全文获取类型
收费全文 | 661篇 |
免费 | 21篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 32篇 |
化学工业 | 191篇 |
金属工艺 | 24篇 |
机械仪表 | 20篇 |
建筑科学 | 27篇 |
能源动力 | 38篇 |
轻工业 | 50篇 |
水利工程 | 1篇 |
无线电 | 27篇 |
一般工业技术 | 148篇 |
冶金工业 | 68篇 |
原子能技术 | 12篇 |
自动化技术 | 51篇 |
出版年
2023年 | 9篇 |
2022年 | 18篇 |
2021年 | 20篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 16篇 |
2017年 | 9篇 |
2016年 | 14篇 |
2015年 | 15篇 |
2014年 | 14篇 |
2013年 | 43篇 |
2012年 | 24篇 |
2011年 | 40篇 |
2010年 | 25篇 |
2009年 | 41篇 |
2008年 | 28篇 |
2007年 | 31篇 |
2006年 | 35篇 |
2005年 | 26篇 |
2004年 | 19篇 |
2003年 | 25篇 |
2002年 | 27篇 |
2001年 | 19篇 |
2000年 | 17篇 |
1999年 | 14篇 |
1998年 | 26篇 |
1997年 | 11篇 |
1996年 | 17篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 8篇 |
1991年 | 1篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 6篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 4篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 1篇 |
1974年 | 4篇 |
排序方式: 共有689条查询结果,搜索用时 5 毫秒
41.
Masaya Shigeta Shota Nakanishi Manabu Tanaka Anthony B. Murphy 《Welding International》2017,31(9):669-680
For gas metal arc welding, the effect of CO2 mixture in a shielding gas on a metal transfer process was investigated through the observation of the plasma characteristics and dynamic behaviour at the droplet’s growth-separation-transfer by the temperature measurement methods which were suitable, respectively, to the argon plasma region and the metal plasma region. At the present experimental conditions, the metal transfer process was a spray transfer type with 100%Ar shielding gas. On the other hand, with 85%Ar + 15%CO2 shielding gas, the metal transfer process was a globular transfer type in which the arc length was shorter, the width was narrower and the time interval of the droplet separation was longer. For both shielding gases, the metal plasma region near the arc central axis exhibited 6500–7500 K, which was lower than the argon plasma region. With 85%Ar + 15%CO2 shielding gas, when the metal droplet grew below the electrode wire, the region below the droplet has a high plasma temperature and a high concentration of iron vapour which surrounded the droplet. The region also exhibited a remarkably high electron number density. At the spray transfer process, the argon plasma region had an electron number density twice as high as the metal plasma region. Meanwhile, at the globular transfer process, the metal plasma region had a higher electron number density than the argon plasma region, which corresponded to a higher electrical conductivity near the arc axis. This means that the electric current goes through the arc axis easier than the spray transfer process. This condition increases the temperature below the droplet. The thermal expansion increases the force preventing the droplet from falling down. In consequence, the metal transfer takes the globular transfer type. 相似文献
42.
43.
SETO Masaru AOKI Atsuhito TANAKA Manabu TASHIRO Shinichi ERA Tetsuo 《Welding International》2018,32(5):312-320
Gas metal arc welding (GMAW) under pure argon shielding gas atmosphere (pure argon-GMAW) is suitable to obtain a high-strength and high toughness welded joint. However, it is difficult that pure argon-GMA welding is applied practically welding structure because of arc instability. In order to perform stable pure argon-GMA welding, duplex current feeding GMAW (DCF-GMAW) has been developed. The DCF-GMAW consists of primary GMA welding current and secondary welding current by constant-current power resource. DFC-GMAW can feed larger current near wire tip. This effect makes that weld penetration depth is deeper, weld bead shape is improved using DCF-GMAW. 相似文献
44.
