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1.
TETRA (TErrestrial Trunked RAdio) is a digital mobile radio standard for voice and data transmission. It aims at satisfying the growing request of applications and facilities coming from professional users and emergency services. The system has been standardized by ETSI (European Telecommunications Standards Institute) and is provided with an European harmonized frequency band. The first TETRA networks appeared on the market in 1997. This paper reports TETRA radio performance evaluated via a simulation software package, named TETRASIM, entirely developed at CSELT according to TETRA specifications. The simulation results have been obtained for some of the traffic and control channels specified by the standard, in terms of BER (Bit Error Rate) and MER (Message Erasure Rate). As far as the simulated receiver scheme is concerned, the characteristics of the equivalent low-pass filters and the adopted synchronization technique are reported. The simulated demodulator uses a differential detection scheme with soft decision outputs in the case of coded channels. Performance analyses and results comparison are provided by taking into account the effects of signal-to-noise ratio, co-channel interference, adjacent channel interference, propagation models defined in the standard and mobile unit speed. The simulation results reported in this work have been included in the ETR (ETSI Technical Report) “TETRA Designers’ Guide Part 2: Radio and Traffic Performance”. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   
2.
Posttraumatic stress (PTS) symptoms have been reported in mothers and fathers of childhood cancer survivors; however, little is known about patterns of PTS in these families. Cluster analysis was applied to the Posttraumatic Stress Disorder (PTSD) Reaction Index scores of 98 couples parenting adolescent childhood cancer survivors to describe patterns of PTS in families, yielding the following 5 clusters: Minimal PTS, Mothers Elevated, Disengaged, Fathers Elevated, and Elevated PTS. The clusters were validated using data from a structured psychiatric interview, an additional self-report measure of PTS, and an index of family functioning. These clinically meaningful patterns reveal that a majority of families had at least one parent with moderate to severe PTS, which supports development of family-based interventions for this population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
3.
Cabergoline (CAB), a long-lasting dopamine-agonist, specific for the D2 receptor, is effective in normalizing serum PRL levels in most patients with microprolactinoma or idiopathic hyperprolactinemia. Because few data are presently available on the effects of CAB treatment in macroprolactinomas, the aim of this open-label study was to investigate whether this drug was effective in producing tumor shrinkage, as well as in normalizing PRL levels. Twenty-three patients with macroprolactinoma entered this study 15 patients had had no treatment, whereas the remaining 8 patients had been previously treated with bromocriptine, which was with-drawn because of intolerance. Three of 23 patients had undergone unsuccessful surgery. Pretreatment serum PRL levels ranged from 100-3860 micrograms/L. CAB was administered at a dose of 0.5-3 mg once or twice a week for 12-24 months. Magnetic resonance imaging (MRI) scans were performed before and 3, 6, 12, and 24 months after the beginning of treatment, to evaluate tumor shrinkage, defined as a decrease of at least 80% of baseline tumor volume. After 3-6 months of treatment with a low dose (0.5-1 mg/week), serum PRL levels normalized in 18 patients. In the remaining 5 patients, whose serum PRL levels were not normalized, the dose was increased to 2-3 mg/week. This schedule caused the normalization of PRL levels in 1 patient, whereas in the remaining 4 patients, PRL levels were reduced to 30-82 micrograms/L. A tumor volume reduction greater than 80% at MRI occurred in 14 of 23 patients (61%) after CAB treatment (from 2609.4 +/- 534.7 to 530.1 +/- 141.3 mm3 at the 12-24th month follow-up, P < 0.001). A volume reduction of 41.8 +/- 3.4% was already evident after 3 months (1436 +/- 285.9 mm3; P < 0.001). The complete disappearance of the tumor mass at MRI occurred after 6 months of treatment with CAB in 1 patient, and in 5 patients after 1 yr of treatment. An improvement of visual field defects was obtained in 9 of the 10 patients presenting visual impairment before CAB treatment. The drug was tolerated well by all patients. Only 1 patient experienced mild nausea, which disappeared spontaneously after the 2nd day of treatment. Long-term, a low dose of the D2 receptor agonist CAB significantly reduced tumor volume and normalized serum PRL levels in a great majority of patients bearing macroprolactinoma. This treatment met with excellent patient compliance. This study suggests that CAB can be used as a first choice drug treatment in macroprolactinomas, as already shown for microprolactinomas and idiopathic hyperprolactinemia.  相似文献   
4.
