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131.
Tip20p is an 80 kDa cytoplasmic protein bound to the cytoplasmic surface of the endoplasmic reticulum (ER) by interaction with the type II integral membrane protein Sec20p. Both proteins are required for vesicular transport between the ER and Golgi complex. Recently, sec20–1 was found to be defective in retrograde transport. A collection of temperature-sensitive tip20 mutants are shown to be lethal in combination with ufe1–1, a target SNARE of the ER and ret2–1, yeast δ-COP. A subset of tip20 mutants was found to be lethal in combination with sec20–1, sec21–1, sec22–3 and sec27–1. Since all pairwise combinations of a tip20 mutant, sec20–1, and ufe1–1 are lethal, Tip20p and Sec20p might be part of the docking complex for Golgi-derived retrograde transport vesicles. Since carboxy-terminal tip20 truncations are lethal in combination with mutants in three coatomer subunits, Tip20p might be involved in binding or uncoating of COPI coated retrograde transport vesicles. © 1998 John Wiley & Sons, Ltd.  相似文献   
132.
Bisphenol A (BPA) is largely used as a monomer in some types of plastics. It accumulates in tissues and fluids and is able to bypass the placental barrier, affecting various organs and systems. Due to huge developmental processes, children, foetuses, and neonates could be more sensitive to BPA-induced toxicity. To investigate the multi-systemic effects of chronic exposure to a low BPA dose (100 μg/L), pregnant Wistar rats were exposed to BPA in drinking water during gestation and lactation. At weaning, newborn rats received the same treatments as dams until sex maturation. Free and conjugated BPA levels were measured in plasma and adipose tissue; the size of cerebral ventricles was analysed in the brain; morpho-functional and molecular analyses were carried out in the liver with a focus on the expression of inflammatory cytokines and Sirtuin 1 (Sirt1). Higher BPA levels were found in plasma and adipose tissue from BPA treated pups (17 PND) but not in weaned animals. Lateral cerebral ventricles were significantly enlarged in lactating and weaned BPA-exposed animals. In addition, apart from microvesicular steatosis, liver morphology did not exhibit any statistically significant difference for morphological signs of inflammation, hypertrophy, or macrovesicular steatosis, but the expression of inflammatory cytokines, Sirt1, its natural antisense long non-coding RNA (Sirt1-AS LncRNA) and histone deacetylase 1 (Hdac1) were affected in exposed animals. In conclusion, chronic exposure to a low BPA dose could increase the risk for disease in adult life as a consequence of higher BPA circulating levels and accumulation in adipose tissue during the neonatal period.  相似文献   
133.
Artificial neural networks (ANNs) are one of the most powerful and versatile tools provided by artificial intelligence and they have now been exploited by chemical engineers for several decades in countless applications. ANNs are computational tools providing a minimalistic mathematical model of neural functions. Coupled with raw data and a learning algorithm, they can be applied to tasks such as modelling, classification, and prediction. Recently, their popularity has grown remarkably and they now constitute one of the most relevant research areas within the fields of artificial intelligence and machine learning. ANNs are large collections of simple classifiers called neurons. Chemical engineers apply them to model complex relationships, predict reactor performance, and to automate process controllers. ANNs can leverage their ability to learn and exploit large data sets, but they can also get stuck in local minima or overfit and are difficult to reverse engineer. In 2016 and 2017, ANNs were cited in 13 245 Web of Science (WoS) articles, 538 of which were in chemical engineering; the top WoS categories were electrical & electronic engineering (1615 occurrences) artificial intelligence (1253), and energy & fuels (980). The top 4 journals mentioning ANNs were Neural Computing & Applications (117), Neurocomputing (84), Energies (76), and Renewable & Sustainable Energy Reviews (76). In the near future, as larger data sets become available (and arduous to analyze), chemical engineers will be able to apply and leverage more sophisticated ANN architectures.  相似文献   
134.
Nanofluids are colloidal dispersions of nanoparticles in homogenous base fluids. Previous studies have shown that nanofluids can increase pool boiling critical heat flux (CHF) by forming a porous deposition on the heated surface. However, questions remain whether nanoparticles can further enhance the CHF on a passively engineered heat transfer surface, such as a sandblasted metal plate. In this study, three water-based nanofluids (diamond, zinc oxide and alumina) were used to modify sandblasted stainless steel 316 plate heaters via boiling induced deposition. The pool boiling CHF of these pre-coated heaters increased by up to 35% with respect to that of the bare, sandblasted heaters. The enhancements are highest for alumina and zinc oxide nanofluids. Detailed surface characterization of these pre-coated heaters showed different surface morphology depending on the type of nanofluids used. Additionally, the deposited nanoparticles layers were found to alter the wettability of the heaters. Contact angle measurement provided quantitative data to determine possible CHF enhancement based on existing correlations.  相似文献   
135.
