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1.
Collagenase-1 (C1) is the predominant matrix metalloproteinase present in newly formed microvessels and serves as a marker of neovascularization. The expression of the oncofetal fragment of fibronectin (Fn-f) was found to be increased during angiogenesis. In the present study, we investigated the relationship between the expression of collagenase-1 and the oncofetal fragment of fibronectin in newly formed microvessels as markers of tumor angiogenesis. In aggressive skin tumors (i.e., morpheaform and recurrent basal cell carcinomas) and squamous cell carcinomas, neovascularization was associated with a marked increase in the number of C1-positive and Fn-f-positive microvessels. At the beginning of elongation, microvessels begin to produce C1 but lose their ability to express type IV collagen and FVIII-related antigen. Later, this endothelium produces both Fn-f and C1. As maturation of microvessels occurs, C1-containing endothelium fails to express Fn-f but begins to produce a type IV collagen-containing basement membrane and FVIII-related antigen. These studies show that there is a selective expression of both Fn-f and collagenase by immature endothelial cells. C1 production begins at early stages of blood vessel formation and continues throughout angiogenesis. In contrast, Fn-f expression is limited to later stages of vasculogenesis, indicating that these proteins are reliable markers of angiogenesis.  相似文献   
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Nine different membrane bioreactor (MBR) systems with different process configurations (submerged and external), membrane geometries (hollow-fiber, flat-sheet, and tubular), membrane materials (polyethersulfone (PES), polyvinylidene fluoride (PVDF), and polytetrafluoroethylene (PTFE)) and membrane nominal pore sizes (0.03-0.2 μm) were evaluated to assess the impact of influent microbial concentration, membrane pore size and membrane material and geometries on removal of microbial indicators by MBR technology. The log removal values (LRVs) for microbial indicators increased as the influent concentrations increased. Among the wide range of MBR systems evaluated, the total and fecal coliform bacteria and indigenous MS-2 coliphage were detected in 32, 9 and 15% of the samples, respectively; the 50th percentile LRVs were measured at 6.6, 5.9 and 4.5 logs, respectively. The nominal pore sizes of the membranes, membrane materials and geometries did not show a strong correlation with the LRVs.  相似文献   
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Software and Systems Modeling - Model-based test case generation (MB-TCG) and prioritization (MB-TCP) utilize models that represent the system under test (SUT) for test generation and...  相似文献   
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The redevelopment of historic cities is often challenged by intricate--and in many cases contradictory--missions. From one side, there is the urge to comprehensively preserve cultural resources. At the same time, opportunities of economic growth should be made available and needs of contemporary living maintained and nourished. The main aim of this paper is to reconcile probable incompatibilities between such missions through promoting "sensitive" redevelopment approaches in historic cities. The paper focuses on the city of Luxor, Egypt with its immensely capturing yet quite undermined legend: the Avenue of Sphinxes. In Luxor, the injection of nonintrusive interventions presents itself as a highly potential candidate in protecting and enhancing the experience of the avenue while meeting contemporary needs of living. Adopting less sensitive development approaches can lead the quality of experiencing the whole city to be worsened for the increasing numbers of tourists and locals.  相似文献   
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Different approaches to study wetting and adhesion by applying density-functional theory (DFT) methods are highlighted. The ab initio thermodynamics method is used to demonstrate the link between the calculated work of separation and the work of adhesion and wetting angles from sessile-drop measurements. An approach to extend DFT calculations to the case of large-scale interfaces relevant for wetting systems is also discussed.  相似文献   
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A function generator is described that basically generates a trapezoidal waveform whose leading and trailing ramps and positive and negative plateaus can be varied in duration, independently, between 0.5 ms and 50 s. By appropriate interconnections between the constituent units of the generator, a total of 12 different waveforms are generated, including triangular, sinusoidal, square, rectangular, and sawtooth waveforms. The output may be either free running or externally triggered to produce an adjustable integral number of cycles.  相似文献   
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The main purpose of tissue engineering is the preparation of fibrous scaffolds with similar structural and biochemical cues to the extracellular matrix in order to provide a substrate to support the cells. Controlled release of bioactive agents such as growth factors from the fibrous scaffolds improves cell behavior on the scaffolds and accelerates tissue regeneration. In this study, nanofibrous scaffolds were fabricated from biocompatible and biodegradable poly(lactic‐co‐glycolic acid) through the electrospinning technique. Nanofibers with a core–sheath structure encapsulating bovine serum albumin (BSA) as a model protein for hydrophilic bioactive agents were prepared through emulsion electrospinning. The morphology of the nanofibers was evaluated by field‐emission scanning electron microscopy and the core–sheath structure of the emulsion electrospun nanofibers was observed by transmission electron microscopy. The results of the mechanical properties and X‐ray diffraction are reported. The scaffolds demonstrated a sustained release profile of BSA. Biocompatibility of the scaffolds was evaluated using the MTT (3(4,5‐ dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide) assay for NIH‐3T3 fibroblast cells. The results indicated desirable biocompatibility of the scaffolds with the capability of encapsulation and controlled release of the protein, which can serve as tissue engineering scaffolds. © 2013 Society of Chemical Industry  相似文献   
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Navigation is a major issue in robotics due to the necessity for the robots’ course of movement. Navigation consists of two essential components known as localization and planning. Localization in robotics refers to one’s location with reference to a well known position inside the map. Planning is considered as the computation of a path through a map which represents the environment. This given path would be chosen based on the potential of the problem so that the expected destination would be achieved. As such, a reliable map is essential for navigation without which robots would not be able to accomplish the goals. In navigational approaches, reliability of the map would be challenged due to the dynamic and unpredictable nature of real-world applications. It is, consequently, crucial to implement solutions for searching such environments—those affected by dynamic and noisy constraints. In the present study, two enhanced versions of particle swarm optimization (PSO) called area extension PSO (AEPSO) and cooperative AEPSO (CAEPSO) are employed. During the study, AEPSO and CAEPSO are employed as decision-makers and movement controllers of simulated robots (hereafter referred to as agents). The agents’ task is to seek for survivors in realistic simulations based on real-world hostile situations. This study examines the feasibility of AEPSO and CAEPSO on uncertain and time-dependent simulated environments. The simulations follow two phases of training and testing model. Agents use past knowledge gathered during the training phase in their testing phase. The study addresses the impacts of past knowledge, homogeneity and heterogeneity in robotic swarm search. The results demonstrate the feasibility of CAEPSO as robot controller and decision-maker.  相似文献   
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