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61.
A new FDTD algorithm is proposed for analyzing ultrasonic pulse propagation in the human body, a problem connected with ESWL (extracorporeal shock wave lithotripsy). In this method, we do not use plane wave approximation but directly employ the original equations, taking into account the Lagrangian to derive new FDTD algorithms. This method is applied to an experimental setup and its numerical model that resembles an actual treatment situation in order to compare the sound pressure distributions obtained numerically with those obtained experimentally. The present method is shown to give clearly better results than the earlier method, from the point of view of the numerical reappearance of a strongly nonlinear waveform. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 169(4): 29–36, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20819 相似文献
62.
Keisuke Fukushima Hiroshi Fujimoto Shinsuke Nakagawa 《Electrical Engineering in Japan》2008,162(1):66-72
In a short‐span seeking‐mode of hard disk drives, the resonance modes are getting crucial obstruction to meet the demand on high‐speed data access. In this paper, a novel vibration suppression perfect tracking control (PTC) method is proposed based on controllable canonical realization. In the proposed method, it is assumed that the plant is modeled as the rigid and primary resonance mode. By using this model, the feed forward controller is designed with PTC by multirate sampling control in order to suppress the primary vibration. Additionally, the higher‐order resonance vibration is attenuated by using the trajectory MHVT. The proposed method achieved 16% faster seeking than MPVT, a conventional method. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 66–72, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20546 相似文献
63.
64.
Selective copper CVD technique involving hydrogen reduction of hexafluoro acetylacetonate copper has been used to fill vias
for fabricating double-level copper interconnect structure. The surface morphology of selectively deposited copper on copper
substrate of the via bottom depends strongly on via opening process. A two-step via opening process consisting of an reactive
ion etching of the insulating interlayer and a wet removal of the interlayer metal results in smooth copper plug formation
by CVD. Double-level copper interconnect structures have been fabricated using this technique and a via resistance as low
as 100 mΩ has been obtained for a 1 μ diameter via. 相似文献
65.
Robert J. Naumann Glen Haulenbeek Hiroshi Kawamura Keisuke Matsunaga 《Microgravity science and technology》2001,13(2):22-32
An instrumented flow cell in the form of a cylinder with differentially heated end walls and adiabatic sidewalls was flown
on STS-95 as the Japan-US Thermal Science Accelerometer Project (JUSTSAP). The purpose of the experiment was to map disturbances
in the thermal field during the course of a Shuttle mission in order to correlated them with various mission events and to
determine if any global transport could be detected from second order, non-zero time average flows resulting from periodic
accelerations (g-jitter).
Significant disturbances in the thermal field were noted each time the Shuttle changed attitude, such as the maneuver to -Z
solar inertial, which is done periodically for thermal conditioning. Burns from the main thrusters associated with the launch
and retrieval of the Spartan satellite produced overturning flows, as might be expected. During extended periods in which
the attitude was held constant, the perturbations to the thermal field correlate extremely well with calculated accelerations
from gravity gradient and drag. Fair agreement was found between the observed temperature perturbations and those predicted
from a modification of the analytical model developed by Bejan and Tien (B&T) for the flow and heat transfer in an infinite
cylinder with a constant axial thermal gradient. A full three-dimensional computational fluid dynamic analysis with more realistic
thermal boundary conditions provided better agreement after adjustments were made to account for the heat flow away from the
measuring thermistors.
Once calibrated with a reliable thermal model, the flow cell was found to serve as a high-precision accelerometer, capable
of measuring the quasi-steady acceleration with a sensitivity of better than 0.1 micro-g in the presence of the higher amplitude
g-jitter typical of Shuttle operations. Further, it was found that the gravity gradient acceleration accounted for virtually
all of the observed quasi-steady accelerations during such extended periods. The thermal response time of the JUSTSAP was
too slow to expect to see the effects of fluctuating first order flows resulting from the vibrational environment of the Shuttle.
However, an indication of a change in the thermal field near the ends of the flow cell was seen during periods of crew exercise
that may possibly be attributed to circulating eddies resulting from the higher order terms in the momentum equation. At higher
amplitudes, these second order effects can produce non-zero time average flows of a global nature, as can the start-up transients
in first-order periodic flows. No such effects were observed, thus it is possible to place an upper limit on the integrated
power spectral density of the vibrational environment experienced as well as the nature of the start-up transients of the
periodic flows. 相似文献
66.
