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991.
Tribology Letters - Micro-grooves have superior hydrodynamic characteristics; therefore, the operating state of the micro-groove rotary seals (MGRSs) used in wet clutches of vehicles change from...  相似文献   
992.
Mitochondrial dysfunction and impairment of the ubiquitin proteasome system have been described as two hallmarks of the ageing process. Additionally, both systems have been implicated in the etiopathogenesis of many age-related diseases, particularly neurodegenerative disorders, such as Alzheimer’s and Parkinson’s disease. Interestingly, these two systems are closely interconnected, with the ubiquitin proteasome system maintaining mitochondrial homeostasis by regulating organelle dynamics, the proteome, and mitophagy, and mitochondrial dysfunction impairing cellular protein homeostasis by oxidative damage. Here, we review the current literature and argue that the interplay of the two systems should be considered in order to better understand the cellular dysfunction observed in ageing and age-related diseases. Such an approach may provide valuable insights into molecular mechanisms underlying the ageing process, and further discovery of treatments to counteract ageing and its associated diseases. Furthermore, we provide a hypothetical model for the heterogeneity described among individuals during ageing.  相似文献   
993.
Two properties of a dynamic network flow model based on a slow process of structural adjustment inspired by principles used in models utilising a priori information is analysed. Initially it is proved that each time period is characterised by monotonically non-increasing transportation costs among flows. Secondly, we analyse the recursive sequence of connected periods. This dynamic sequence is shown to converge to the linear programming solution connected with cost minimisation. Evidently those properties have to be taken into consideration when this class of network flow models is used in forecasting of future transport flows in the process of infrastructure planning. Received: November 1996 / Accepted: November 1997  相似文献   
994.
Both a new modeling approach and new experimental data for the sediment build‐up in centrifuges are presented. In semibatch apparatus, the suspension is continuously fed to the centrifuge, separating the particles inside the rotor and discharging the clarified liquid. The solid phase is removed once the capacity of the centrifuge is reached. The solids fraction of the sediment depends on the rheological properties of the cake. The sediment growth and consolidation throughout the process can be calculated using a pseudo two‐dimensional approach that takes into account particle‐size dependent settling, sediment compressibility, the centrifugal force field, and the geometry of the bowl. The predictions of the separation behavior and the particle‐size distributions of the sediment and overflow are compared with experimentally obtained results, showing improved accuracy when compared to simpler models. The model presented is applicable to all solid‐bowl centrifuges without conveying systems. © 2013 American Institute of Chemical Engineers AIChE J, 59: 3843–3855, 2013  相似文献   
995.
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997.
The effect of shear on the crystallization kinetics of anhydrous milk fat (AMF) and blends with 20 and 30 % w/w added rapeseed oil (RO) was studied. Pulse 1H NMR was used to follow the α to β′ polymorphic transition. The NMR method was confirmed and supported by SAXS/WAXS experiments. Samples were crystallized at 5 °C and shear of 0, 74 or 444 s?1 was applied during early crystallization, in the NMR tube. High shear rates decreased the amount of α polymorph formed and accelerated the polymorphic transition; however, shear did not affect the final solid fat content (SFC). The α to β′ transition occurred faster in the presence of RO allowing more room for the conformational changes to occur. Final SFC decreased with increasing RO content. Shear applied in 20 and 30 % blends caused the destruction of β′‐related 3L structure leaving only 2L packing. In AMF and statically crystallized samples, both 3L and 2L packing existed. Shear did not affect the amount of β crystals formed. The study shows that both shear and RO affect the polymorphic behavior of milk fat, and that 1H NMR is able to detect polymorphic transition in blends with up to 30 % w/w RO.  相似文献   
998.
Nanosheets of zeolite H-ZSM-5 were synthesized and characterized by X-ray diffraction, transmission electron microscopy (TEM), N2-physisorption, FT-IR spectroscopy, 27Al and 29Si MAS NMR spectroscopy in addition to catalytic testing in conversion of methanol to hydrocarbons (MTH). It was found that Rietveld analysis, involving anisotropic broadening parameters, gave average crystallite dimensions in good agreement with TEM images. The selectivities in MTH is intact in the mesoporous nanosheet H-ZSM-5 with the largest difference being a higher C3/C2 ratio compared to regular H-ZSM-5.  相似文献   
999.
Immune checkpoint inhibitors (ICI) represented a step forward in improving the outcome of patients with various refractory solid tumors and several therapeutic regimens incorporating ICI have already been approved for a variety of tumor entities. However, besides remarkable long-term responses, checkpoint inhibition can trigger severe immune-related adverse events in some patients. In order to improve safety of ICI as well as T cell therapy, we tested the feasibility of combining T cell-based immunotherapy with genetic disruption of checkpoint molecule expression. Therefore, we generated H-Y and ovalbumin antigen-specific CD8+ T cells with abolished PD-1, LAG-3, and TIM-3 expression through CRISPR/Cas9 technology. CD8+ T cells, subjected to PD-1, LAG-3, and TIM-3 genetic editing, showed a strong reduction in immune checkpoint molecule expression after in vitro activation, while no relevant reduction in responsiveness to in vitro stimulation was observed. At the same time, in B16-OVA tumor model, transferred genetically edited OT-1 CD8+ T cells promoted longer survival compared to control T cells and showed enhanced expansion without associated toxicity. Our study supports the notion that antigen-specific adoptive T cell therapy with concomitant genetic disruption of multiple checkpoint inhibitory receptors could represent an effective antitumor immunotherapy approach with improved tolerability profile.  相似文献   
1000.
The deformation of a drop flowing along the centre streamline of a four-roll mill (4RM) has been investigated. The velocities and elongation rates along the centre streamline in the 4RM were measured using particle tracking velocimetry. The deformation and position of the deforming drops were photographed with a video camera. A dynamic, one-dimensional, analytical simulation model describing the drop deformation has been developed. The model is based on Taylor's [1964. International Congress on Applied Mechanics, vol. 11, 790-796] static conical drop shape model, but has been extended to include elliptic drops undergoing rapid deformation. The model was incorporated into a numerical scheme using Matlab and the drop deformation in the 4RM was simulated. The simulations were compared with the results of the experiments with the help of a dynamic Weber number incorporating the exact effect of the continuous phase stress on the deformation of the drop. With a dynamic Weber number of 0.42 the agreement between the experiments and the simulations along the whole deformation process was excellent for all three drop diameters studied. With this model the deformation of drops of all sizes in different elongation fields can be calculated, for example sub-micron-sized drops in a high-pressure homogeniser.  相似文献   
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