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1.
40 college students who differed on defensiveness and anxiety (as measured by the Marlowe-Crowne Social Desirability Scale and Shimkunas's Uncertainty Anxiety Scale) predicted, and in a later experimental interview evaluated, their verbal exploration and subjective comfort following a role-induction exercise. Behavioral measures also included content ratings, speech duration, silence quotient, and reaction time. Low-defensive, low-anxious Ss were most successful in their overall participation, whereas low-defensive, high-anxious Ss comprehended role requirements but were restrained in their approach. High-defensive, low-anxious Ss failed to acquire an accurate impression of their role behavior. Contrary to expectation, high-defensive, high-anxious Ss were motivated to comply with situational demands and were not most avoidant. Alternative role-training procedures are discussed in relation to individual differences. (17 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Weanling male white rats were fed a diet containing a commercially available breakfast cereal. In 28 days they developed a mild anemia coupled with an increased amount of iron in the liver. In parallel work, this same diet was supplemented in a factorial fashion with casein, iron, copper and zinc. The zinc had no effect. Copper supplementation increased the hemoglobin level. Casein decreased liver iron. The copper and casein, when fed together, produced results approaching normal control levels. Supplementation of the diet with additional iron did not increase the hemoglobin or hematocrit but it did further increase iron storage in the liver. It is suggested that cereal enrichment programs might do well to consider copper and protein rather than focus total attention on additional iron and zinc.  相似文献   
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Chronic infection with Helicobacter pylori increases risk of gastric diseases including gastric cancer. Despite development of a robust immune response, H. pylori persists in the gastric niche. Progression of gastric inflammation to serious disease outcomes is associated with infection with H. pylori strains which encode the cag Type IV Secretion System (cag T4SS). The cag T4SS is responsible for translocating the oncogenic protein CagA into host cells and inducing pro-inflammatory and carcinogenic signaling cascades. Our previous work demonstrated that nutrient iron modulates the activity of the T4SS and biogenesis of T4SS pili. In response to H. pylori infection, the host produces a variety of antimicrobial molecules, including the iron-binding glycoprotein, lactoferrin. Our work shows that apo-lactoferrin exerts antimicrobial activity against H. pylori under iron-limited conditions, while holo-lactoferrin enhances bacterial growth. Culturing H. pylori in the presence of holo-lactoferrin prior to co-culture with gastric epithelial cells, results in repression of the cag T4SS activity. Concomitantly, a decrease in biogenesis of cag T4SS pili at the host-pathogen interface was observed under these culture conditions by high-resolution electron microscopy analyses. Taken together, these results indicate that acquisition of alternate sources of nutrient iron plays a role in regulating the pro-inflammatory activity of a bacterial secretion system and present novel therapeutic targets for the treatment of H. pylori-related disease.  相似文献   
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Control of water mass inventory in Nuclear Steam Generators is important to insure sufficient cooling of the nuclear reactor. Since downcomer water level is measurable, and a reasonable indication of water mass inventory near steady-state, conventional feedwater control system designs attempt to maintain downcomer water level within a relatively narrow operational band. However, downcomer water level can temporarily react in a reverse manner to water mass inventory changes, commonly known as shrink and swell effects. These complications are accentuated during start-up or low power conditions. As a result, automatic or manual control of water level is difficult and can lead to high reactor trip rates.This paper introduces a new feedwater control strategy for Nuclear Steam Generators. The new method directly controls water mass inventory instead of downcomer water level, eliminating complications from shrink and swell all together. However, water mass inventory is not measurable, requiring an online estimator to provide a mass inventory signal based on measurable plant parameters. Since the thermal-hydraulic response of a Steam Generator is highly nonlinear, a linear state-observer is not feasible. In addition, difficulties in obtaining flow regime and density information within the Steam Generator make an estimator based on analytical methods impractical at this time.This work employs a water mass estimator based on feedforward neural networks. By properly choosing and training the neural network, mass signals can be obtained which are suitable for stable, closed-loop water mass inventory control. Theoretical analysis and simulation results show that water mass control can significantly improve the operation and safety of Nuclear Steam Generators.  相似文献   