Shiori Mori Rina Fujiwara-Tani Shingo Kishi Takamitsu Sasaki Hitoshi Ohmori Kei Goto Chie Nakashima Yukiko Nishiguchi Isao Kawahara Yi Luo Hiroki Kuniyasu 《International journal of molecular sciences》2021,22(15)
β-Casomorphin-7 (BCM) is a degradation product of β-casein, a milk component, and has been suggested to affect the immune system. However, its effect on mucosal immunity, especially anti-tumor immunity, in cancer-bearing individuals is not clear. We investigated the effects of BCM on lymphocytes using an in vitro system comprising mouse splenocytes, a mouse colorectal carcinogenesis model, and a mouse orthotopic colorectal cancer model. Treatment of mouse splenocytes with BCM in vitro reduced numbers of cluster of differentiation (CD) 20+ B cells, CD4+ T cells, and regulatory T cells (Tregs), and increased CD8+ T cells. Administration of BCM and the CD10 inhibitor thiorphan (TOP) to mice resulted in similar alterations in the lymphocyte subsets in the spleen and intestinal mucosa. BCM was degraded in a concentration- and time-dependent manner by the neutral endopeptidase CD10, and the formed BCM degradation product did not affect the lymphocyte counts. Furthermore, degradation was completely suppressed by TOP. In the azoxymethane mouse colorectal carcinogenesis model, the incidence of aberrant crypt foci, adenoma, and adenocarcinoma was reduced by co-treatment with BCM and TOP. Furthermore, when CT26 mouse colon cancer cells were inoculated into the cecum of syngeneic BALB/c mice and concurrently treated with BCM and TOP, infiltration of CD8+ T cells was promoted, and tumor growth and liver metastasis were suppressed. These results suggest that by suppressing the BCM degradation system, the anti-tumor effect of BCM is enhanced and it can suppress the development and progression of colorectal cancer. 相似文献
45.
Vitaliy Kholodnyy Borys Dzyuba Marek Rodina Hermes Bloomfield-Gadêlha Manabu Yoshida Jacky Cosson Sergii Boryshpolets 《International journal of molecular sciences》2021,22(17)
The fertilization of freshwater fish occurs in an environment that may negatively affect the gametes; therefore, the specific mechanisms triggering the encounters of gametes would be highly expedient. The egg and ovarian fluid are likely the major sources of these triggers, which we confirmed here for rainbow trout (Oncorhynchus mykiss). The ovarian fluid affected significantly spermatozoa performance: it supported high velocity for a longer period and changed the motility pattern from tumbling in water to straightforward moving in the ovarian fluid. Rainbow trout ovarian fluid induced a trapping chemotaxis-like effect on activated male gametes, and this effect depended on the properties of the activating medium. The interaction of the spermatozoa with the attracting agents was accompanied by the “turn-and-run” behavior involving asymmetric flagellar beating and Ca2+ concentration bursts in the bent flagellum segment, which are characteristic of the chemotactic response. Ovarian fluid created the optimal environment for rainbow trout spermatozoa performance, and the individual peculiarities of the egg (ovarian fluid)–sperm interaction reflect the specific features of the spawning process in this species. 相似文献
46.
Abidur Rahman Makoto Kobayashi Kotaro Sugimoto Yuta Endo Manabu Kojima Shigenori Furukawa Takafumi Watanabe Shu Soeda Yuko Hashimoto Keiya Fujimori Hideki Chiba 《International journal of molecular sciences》2021,22(7)
Background: Within the claudin (CLDN) family, CLDN12 mRNA expression is altered in various types of cancer, but its clinicopathological relevance has yet to be established due to the absence of specific antibodies (Abs) with broad applications. Methods: We generated a monoclonal Ab (mAb) against human/mouse CLDN12 and verified its specificity. By performing immunohistochemical staining and semiquantification, we evaluated the relationship between CLDN12 expression and clinicopathological parameters in tissues from 138 cases of cervical cancer. Results: Western blot and immunohistochemical analyses revealed that the established mAb selectively recognized the CLDN12 protein. Twenty six of the 138 cases (18.8%) showed low CLDN12 expression, and the disease-specific survival (DSS) and recurrence-free survival rates were significantly decreased compared with those in the high CLDN12 expression group. We also demonstrated, via univariable and multivariable analyses, that the low CLDN12 expression represents a significant prognostic factor for the DSS of cervical cancer patients (HR 3.412, p = 0.002 and HR 2.615, p = 0.029, respectively). Conclusions: It can be concluded that a reduced CLDN12 expression predicts a poor outcome for cervical cancer. The novel anti-CLDN12 mAb could be a valuable tool to evaluate the biological relevance of the CLDN12 expression in diverse cancer types and other diseases. 相似文献
47.
