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101.
ABSTRACT: :
The extent of glucose and fructose utilization during cucumber juice fermentation was affected differentially by the addition of 10 to 360 mM of selected anions (chloride, nitrate, sulfate, phosphate, acetate, lactate, and citrate) and cations (Na+ , K+ , NH4 + , Ca2+ , Mg2+ , and Mn2+ ). Inorganic anions generally suppressed utilization of both sugars, particularly at higher concentrations. Acetate and lactate increased utilization of fructose, but not glucose, while citrate increased utilization of both sugars. Of the cations tested, 10-60 mM Mn+2 significantly (P < 0.05) increased utilization of both sugars, but higher concentrations reduced utilization, as compared with the control. Evidence indicates that brine composition can significantly influence sugar utilization during cucumber fermentation, and may be important in developing controlled fermentation strategies for brined cucumbers. 相似文献
The extent of glucose and fructose utilization during cucumber juice fermentation was affected differentially by the addition of 10 to 360 mM of selected anions (chloride, nitrate, sulfate, phosphate, acetate, lactate, and citrate) and cations (Na
102.
Genomic selection has the potential to increase the accuracy of selection and, therefore, genetic gain, as well as reducing the rate of inbreeding, yet few studies have evaluated the potential benefit of the contribution of females in genomic selection programs. The objective of this study was to determine the effect on genetic gain, accuracy of selection, generation interval, and inbreeding, of including female genotypes in a genomic selection breeding program. A population of approximately 3,500 females and 500 males born annually was simulated and split into an elite and commercial tier representation of the Irish national herd. Several alternative breeding schemes were evaluated to quantify the potential benefit of female genomic information within dairy breeding schemes. Results showed that the inclusion of female phenotypic and genomic information can lead to a 3-fold increase in the rate of genetic gain compared with a traditional BLUP breeding program and decrease the generation interval of the males by 3.8 yr, while maintaining a reasonable rate of inbreeding. The accuracy of the selected males was increased by 73% in the final 3 yr of the genomic schemes compared with the traditional BLUP scheme. The results of this study have several implications for national breeding schemes. Although an investment in genotyping a large population of animals is required, these costs can be offset by the greater genetic gain achievable through the increased accuracy of selection and decreased generation intervals associated with genomic selection. 相似文献
103.
Kimberly J. Curtis Jessica Schiavi Myles J. Mc Garrigle Vatsal Kumar Laoise M. McNamara Glen L. Niebur 《Journal of the Royal Society Interface》2020,17(173)
Most patients who succumb to cancer have metastases to bone that contribute to their death. Cancer cells that metastasize to bone are regularly subjected to mechanical stimuli that may affect their proliferation, growth and protein expression. Understanding why some cancer cells thrive in this environment could provide insight into new approaches to prevent or treat metastasis to bone. We used 4T1 cells as a model of breast cancer cells, and implanted them in gelatin hydrogels with moduli of 1 or 2.7 kPa to mimic the properties of bone marrow. The constructs were subjected to either perfusion of media through the hydrogel or combined perfusion and cyclic mechanical compression for 1 h d−1 for 4 d. Controls were cultured in free-swelling conditions. The cells formed spheroids during the 4 d of culture, with larger spheroids in the statically cultured constructs than in perfusion or compressed constructs. In stiffer gelatin, smaller spheroids formed in compressed constructs than perfusion alone, while compression had no effect compared to perfusion in the softer gelatin. Immunostaining indicated that the spheroids expressed osteopontin, parathyroid hormone-related protein and fibronectin, which are all hallmarks of bone metastasis. The proliferative marker Ki67 was present in all spheroids on day 4. In the 1 kPa gelatin, Ki67 staining intensity was greater in the statically cultured, free-swelling constructs than in bioreactor culture, regardless of dynamic compression. By contrast, proliferation was higher in the compressed gelatins compared to perfusion alone in the 2.7 kPa constructs, although the spheroids were smaller, on average. This suggests the stiffer gelatin may restrict spheroid growth at the same time that it enhances mechanobiological signalling during compression. Taken together, 4T1 breast cancer cells are mechanically sensitive, and mechanical stimuli can alter their proliferation and protein expression within soft materials with mechanical properties similar to bone marrow. As such, both in vivo and in vitro models of cancer metastasis should consider the role of the mechanical environment in the bone. 相似文献
104.
The following materials have been prepared having monolayer equivalent loadings of the indicated dopants: Li+/MgO, Ca2+/MgO, Sr2+/MgO and Ba2+/MgO. A continuous-flow microcatalytic reactor system has been used to compare activities of these surface-doped materials for : (a) the catalytic dissociation of N2O alone at 760K and 958K; (b) N2O dissociation accompanied by methane coupling and oxidation in a flow of (N2O + CH4) reactants at temperatures 760–958K; (c) Methane coupling and oxidation in (O2 + CH4) at temperatures 760–993K. The methane-activation roles proposed for various surface sites/intermediates on MgO-based materials are reconsidered in the light of these results. 相似文献
105.
