首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   147篇
  免费   10篇
电工技术   6篇
化学工业   51篇
金属工艺   7篇
建筑科学   5篇
能源动力   8篇
轻工业   3篇
无线电   7篇
一般工业技术   26篇
冶金工业   25篇
原子能技术   2篇
自动化技术   17篇
  2022年   1篇
  2021年   5篇
  2020年   2篇
  2019年   3篇
  2018年   2篇
  2017年   1篇
  2016年   3篇
  2015年   3篇
  2014年   6篇
  2013年   5篇
  2012年   10篇
  2011年   4篇
  2010年   8篇
  2009年   10篇
  2008年   5篇
  2007年   5篇
  2006年   3篇
  2005年   6篇
  2004年   1篇
  2003年   3篇
  2002年   8篇
  2001年   6篇
  2000年   4篇
  1999年   4篇
  1998年   11篇
  1997年   8篇
  1996年   6篇
  1995年   2篇
  1994年   2篇
  1993年   1篇
  1992年   3篇
  1990年   2篇
  1989年   2篇
  1985年   1篇
  1984年   1篇
  1982年   3篇
  1980年   1篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1976年   2篇
排序方式: 共有157条查询结果,搜索用时 714 毫秒
91.
This is a report of successful management for a far advanced, chemorefractory testicular cancer patient. A 29-year-old male was referred to our hospital for the treatment of progressive lung metastases with elevated hCG level, which had recurred after complete remission following 3 courses of BEP chemotherapy and progressed after transient partial regression following 2 courses of intensified EP chemotherapy. In addition, a 3 cm in diameter, solitary brain metastasis was detected on CT. First, we performed wedge resection of bilateral pulmonary lower lobe for chemorefractory pulmonary metastases. Histological examination revealed viable embryonal carcinoma identical to the primary one. Thereafter, whole brain irradiation in combination with VIP chemotherapy (etoposide 100 mg/m2, cisplatin 20 mg/m2 and ifosfamide 1200 mg/m2 daily for 5 consecutive days) was carried out to treat brain metastasis. By 2 cycles of VIP therapy and irradiation (36 Gy), partial tumor regression and normalization of hCG level were achieved, leading to salvage surgery of the brain metastasis which histologically proved to be necrosis. Following an additional cycle of VIP therapy, the patient has been free of recurrence 24 months after completion of the treatment.  相似文献   
92.
Boron-rich cluster compounds are studied for their potential as high-temperature thermoelectric materials with low thermal conductivity. Two B12 icosahedra systems with attractive thermoelectric properties have recently been discovered: p-type REB44Si2 (where RE stands for rare earth) and the anomalous n-type series of RE-B-C(N) homologous compounds. Three different doping effects of these compounds were investigated in this work in an attempt to control the properties: doping disorder into REB44Si2, which is a variable-range hopping system, V-doping of YB44Si2, and C-doping (carbon composition control) of YB28.5C4. The attempt to enhance the Seebeck coefficient in TbB44Si2 through disorder was inconclusive, while V-doping of YB44Si2 had a negative effect on the thermoelectric properties. Controlling the carbon composition of YB28.5C4 appeared to be a promising route for increasing the absolute value of the Seebeck coefficient.  相似文献   
93.
Sudden three‐phase short‐circuit current of a turbine generator was calculated by a three‐dimensional magnetic field analysis. That analysis takes into account the rotation, magnetic saturation, and eddy current at a rotor part. To compare test results and calculated results, a method was proposed for short‐circuit phase estimation at sudden three‐phase short‐circuit test by line voltage waveform of the test results. The calculated results of short‐circuit current waveform are in good agreement with the test results. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(1): 54–62, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20110  相似文献   
94.
This paper deals with a design problem of robust parallel compensator which guarantees the existence of a constant gain output feedback controller for plants with structured uncertainty. First, robust design conditions of such a compensator are derived by using Kharitonov’s Theorem. Then, based on conditions provided, the parallel compensator is designed by utilizing the maximal range of interval perturbations of the plant. A numerical example is given to demonstrate the validity of the results.  相似文献   
95.
96.