The electricity for the electrolyzer is supplied by a variable electricity supply unit that simulates actual outputs of both series and parallel combinations of solar cells exposed to various solar intensities. An amorphous-silicon solar cell is used as a sensor for the unit The operation was continued for more than 600 days without trouble. The case of direct connection of the solar cell and polymer electrolyte (PE) water electrolyzer is simulated: the test results show that more than 95% of the peak electricity power of the solar battery can be utilized for the electrolyzer over various solar radiation conditions. 相似文献
67.
We describe the electrochemical detection of DNA methylation through the direct oxidation of both 5-methylcytosine (mC) and cytosine (C) in 5'-CG-3' sequence (CpG) oligonucleotides using a sputtered nanocarbon film electrode after digesting a longer CpG oligonucleotide with endonuclease P1. Direct electrochemistry of the longer CpG oligonucleotides was insufficient for obtaining the oxidation currents of these bases because the CG rich sequence inhibited the direct oxidation of each base in the longer CpG oligonucleotides, owing to the conformational structure and its very low diffusion coefficient. To detect C methylation with better quantitativity and sensitivity in the relatively long CpG oligonucleotides, we successfully used an endonuclease P1 to digest the target CpG oligonucleotide and yield an identical mononucleotide 2'-deoxyribonucleoside 5'-monophosphate (5'-dNMP). Compared with results obtained without P1 treatment, we achieved 4.4 times higher sensitivity and a wider concentration range for mC detection with a resolution capable of detecting a subtle methylated cytosine difference in the CpG oligonucleotides (60mer). 相似文献
68.
Keisuke Nakajima Saori Oka Takashi Tanikawa Yoko Nemoto-Sasaki Naoki Matsumoto Hiroki Ishiguro Yoichiro Arata Takayuki Sugiura Atsushi Yamashita 《International journal of molecular sciences》2022,23(18)
We previously reported that lysophosphatidylinositol (LPI) functions as an endogenous agonist of GPR55, a novel cannabinoid receptor. However, the physiological roles of LPI-GPR55 have not yet been elucidated in detail. In the present study, we found that LPI induced morphological changes in GPR55-expressing HEK293 cells. LPI induced the cell rounding of GPR55-expressing HEK293 cells but not of empty-vector-transfected cells. LPI also induced the activation of small GTP-binding protein RhoA and increased stress fiber formation in GPR55-expressing HEK293 cells. The inhibition of RhoA and Rho kinase ROCK by the C3 exoenzyme and the ROCK inhibitor reduced LPI-induced cell rounding and stress fiber formation. These results clearly indicated that the LPI-induced morphological changes and the assembly of the cytoskeletons were mediated through the GPR55-RhoA-ROCK pathway. 相似文献
69.
Keisuke TanizawaTetsuo Sekiya Shigeo OhshioHiroki Akasaka Hidetoshi Saitoh 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(3):313-317
The development of an intense X-ray source using backscattered X-ray produced using an advanced electrode configuration is described. The electrodes were composed of field emitters deposited on a wire mounted on a perforated plate as the cathode and a copper plate as the anode. Electrons from these emitters collided with the copper plate and X-ray was generated at collision points. The backscattered X-ray in the direction normal to the electron trajectory through a hole in the anode escaped from the vacuum chamber through a beryllium window. Continuous and characteristic X-rays were detected at an applied voltage lower than that of a conventional X-ray source from 3.0 to 9.4 kV, respectively. Moreover, the X-ray dosage measured with a survey meter reached 0.95 mSv/h at 5.0 kV of applied voltage. The transmission images of three types of material used as an X-ray source for the X-ray imaging system indicate three advantages; low power consumption, focal point controllable by adjusting applied voltage, and photographable motion picture of X-ray transmission. 相似文献
70.
Keisuke Fujita Kohji Higuchi Kazushi Nakano Koji Matsushita Tatsuyoshi Kajikawa Fumiho Chino 《Artificial Life and Robotics》2009,14(3):433-439
There is a need for robust current control of a pulse width modulation (PWM) power amplifier whose transient response characteristics
do not deteriorate with extensive load changes and/or direct-current power supply voltage changes. In this article, we propose
a digital robust controller with bumpless mode switching to control the current of a PWM power amplifier to satisfy the demands
and extend the range of an inductive load width. It is necessary to measure the value of the load in order to implement this
bumpless mode switching automatically depending on the load range. Therefore, a method of estimating the inductive load is
shown. The bumpless mode switching is automatically performed by estimating an inductive value without specifying the value
of the inductive load beforehand. That is, the value of the inductive load is estimated during the DDC execution, and the
control mode is automatically switched bumplessly according to this estimated value. A digital controller equipped with inductance
estimation and bumpless mode switching is realized by a DSP. Some experiments show that the digital controller with the proposed
bumpless mode switching can satisfy larger specifications. 相似文献