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排序方式: 共有115条查询结果,搜索用时 156 毫秒
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2.
We investigated the phase coherence length, lφ, in large Si-MOSFET's fabricated using current process technology, with a particular emphasis on highly doped silicon substrates, and then studied the effects of quantum conductance fluctuations in deep sub-μm MOSFET's, with channel length comparable to lφ. We identified, in a 0.2 μm MOSFET, universal conductance fluctuations in the strong inversion regime and conductance fluctuations due to variable range hopping in the weak inversion regime. The drain bias dependence of these fluctuations indicates clearly that they become a serious concern only at drain voltages lower than 10 mV. Therefore, even if the wave nature of electrons results in quantum conductance fluctuations, it will not lead to a limitation on device miniaturization in future Si-ULSI's 相似文献
3.
Koga J. Takahashi M. Niiyama H. Iwase M. Fujisaki M. Toriumi A. 《Electron Devices, IEEE Transactions on》1994,41(7):1179-1183
Under cryogenic operation, a low Vth realizes a high speed performance at a greatly reduced power-supply voltage, which is the most attractive feature of Cryo-CMOS. It is very important in sub-0.25 μm Cryo-CMOS devices to reconcile the miniaturization and the low Vth. Double implanted MOSFET's technology was employed to achieve the low Vth while maintaining the short channel effects immunity. We have investigated both the DC characteristics and the speed performance of 0.25 μm gate length CMOS devices for cryogenic operation. The measured transconductances in the saturation region were 600 mS/mm for 0.2 μm gate length n-MOSFET's and 310 mS/mm for 0.25 μm gate length p-MOSFET's at 80 K. The propagation delay time in the fastest CMOS ring oscillator was 22.8 ps at Vdd=1 V at 80 K. The high speed performance at extremely low power-supply voltages has been experimentally demonstrated. The speed analysis suggests that the sub-l0 ps switching of Cryo-CMOS devices will be realized by reducing the parasitic capacitances and through further miniaturization down to 0.1 μm gate length or below 相似文献
4.
This paper reports on a study of the inversion-layer mobility in n-channel Si MOSFETs fabricated on a silicon-on-insulator (SOI) substrate. In order to make clear the influences of the buried-oxide interface on the inversion-layer mobility in ultra-thin film SOI transistors, SOI wafers of different quality at the buried-oxide interface were prepared, and the mobility behaviors were compared quantitatively. The transistors with a relatively thick SOI film exhibited the universal relationship between the effective mobility and the effective normal field, regardless of the buried-oxide interface quality. It was found, however, that Coulomb scattering due to charged centers at the backside interface between SOI films and buried oxides has great influence on the effective mobility in the thin SOI thickness region, depending on the buried-oxide interface quality. This means that Coulomb scattering due to charged centers at the buried-oxide interface can degrade the mobility with decreasing SOI thickness, unless the SOI wafer quality at the buried-oxide interface is controlled carefully 相似文献
5.
M. Toriumi N. Hayashi M. Hashimoto S. Nonogaki T. Ueno T. Iwayanagi 《Polymer Engineering and Science》1989,29(13):868-873
The design and preparation of a series of negative resists for KrF excimer laser lithography are described. Each resist is composed of poly(hydroxystyrene) and an aromatic azide. The base resin shows high transmittance of 62%/μm at 248 nm, when p-ethylphenyl p-azidophenylsulfonate. 4-azido-4α-methoxy-chalcone, 1-(4 azidobenzylidene)-3-(α-hydroxy-4-azidobenzyl)-indene, 4,4α-diazido-3,3α-dimethoxybiphenyl, or 1-(4-azidostyryl)-5, 5-dimethyl-2-cyclohexen-1-one is employed as a sensitizer. These azides are obtained by red-shifting the absorption maxima to lower energy regions than the exposing wavelength of 248 nm. Transmittance of resists can be controlled from 10 to 30%. The resist is exposed with a KrF excimer laser stepper and developed in an alkaline solution. Sensitivities of about 15 mJ/cm2 are observed. A good, subhalf-micron resist profile is achieved. The photochemical reaction mechanisms of poly(hydroxystyrene) and 4,4α-diazido-3,3α-dimethoxybiphenyl were studied at 248 nm and 313 nm exposure. Quantum yield for photodecomposition at 248 nm is seven times larger than that at 313 nm, but dissolution-inhibition effects are larger at 313 nm exposure. Consequently, the resist shows higher sensitivity at 313 nm than at 248 nm. 相似文献
6.
