全文获取类型
收费全文 | 325篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 11篇 |
综合类 | 1篇 |
化学工业 | 64篇 |
金属工艺 | 4篇 |
机械仪表 | 8篇 |
建筑科学 | 1篇 |
能源动力 | 6篇 |
轻工业 | 23篇 |
水利工程 | 1篇 |
无线电 | 55篇 |
一般工业技术 | 73篇 |
冶金工业 | 19篇 |
原子能技术 | 13篇 |
自动化技术 | 53篇 |
出版年
2022年 | 4篇 |
2021年 | 12篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 4篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 3篇 |
2013年 | 21篇 |
2012年 | 8篇 |
2011年 | 22篇 |
2010年 | 19篇 |
2009年 | 26篇 |
2008年 | 14篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 9篇 |
2004年 | 13篇 |
2003年 | 13篇 |
2002年 | 8篇 |
2001年 | 10篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 10篇 |
1997年 | 8篇 |
1996年 | 2篇 |
1995年 | 8篇 |
1994年 | 8篇 |
1993年 | 8篇 |
1992年 | 5篇 |
1991年 | 4篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有332条查询结果,搜索用时 31 毫秒
1.
Photocatalysts have attracted great research interest owing to their excellent properties and potential for simultaneously addressing challenges related to energy needs and environmental pollution. Photocatalytic particles need to be in contact with their respective media to exhibit efficient photocatalytic performances. However, it is difficult to separate nanometer-sized photocatalytic materials from reaction media later, which may lead to secondary pollution and a poor recycling performance. Hydrogel photocatalysts with a three-dimensional (3D) network structures are promising support materials for photocatalysts based on features such as high specific surface areas and adsorption capacities and good environmental compatibility. In this review, hydrogel photocatalysts are classified into two different categories depending on their elemental composition and recent progresses in the methods for preparing hydrogel photocatalysts are summarized. Moreover, current applications of hydrogel photocatalysts in energy conversion and environmental remediation are reviewed. Furthermore, a comprehensive outlook and highlight future challenges in the development of hydrogel photocatalysts are presented. 相似文献
2.
Mutoh N. Nakashima J. Kanesaki M. 《Industrial Electronics, IEEE Transactions on》2003,50(6):1085-1094
Electromagnetic interference (EMI) noises generated in power converters are diffused on the surface of conductors. This means influences occur from radiated EMI noises emitted from power transmission lines as well as conducted EMI noises transmitted from them. EMI noises diffusing on the surface of conductors are generally difficult to control using conventional concentrated constant theory. Thus, a new approach based on distributed constant circuit theory is needed in order to control EMI noises. A power converter structure to control EMI noises using multilayer power printed circuit technology is studied in this paper. A structure which can control EMI noises should simultaneously satisfy two conditions, i.e., one to shut down and one to attenuate EMI noises. The structure satisfying these conditions is studied through simulations using the Transmission-Line Modeling Method. The simulations show that the diffusion of EMI noises is controlled by dividing the flow of currents produced by EMI noises into the horizontal and perpendicular directions. That is, the horizontal current flow is controlled inside using the differences in the resistance produced from differences between inner and outer diameter of power transmission lines and the perpendicular current flow can be controlled by properly designing the thickness of the dielectric layer sandwiched between P-and N-power transmission lines with the symmetrical structure. Moreover, it is confirmed by simulations and experiments that the attenuation of EMI noises is affected by the width of the power transmission lines. It is expected that the results obtained in this paper can provide important rules when designing power converters with EMI noise control functions which use the multilayer power printed circuit technology. 相似文献
3.
Yamada T. Kawakami Y. Nakano T. Mutoh N. Orihara K. Teranishi N. 《Electron Devices, IEEE Transactions on》1997,44(10):1580-1587
This study reports an optimum design for a two-phase charge-coupled device (CCD) and limitations on its driving voltage reduction. The two-phase CCD to be used as a horizontal-CCD (H-CCD) in a CCD image sensor requires low-voltage and high-speed operation. Reducing the driving voltage, however, may induce potential pockets in the channel under the inter-electrode gaps which results in a fatal decrease in charge-transfer efficiency. In this case it is necessary to optimize the CCD design to be free of pocket generation. For this requirement, we conducted two-dimensional (2-D) device simulations for the two-phase CCD, whose potential barriers are formed by boron ion-implantation. Our simulations indicated that the edge position of the potential barrier region and the dose of boron-ion implantation would be important parameters for controlling the size of potential pockets. At an optimum edge position and a boron dose, the minimum driving voltage appears to be reducible to 1.1 V. Characteristics of potential pockets and methods of their suppression are also discussed 相似文献
4.
Takeshi Shiofuku Norihiro Abe Yoshihiro Tabuchi Hirokazu Taki Shoujie He 《Artificial Life and Robotics》2008,13(1):290-293
This paper presents an approach of measuring in real-time the vector of finger that is pointing to an object. DSP is used
in the operation processing unit in order to do the real-time processing. The steps include the extraction of flesh-colored
regions from an image, the labeling of the flesh-colored regions, and the detection of two characteristic positions on the
finger so that the direction that the finger is pointing at will be calculated. The entire process takes about 29 msec, which
makes it possible to have the frame rate of 34 fps. With this frame rate, this measurement approach is considered real-time
and promising to be merged into other application systems.
This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January
31–February 2, 2008 相似文献
5.