The exact mechanism underlying selective dopaminergic neurodegeneration is not completely understood. The complex interplay among toxic alpha-synuclein aggregates, oxidative stress, altered intracellular Ca2+-homeostasis, mitochondrial dysfunction and disruption of mitochondrial integrity is considered among the pathogenic mechanisms leading to dopaminergic neuronal loss. We herein investigated the molecular mechanisms leading to mitochondrial dysfunction and its relationship with activation of the neuroinflammatory process occurring in Parkinson’s disease. To address these issues, experiments were performed in vitro and in vivo in mice carrying the human mutation of α-synuclein A53T under the prion murine promoter. In these models, the expression and activity of NCX isoforms, a family of important transporters regulating ionic homeostasis in mammalian cells working in a bidirectional way, were evaluated in neurons and glial cells. Mitochondrial function was monitored with confocal microscopy and fluorescent dyes to measure mitochondrial calcium content and mitochondrial membrane potential. Parallel experiments were performed in 4 and 16-month-old A53T-α-synuclein Tg mice to correlate the functional data obtained in vitro with mitochondrial dysfunction and neuroinflammation through biochemical analysis. The results obtained demonstrated: 1. in A53T mice mitochondrial dysfunction occurs early in midbrain and later in striatum; 2. mitochondrial dysfunction occurring in the midbrain is mediated by the impairment of NCX3 protein expression in neurons and astrocytes; 3. mitochondrial dysfunction occurring early in midbrain triggers neuroinflammation later into the striatum, thus contributing to PD progression during mice aging.  相似文献   
5.
In order to optimise the use of the available means and to constitute sustainable research groups in the European Union, the Severe Accident Research NETwork of Excellence (SARNET) has gathered, between 2004 and 2008, 51 organizations representing most of the actors involved in severe accident (SA) research in Europe plus Canada. This project was co-funded by the European Commission (EC) under the 6th Euratom Framework Programme. Its objective was to resolve the most important pending issues for enhancing, in regard of SA, the safety of existing and future nuclear power plants (NPPs).SARNET tackled the fragmentation that existed between the national R&D programmes, in defining common research programmes and developing common computer codes and methodologies for safety assessment. The Joint Programme of Activities consisted in:
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Implementing an advanced communication tool for accessing all project information, fostering exchange of information, and managing documents;
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Harmonizing and re-orienting the research programmes, and defining new ones;
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Analyzing the experimental results provided by research programmes in order to elaborate a common understanding of relevant phenomena;
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Developing the ASTEC code (integral computer code used to predict the NPP behaviour during a postulated SA) by capitalizing in terms of physical models the knowledge produced within SARNET;
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Developing scientific databases, in which the results of research experimental programmes are stored in a common format;
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Developing a common methodology for probabilistic safety assessment of NPPs;
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Developing short courses and writing a text book on severe accidents for students and researchers;
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Promoting personnel mobility amongst various European organizations.
This paper presents the major achievements after four and a half years of operation of the network, in terms of knowledge gained, of improvements of the ASTEC reference code, of dissemination of results and of integration of the research programmes conducted by the various partners.Most initial objectives were reached but the continuation of the SARNET network, co-funded by EC in the 7th Framework Programme (SARNET2 project that started in April 2009 for 4 years), will consolidate the first assets and focus mainly on the highest priority pending issues as determined during the first period. The objective will be also to make the network evolve towards a complete self-sustainability.  相似文献   
6.
