全文获取类型
收费全文 | 403篇 |
免费 | 8篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 413篇 |
出版年
2023年 | 2篇 |
2022年 | 4篇 |
2021年 | 6篇 |
2020年 | 5篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 6篇 |
2016年 | 13篇 |
2015年 | 5篇 |
2014年 | 12篇 |
2013年 | 24篇 |
2012年 | 25篇 |
2011年 | 19篇 |
2010年 | 19篇 |
2009年 | 25篇 |
2008年 | 27篇 |
2007年 | 19篇 |
2006年 | 15篇 |
2005年 | 11篇 |
2004年 | 9篇 |
2003年 | 13篇 |
2002年 | 10篇 |
2001年 | 5篇 |
2000年 | 6篇 |
1999年 | 8篇 |
1998年 | 19篇 |
1997年 | 6篇 |
1996年 | 9篇 |
1995年 | 9篇 |
1994年 | 6篇 |
1993年 | 6篇 |
1992年 | 7篇 |
1991年 | 4篇 |
1989年 | 4篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 4篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1981年 | 6篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1972年 | 1篇 |
1970年 | 1篇 |
排序方式: 共有413条查询结果,搜索用时 78 毫秒
51.
Yasunori Oumi Hideo Yamano Momoji Kubo Rajappan Vetrivel Akira Miyamoto 《Catalysis Today》1995,23(4):417-423
The destruction processes of various zeolites, such as a silicalite with the ZSM-5 structure (SiO2-MFI), Cu-ZSM-5, and a silicalite with the faujasite structure (SiO2-FAU), with increasing temperature were investigated by using molecular dynamics and computer graphics methods. The mobility of atoms in SiO2-MFI was increased and the framework became unstable, as the temperature was increased. Finally the framework was destroyed to an amorphous phase. Increasing the Al content led to a decrease in the heat-resistance in Cu-ZSM-5. The change in the Si-O, Al-O, and Cu-Al distances as well as the change in the pairs of Si-O bonds are discussed to clarify the mechanism of Cu-ZSM-5 destruction. The destruction process of SiO2-FAU was also investigated in order to understand the effect of framework structure, and it was suggested that the presence of the 4-membered ring provides one of the reasons for the inferior heat-resistance of SiO2-FAU to that of SiO2-MFI. 相似文献
52.
S Nakata Y Takezawa M Kobayashi H Kuribara K Matumoto N Kosaku T Suzuki H Yamanaka 《Canadian Metallurgical Quarterly》1998,56(8):2026-2030
Prostate-specific antigen(PSA) increases exponentially in prostate cancer patients before treatment and in refractory status. PSA increases in 68-86% of prostate cancer patients before treatment, and that of the remaining 14-32% of the patients is stable. Those patients with a higher pre-treatment PSA level are more likely to have a shorter PSA-doubling time(PSA-DT). The relationship between pre-treatment stage, grade and PSA-DT is controversial. PSA-DT in biochemical failure patients predicts the risk of clinical recurrence. PSA-DT was correlated well with time to clinical recurrence after biochemical failure. Distant recurrence was associated with short PSA-DT. Higher clinical stage and lower differentiation before treatment correlated with shorter PSA-DT in recurrent cancer patients. PSA-DT is an important parameter for judging malignant potential of each cancer. 相似文献
53.
Elastic-plastic analysis of composite beams with incomplete interaction by finite element method 总被引:3,自引:0,他引:3
This paper presents a nonlinear finite element analysis of composite beams with incomplete interaction. A simplified nonlinear model is assumed in this approach. This is applied to the elastic-plastic analysis of reinforced concrete beams and composite beams with incomplete interaction. The numerical results are compared with the test results and existing values based on other numerical methods, and found to be in good agreement. The elastic-plastic behavior of partial composite beams without shear connectors in the negative bending moment region is discussed by the proposed method. 相似文献
54.
Akira Matsumoto Takayuki Nakagawa Masatoshi Sato Yasunori Kimura Kenji Nishida Atsuhiro Goto 《New Generation Computing》1991,9(2):149-169
The parallel inference machine (PIM) is now being developed at ICOT. It consists of a dozen or more clusters, each of which
is a tightly coupled multiprocessor (comprising about eight processing elements) with shared global memory and a common bus.
Kernel language 1 (KL1), a parallel logic programming language based on Guarded Horn Clauses (GHC), is executed on each PIM
cluster.
This paper describes the memory access characteristics in KL1 parallel execution and a locally parallel cache mechanism with
hardware lock. The most important issue of locally parallel cache design is how to reduce common bus traffic. A write-back
cache protocol having five cache states specially optimized for KL1 execution on each PIM cluster is described. We introduced
new software controlled memory access commands, named DW, ER, and RP. A hardware lock mechanism is attached to the cache on
each processor. This lock mechanism enables efficient word-by-word locking, reducing common bus traffic by using the cache
states. 相似文献
55.
The complexity of several decision problems concerning two-dimensional isometric array grammars (IAG) is studied. Because of the two-dimensional and the “isometric” properties of IAG, many decision problems become very hard to solve even for regular array grammars (RAG), the lowest subclass of IAG in the Chomsky-like hierarchy. In this paper, it is shown that the membership problems for RAGs and for context-free array grammars (CFAG) are both NP-complete. The emptiness problem and the equivalence problem for RAGs are shown to be undecidable. 相似文献
56.
