全文获取类型
收费全文 | 227篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
综合类 | 1篇 |
化学工业 | 18篇 |
金属工艺 | 7篇 |
机械仪表 | 8篇 |
建筑科学 | 2篇 |
能源动力 | 4篇 |
轻工业 | 10篇 |
无线电 | 72篇 |
一般工业技术 | 41篇 |
冶金工业 | 27篇 |
原子能技术 | 13篇 |
自动化技术 | 23篇 |
出版年
2023年 | 4篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 3篇 |
2018年 | 1篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 11篇 |
2012年 | 5篇 |
2011年 | 8篇 |
2010年 | 9篇 |
2009年 | 9篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 12篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 7篇 |
1999年 | 7篇 |
1998年 | 15篇 |
1997年 | 9篇 |
1996年 | 8篇 |
1995年 | 10篇 |
1994年 | 3篇 |
1993年 | 8篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有229条查询结果,搜索用时 31 毫秒
91.
Sebastian O.H. Madgwick Andrew J.L. Harrison Paul M. Sharkey Ravi Vaidyanathan William S. Harwin 《Mechatronics》2013,23(5):518-529
This work presents two schemes of measuring the linear and angular kinematics of a rigid body using a kinematically redundant array of triple-axis accelerometers with potential applications in biomechanics. A novel angular velocity estimation algorithm is proposed and evaluated that can compensate for angular velocity errors using measurements of the direction of gravity. Analysis and discussion of optimal sensor array characteristics are provided. A damped 2 axis pendulum was used to excite all 6 DoF of the a suspended accelerometer array through determined complex motion and is the basis of both simulation and experimental studies. The relationship between accuracy and sensor redundancy is investigated for arrays of up to 100 triple axis (300 accelerometer axes) accelerometers in simulation and 10 equivalent sensors (30 accelerometer axes) in the laboratory test rig. The paper also reports on the sensor calibration techniques and hardware implementation. 相似文献
92.
Dong LeVijay Vaidyanathan Shailesh VidhateJaycee Chung Nandika D’Souza 《Measurement》2011,44(1):159-163
Intrinsically smart structural composites are materials, which can perform function such as sensing strain, stress damage or temperature. Electrical resistance could potentially serve as an indicator of structural well-being or damage in the structure. To this end, the development of an automated resistance measurement system is desired. An automated nodal electrical resistance acquisition circuitry (NERAC) was designed, and interfaced to a laptop for measurement of electrical resistance/impedance from the substrate of interest. Measurements were carried out using DC/AC method with four-point probe technique. Baseline reading before damage was noted and compared with the resistance measured after damage. The device was calibrated and validated on three different substrates: PVDF samples, composite panels and smart concrete. Results conformed to previous work done on these substrates, validating the effective working of the NERAC device. Change of state of the substrate, after damage was assessed by measurement of resistance/impedance. 相似文献
93.
R. Senthilkumar S. Vaidyanathan B. Sivaraman 《Journal of Mechanical Science and Technology》2011,25(4):923-929
The orientation of the heat pipe plays the significant role in its performance. In specific orientations, the performance
of the heat pipe is directly related to the wick structure. In conventional heat pipe, the working fluid is used a negative
surface-tension gradient with temperature. It is an unfavorable one and it decreases the heat transport between the evaporator
section and the condenser section. An Aqueous solution of n-Pentanol having a positive surface tension gradient with temperature
is suggested as a working medium for heat pipe to improve the performance of capillary limit and operating stability. The
objective of this paper is to perform a comparative study of heat pipe performance using the aqueous solution of n-Pentanol
with water at various inclinations. The results are presented to demonstrate the merits and suitability of the aqueous solution
of n-Pentanol as a working fluid for heat pipe. 相似文献
94.
95.
Kunal Mishra Krishna P. Bastola Raman P. Singh Ranji Vaidyanathan 《Polymer Engineering and Science》2019,59(6):1199-1208
Graphene oxide (GO) nanoparticles were introduced in the interlaminar region of carbon fiber–epoxy composites by dispersing it in a thermoplastic polymer carrier such as polyvinylpyrrolidone (PVP). Mode‐I fracture toughness (GIC) was investigated using double cantilever beam testing to evaluate the effect of the GO on the delamination behavior of the composite. The GO content was varied from 0% to 7% by weight as a function of the PVP content. Improvement of ~100% in the Mode I fracture toughness (GIC) was observed compared to composites with no GO. The optimum amount of nanoparticles for improving the interlaminar fracture toughness was found to be ~0.007% by weight of the composite. The increase in the value of flexural strength value was also observed. Scanning electron microscopy of fracture surfaces, X‐ray diffraction, and transmission electron microscopy, and reflectance Fourier transform infrared spectra, as well as Raman spectroscopy results, are presented to support the conclusions. POLYM. ENG. SCI., 59:1199–1208 2019. © 2019 Society of Plastics Engineers 相似文献
96.