Norihiro Kamide 《Journal of Logic, Language and Information》2002,11(4):453-470
We introduce Kripke semantics for modal substructural logics, and provethe completeness theorems with respect to the semantics. Thecompleteness theorems are proved using an extended Ishihara's method ofcanonical model construction (Ishihara, 2000). The framework presentedcan deal with a broad range of modal substructural logics, including afragment of modal intuitionistic linear logic, and modal versions ofCorsi's logics, Visser's logic, Méndez's logics and relevant logics. 相似文献
6.
Patients with thalassemia major require multiple blood transfusions leading to hemochromatosis. These patients often have pubertal delay and growth failure, the etiology of which has not been fully elucidated. We performed an extensive endocrine evaluation which included measurements of spontaneous and stimulated levels of gonadotropins, GH, thyroid hormone, and adrenal hormones in 17 patients between the ages of 12 and 18 yr with hemochromatosis receiving desferoxamine therapy. All of the 17 patients had at least one endocrine abnormality, and 12 had more than one abnormality. Abnormalities of the hypothalamic-pituitary-gonadal axis were the most common. Six patients had clinical evidence of delayed puberty with spontaneous and stimulated gonadotropin and sex steroid levels appropriate for their delayed pubertal stage. All 14 children in puberty LH pulsatility index below the mean for pubertal stage compared to normal children. Six of the 14 had LH pulsatility index more than 2 SD below the mean for pubertal stage. This may be an indicator of abnormal pituitary function. Six patients failed either the provocative GH tests (peak GH < 7 micrograms/L) or had a mean spontaneous GH less than 1 microgram/L. The 4 patients who failed provocative tests had growth velocities more than 2 SD below the mean for bone age. Three patients had evidence of primary hypothyroidism. We conclude that all patients with hemochromatosis need periodic careful endocrine evaluations because the incidence of endocrine dysfunction is substantial and they may benefit from hormonal therapy. 相似文献
7.
R. Gnanamoorthy N. Rajiv K. Gopinath Y. Miyahsita Y. Mutoh 《Journal of Failure Analysis and Prevention》2002,2(4):71-75
Powder-metal-processed bearings and gears are finding increasing application because of their economical and technical advantages.
The residual pores from the sintering operatives act as lubricant pockets and dampen sound and vibration. However, porosity
also decreases the mechanical strength and reduces the life of components fabricated by powder processing relative to similar
wrought components. The rolling contact fatigue behavior of sintered and heat treated steel rollers was investigated using
a fatigue test machine designed and fabricated for that purpose. The powder-metal-processed and the wrought steel rollers
that were tested had similar composition and hardness and were mated against wrought steel rollers of high hardness. The contact
stress versus number of cycles to failure data showed that the wrought steel had a very high endurance limit under rolling
contact fatigue compared to the sintered steels investigated. Rolling contact fatigue behavior was found to depend on the
porosity present in the material. Large surface peeling failures and pitting type fatigue failures were observed in the sintered
and hardened steels, while only pitting type failures were observed in the wrought steels 相似文献
8.
Mutoh N. Morimoto M. Nishimura M. Teranishi N. Oda E. 《Electron Devices, IEEE Transactions on》1991,38(5):1048-1051
A new low-noise charge-coupled-device (CCD) output amplifier, the RJG detector, has been developed. The RJG detector incorporates a JFET which has an electrically floating ring-junction gate (RJG). The operating principle of the amplifier is that signal charges, transferred from the CCD into the RJG, directly modulate the drain current in the detection JFET. The performance of the detector was evaluated by operating test devices under a 37-MHz clock frequency, which is the same frequency as that for the horizontal CCD operation in the recently developed 2-million-pixel high-definition CCD image sensor. It was found that 1/f noise was reduced by introducing the JFET and that reset noise was completely eliminated by achieving complete charge transfer through the reset operation. As a result, input referred noise equivalent electrons within the 18.5-MHz baseband were reduced to 17 (electrons) 相似文献
9.
Chaosuan Kanchanomai Yukio Miyashita Yoshiharu Mutoh 《Journal of Electronic Materials》2002,31(5):456-465
Low-cycle fatigue (LCF) tests on as-cast Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-3Ag-0.5Cu-1Bi, and Sn-3Ag-0.5Cu-3Bi solders was carried
out using a noncontact strain-controlled system at 20°C with a constant frequency of 0.1 Hz. The addition of Cu does not significantly
affect the fatigue life of eutectic Sn-Ag solder. However, the fatigue life was significantly reduced with the addition of
Bi. The LCF behavior of all solders followed the Coffin-Manson relationship. The fatigue life of the present solders is dominated
by the fracture ductility and can be described by the ductility-modified Coffin-Manson’s relationship. Steps at the boundaries
of dendrite phases were the initiation sites for microcracks for Sn-3.5Ag, Sn-3Ag-0.5Cu, and Sn-3Ag-0.5Cu-1Bi solders, while
for Sn-3Ag-0.5Cu-3Bi solder, cracks initiated along both the dendrite boundaries and subgrain boundaries in the dendrite phases.
The linking of these cracks and the propagation of cracks inside the specimen occurred both transgranularly through eutectic
phases and intergranularly along dendrite boundaries or subgrain boundaries. 相似文献
10.
In this study, we introduce Gentzen-type sequent calculi BDm and BDi for a modal extension and an intuitionistic modification, respectively, of De and Omori’s extended Belnap–Dunn logic BD+ with classical negation. We prove theorems for syntactically and semantically embedding BDm and BDi into Gentzen-type sequent calculi S4 and LJ for normal modal logic and intuitionistic logic, respectively. The cut-elimination, decidability, and completeness theorems for BDm and BDi are obtained using these embedding theorems. Moreover, we prove the Glivenko theorem for embedding BD+ into BDi and the McKinsey–Tarski theorem for embedding BDi into BDm.
相似文献