Summary It was found that radical polymerization occurs when the mixture of p-methoxystyrene and styrene in the presence of electron acceptors is photoexcited in basic solvents. Concomitantly, p-methoxystyrenestyrene co-dimers: trans-1-(4-methoxyphenyl)-2-phenyl-cyclobutane and 1-(4-methoxyphenyl)-1,2,3,4-tetrahydronaphthalene are produced. From the results of some polymerization runs and the co-dimer structure, it is considered that the linear co-dimer cation radical is the common precursor for both radical polymerization and cationic dimerization, and the radical polymerization is initiated by its radical end. 相似文献
57.
Kosuke Yamaguchi Kei Inumaru Yasunori Oumi Tsuneji Sano Shoji Yamanaka 《Microporous and mesoporous materials》2009,117(1-2):350-355
Fundamental photocatalytic behaviors were investigated for mechanical mixtures of TiO2 crystalline particles (P25) and MFI type zeolite (silicalite) in the decomposition reaction of 2-propanol vapor in air for the first time. Mechanical mixing enables reliable comparisons to be made between photocatalysts because the contents of TiO2 and the adsorbent can be widely varied (51 times in this study) while keeping the particle size and crystallinity of TiO2 unchanged. That is, the use of mechanical mixture highlights the behavior of molecules adsorbed in the microporous crystals, keeping the TiO2 unchanged. In the case of the mixed photocatalysts, the initial 2-propanol concentration in the gas phase was significantly reduced because of adsorption into the zeolite. After photo-irradiation started, 2-propanol was decomposed to CO2 with no (or trace amount of) acetone detected in the gas phase. The analysis of final amount of CO2 formed by the decomposition demonstrated that just by the mechanical mixing of TiO2 and zeolite, the TiO2 photocatalyst decomposed completely the reactant and intermediate molecules strongly adsorbed into the zeolite. On the other hand, in reference experiments in which TiO2 and zeolite were not mixed and were separately placed in a photoreactor, the organic compounds strongly adsorbed in the zeolite could not be decomposed to CO2 by the photocatalyst. It is notable that the CO2 formation rates for the mixed photocatalysts were mostly constant for those comprising 40 wt% or larger amounts of zeolite, while being slower than for pure TiO2. The rate-determining step was discussed based on these data. The present study showed that the mixed photocatalyst could remove organic vapors by adsorption in the dark and decompose completely to CO2 at moderate reaction rates under photo-irradiation with minimized evolution of intermediate molecules into the gas phase. 相似文献
58.
The micro-nanoformability of Pt-based metallic glass and the nanoforming of three-dimensional structures 总被引:1,自引:0,他引:1
Yasunori Saotome Kenichi Imai Shigeo Shioda Susumu Shimizu Tao Zhang Akihisa Inoue 《Intermetallics》2002,10(11-12)
Pt48.75Pd9.75Cu19.5P22 amorphous alloy exhibits obvious glass transition behavior at a temperature of Tg=502 K, which is below the crystallization temperature Tx=588 K, and develops a supercooled liquid state in a wide temperature range of ΔTx (=Tx−Tg)=86 K. The present paper investigates the macroscopic and microscopic deformation behavior of the material and the possibility of micro-nano forming as a fabrication method and material for nano-devices. On a macroscopic scale, the material exhibits a Newtonian viscous flow in a supercooled liquid state. An index of the microformability is also evaluated by the geometrical transferability of a die shape to the material. For this study, we fabricated V-grooved micro dies of (100) Si by a silicon process. The V-groove dies are from 100 nm to 1 μm wide. The material exhibits superior formability on micrometer and nanometer scales and may possibly be applied to micro-nanomaterials for micro-nano devices. 相似文献
59.
An electric-field sensor consisting of thin copper plates is designed to measure an oscillating electric field produced by charge separations on a plasma column. The sensor installed in a vacuum region around plasma detects charges induced by the electric field on the copper plates. The value of the induced charges depends not only on the strength of the electric field, but also on the design of the sensor. To obtain the correct strength of the electric field, a correction factor arising from the design of the sensor must be known. The factor is calculated numerically using Laplace's equation and compared with a value measured using a uniform electric field in the frequency range of 10-500 kHz. When an external circuit is connected to the sensor to measure the induced charges, the electric field around the sensor is disturbed. Therefore, a double-sensor method for excluding a disturbed component in the measured electric field is proposed. The reliability of the double-sensor method is confirmed by measuring dipole-like and quadrupole-like electric fields. 相似文献
60.
Yuichi Tominaga Keiji Fukushima Yoshitaka Takezawa Daisuke Shimamoto Yusuke Imai Yuji Hotta 《Advanced Powder Technology》2017,28(8):1911-1919
The exfoliation of layered muscovite with non-swelling property has been performed by combining various processes, such as heating, intercalation, and wet-jet milling. The c axis of muscovite was expanded from 2004.0 to 2022.8 pm at 800 °C without the destruction of crystallinity of muscovite. The heating at 800 °C led to the weak attraction force between potassium ions and silicate layers by hydroxylation of muscovite. The muscovite heated at 800 °C progressed the intercalation of dodecylammonium chloride (DDAC) into the layers effectively. Furthermore, the DDAC molecules were inserted to the interlayer of muscovite effectively by suppressing the formation of micelle of DDAC. The sedimentation test of wet-jet milled muscovite slurry showed that the relative packing density of muscovite was decreasing with increasing the amount of the intercalated DDAC. As results, the aspect ratio of muscovite prepared with combining the heating, the intercalation and the wet-jet milling was increased by 253% as compared to the raw muscovite. The aspect ratio was calculated from laser particle size distribution and thickness size distribution which was estimated from field emission-scanning electron microscopic images. The expansion of the interlayer led to the effective exfoliation of muscovite with high aspect ratio. 相似文献