Infrared thermometry was used to obtain first-of-a-kind, time- and space-resolved data for pool boiling phenomena in water-based nanofluids with diamond and silica nanoparticles at low concentration (<0.1 vol.%). In addition to macroscopic parameters like the average heat transfer coefficient and critical heat flux [CHF] value, more fundamental parameters such as the bubble departure diameter and frequency, growth and wait times, and nucleation site density [NSD] were directly measured for a thin, resistively heated, indium-tin-oxide surface deposited onto a sapphire substrate. Consistent with other nanofluid studies, the nanoparticles caused deterioration in the nucleate boiling heat transfer (by as much as 50%) and an increase in the CHF (by as much as 100%). The bubble departure frequency and NSD were found to be lower in nanofluids compared with water for the same wall superheat. Furthermore, it was found that a porous layer of nanoparticles built up on the heater surface during nucleate boiling, which improved surface wettability compared with the water-boiled surfaces. Using the prevalent nucleate boiling models, it was possible to correlate this improved surface wettability to the experimentally observed reductions in the bubble departure frequency, NSD, and ultimately to the deterioration in the nucleate boiling heat transfer and the CHF enhancement.  相似文献   
136.
The non-orthotopic expression of olfactory receptors (ORs) includes the male reproductive system, and in particular spermatozoa; their active ligands could be essential to sperm chemotaxis and chemical sperm–oocyte communication. OR51E2 expression has been previously reported on sperm cells’ surface. It has been demonstrated in different cellular models that olfactory receptor 51E2 (OR51E2) binds volatile short-chain fatty acids (SCFAs) as specific ligands. In the present research, we make use of Western blot, confocal microscopy colocalization analysis, and the calcium-release assay to demonstrate the activation of sperm cells through OR51E2 upon SCFAs stimulus. Moreover, we perform a novel modified swim-up assay to study the involvement of OR51E2/SCFAs in sperm migration. Taking advantage of computer-assisted sperm analysis (CASA system), we determine the kinematics parameters of sperm cells migrating towards SCFAs-enriched medium, revealing that these ligands are able to promote a more linear sperm-cell orientation. Finally, we obtain SCFAs by mass spectrometry in cervico-vaginal mucus and show for the first time that a direct incubation between cervical mucus and sperm cells could promote their activation. This study can shed light on the possible function of chemosensory receptors in successful reproduction activity, laying the foundation for the development of new strategies for the treatment of infertile individuals.  相似文献   
137.
Enterprise IT is currently facing the challenge of coordinating the management of complex, multicomponent applications across heterogeneous cloud platforms. Containers and container orchestrators provide a valuable solution to deploy multicomponent applications over cloud platforms, by coupling the lifecycle of each application component to that of its hosting container. We hereby propose a solution for going beyond such a coupling, based on the OASIS standard TOSCA and on Docker. We indeed propose a novel approach for deploying multicomponent applications on top of existing container orchestrators, which enables managing each component independently from the container used to run it. We also present prototype tools that implement our approach, and we show how we effectively exploited them to carry out a concrete case study.  相似文献   
138.
Nanocomposite membranes based on polyethersulfone (PES) and nanomagnetite have been investigated with regards to the effect of pretreatments on the electrochemical performance of microbial fuel cells (MFCs). Nanocomposite membranes containing various amounts of Fe3O4 (5, 10, and 20 wt%) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry, and tensile tests. The application in MFC systems requires also chemical characterizations such as ion exchange capacity, water uptake, and oxygen permeability. The best formulation (PES10) showed electrochemical properties similar to the PES20. With the aim of obtaining a high-performance membrane with a low filler dosage, a pretreatment procedure (1 h of boiling step in deionized water and 1 h of immersion in 0.5 M of H2SO4) was adopted. The results of such pretreatment in terms of maximum power and current density were 10.59 ± 0.72 mW/m2 and 52.07 ± 0.86 mA/m2, respectively. The adoption of a pretreatment avoids the need of higher amount of nanofillers that can affect membrane surface roughness and its processing. Overall, the nanocomposite membranes represent a suitable technology in the MFC process. POLYM. ENG. SCI., 60: 371–379, 2019. © 2019 Society of Plastics Engineers  相似文献   
139.
140.
A Review on Agri-food Supply Chain Traceability by Means of RFID Technology   总被引:2,自引:0,他引:2  
Radio Frequency Identification (RFID) is a technology which provides appealing opportunities to improve the management of information flow within the supply chain and security in the agri-food sector. Nowadays, food safety is considered a major requirement in several countries, in particular, the traceability of food products which is mandatory by law. Thus, technological implementation leading to traceability strengthening in the agri-food sector is crucial. The first aim of this review is to analyze the current developments in RFID technology in the agri-food sector, through an operative framework which organizes the literature and facilitate a quick content analysis identifying future research direction. RFID technology seems to be able to bring great opportunities to this sector; nevertheless, several constraints are slowing its adoption. This survey may provide readers with an exhaustive overview of opportunities and constraints for the wide adoption of RFID. The second aim of this review is to provide an updated analysis on the current developments of RFID technology for different product typologies within the agri-food industry, discussing at the same time its potential in technological and logistical development regarding different sectors of the production/distribution chain. As referenced here, RFID implementations in the agri-food sector are increasing at a fast rate, and technological advancement follows the applicability opportunities. However, real applications of RFID technologies are still limited because of various technical and economical obstacles which are also discussed.  相似文献   
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