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71.
An indirect immunofluorescence assay (IFA) was used to identify patients with antibodies reactive to the human granulocytic ehrlichiosis (HGE) agent. Serum samples collected from clinically ill individuals were submitted to the Centers for Disease Control and Prevention by physicians via state health departments from throughout the United States and tested against a panel of ehrlichial and rickettsial pathogens. Antibodies reactive to the HGE agent were detected in 142 (8.9%) of 1,602 individuals tested. There were 19 confirmed and 59 probable (n = 78) cases of HGE as defined by seroconversion or a fourfold or higher titer to the HGE agent than to the Ehrlichia chaffeensis antigens. The average age of patients with HGE was 57 years, and males accounted for 53 (68%) of the patients. Cases of HGE occurred in 21 states; 47 (60%) of the cases occurred in Connecticut (n = 14), New York (n = 18), and Wisconsin (n = 15). Onset of HGE was identified from April through December, with cases peaking in June and July. The earliest confirmed cases of HGE occurred in 1987 in Wisconsin and 1988 in Florida. No fatalities were reported among the 78 patients with confirmed or probable HGE. Reactivity to the HGE agent and to either Coxiella burnetii, Rickettsia rickettsii, or Rickettsia typhi was infrequent; however, 74 (52%) of the 142 individuals who were positive for HGE had at least one serum sample that also reacted to the E. chaffeensis antigen. Thirty-four persons with confirmed or probable human monocytic ehrlichiosis due to E. chaffeensis also had antibodies to the HGE agent in at least one serum sample. The specific etiologic agent for 30 patients was not ascribed because of similarity of titers to both ehrlichial antigens. The use of both antigens may be required to correctly diagnose most cases of human ehrlichiosis, especially in geographic regions where both the HGE agent and E. chaffeensis occur. 相似文献
72.
Jun Ho Ji Gwi-Nam Bae Sun Hwa Yun Jae Hee Jung Hyung Soo Noh Sang Soo Kim 《Aerosol science and technology》2013,47(8):786-793
Silver has been known to show antibacterial activity. Recently, silver nanoparticles have been become widely used in diverse applications. In a previous work by the authors, a small nanoparticle generator that uses a ceramic heater with a local heating area was developed. The performance of the device was evaluated in terms of the silver nanoparticles it generated. In the present article, a feasibility study regarding the inactivation of bacteria bioaerosols by the developed small silver nanoparticle generator is conducted to assess its possible use for the active control of indoor bioaerosols. To simulate the inactivation of bacteria on a surface exposed to air, an antibacterial test system consisting of an airborne silver nanoparticle generator, a bacteria bioaerosol generator, and two airborne bacteria samplers with membrane filters was utilized. Spherical polydisperse silver nanoparticles with mode diameters in the range of 10 ~ 27 nm were generated. Their size distribution was changed according the applied voltage and the airflow rate. S. epidermidis gram-positive bacteria having mode diameter of approximately 800 nm were aerosolized using a single-jet Collison nebulizer in an effort to verify the antibacterial activity of the silver nanoparticles in an air environment. With variables of 100 V and 6 L/min, the viability of S. epidermidis bacteria exposed to silver nanoparticles was lower than 5% for an exposure time ranging from 1 ~ 9 min. The viability curve was well represented in terms of the total surface area of the exposed silver nanoparticles. From the results, it was concluded that the developed small airborne silver nanoparticle generator has considerable potential as an active antimicrobial device for use in indoor air applications. 相似文献
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75.
Jae Seung Yun Hang Suk Noh Soon Ick Jeon Chang Ju Kim 《Electronics letters》2003,39(17):1228-1230
A TX/RX dual microstrip 8/spl times/4 array antenna for satellite communication is designed, fabricated and measured and its element characteristics are analysed using finite difference time domain (FDTD) method. TX/RX frequency ranges are 14.0-14.5 GHz, 11.7-12.75 GHz, respectively, and vertical and horizontal polarisations are used for TX and RX. This antenna uses microstrip direct feeding for RX and aperture coupled stripline feeding for TX and accommodates stacked elements for a high directivity and wide impedance bandwidth. FDTD gives more accurate results because of the consideration of finite structure and two imperfect ground planes. This element has a return loss below -8 and -14 dB over the TX and RX frequency ranges and a gain of 7.5 and 8.3 dBi at the centre frequency of TX and RX. Return loss below -10 and -14 dB and a gain of 21.4 and 20.0 dBi were achieved for the TX and RX array, respectively. 相似文献
76.
The design of a very simple, ultra-broadband, on-glass antenna for automobiles is described. A 250 /spl Omega/ impedance system is proposed and a loop-based antenna structure with tuning arms is optimised by a genetic algorithm. The measured results on a prototype antenna show an average VSWR of 1.61 in the UHF and L bands. 相似文献
77.
Byeong Il Noh Gang Choon Lee Tae Kyung Yoon 《Korean Journal of Chemical Engineering》2005,22(3):457-464
Experimental data were obtained to evaluate the effects of amine additives for pH control of solution and the volumetric flow
rate of feed solution on the performance of mixed-bed ion exchange for the removal of ionic impurities in solution. The experiments
were performed under various temperatures and cation resin ratios by using a continuous column system with NaCl solution.
The breakthrough curves of ions, plotted as the ratio of the effluent to influent concentration versus run time or treated
solution volume, give detailed results about the effects of the existence of the pH controller, such as ammonia and morpholine,
and the variable flow rate on the fate of each ion in the units. The experimental results show that the morpholine breakthrough
occurs earlier than the ammonia breakthrough and that the effect of ammonia on both sodium and chloride exchange rates is
more significant than that of morpholine. The addition of ammonia in solution results in the decrease of cation resin capacity
for the sodium removal much more than the addition of morpholine. The step changes in the flow rate affect significantly the
shapes of sodium and chloride breakthrough curves. The effluent concentrations of sodium and chloride change according to
the flow rate. However, the effect increases with decreasing operation capacity of cation resin, while it becomes serious
around the breakthrough time of chloride and negligible after the time. 相似文献
78.
Dramatic Inversion of Charge Polarity in Diketopyrrolopyrrole‐Based Organic Field‐Effect Transistors via a Simple Nitrile Group Substitution
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79.
80.
“Multipoint Force Feedback” Leveling of Massively Parallel Tip Arrays in Scanning Probe Lithography
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Hanaul Noh Goo‐Eun Jung Sukhyun Kim Seong‐Hun Yun Ahjin Jo Se‐Jong Kahng Nam‐Joon Cho Sang‐Joon Cho 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(35):4526-4531
Nanoscale patterning with massively parallel 2D array tips is of significant interest in scanning probe lithography. A challenging task for tip‐based large area nanolithography is maintaining parallel tip arrays at the same contact point with a sample substrate in order to pattern a uniform array. Here, polymer pen lithography is demonstrated with a novel leveling method to account for the magnitude and direction of the total applied force of tip arrays by a multipoint force sensing structure integrated into the tip holder. This high‐precision approach results in a 0.001° slope of feature edge length variation over 1 cm wide tip arrays. The position sensitive leveling operates in a fully automated manner and is applicable to recently developed scanning probe lithography techniques of various kinds which can enable “desktop nanofabrication.” 相似文献