Hubby Izzuddin Shigenari Hayashi Suzue Yoneda Takashi Kogin Eiji Ishikawa Manabu Noguchi 《工业材料与腐蚀》2020,71(9):1488-1499
The effect of Mo on the corrosion behavior of Ni20Cr–xMo alloys in an oxidizing chlorine-containing atmosphere using air mixed with the salt-vapor mixture of NaCl–KCl–CaCl2 at 570°C was investigated. The results revealed that the corrosion performance of the Ni20Cr alloys in the oxidizing chlorine atmosphere was improved by Mo addition of up to 3 wt%. The Mo-free alloy formed a potassium chromate during corrosion as a result of the reaction between the Cr2O3 scale and KCl vapor. The chromate formation increased the chlorine potential at the scale surface and induced the breakdown of the protective Cr2O3 scale, resulting in internal chromium chloride precipitates and a Cr-depleted zone. In contrast, the presence of Mo resulted in the formation of a NiO scale, which did not react with the salt vapors and, therefore, prevented the formation of chromates. The beneficial effect of Mo on the high-temperature chlorination of Ni–Cr alloys in salt-vapor-containing atmospheres was ascribed to the suppression of chlorine generation due to NiO scale formation. 相似文献
48.
Manabu Nishijima Irina D. Gocheva Shigeto Okada Takayuki Doi Jun-ichi Yamaki Tetsuaki Nishida 《Journal of power sources》2009,190(2):558-562
Fluorine compounds have high discharge voltage due to its highly ionic metal-ligand bonds. In them, perovskite-type metal trifluorides with corner sharing matrix have large bottlenecks of diffusion pathways for intercalants. Iron trifluoride composites (FeF3-C) prepared by planetary ball milling with carbon showed reversible charge/discharge behavior not only for Li, but also for Na anodes. X-ray diffraction and 57Fe Mössbauer spectroscopy were applied to characterize the electrochemical properties of FeF3 vs. Li and Na anodes. The cathode performances of the other commercially available transition metal trifluorides such as MF3 (M = Ti, V, Mn, Co) have been also investigated. 相似文献
49.
We experimentally demonstrated that the technique to stabilize the output signal by harmonic intensities is useful in heterodyne detection with an incoherent light source such as a halogen lamp. The relation between the relative standard deviation of an output signal and the fluctuation of the light intensity is analyzed and simulated. Using the fundamental to sixth harmonics increases the stabilities of output signal approximately 3 times, and subtracting the relative standard deviation of the intensity of light source enhances the stabilities 49 times. The fluctuating phase that is due to the fluctuating frequency and temperature and its power spectrum density for an interferometer is also calculated with the Allan variance. 相似文献
50.
Keisuke Omae In-Tae Bae Muneyuki Naito Manabu Ishimaru Yoshihiko Hirotsu James A. Valdez Kurt E. Sickafus 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2006,250(1-2):300-302
We have performed high-dose Fe ion implantation into Si and characterized ion-beam-induced microstructures as well as annealing-induced ones using transmission electron microscopy (TEM) and grazing-incidence X-ray diffraction (GIXRD). Single crystals of Si(1 0 0) substrate were irradiated at 623 K with 120 keV Fe+ ions to a fluence of 4 × 1017 cm−2. The irradiated samples were then annealed in a vacuum furnace at temperatures ranging from 773 K to 1073 K. Cross-sectional TEM observations and GIXRD measurements revealed that a layered structure is formed in the as-implanted specimen with ε-FeSi, β-FeSi2 and damaged Si, as component layers. A continuous β-FeSi2 layer was formed on the topmost layer of the Si substrate after thermal annealing. 相似文献