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991.
Peterson Roger L.; Hodge Elaine A.; Kafer Lowell G.; Matthews Scott R.; Pfeifle Henry H.; Van House Carole L. 《Canadian Metallurgical Quarterly》1981,18(4):525
Describes a service delivery system with a group personal counseling emphasis, based on the authors' 2 yrs of experience at a university counseling center. The local background and rationale for this system are discussed, and the practical logistics, the operational policies, and the group ground rules are presented. Utilization data are summarized: 36% of all clients and 88% of clients with 8 or more sessions were group members; groups typically grew to 9 clients and had 60% attendance. Results for a self-report outcome survey of 128 students are exemplified by the 95.1% who reported some level of improvement and the 92.2% who rated their psychologist "very" to "exceptionally effective." (8 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
R. A. Outlaw D. T. Peterson F. A. Schmidt 《Metallurgical and Materials Transactions A》1981,12(10):1809-1816
A statistical analysis of the porosity in 99.995 wt pct pure commercially available cast aluminum has been correlated with
real time hydrogen evolution data obtained in an ultrahigh vacuum furnace in order to estimate the hydrogen partitioning in
the aluminum. The dynamic technique employed permitted the detection and separation of hydrogen evolved from solid solution,
hydrogen released by the rupture of large pores, and gases desorbed from the aluminum surface. Results of the statistical
analysis indicate average pore diameters in pure cast aluminum extend from less than 1 to over 400 μm. Interdendritic pores
having diameters greater than 25 μm constitute over 98 pct of the pore volume. The overall volume fraction of pores was determined
to be 0.71 pct. Compared to vacuum remelted rolled aluminum, the porosity resulted in a reduction of ultimate tensile strength
of 13 pct and a reduction in yield strength of 21 pet. The evolution of hydrogen from the aluminum was observed to occur by
large hydrogen pressure pulses due to the rupture of pores near the surface and by a smooth steady desorption from solid solution.
The rupturing pores were observed visually and found to occur both in the solid state and after melting. A substantial change
in slope of the desorption curve following the pulse train suggests the pores are the primary sources of hydrogen in the bulk.
Analysis of the pore and pulse size distributions indicates more than 99 pct of the bulk hydrogen is partitioned in pores
greater than 25 μm. Pressures within the larger pores (≈270 μm) were determined to be about 2.4 atm at room temperature. Hydrogen
content in the large pores was found to be as high as 2 × 1016 molecules. The total hydrogen content in the pores and in solid solution was determined to be 6.3 × 1017 atoms/cm3 (0.43 cm3/100 g). Measurements on commercially available 99.9995 wt pct cast aluminum indicate the total hydrogen content to be 4.8
× 1017 atoms/cm3 (0.33 cm3/100 g). 相似文献
993.
To test the hypothesis that renal kinins act as natriuretic and diuretic hormones, we examined the effect of inhibiting glandular kallikrein on renal function in normotensive unanesthetized rats during normal sodium intake. To inhibit kallikrein at both the luminal and basolateral sides of the distal nephron, we used Fab fragments of monoclonal antibodies to rat urinary kallikrein (Fab-kallikrein). Fab fragments have advantages over intact IgG: they are filtered through the glomerulus and reach the lumen of the distal nephron, where kallikrein is localized and urinary kinins are released. Furthermore, the Fab fragment-antigen complex does not activate the complement system, avoiding the side effects associated with intact antibodies. Fab-kallikrein effectively blocked generation of kinins in the nephron lumen, decreasing urinary kininogenase activity (kallikrein) by 74% to 85% and kinin excretion by 76% to 79%. Fab-kallikrein induced a 30% decrease in urine volume and a 20% to 40% decrease in urinary sodium excretion but did not alter blood pressure, glomerular filtration rate, or renal blood flow. Although urinary prostaglandin E2 excretion also tended to decrease, this change was slower and of lesser magnitude than those of kinin and kininogenase excretion and did not attain statistical significance after Bonferroni's correction. In controls injected with either vehicle or Fab fragments of monoclonal antibodies to ricin (a vegetable protein not present in mammals), none of these parameters decreased significantly. We conclude that renal kinins participate in the short-term regulation of water and sodium excretion in normotensive unanesthetized rats, acting as diuretic and natriuretic hormones.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
994.