OBJECTIVES: The aim of this study was to clarify how myocardial perfusion is impaired by asynchronous contraction. BACKGROUND: False septal hypoperfusion is noted in some patients with left bundle branch block. METHODS: Eight dogs were examined with epicardial pacing at the left ventricular posterior wall, the right ventricular anterior wall and, as a control, the right atrial appendage. The pacing rate was 80, 110 and 150 beats/min (bpm). Myocardial perfusion was assessed by contrast echocardiography. RESULTS: Left ventricular pacing at 80 and 110 bpm did not change systolic wall thickening or contrast intensity at the pacing site, although an early excitation notch was noted at the pacing site. However, at 150 bpm, systolic thickening was impaired (23.3 +/- 4.2% vs. 37.0 +/- 2.6% during atrial pacing, p < 0.05), and the peak intensity ratio of the pacing site to the ventricular septum was significantly decreased (24.1 +/- 5.7% vs. 37.0 +/- 2.8% at a pacing rate of 80 bpm, p < 0.01). The peak intensity ratio correlated with systolic wall thickening at the pacing site (y = 0.413 x -0.028, r = 0.81, p < 0.0001). However, right ventricular pacing did not change either systolic thickening or the peak intensity ratio at any pacing rate, although an early excitation notch was noted on the ventricular septum. CONCLUSIONS: Wall motion abnormalities after early excitation vary depending on the pacing mode. When tachycardia induces regional wall motion abnormalities, the ventricular wall of the pacing site is functionally hypoperfused.  相似文献   
97.
The effects of a newly synthesized cationized arginine vasopressin fragment 4-9 analogue (C-AVP-(4-9)) on learning and memory in rats were studied by the passive avoidance test. C-AVP-(4-9) and its parent peptide, arginine vasopressin fragment 4-9 (AVP-(4-9)), a well known potent neuropeptide, were subcutaneously injected 1.5 hr prior to the retention test. The most effective doses of C-AVP-(4-9) and AVP-(4-9) were 8.6 x 10(-2) and 1.3 nmol/kg, respectively. To evaluate the distribution of C-AVP-(4-9) in the control nervous system (CNS), apparent tissue-plasma concentration rations (Kp.app) of intravenously administered radioiodinated C-AVP-(4-9) (125I-C-AVP-(4-9)) in the CNS in mice were determined. At the apparent steady state of plasma concentration of 125I-C-AVP-(4-9), the Kp.app values of the 125I-C-AVP-(4-9) in the cerebrum, cerebellum and spinal cord were over 12 times higher than that of the vascular space marker which slightly penetrates the BBB. Moreover, the rat cerebral homogenate converted C-AVP-(4-9) into its parent peptide AVP-(4-9). These results suggest that the potent effects of C-AVP-(4-9) on learning and memory may be due to AVP-(4-9) generated as a result of distribution and metabolism of peripherally administered C-AVP-(4-9) in the CNS.  相似文献   
98.
The photomechanical behavior of cross-linked azobenzene-containing liquid-crystalline polymer films was investigated by means of simultaneous measurement of their optical and mechanical properties. The connection between photoisomerization of the azobenzene moieties, photoinduced change in molecular alignment, photoinduced stress generation, and macroscopic bending was analyzed. Upon UV irradiation, the films exhibited bending due to gradient in cis-azobenzene content, and subsequent unbending when cis-azobenzene content became uniform throughout the film. The maximum photoinduced stress was generated in the same time scale as the time required to reach photostationary state in the cis-azobenzene concentration. The maximum values of photogenerated stress strongly depended on the crosslinker concentration, even if the azobenzene concentration and the cis-azobenzene content in the photostationary state were similar for all the polymer films. The stress is connected to the initial Young's modulus and also to the photoinduced change in birefringence of the polymer films. In addition, a significant photoinduced decrease in Young's modulus was for the first time observed in cross-linked azobenzene-containing liquid-crystalline polymers, which is likely to be an important factor in dictating their photomechanical behavior.  相似文献   
99.
The melt-growth conditions to obtain SiGe multicrystals with microscopic compositional distribution are presented. These SiGe multicrystals are useful for new solar cells whose wavelength dependence of the absorption coefficient can be freely designed. The multicrystals with wide compositional distribution from Si to Ge can be grown by a melt growth technique such as the practical casting method. In this work, it was studied as to how much the micro- and macroscopic compositional distribution in SiGe multicrystals grown from binary Si–Ge melts could be controlled by the melt composition and the cooling process. Such SiGe multicrystals with wide distribution of the composition would also have wide distribution of the absorption coefficient, and could be hopeful for new solar cell applications using the practical casting method.  相似文献   
100.
This paper deals with a design problem of an adaptive output feedback control for discrete‐time systems with a parallel feedforward compensator (PFC), which is designed for making the augmented controlled system “Almost Strictly Positive Real” (ASPR). A PFC design scheme by a fictitious reference iterative tuning (FRIT) approach with only using an input/output experimental data set will be proposed for discrete‐time systems in order to design an adaptive output feedback control system. Furthermore, the effectiveness of the proposed PFC design method will be confirmed through numerical simulations by designing an adaptive control system with adaptive NN (neural network) for an uncertain discrete‐time system. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(1): 24–32, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22456  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号