The phenomenon of crack closure, which involves the premature closing of fatigue cracks during the unloading portion of a fatigue cycle resulting in the development of crack-tip shielding due to crack wedging, has become widely accepted as a critical mechanism influencing many aspects of the behaviour of fatigue cracks in metallic materials; these include effects of load ratio, variable-amplitude loading, crack size, microstructure, environment and the magnitude of the fatigue threshold. Recently, however, the significance of crack closure has been questioned and alternative suggestions made for many of these phenomena, e.g. the effect of the load ratio (i.e. the ratio R of the minimum to maximum loads) on threshold behaviour. In the light of this, the present paper provides evidence to rebut the assertion that crack closure is an insignificant process. Particular attention is given to the effect of crack closure on the threshold level as a function of load ratio. 相似文献
106.
107.
Polytetrafluoroethylene (PTFE) was solid state extruded to fiber form at temperatures between 250 and 300°C and at pressures between 7000 and 15,000 psi. The PTFE fibers had a diameter of 0.0502 inches and the reduction ratio for extrusion was 55.8. The fibers were tested for mechanical strength, and examined with a scanning electron microscope, which revealed a fibrous structure at high magnifications. The melting point of the fibers was 342°C by differential scanning calorimetry. The tensile properties were enhanced with an increase in processing temperature and pressure, the highest properties resulting from an extrusion temperature of 300°C and pressures greater than 10,000 psi. A tensile strength of 5500 psi and a secant modulus of 250,000 psi were obtained. 相似文献
108.
Optimum Filters for Estimating Evoked Potential Waveforms 总被引:1,自引:0,他引:1
The design of time-invariant and time-varying minimum mean square error filters for processing event related brain potentials is considered. A model for taking into account the randomness associated with the signal as well as that of the noise is described. Results using simulated data show the perfonnance of the time-varying filter to be greatly superior to that of the time-invariant filter. Results of processing measured visual evoked potentials are presented. 相似文献
109.
A new method of investigating structures below a surface in a dual beam microscope is presented. It comprises electrical measurements in depth profiles of sequential focused ion beam (FIB) cuts by the use of two or more nanomanipulators with plugged in probe needles. The sample is oriented such that the structures are observed with the electron beam while they are cut free with the FIB. The nanomanipulators are moved to contact the structures for examination. The FIB cut is extended step by step, and after each cut the nanomanipulators are repositioned and measurements of the new structures that appear in the FIB cut are made. The measurement series provide a three dimensional electrical characterization of the examined sample volume. 相似文献
110.
Mobile intelligent multimedia presentation systems are subject to various resource constraints including mobile network characteristics,
mobile device capabilities and user preferences. Those presentation systems which incorporate remote multimedia content accessed
across HTTP (Hyper Text Transfer Protocol) or RTP (Real Time Transfer Protocol) protocols are particularly reliant on the
capabilities of the connecting mobile network (i.e. minimum, average and maximum bandwidth) and in particular on the real-time
constraints (i.e. currently available bandwidth, packet loss, bit error rate, latency) which prevail during actual content
transmission. One approach to address this is to scale content, thus reducing its datarate requirement, although this technique
is inherently limited by the lowest acceptable quality of that media element. Alternatively, content can be converted from
one modality to another with a lower resource requirement. TeleMorph, a cross-modality adaptation control platform is detailed
here. Initially a brief introduction to Intelligent Multimedia and to Mobile Intelligent Multimedia is given, and key systems
discussed. The main premise of TeleMorph is that cross-modality adaptations in mobile presentation systems must be controlled
in a manner which gives primary consideration to bandwidth fluctuations as well as the constraints listed above. The current
prototype of TeleMorph, which uses a fuzzy inference system to control cross-modality adaptations between video and audio,
is described. Particular focus is given to the fuzzy inputs, fuzzy control rules and fuzzy outputs which have been utilised
in decision making. TeleTuras, a tourist information application which has been implemented as a testbed for TeleMorph, gives
promising evaluation results based on multimedia and bandwidth specific test scenarios. TeleMorph is related to other approaches
in the area of Mobile Intelligent Multimedia Presentation Systems. TeleMorph differs from other approaches in that it focuses
specifically on the challenges posed by controlling bandwidth determined cross-modality adaptations in a mobile network environment.
Future work on TeleMorph’s output presentation composition will incorporate images and text also, thus allowing for extended
adaptation between video, audio, images and text, as well as multimodal combinations of these media elements. 相似文献