Graglia R.D. Wilton D.R. Peterson A.F. Gheorma I.-L. 《Antennas and Propagation, IEEE Transactions on》1998,46(3):442-450
Triangular prism elements are useful in numerical solutions of electromagnetic field problems since they permit a three-dimensional (3-D) geometry to be generated by the extrusion of a triangular mesh. Few applications have employed vector basis functions on prism elements and the extension to distorted prisms reported in the literature apparently does not ensure cell-to-cell continuity. In this paper, we define interpolatory higher order curl- and divergence-conforming vector basis functions of the Nedelec type on prism elements, with extension to curved prisms, and discuss their completeness properties. Vector bases of arbitrary polynomial order are given and various results to confirm the faster convergence of higher order functions are presented 相似文献
995.
Spatscheck O. Hansen J.S. Hartman J.H. Peterson L.L. 《Networking, IEEE/ACM Transactions on》2000,8(2):146-157
A TCP forwarder is a network node that establishes and forwards data between a pair of TCP connections. An example of a TCP forwarder is a firewall that places a proxy between a TCP connection to an external host and a TCP connection to an internal host, controlling access to a resource on the internal host. Once the proxy approves the access, it simply forwards data from one connection to the other. We use the term TCP forwarding to describe indirect TCP communication via a proxy in general. This paper characterizes the behavior of TCP forwarding, and illustrates the role TCP forwarding plays in common network services like firewalls and HTTP proxies. We then introduce an optimization technique, called connection splicing, that can be applied to a TCP forwarder, and report the results of a performance study designed to evaluate its impact. Connection splicing improves TCP forwarding performance by a factor of two to four, making it competitive with IP router performance on the same hardware 相似文献
996.
Peterson A.F. Greene B.S. Mittra R. 《Antennas and Propagation, IEEE Transactions on》1990,38(4):578-584
An equation is presented to describe the dispersion characteristics of a tape helix separated from a concentric conducting core by a dielectric substrate. Numerical solutions of the complex-valued propagation constant can be used to obtain the complete k -β diagram of the helical geometry. The k -β diagram provides information regarding the real-valued solutions for β that represent true axial propagation, as well as the complex-valued solutions that represent surface waves and leaky waves. Several different helix geometries are considered. Under the assumption that these same solutions exist on a finite-length structure, the radiation pattern can be obtained for a given mode of propagation 相似文献
997.
Ardebili H. Hillman C. Natishan M.A.E. McCluskey P. Pecht M.G. Peterson D. 《Components and Packaging Technologies, IEEE Transactions on》2002,25(1):132-139
In this paper, the issues pertaining to moisture diffusion in PEMs are explored and discussed. The existing models of moisture diffusion in plastic molding compounds and PEMS are reviewed. Results, modeling and analysis of moisture sorption experiments performed in this study are presented. The moisture sorption experiments were conducted on a set of PEM samples with a common type of encapsulant material to 1) characterize sorption behavior; 2) compare weight gain measurement to the measurement of moisture concentration using a moisture sensor device at the die surface; 3) assess the moisture sensor measurement method. In the case of PEM samples tested in this study, simple Fickian diffusion was shown to agree closely with the experimental results. In one case, a relatively small anomaly from Fickian diffusion was observed and was attributed to swelling and relaxation phenomena at later stages of moisture sorption in the molding compound. The calibration constants determined for the sensors in this study were found to be significantly different from those collected by the manufacturer prior to the encapsulation of the devices. This problem is believed to be degradation in sensitivity of the moisture sensor due to exposure to high temperatures and storage conditions 相似文献
998.
