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11.
Prevention of fungal spoilage is a key microbiological issue for the shelf life of fat spreads. Our aim was to assess and model the scope of (natural) antimicrobials for extending shelf life of spreads (water-in-oil emulsions). Production conditions were established to make 60% model fat spreads with reproducible droplet size distributions. The mould vulnerabilities ranged from 1 to 20 weeks. The system allowed feasibility testing of lytic enzymes (Novozym 234) and LMW compounds against Penicillium roqueforti, a key-spoilage mould. The action of Novozym 234, carvacrol, undecanol and dihydrocarveol was benchmarked against sorbate and preservative-free controls under ambient and chilled conditions. Novozym 234 was ineffective to prevent outgrowth of P. roqueforti. Carvacrol, undecanol and dihydrocarveol had limited effects on shelf-life extension compared to sorbate. Fungal growth boundaries of (un-)preserved spreads were modelled. The emulsion droplet size distribution (DSD) was first captured in a mechanistic parameter DSD-I (I = Influence). DSD-I was a move away from the mean droplet diameter D3,3 as sole quantitative droplet-size distribution parameter for mould susceptibility of emulsions. DSD-I is a combination of available water droplets and surface area to initiate and sustain fungal outgrowth. Followup experiments showed that modelling D3,3 and distribution width (e(sigma)) instead of DSD-I gave better results for emulsions with high e(sigma). Empirical predictive models were subsequently developed for the effects of D3,3, e(sigma) and undissociated sorbic acid (HSO) on the shelf life of emulsions.  相似文献   
12.
Diffusion Tensor Imaging (DTI) has made feasible the visualization of the fibrous structure of the brain white matter. In the last decades, several fiber‐tracking methods have been developed to reconstruct the fiber tracts from DTI data. Usually these fiber tracts are shown individually based on some selection criteria like region of interest. However, if the white matter as a whole is being visualized clutter is generated by directly rendering the individual fiber tracts. Often users are actually interested in fiber bundles, anatomically meaningful entities that abstract from the fibers they contain. Several clustering techniques have been developed that try to group the fiber tracts in fiber bundles. However, even if clustering succeeds, the complex nature of white matter still makes it difficult to investigate. In this paper, we propose the use of illustration techniques to ease the exploration of white matter clusters. We create a technique to visualize an individual cluster as a whole. The amount of fibers visualized for the cluster is reduced to just a few hint lines, and silhouette and contours are used to improve the definition of the cluster borders. Multiple clusters can be easily visualized by a combination of the single cluster visualizations. Focus+context concepts are used to extend the multiple‐cluster renderings. Exploded views ease the exploration of the focus cluster while keeping the context clusters in an abstract form. Real‐time results are achieved by the GPU implementation of the presented techniques.  相似文献   
13.
百欧仕EGSB厌氧处理PTA废水工程实例分析   总被引:1,自引:0,他引:1  
Biothane(荷兰百欧仕)公司是一家国际性污水处理公司,其在全世界已拥有500多项污水处理业绩。本工程实例是采用百欧仕的EGSB厌氧技术处理对苯二甲酸(PTA)污水,经过一年的实际运行,容积负荷率逐步提升到约10-15kgCOD/m3.d,SCOD的去除率保持在45-65%,苯甲酸去除率达约90%。经2个月时间的启动驯化期后,当进水PTA浓度低于800mg/L时,去除率可稳定在90%以上。偏苯三酸则需1年的滞后期后去除率稳定在80-90%。  相似文献   
14.
We report on a 3He-magnetometer capable of detecting tiny magnetic field fluctuations of less than 10−14 T in experiments for measuring the electric dipole moment (EDM) of the neutron. It is based on the Ramsey technique of separated oscillating fields and uses nuclear spin-polarized 3He gas which is stored in two vessels of V10 l in a sandwich-type arrangement around the storage bottle for ultra-cold neutrons (UCN). The gas is polarized by means of optical pumping in a separate, small discharge cell at pressures around 0.5 mbar and is then expanded into the actual magnetometer volume. To detect the polarization of 3He gas at the end of the storage cycle the gas is pumped out by means of an oil-diffusion pump and compressed again into the discharge cell where optical detection of nuclear polarization is used.  相似文献   
15.
16.
The wetting behavior of quenched-condensed solid D2 films has been investigated by means of light scattering. On the substrates used here (graphite and aluminum) molecular deuterium displays triple point wetting and hence dewets in the solid state, provided the temperature is high enough that thermally activated diffusion processes can take place. This manifests itself in a coarse-graining of the D2 film. In order to avoid this process and to obtain complete wetting of solid D2 we have modified the adsorbate-substrate interaction potential by preplating the substrates with thin inert layers of Ne, Ar, CH4 or C2H6. The predicted change in the wetting properties was not observed, however, suggesting that the existing picture of triple point wetting of van der Waals systems is not complete. The implications of these results for a neutrino mass experiment where quenched-condensed molecular tritium films are used as a source are discussed.  相似文献   
17.
The strongly spin-dependent absorption of neutrons in nuclear spin-polarized 3He opens up the possibility of polarizing neutrons from reactors and spallation sources over the full kinematical range of cold, thermal and hot neutrons. This paper gives a report on the neutron spin filter (NSF) development program at Mainz. The polarization technique is based on direct optical pumping of metastable 3He atoms combined with a polarization preserving mechanical compression of the gas up to a pressure of several bar, necessary to run a NSF. The concept of a remote type of operation using detachable NSF cells is presented which requires long nuclear spin relaxation times of order 100 hours. A short survey of their use under experimental conditions, e.g. large solid-angle polarization analysis, is given. In neutron particle physics NSFs are used in precision measurements to test fundamental symmetry concepts.  相似文献   
18.
Linear motor motion control using a learning feedforward controller   总被引:9,自引:0,他引:9  
The design and realization of an online learning motion controller for a linear motor is presented, and its usefulness is evaluated. The controller consists of two components: (1) a model-based feedback component, and (2) a learning feedforward component. The feedback component is designed on the basis of a simple second-order linear model, which is known to have structural errors. In the design, an emphasis is placed on robustness. The learning feedforward component is a neural-network-based controller, comprised of a one-hidden-layer structure with second-order B-spline basis functions. Simulations and experimental evaluations show that, with little effort, a high-performance motion system can be obtained with this approach  相似文献   
19.
The authors adopt an interdependence analysis of social value orientation, proposing that prosocial, individualistic, and competitive orientations are (a) partially rooted in different patterns of social interaction as experienced during the periods spanning early childhood to young adulthood and (b) further shaped by different patterns of social interaction as experienced during early adulthood, middle adulthood, and old age. Congruent with this analysis, results revealed that relative to individualists and competitors, prosocial individuals exhibited greater levels of secure attachment (Studies 1 and 2) and reported having more siblings, especially sisters (Study 3). Finally, the prevalence of prosocials increased—and the prevalence of individualists and competitors decreased—from early adulthood to middle adulthood and old age (Study 4). (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
20.
Parts of katG and rpoB from 27 Russian Mycobacterium tuberculosis isolates were sequenced to detect mutations causing resistance to isoniazid (INH) and rifampin (RMP), respectively. All 24 INH-resistant isolates had a mutated katG, and 22 of them (91.7%) carried a mutation coding for a Ser315Thr shift. An rpoB mutation was noted for each of the 21 RMP-resistant isolates, with Ser531Leu being the most prevalent change encoded. Only two isolates had identical IS6110 fingerprints.  相似文献   
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