Glioblastoma (GBM), the most commonly occurring primary tumor arising within the central nervous system, is characterized by high invasiveness and poor prognosis. In spite of the improvement in surgical techniques, along with the administration of chemo- and radiation therapy and the incessant investigation in search of prospective therapeutic targets, the local recurrence that frequently occurs within the peritumoral brain tissue makes GBM the most malignant and terminal type of astrocytoma. In the current study, we investigated both GBM and peritumoral tissues obtained from 55 hospitalized patients and the expression of three molecules involved in the onset of resistance/unresponsiveness to chemotherapy: O6-methylguanine methyltransferase (MGMT), breast cancer resistance protein (BCRP1), and A2B5. We propose that the expression of these molecules in the peritumoral tissue might be crucial to promoting the development of early tumorigenic events in the tissue surrounding GBM as well as responsible for the recurrence originating in this apparently normal area and, accordingly, for the resistance to treatment with the standard chemotherapeutic regimen. Notably, the inverse correlation found between MGMT expression in peritumoral tissue and patients’ survival suggests a prognostic role for this protein.  相似文献   
7.
Hydro- and thermal-peaking waves, generated by hydroelectric power generation, have a strong impact on the ecological integrity of aquatic ecosystems. In order to reduce such effects, mitigation procedure must be studied and implemented. To this end a one-dimensional model which solves the coupling of hydrodynamics with heat transport is developed. The solution is obtained advancing simultaneously the hydrodynamic and thermal module with the same accuracy. For the numerical solution of the governing advection-reaction/diffusion problem a splitting procedure is adopted: the advection-reaction part is solved by means of the weight average flux (WAF) finite volume explicit method, while the diffusion part is solved using a nonlinear version of the implicit Crank-Nicolson method. The WAF method is extended to second-order in the presence of reaction terms. Numerical results are presented for different test examples, which demonstrate the accuracy and robustness of the scheme and its applicability in predicting temperature transport by shallow water flows. Application to the Adige River (Northern Italy) of this framework proves that the model is an effective tool for designing hydro- and thermal-peaking waves mitigation procedures.  相似文献   
8.
Coupling the Saint-Venant equations with the Exner equation a morphodynamic model is produced, which can be used to describe flow and bed evolution in natural rivers. The system of governing equations is hyperbolic and is expressed in nonconservative form. For this reason, fully primitive formulations of the model are often adopted for the solution, which however are known to incorrectly compute strength and celerity of shock waves (bores). In the present work a quasi-conservative formulation of the differential system is proposed, which aims at reducing these errors to a minimum. The performances of the model are assessed by comparison with primitive formulations applied to some schematic cases and with experimental observations obtained on a physical model of a river reach. Results are satisfactory and overcome predictions based on fully primitive formulations.  相似文献   
9.
Complete-arch implant prostheses continue to exhibit horizontal and vertical misfit between frameworks and abutments. It has been suggested that these gaps may be eliminated and that restoration-induced stresses may be reduced by luting frameworks to screw-retained abutments intraorally. This study measured and compared the strains generated by clinically acceptable, conventional frameworks were made from a single master cast representing a bone simulant model of an edentulous mandible with five Nobel Biocare implants and 4-mm abutments. Two strain gauges were also embedded in the bone simulant model to measure strains at two locations. Resin-luted frameworks were made by securing abutments to the clinical model with five gold slot screws tightened to 10 Ncm. Strain-indicator readings were recorded at a standardized time following the initial fastening of each prosthesis (n = 3). Mean principal strains were determined and compared using a one-way repeated measures analysis of variance. A statistically significant difference was found in the principal strains between the conventional cast and the resin-luted frameworks. Overall, there was a decrease in the magnitude of strain for the resin-luted frameworks. Intraoral luting of frameworks may decrease the strains produced in the bone around implants.  相似文献   
10.
The paper summarizes relevant results from the pre- and post-test calculations of fuel coolant interaction and quenching tests performed in the FARO and KROTOS test facilities. The main analytical tools adopted at JRC Ispra are the COMETA and the TEXAS codes. COMETA pre and post-test calculations of FARO Test L-20 as well as an application of the code to KROTOS test facility are presented. The analysis provides the need to account for H2 generation models into the pre-mixing calculations. In addition salient results from the application of TEXAS to FARO and KROTOS tests are shown.  相似文献   
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