Hicks Brian M.; Vaidyanathan Uma; Patrick Christopher J. 《Canadian Metallurgical Quarterly》2010,1(1):38
Recent empirical investigations utilizing male prisoners have begun to validate clinical conceptualizations of primary and secondary psychopathy subtypes. We extended this literature by identifying similar psychopathic subtypes in female prisoners on the basis of personality structure using model-based cluster analysis. Secondary psychopaths (n = 39) were characterized by personality traits of negative emotionality and low behavioral constraint, an early onset of antisocial and criminal behavior, greater substance use and abuse, more violent behavior and institutional misconduct, and more mental health problems, including symptoms of posttraumatic stress disorder and suicide attempts. Primary psychopaths (n = 31) exhibited few distinguishing personality features but were prolific criminals especially in regards to nonviolent crime, and exhibited relatively few mental health problems despite substantial exposure to traumatic events. The results support alternative etiological pathways to antisocial and criminal behavior that are evident in personality structure as well as gender similarities and differences in the manifestation of psychopathic personalities. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
97.
It is shown that the extrapolated fmax of heterojunction bipolar transistors (HBT's) can be written in the form f max=√fT/8π(RC)eff, where fT is the common-emitter, unity-current-gain frequency, and where (RC)eff is a general time constant that includes not only the effects of the base resistance and collector-base junction capacitance, but also the effects of the parasitic emitter and collector resistances, and the dynamic resistance 1/gm, where gm is the transconductance. Simple expressions are derived for (RC) eff, and these are applied to two state-of-the-art devices recently reported in the literature. It is demonstrated that, in modern HBT's, (RC)eff can differ significantly from the effective base-resistance-collector-capacitance product conventionally assumed to determine fmax 相似文献
98.
Maurice Gell Krishnakumar Vaidyanathan Brent Barber Eric Jordan Jiangtian Cheng 《Metallurgical and Materials Transactions A》1999,30(2):427-435
The spallation failure of a commercial thermal barrier coating (TBC), consisting of a single-crystal RENE N5 superalloy, a
platinum aluminide (Pt-Al) bond coat, and an electron beam-deposited 7 wt pct yttria-stabilized zirconia ceramic layer (7YSZ),
was studied following cyclic furnace testing. In the uncycled state and prior to deposition of the ceramic, the Pt-Al bond-coat
surface contains a cellular network of ridges corresponding to the underlying bond-coat grain-boundary structure. With thermal
cycling, the ridges and associated grain boundaries are the sites of preferential oxidation and cracking, which results in
the formation of cavities that are partially filled with oxide. Using a fluorescent penetrant dye in conjunction with a direct-pull
test, it is shown that, when specimens are cycled to about 80 pct of life, these grain-boundary regions show extensive debonding.
The roles of oxidation and cyclic stress in localized grain boundary region spallation are discussed. The additional factors
leading to large-scale TBC spallation are described. 相似文献
99.
This study examined the characteristics of students with specific learning disabilities in either reading and spelling or arithmetic. Based on scores obtained using the revised Woodcock-Johnson Psycho-Educational Battery, students with a marked weakness in arithmetic relative to reading and spelling were designated as Group A. Group R-S showed the opposite pattern. Each group included 30 participants ranging in age from 7 to 16 years, with a mean age of 10 years. The boy-to-girl ratios were 16:14 and 19:11 in Group A and Group R-S, respectively. Comparisons using measures from the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) indicated that Group A was weaker in nonverbal skills than Group R-S, despite equivalent overall IQ scores between the two groups. Group R-S showed a within-group strength in nonverbal versus verbal skills. Group A students were more likely than Group R-S students to have counseling provided as part of their Individualized Education Program, suggesting greater socioemotional difficulty among Group A students. The present study supports the connection between nonverbal skills and socioemotional functioning noted by previous researchers, and generalizes findings from earlier studies to more current test editions. 相似文献
100.
Viet Thanh Pham Sajad Jafari Sundarapandian Vaidyanathan Christos Volos Xiong Wang 《中国科学:技术科学(英文版)》2016,59(3):358-363
Neural networks have been applied in various fields from signal processing, pattern recognition, associative memory to artificial intelligence. Recently, nanoscale memristor has renewed interest in experimental realization of neural network. A neural network with a memristive synaptic weight is studied in this work. Dynamical properties of the proposed neural network are investigated through phase portraits, Poincaré map, and Lyapunov exponents. Interestingly, the memristive neural network can generate hyperchaotic attractors without the presence of equilibrium points. Moreover, circuital implementation of such memristive neural network is presented to show its feasibility. 相似文献