Hiroki Ishikawa Ryoko Komaki Haruo Naitoh Akira Yamaba Hiroki Katoh 《Electrical Engineering in Japan》2010,173(1):51-59
This paper presents a current control design for switched reluctance motors (SRMs). The electric transfer characteristic of the motors is studied first. Their transfer function is shown to be expressible by a pure resistive component, which is not constant but varies depending on the motor current and speed. The current control design for SRMs follows the classical design technique used for DC machines, where the zeros of the PI controller cancel the poles of Ls+R. Because the transfer function of SRMs does not have any poles, an I controller is suitable for them. The integral gain should be adjusted in order to compensate the nonlinearity, that is, the variation in the equivalent resistor of the SRMs' transfer function. The values of the integral gain are tuned and tabulated for the motor speed and current. Simulation and experiment demonstrate that the current and speed of the SRMs present good responses without dependence on the motor speed and current. © 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 173(1): 51–59, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20987 相似文献
7.
Today, firms are facing many contradictions: efficiency versuscreativity; exploitation versus exploration; speed versus time-consumingresource building. This paper argues that a firm's capabilityto synthesize such contradictions is the key to understandingwhy a firm can be more efficient at producing knowledge thanmarket. A firm can create new knowledge and capability thatgo beyond the balancing point in the existing frontier withits synthesizing capability, which is embedded in its knowledgevision, its ba, its creative routines, its incentive systemsand its distributed leadership. 相似文献
8.
The fluorogenic derivatization reagents with a positive charge, 4-(dimethylaminoethylaminosulfonyl)-7-chloro-2,1,3-benzoxadiazole (DAABD-Cl) and 7-chloro-2,1,3-benzoxadiazole-4-sulfonylaminoethyltrimethylammonium chloride (TAABD-Cl), are proposed for use in proteomics studies. Following derivatization of protein mixtures with these reagents, a series of standard processes of isolation, digestion, and identification of the proteins were performed utilizing high-performance liquid chromatography-fluorescence detection and tandem mass spectrometry with the probability-based protein identification algorithm. Both DAABD and TAABD derivatives were detected fluorometrically at the femtomole level and showed more than 100-fold improvement in sensitivity compared to the underivatized original compounds with an electrospray ionization ion trap mass spectrometer analysis. The modification of the MASCOT database search system memorized with the fragment information of a DAABD-attached Cys residue allowed the identification of the proteolytic peptide fragments of the derivatized bovine serum albumin (BSA) with an estimated 38% sequence coverage of BSA. Utilizing DAABD-Cl as a derivatization reagent, identification of several proteins was also possible in a soluble extract of Caenorhabditis elegans (10 microg of protein). Consequently, for identification of proteins in the complex matrixes of proteins, DAABD-Cl could be a more appropriate reagent than ammonium 7-fluoro-2,1,3-benzoxadiazole-4-sulfonate as reported previously. 相似文献
9.
Yuko Hamabe Ryoko Matsuura Akinori Jyo Masao Tamada Akio Katakai 《Reactive and Functional Polymers》2009,69(1):1-8
Bifunctional fibers containing phosphonate and sulfonate were derived from chloromethylstyrene grafted polyolefin fibers (PPPE-g-CMS) by phosphorylation and subsequent sulfonation reactions. It was clarified that phosphorylation of PPPE-g-CMS by Arbusov reaction is more suitable than one by the reaction with PCl3 in the presence of AlCl3, because the latter damaged fibers and gave phosphinate groups in addition to phosphonate ones. Then, bifunctional fibers containing phosphonate and sulfonate groups were prepared by sulfonation of monofunctional phosphonate fibers obtained via Arbusov reaction with chlorosulfonic acid. The metal ion selectivity of the bifunctional fibers was governed by both phosphonate and sulfonate groups. In addition, bifunctional fibers gave much more excellent kinetic performances in column-mode uptake of Cu(II) than the monofunctional phosphonate fibers and resin. 相似文献
10.
A new I-V model to quantitatively represent stress-induced leakage current (SILC) is presented and compared with the experimental I-V characteristics. The trap-assisted tunneling model is modified so as to include the energy relaxation of tunneling electrons, which has been experimentally verified by applying the carrier separation technique to MOSFETs with the SILC component. The energy relaxation is treated in the new model as the change in the energy level of traps before and after the capture of electrons during two-step tunneling. It is demonstrated that this model successfully represents the experimental I-V characteristics of the SILC component and, particularly, the low apparent barrier height in the Fowler-Nordheim (FN) plot of the SILC component. The calculated low barrier height is attributed to the dominance of direct tunneling mechanism on both tunneling into traps and out of traps. The impact of the energy relaxation during tunneling, used in the present model, on the I-V characteristics is discussed in terms of the trap distribution inside the gate oxide, compared with conventional elastic tunneling model 相似文献