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排序方式: 共有139条查询结果,搜索用时 406 毫秒
81.
Pravin Sawant 《Nuclear Engineering and Design》2011,241(9):3824-3838
This paper focuses on the assessment of pressure suppression pool hydrodynamics in the advanced boiling water reactor (ABWR) containment under design-basis, loss-of-coolant accident (LOCA) conditions. The paper presents a mechanistic model for predicting various suppression pool hydrodynamics parameters. A phenomena identification and ranking table (PIRT) applicable to the ABWR containment pool hydrodynamics analysis is used as a basis for the development of the model. The highly ranked phenomena are represented by analytic equations or empirical correlations. The best estimate and several sensitivity calculations are performed for the ABWR containment using this model. Results of the sensitivity calculations are also presented that demonstrate the influence of key model parameters and assumptions on the pool hydrodynamics parameters. A comparison of model predictions to the results of the licensing analyses shows reasonable agreement. Comparison of the results of the proposed model to experimental data shows that the model predicted top vent clearance time, the pool swell height, and the bubble breakthrough elevation are within 10% of the data. The predicted pool surface velocity and the liquid slug thickness are within 30% of the measurements, which is considered adequate given the large uncertainties in the experimental measurements. 相似文献
82.
采用塑性功曲率(plastic work curvature,PWC)准则和非线性有限元技术相结合的直接法计算了工业封头产品的塑性压力和塑性接管载荷,并将其与其他方法的计算结果进行了比较。分析结果表明,PWC准则塑性压力在理想塑性分析条件下与Cloud-Rodabaugh极限压力和ASME极限压力很接近;PWC准则塑性载荷以总塑性功作为结构整体塑性失效的全局指标,其应变硬化分析条件下的结果能反映材料应变硬化对封头强度的强化效果,克服了TES(twice elastic slope)准则需凭经验选择变形参数的缺点;直接法避免了弹性应力分类的困难,方法简便。研究表明,基于PWC准则的直接法是解决板翅式换热器封头这种复杂结构分析设计问题的有效方法。 相似文献
83.
84.
Paola Pontrelli Francesca Conserva Rossella Menghini Michele Rossini Alessandra Stasi Chiara Divella Viviana Casagrande Claudia Cinefra Mariagrazia Barozzino Simona Simone Francesco Pesce Giuseppe Castellano Giovanni Stallone Anna Gallone Francesco Giorgino Massimo Federici Loreto Gesualdo 《International journal of molecular sciences》2021,22(10)
Diabetic nephropathy (DN) is the most frequent cause of end-stage renal disease. Tubulointerstitial accumulation of lysine 63 (K63)-ubiquitinated (Ub) proteins is involved in the progression of DN fibrosis and correlates with urinary miR-27b-3p downregulation. We explored the renoprotective effect of an inhibitor of K63-Ub (NSC697923), alone or in combination with the ACE-inhibitor ramipril, in vitro and in vivo. Proximal tubular epithelial cells and diabetic DBA/2J mice were treated with NSC697923 and/or ramipril. K63-Ub protein accumulation along with α-SMA, collagen I and III, FSP-1, vimentin, p16INK4A expression, SA-α Gal staining, Sirius Red, and PAS staining were measured. Finally, we measured the urinary albumin to creatinine ratio (uACR), and urinary miR-27b-3p expression in mice. NSC697923, both alone and in association with ramipril, in vitro and in vivo inhibited hyperglycemia-induced epithelial to mesenchymal transition by significantly reducing K63-Ub proteins, α-SMA, collagen I, vimentin, FSP-1 expression, and collagen III along with tubulointerstitial and glomerular fibrosis. Treated mice also showed recovery of urinary miR-27b-3p and restored expression of p16INK4A. Moreover, NSC697923 in combination with ramipril demonstrated a trend in the reduction of uACR. In conclusion, we suggest that selective inhibition of K63-Ub, when combined with the conventional treatment with ACE inhibitors, might represent a novel treatment strategy to prevent the progression of fibrosis and proteinuria in diabetic nephropathy and we propose miR-27b-3p as a biomarker of treatment efficacy. 相似文献
85.
Mackenzie E. Malo Kevin J. H. Allen Rubin Jiao Connor Frank David Rickles Ekaterina Dadachova 《International journal of molecular sciences》2020,21(22)
Melanoma incidence continues to rise, and while therapeutic approaches for early stage cases are effective, metastatic melanoma continues to be associated with high mortality. Immune checkpoint blockade (ICB) has demonstrated clinical success with approved drugs in cohorts of patients with metastatic melanoma and targeted radionuclide therapy strategies showed promise in several clinical trials against various cancers including metastatic melanoma. This led our group to investigate the combination of these two treatments which could be potentially offered to patients with metastatic melanoma not responsive to ICB alone. Previously, we have demonstrated that a combination of humanized anti-melanin antibody conjugated to 213Bismuth and anti-PD-1 ICB reduced tumor growth and increased survival in the Cloudman S91 murine melanoma DBA/2 mouse model. In the current study, we sought to improve the tumoricidal effect by using the long-lived radionuclides 177Lutetium and 225Actinium. Male Cloudman S91-bearing DBA/2 mice were treated intraperitoneally with PBS (Sham), unlabeled antibody to melanin, anti-PD-1 ICB, 177Lutetium or 225Actinium RIT, or a combination of ICB and RIT. Treatment with anti-PD-1 alone or low-dose 177Lutetium RIT alone resulted in modest tumor reduction, while their combination significantly reduced tumor growth and increased survival, suggesting synergy. 225Actinium RIT, alone or in combination with ICB, showed no therapeutic benefit, suggesting that the two radionuclides with different energetic properties work in distinct ways. We did not detect an increase in tumor-infiltrating T cells in the tumor microenvironment, which suggests the involvement of alternative mechanisms that improve the effect of combination therapy beyond that observed in the single therapies. 相似文献
86.
动态带宽分配(DBA)是EPON的关键技术,根据数据业务流量的突发性调整了ONU授权时隙的顺序,提出了一种改进的轮询算法,构造了微粒群(PSO)优化的神经网络预测模型,提高了轮询周期内ONU新增数据的预测精度,从而保证了带宽分配公平性。仿真结果表明,该算法在优化带宽资源分配、降低平均数据时延方面均优于传统DBA算法。 相似文献
87.
er-ONU and intra-ONU fairness. Most importantly, it can flexibly adapt to the system composition variations and save efforts needed to modify the bandwidth scheduling mechanism during the migration process from GEPON to 10G EPON. 相似文献
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89.
文章分析一种改进的基于分布式的以太网无源光网络的接入结构.根据该结构的特点.在IPACT取制DBA算法的基础上进行改进.设计了两种DBA算法,一种是支持ONU传输的顺序DBA算法.另一种是支持全局考虑机制的DBA算法. 相似文献
90.
首先介绍了吉比特无源光网络(GPON)的复用结构和所承载的业务,随后就GPON的关键技术之一——动态带宽分配作了详细论述,分别从带宽分配的功能、对象和过程这几个方面作了介绍,最后比较了GPON和宽带无源光网络(BPON)在动态带宽分配方面的不同。 相似文献