全文获取类型
收费全文 | 229篇 |
免费 | 9篇 |
专业分类
电工技术 | 7篇 |
化学工业 | 65篇 |
金属工艺 | 3篇 |
机械仪表 | 1篇 |
建筑科学 | 9篇 |
能源动力 | 6篇 |
轻工业 | 26篇 |
无线电 | 10篇 |
一般工业技术 | 45篇 |
冶金工业 | 61篇 |
原子能技术 | 1篇 |
自动化技术 | 4篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 2篇 |
2019年 | 3篇 |
2018年 | 4篇 |
2017年 | 7篇 |
2015年 | 4篇 |
2014年 | 2篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 3篇 |
2010年 | 8篇 |
2009年 | 7篇 |
2008年 | 11篇 |
2007年 | 5篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 13篇 |
2003年 | 5篇 |
2002年 | 3篇 |
2001年 | 4篇 |
2000年 | 4篇 |
1999年 | 14篇 |
1998年 | 24篇 |
1997年 | 13篇 |
1996年 | 10篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1990年 | 3篇 |
1989年 | 1篇 |
1988年 | 4篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1977年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1971年 | 2篇 |
1968年 | 1篇 |
排序方式: 共有238条查询结果,搜索用时 0 毫秒
41.
M. Nantoh T. Hasegawa M. Kawasaki J. P. Gong K. Fujito A. Takagi W. Yamaguchi M. Ogino H. Koinuma K. Kitazawa 《Journal of Superconductivity》1994,7(2):349-353
The topographic and electronic properties of the surfaces of (001) and (110) oriented YBa2Cu3Oy, epitaxial films have been probed by atomic resolution STM/STS at 4.2 K. The STM image on the (001) surface clearly revealed the atomic corrugation of the tetragonal lattice with an average spacing of 0.4 nm. while on the (110) surface the orthorhombic atomic lattice, corresponding to the Cu atoms of both CuO2 and CuO chain planes, was observed. The STS result on the (001) surface indicated the semiconducting nature of the terminating layer. As the tunneling tip came closer to the surface, however, the shape of the tunneling spectrum became more metallic and showed a superconducting energy gap, which seems to arise from the underlying superconducting layer. On the other hand, the tunneling spectra on the (110) surface indicated superconducting gap structures, independent of the tip-sample distance. 相似文献
42.
Dr. Fumika Karaki Sho Umemoto Karin Ashizawa Tomoya Oki Noriko Sato Takumi Ogino Naoto Ishibashi Ryoto Someya Dr. Kanako Miyano Dr. Shigeto Hirayama Prof. Yasuhito Uezono Prof. Hideaki Fujii 《ChemMedChem》2019,14(21):1840-1848
Although the advantages of sp3-rich, sterically complicated molecules in drug development have been pointed out, modern screening libraries are filled with planar, sp2-rich components. Compounds that are sp3-rich are difficult to synthesize, and thus we aimed to invent an efficient method to construct sp3-rich libraries. By modifying sp3-rich 7-azanorbornane scaffolds through click chemistry, we efficiently prepared a small set of compounds. These compounds were not only sp3-rich, but also had sufficient “lead-like” properties in view of molecular weights and hydrophobicity. Screening assays of this library provided weak κ opioid receptor agonists and growth hormone secretagogue receptor agonists with high hit rates. These results indicate that the 7-azanorbornane scaffold may be a “privileged structure” for lead identification in drug discovery. 相似文献
43.
Keizo Ogino Toshlaki Kakihara Hirotaka Uchiyama Masahiko Abe 《Journal of the American Oil Chemists' Society》1988,65(3):405-411
The effect of oxyethylene groups in a nonionic surfactant on the solution properties of anionicnonionic systems is described;
these systems are sodium dodecyl sulfate (SDS)—hexadecyl polyoxyethylene ethers (C16POEn, where n=10, 20, 30 and 40). The degree of ionic dissociation of the mixed micelles decreases with increasing numbers of
oxyethylene groups in the nonionic surfactant. As polyoxyethylene chain lengths increase, the electrical conductivities of
the mixed surfactant solutions decrease, in spite of the decrease in activation energy for conduction. The radius of the mixed
micelle with the electric double layer is larger for a nonionic surfactant having a shorter polyoxyethylene chain length than
for one having a long polyoxyethylene chain. This may be attributed to the fact that the mixed micelle is formed more easily
by a nonionic surfactant with a shorter polyoxyethylene chain length than by one with a longer chain. 相似文献
44.
Masaaki Nagatsu Takaaki Yoshida Marcel Mesko Akihisa Ogino Takafumi Matsuda Takayuki Tanaka Hirokazu Tatsuoka Kenji Murakami 《Carbon》2006,44(15):3336-3341
The use of graphene layer encapsulated catalytic metal particles for the growth of narrower multi-walled carbon nanotubes (MWCNTs) has been studied using plasma-enhanced chemical vapor deposition and conventional thermal CVD. Ni–C or Fe–C composite nanoclusters were fabricated using the dc arc discharge technique with metal–graphite composite electrodes carrying a current of 100–200 A in a stainless-steel chamber filled with He and CH4 mixture gas at 27 kPa. Nano-sized grains with diameters less than 10 nm were fabricated and deposited on a Si substrate, and were used as a catalyst for MWCNT growth. Structural analyses of the composite nanoclusters and MWCNTs were carried out using transmission electron microscopy. The results show that the diameters of the MWCNTs were reduced from 50–100 nm for a conventional Ni thin film-evaporated Si substrate to a minimum of roughly 2–4 nm in the present study. 相似文献
45.