M. F. Vilela A. A. Buell M. D. Newton G. M. Venzor A. C. Childs J. M. Peterson J. J. Franklin R. E. Bornfreund W. A. Radford S. M. Johnson 《Journal of Electronic Materials》2005,34(6):898-904
Middle wave infrared (MWIR) HgCdTe p-on-n double-layer heterojunctions (DLHJs) for infrared detector applications have been
grown on 100-mm Si (112) substrates by molecular beam epitaxy (MBE) for large format 2,560×512 focal plane arrays (FPAs).
In order to meet the performance requirements needed for these FPAs, cutoff and doping uniformity across the 100-mm wafer
are crucial. Reflection high-energy electron diffraction (RHEED), secondary ion mass spectrometry (SIMS), Fourier transform
infrared spectrometry (FTIR), x-ray, and etch pit density (EPD) were monitored to assess the reproducibility, uniformity,
and quality of detector material grown. Material properties demonstrated include x-ray full width half maximum (FWHM) as low
as 64 arc-sec, typical etch pit densities in mid-106 cm−2, cutoff uniformity below 5% across the full wafer, and typical density of macrodefects <1000 cm−2. The detector quality was established by using test structure arrays (TSAs), which include miniarray diodes with the similar
pitch as the detector array for easy measurement of critical parameters such as diode I-V characteristics and detector quantum
efficiency. Typical I-V curves show excellent R0A products and strong reverse breakdown characteristics. Detector quantum efficiency was measured to be in the 60–70% range
without an antireflection coating. 相似文献
999.
The aim of this study was to examine the function of granulosa cells and hormone concentrations in follicular fluid in bovine ovarian follicles during selection of the first dominant follicle. Ovaries were obtained from beef heifers on days 1-5 after ovulation: follicles > 4 mm in diameter were dissected and follicular fluid and granulosa cells were collected from individual follicles. Oestradiol production by granulosa cells after culture with testosterone was used to determine aromatase activity and responsiveness to gonadotrophins was determined by cAMP production after culture with FSH or LH. Concentrations of oestradiol, progesterone and insulin-like growth factor binding proteins (IGFBPs)-4 and -5 were measured in follicular fluid. Follicles were classified as largest or smaller (days 1 and 2), or dominant or subordinate (days 3-5). Aromatase activity was greater in granulosa cells from the largest follicle than in granulosa cells from smaller follicles on days 1, 3, 4 and 5 (P < 0.05). Responsiveness to LH was not detected in granulosa cells on day 1, but from day 2 to day 5 cells from the largest follicle were significantly more responsive than cells from smaller follicles (P < 0.05). Responsiveness to FSH was detected in granulosa cells from all follicles from day 1 onwards and did not differ between cells from the largest follicle or smaller follicles on any day. Follicular fluid concentrations of oestradiol and the ratio of oestradiol:progesterone were greater and concentrations of IGFBP-4 and -5 were lower in the largest follicle than in smaller follicles from day 2 to day 5 (P < 0.05). In conclusion, selection of the dominant follicle is associated with increased granulosa cell aromatase activity followed by increased cAMP response to LH and follicular fluid oestradiol concentrations, and decreased follicular fluid concentrations of IGFBP-4 and -5 within 2 days after ovulation. 相似文献
1000.
An iterative procedure based on the conjugate gradient method is used to solve a variety of matrix equations representing electromagnetic scattering problems, in an attempt to characterize the typical rate of convergence of that method. It is found that this rate depends on the cell density per wavelength used in the discretization, the presence of symmetries in the solution, and the degree to which mixed cell sizes are used in the models. Assuming cell densities used in the discretization are in the range of ten per linear wavelength, the iterative algorithm typically requiresN/4 toN/2 steps to converge to necessary accuracy, whereN is the order of the matrix under consideration. 相似文献