memory system. 相似文献
525.
Hideyuki Hara Junji Chida Agriani Dini Pasiana Keiji Uchiyama Yutaka Kikuchi Tomoko Naito Yuichi Takahashi Junji Yamamura Hisashi Kuromatsu Suehiro Sakaguchi 《International journal of molecular sciences》2021,22(6)
Prions are infectious agents causing prion diseases, which include Creutzfeldt–Jakob disease (CJD) in humans. Several cases have been reported to be transmitted through medical instruments that were used for preclinical CJD patients, raising public health concerns on iatrogenic transmissions of the disease. Since preclinical CJD patients are currently difficult to identify, medical instruments need to be adequately sterilized so as not to transmit the disease. In this study, we investigated the sterilizing activity of two oxidizing agents, ozone gas and vaporized hydrogen peroxide, against prions fixed on stainless steel wires using a mouse bioassay. Mice intracerebrally implanted with prion-contaminated stainless steel wires treated with ozone gas or vaporized hydrogen peroxide developed prion disease later than those implanted with control prion-contaminated stainless steel wires, indicating that ozone gas and vaporized hydrogen peroxide could reduce prion infectivity on wires. Incubation times were further elongated in mice implanted with prion-contaminated stainless steel wires treated with ozone gas-mixed vaporized hydrogen peroxide, indicating that ozone gas mixed with vaporized hydrogen peroxide reduces prions on these wires more potently than ozone gas or vaporized hydrogen peroxide. These results suggest that ozone gas mixed with vaporized hydrogen peroxide might be more useful for prion sterilization than ozone gas or vaporized hydrogen peroxide alone. 相似文献
526.
Doi Kouki Nishimura Takahiro Takei Masumi Sakaguchi Saito Fujimoto Hiroshi 《Universal Access in the Information Society》2021,20(1):45-56
Universal Access in the Information Society - This study clarifies a previously established method in which Braille reading novices obtained Braille information aurally. Therein, users touched the... 相似文献