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51.
Resistive oxygen sensors based on gallium oxide were fabricated in order to analyze their sensing performances (as sensitivity, response, and recovery time) in an oxygen atmosphere at 1000°C. We prepared three types of sensors using a β-Ga2O3 single crystal in a sandwich structure with Pt pad electrodes and β-Ga2O3 polycrystalline thin films deposited by using both the sputtering technique and the chemical solution deposition method. For thin-film sensors, Pt interdigital electrodes were deposited on the surface of the films using the lift-off method. X-ray diffraction and atomic force microscopy investigations were performed to compare the structure and surface morphology of the samples. We achieved a response time of 10 s at 1000°C, while the sensitivity was 1.03 for the single crystal and 1.35–1.45 for thin films. The sensing properties depend on the preparation condition of Ga2O3 devices.  相似文献   
52.
Additional new lupane lactones were isolated from the stem bark of Kokoona ochracea (Celastraceae). Their structures have been elucidated, through the application of 1D and 2D nmr spectroscopic methods, as 20,29-dihydroxy-3-oxolupan-30,21 alpha-olide (ochraceolide D) [1] and 28-hydroxy-3-oxolup-20(29)-en-30,21 alpha-olide (ochraceolide E) [2]. These compounds and the mono- and di-acetates of ochraceolide D (4 and 5, respectively) were evaluated for in vitro cytotoxic activity against P-388 murine lymphocytic leukemia cells and a panel of human cancer cell systems. Ochraceolide D [1] was significantly cytotoxic (ED50, 3.9 micrograms/ml) against human glioblastoma (U373) cells. Other compounds (4, 5, and 2) exhibited only a weak cytotoxic response in certain cancer cell lines.  相似文献   
53.
Pancreatic cancer is a unique cancer in that up to 90% of its tumour mass is composed of a hypovascular and fibrotic stroma. This makes it extremely difficult for chemotherapies to be delivered into the core of the cancer mass. We tissue-engineered a biomimetic 3D pancreatic cancer (“tumouroid”) model comprised of a central artificial cancer mass (ACM), containing MIA Paca-2 cells, surrounded by a fibrotic stromal compartment. This stromal compartment had a higher concentration of collagen type I, fibronectin, laminin, and hyaluronic acid (HA) than the ACM. The incorporation of HA was validated with alcian blue staining. Response to paclitaxel was determined in 2D MIA Paca-2 cell cultures, the ACMs alone, and in simple and complex tumouroids, in order to demonstrate drug sensitivity within pancreatic tumouroids of increasing complexity. The results showed that MIA Paca-2 cells grew into the complex stroma and invaded as cell clusters with a maximum distance of 363.7 µm by day 21. In terms of drug response, the IC50 for paclitaxel for MIA Paca-2 cells increased from 0.819 nM in 2D to 3.02 nM in ACMs and to 5.87 nM and 3.803 nM in simple and complex tumouroids respectively, indicating that drug penetration may be significantly reduced in the latter. The results demonstrate the need for biomimetic models during initial drug testing and evaluation.  相似文献   
54.
Oxidative stress occurs because of an imbalance in the production of reactive oxygen species. Nuts are rich in bioactive compounds, including phenolic compounds, tannins, and phytosterols. Although nuts are widely consumed because of their beneficial effects on nutrition and health, there is limited information about bioactive peptides from nuts. Pine nut and walnut-derived peptides are the most studied because these nuts contain a higher amount of protein. Different biological activities have been demonstrated for nut peptides; many of them exhibit antioxidant, anticancer, antihypertensive, antidiabetic, immunomodulatory, antiseizure, or neuroprotective activity. Recent studies have focused on increasing the bioactivity of identified bioactive peptides by applying new technologies and chemosynthetic strategies. Research tendency points to the generation of peptides with specific sequences for application in specific diseases. Nut bioactive peptides can become key functional ingredients for food, pharmaceuticals, or cosmetics.  相似文献   
55.
Generalized cross-validation (GCV) is a popular tool for specifying the tuning parameter in linear regression model or equivalently the regularization parameter in Tikhonov regularization. In this work, we are concerned with the estimation and minimization of the GCV function by using a combination of an extrapolation procedure and a statistical approach. In particular, we derive families of estimates for the GCV function. By minimizing the estimated GCV function over a grid of values, a GCV estimate of the regularization parameter is achieved. We present several numerical examples to illustrate the effectiveness of the derived families of estimates for approximating the regularization parameter for several linear discrete ill-posed problems.  相似文献   
56.