Incorporation of benzothiadiazole moiety at junction of polyfluorene–polytriarylamime block copolymer for effective color tuning in organic light emitting diode 下载免费PDF全文
Block copolymer consisting of polyfluorene and polytriarylamine with benzothiadiazole moiety at the junction is prepared in order to obtain an orange emitting polymer via Suzuki‐Miyaura followed by Buchwald‐Hartwig coupling reactions. Electroluminescent device fabricated with resulting block copolymer exhibit only orange emission, although slight blue emission is observed in the fluorescent spectrum for the thin film, indicating that benzothiadiazole part plays a role of an effective trap site. Devices based on polyfluorene homopolymer doped with block copolymer (10 wt %) or an orange emitting model compound at the corresponding content of benzotiadiazole unit are also fabricated. The device with the model compound exhibits orange emission with Commission Internationale de l'Éclairage (CIE) coordinate of (0.58, 0.42), whereas that with block copolymer pale orange with the coordinate of (0.44, 0.38). This fact is probably due to the preferential distribution of block copolymer at the vicinity of anode via hydrophilic interaction of trioxyethylene side chains with poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45393. 相似文献
46.
Yui Ishii Yuhya Yamazaki Takayoshi Nakashima Hiraku Ogino Jun-ichi Shimoyama Shigeru Horii Kohji Kishio 《Materials Science and Engineering: B》2008,151(1):69
The dilute impurity doping for CuO-chain site was found to largely improve the critical current properties of both Y123 single crystals and Y123 melt-solidified bulks in our previous study. In addition, dilute Sr-doping to Ba site is also effective for enhancement of Jc without serious decrease in Tc as in the case of dilute Zn doping for CuO2-plane site. In the present study, we have attempted further enhancement of flux pinning force of the Dy123 melt-solidified bulk, which is essentially more promising materials than Y123, by impurity doping for Cu site in the CuO-chain and for Ba site. Although the (Sr,Co)-co-doped Dy123 melt-solidified bulks showed systematically suppressed Tc with their doping levels, high Tc's well exceeding 90 K were maintained. All the Sr-doped or Co-doped Dy123 bulks exhibited higher Jc than the undoped one. More improved Jc properties were achieved by (Sr,Co)-co-doping, suggesting that pinning potential at local regions around doped impurities become deeper by Co-doping, resulting in stronger point-defect-like pinning sites. In addition, more detailed studies on the dilute Sr-doping and the dilute (Sr,Co)-Co-doping were carried out for Y123 single crystals in order to clarify the difference between their doping effects on the Jc properties. The vortex transition field, H*, to the disordered state in the M–H loops for the Co-doped Y123 single crystal was located at the lower field than that of the Sr-doped one, meaning that the Co ions strongly affect the vortex system compared with the Sr ions. 相似文献
47.
Triacylglycerin in Palm Oil contains POP (1,3-dipalmitoyl-2-oleoyl-glycerol) at 30%, POO (1,2-dioleoyl-3-palmitoyl-glycerol) at 20% and PPP (tripalmitoylglycerol) at 5%. The crystallization temperature of PPP is high and the rates of crystal nuclear formation and growth are fast. It is thus considered that PPP may have some effect on the manner or mode of Palm Oil. Examination was thus made to clarify how PPP may affect the crystallization of POP and POO by differential scanning calorimetry (DSC) and X ray diffractometry (XRD) conducted on PPP/POP and PPP/POO mixtures. High and low temperature peaks were noted to appear on the DSC crystallization curve for either of these mixtures. The high temperature peak was considered possibly due to PPP, and the low temperature peak, to POP or POO. DSC isothermal analysis indicated the rate of crystal growth of either mixture to exceed that of pure of POP or POO. Crystal mixture structure was also seen to be complicated than either compound in pure form. The present findings thus clearly indicate that clarification should be made of the effects of high melting point triacylglycerin, such as PPP, on the crystallization of Palm Oil. 相似文献
48.
Widjaja A Yasuda M Ogino H Nakajima H Ishikawa H 《Journal of Bioscience and Bioengineering》1999,87(5):693-696
The enzymatic production of fructose 1,6-diphosphate (FDP) from glucose was performed in a batch reactor and a semibatch reactor using the crude cell extract of Bacillus stearothermophilus which contains all four enzymes required for the synthesis. The experimental results of the yield and the time courses of FDP production obtained using various enzyme concentrations were in good agreement with the theoretical predictions calculated based on the differential equations including the rate equations of the four enzymes, which were determined using the purified enzymes of B. stearothermophilus. 相似文献
49.
50.
Atomic step configurations on the vicinal surfaces of patterned and non-patterned Si(111) during homoepitaxial step-flow growth were studied as a function of film thickness, deposition temperature, deposition rate, and substrate miscut. We found, for the first time, that step-flow growth on the vicinal surfaces of Si(111) miscut toward the [11
] direction results in the formation of collective, in-phase zigzag arrays of [2
]- and [1̄21̄]-type steps. We also found that step-flow growth on the lower-level region around the edge of Si(111) mesa ridges significantly improves period uniformity. We explained the shape of atomic steps on the basis of the stability of surface reconstruction on Si(111), and the atomic step ordering on the assumption of the anisotropic barrier for diffusion at the growing steps. 相似文献