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The simulation of multi-phase flow at low capillary numbers (Ca) remains a challenge. Approximate computations of the capillary forces tend to induce parasitic currents (PC) around the interface. These PC induce additional viscous dissipation and shear forces that potentially lead to wrong calculations of the general flow dynamics. Here, we focus on the case of spontaneous imbibition in a microchannel of Hele-Shaw cell symmetry with capillarity being the only driving force. We extend the Lucas–Washburn equation to account for arbitrary viscosity ratios and assess four volume-of-fluid (VOF) formulations against the analytical solution. More specifically, we evaluate the continuum surface force (CSF) formulation, the sharp surface force (SSF) formulation, the filtered surface force (FSF) formulation and the piecewise linear interface calculation (PLIC) formulation extended by a higher order discretisation of the interface curvature through a height function with respect to accuracy, performance and heuristic parameters. We quantify PC for each formulation and investigate their impact on flow with \(\mathrm{Ca} < 10^{-2}\). The magnitude of PC are largest for CSF and are reduced two fold by SSF. FSF reduces PC considerably more but shows periodic short bursts in the velocity field. PLIC shows no PC for the studied \(\mathrm{Ca}\) and viscosity ratios. However, it fails when a denser fluid displaces a lighter fluid. Despite PC, all formulations are accurate within 10%. PLIC is suited to serve as a reference but relies on a structured mesh and is computationally expensive. FSF requires more heuristic parameters. Together with periodic bursts, this prevents a conclusive statement on the best choice between SSF and FSF.  相似文献   
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Investigated the effectiveness of the interviewer as a model of and recipient for interviewee self-disclosure when modeled content revealed favorable or unfavorable personal information. Of 24 undergraduate males who served as Ss, 8 were in a control condition and received only minimal interview structuring. During a 30-min interview, Ss talked about their relationship with 4 target persons. Contrary to a "model status loss" hypothesis suggested by previous research, the disclosure of unfavorable information did not decrease the effectiveness of the interviewer's interventions. Although Ss' perceptions of their disclosing interviewer were in the expected direction on 9 of 10 interpersonal rating dimensions, between-group differences did not reach significance. Ss talked longer and achieved higher levels of self-exploration in both modeling conditions than in the no-model control situation. Frequency and patterning of Ss' positive and negative self-references also were related to treatment conditions. Implications for psychotherapy interventions and continued interview behavior research are discussed. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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We studied apoptosis caused by porcine reproductive and respiratory syndrome virus (PRRSV) in vivo, focusing on the tissues that constitute the main targets for infection: lung and lymphoid tissues. Previous investigators have shown that the PRRSV glycoprotein p25, encoded by PRRSV open reading frame 5, induces apoptosis when expressed in COS-1 cells. Results of studies conducted in our laboratory indicate the simultaneous occurrence of PRRSV-induced alterations of spermatogenesis and apoptotic death of germinal epithelial cells in the testicle. In this study, the goal was to determine whether virus-induced apoptosis is a direct mechanism of cell death caused by PRRSV in infected pigs. Eight 3-week-old pigs were intranasally inoculated with PRRSV 16244B, a highly virulent field strain. Lung, tonsil, bronchial lymph node, spleen, and heart were assessed histologically at 4 and 7 days postinfection. To characterize PRRSV-infected cells and apoptotic cell death, we used immunohistochemical methods for detection of viral antigen, DNA electrophoresis for detection of DNA fragmentation, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-fluorescein nick end labeling method for in situ detection of DNA strand breaks, and electron microscopy for ultrastructural morphologic studies. PRRSV infection resulted in widespread apoptosis in the lungs and lymphoid tissues of infected pigs. Virus infection-induced apoptotic cells were more abundant than PRRSV-infected cells in all tissues. DNA laddering was detected in lung and lymphoid tissues. However, double-labeling experiments demonstrated that the majority of apoptotic cells did not colocalize with PRRSV-infected cells. Our findings suggest the presence of an indirect mechanism in the induction of apoptosis for PRRSV.  相似文献   
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We present a local equilibrium theory for the reactive transport of two salts that share an anion in an ideal solution. We revisit this classic problem using the theory of hyperbolic partial differential equations accounting for the volume of precipitates. We construct analytical solutions for the 2 × 2 system of conservation laws in the absence of hydrodynamic dispersion. The character of the system depends on the saturation of the salts, that is, whether the fluid is saturated with both, either of the two or none of the salts. We provide a comprehensive analysis of the system and its solution. Each primitive variable, the amount of precipitate and the concentration of ions, remains constant along one class of waves that propagate in the system. The analysis of the system allows identification of seven bifurcations with respect to the intermediate state.  相似文献   
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