Systems evolve in order to adjust and survive. The paper’s contribution is that this evolvement is inadequate without an evolutionary telos. It is argued that without the presence of self-destruction in multiple levels of our existence and surroundings, our survival would have been impossible. This paper recognises an appreciation of auto-catastrophe at the cell level, in human attitudes (both as an individual and in societies), and extended to Earth and out to galaxies. Auto-Catastrophic Theory combines evolution with auto-catastrophic behaviours and innovative machinery by offering new themes of understanding their merging such as (a) protogenic and deuterogenic auto-catastrophic processes, (b) protogenic and deuterogenic survival processes, and (c) ‘alive’, partially ‘alive’, and non-‘alive’ systems. The value of self-destruction relies on a numerical stability within a system and correlational relationships between systems. Auto-Catastrophic Theory provides novel justifications why artificial intelligence: (a) is crucial to overcome the extinction of humanity (via H+), (b) is crucial to offer indirect survival of humanity (by saving its history), and (c) is at the same time a threat for humanity. These novel justifications and themes, developed by combining evolution with catastrophe as well as innovative machinery, expand our knowledge of how best to handle fresh challenges ahead.  相似文献   
57.
This work presents an efficient method to map the Full Search algorithm for Motion Estimation (ME) onto General Purpose Graphic Processing Unit (GPGPU) architectures using Compute Unified Device Architecture (CUDA) programming model. Our method jointly exploits the massive parallelism available in current GPGPU devices and the parallelism potential of Full Search algorithm. Our main goal is to evaluate the feasibility of video codecs implementation using GPGPUs and its advantages and drawbacks compared to other platforms. Therefore, for comparison reasons, three solutions were developed using distinct programming paradigms for distinct underlying hardware architectures: (i) a sequential solution for general-purpose processor (GPP); (ii) a parallel solution for multi-core GPP using OpenMP library; (iii) a distributed solution for cluster/grid machines using Message Passing Interface (MPI) library. The CUDA-based solution for GPGPUs achieves speed-up compatible to the indicated by the theoretical model for different search areas. Our GPGPU Full Search Motion Estimation provides 2×, 20× and 1664× speed-up when compared to MPI, OpenMP and sequential implementations, respectively. Compared to state-of-the-art, our solution reaches up to 17× speed-up.  相似文献   
58.
Lactococcus lactis 19.3 produces a bacteriocin with a wide inhibitory spectrum, including the food pathogen Listeria monocytogenes. The producing strain was able to grow and produce similar amounts of bacteriocin in MRS medium, cow's milk and soya milk, respectively. The mode of action of this bacteriocin was further investigated using two indicator strains, Lactobacillus delbrueckii subsp. bulgaricus LMG 6901T and Listeria monocytogenes ATCC 1911‐1. The bacteriocin displayed a bactericidal effect, causing a rapid decrease of the cell viability. Bacteriocin treatment of the sensitive strains resulted in major morphological changes, including pore formation, as shown by scanning electron microscopy. Finally, the bacteriocin‐encoding gene was identified by sequencing. The presence of nisin gene was confirmed. Based on all our data gathered so far, L. lactis 19.3 is a good candidate for a starter or protective culture in the manufacturing of both fermented dairy and vegetarian food products.  相似文献   
59.
The aim of this paper was to provide a background review to assist experimental, survey and field studies that will start emerging on the effects of robot crime interviewers on children and on forensic investigations. The paper captures topics such as describing how, historically, technology has determined our legal systems, criminal investigations and, of course, children’s forensic testimonies. It discusses studies that have already explored the idea of robot crime interviewers in the context of relevant ethical concerns as well as experimental studies on the different ways in which children react in an interview elicited by a human compared with a robot interviewer. The article continues by suggesting research methodological designs that could benefit studies exploring robot interviews with children such as a robot exposure phase prior to the main data collection, the robot’s “personality” and the instructions given to children for semi-autonomous interviewers. This is based on the available literature on human–robot interactions. There is an attempt here to provide a literature review and methodological suggestions to form future studies on robot crime interviewers.  相似文献   
60.
Although mushroom poisoning is a rare cause of acute renal injury, in some cases it may lead to the development of a severe and irreversible renal failure. Orellanus syndrome is the most important example of organic renal damage related to mushroom consumption. It is caused by the ingestion of orellanine, the main toxin of different types of Cortinarius mushrooms (Cortinarius speciosissimus, C. orellanus, C. orellanoides, etc.), and it is characterized by progressive clinical phases with a predominant kidney involvement, finally requiring renal replacement therapy in about 10% of cases. Renal damage is often late and associated with a histological picture of interstitial nephritis. Diagnosis is essentially clinical and no specific therapy has been shown to be effective in preventing and treating renal damage. Here, we describe the case of a patient with mixed wild mushroom poisoning, presenting the typical clinical signs and course of the Orellanus syndrome. This case offers us the opportunity to review the main clinical features of this severe and little‐known intoxication.  相似文献   
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