战术导弹飞行试验的检验方法比较

检验方法对于战术导弹飞行试验与鉴定至关重要,介绍了定型与批检试验的检验方法及其发展变化,并对它们的特点及使用做了比较.     

RB Regulates DNA Double Strand Break Repair Pathway Choice by Mediating CtIP Dependent End Resection

Inactivation of the retinoblastoma tumor suppressor gene (RB1) leads to genome instability, and can be detected in retinoblastoma and other cancers. One damaging effect is causing DNA double strand breaks (DSB), which, however, can be repaired by homologous recombination (HR), classical non-homologous end joining (C-NHEJ), and micro-homology mediated end joining (MMEJ). We aimed to study the mechanistic roles of RB in regulating multiple DSB repair pathways. Here we show that HR and C-NHEJ are decreased, but MMEJ is elevated in RB-depleted cells. After inducing DSB by camptothecin, RB co-localizes with CtIP, which regulates DSB end resection. RB depletion leads to less RPA and native BrdU foci, which implies less end resection. In RB-depleted cells, less CtIP foci, and a lack of phosphorylation on CtIP Thr847, are observed. According to the synthetic lethality principle, based on the altered DSB repair pathway choice, after inducing DSBs by camptothecin, RB depleted cells are more sensitive to co-treatment with camptothecin and MMEJ blocker poly-ADP ribose polymerase 1 (PARP1) inhibitor. We propose a model whereby RB can regulate DSB repair pathway choice by mediating the CtIP dependent DNA end resection. The use of PARP1 inhibitor could potentially improve treatment outcomes for RB-deficient cancers.     

Bi2O3-ZnO-Nb2O3(BZN)系复相陶瓷的相转变

重新讨论了ＢＺＮ系（α＋ β） 复相陶瓷中α相与β相之间的相转变． 研究表明：ＢＺＮ系α相与β相是有一定固溶范围的三元化合物,α相的固溶范围受温度的影响较大,β相的固溶范围受温度的影响较小． 复相（α＋ β） 的相组成因此受温度的影响,随温度升高,α相的固溶范围变大,对β相的固溶度增加,复相中β相减少,α相增加． 随温度降低,α相的固溶范围变小,对β相的固溶度减小,β相从α相中脱溶,复相中α相减少,β相增加．     

浅谈苏州古典园林植物配置

介绍了苏州古典园林植物,从其植物的选用特点及配置特点两方面进行了论述,指出苏州古典园林充分发挥出了自身的地域特色,创造出了风格鲜明的江南园林,形成了我国古代历史上私家园林的代表流派。     

童寯视角下的中外园林差异

童寯先生不遗余力的致力于研究中国古典园林遗产达半世纪之久,为中国古典园林研究提供了大量的珍贵资料。曾著《江南园林志》、《造园史纲》等多部著作,对中国园林进行了深入的研究,并将其放在世界各国园林的大环境中进行比较研究。本文就以这些著作中童寯先生的观点为基础,探讨中外园林的差异性。     

Combustion stability limits and NOx emissions of nonpremixed ammonia-substituted hydrogen–air flames

The combustion stability (extinction) limits and nitrogen oxide (NO_x) emissions of nonpremixed ammonia (NH₃)–hydrogen (H₂)–air flames at normal temperature and pressure are studied to evaluate the potential of partial NH₃ substitution for improving the safety of H₂ use and to provide a database for the nonpremixed NH₃-substituted H₂–air flames. Considering coflow nonpremixed NH₃–H₂–air flames for a wide range of fuel and coflow air injection velocities (V_fuel and V_coflow) and the extent of NH₃ substitution, the effects of NH₃ substitution on the stability limits and NO_x emissions of the NH₃–H₂–air flames are experimentally determined, while the nonpremixed NH₃–H₂–air flame structure is computationally predicted using a detailed reaction mechanism. Results show significant reduction in the stability limits and unremarkable increase in the NO_x emission index for enhanced NH₃ substitution, supporting the potential of NH₃ as an effective, carbon-free additive in nonpremixed H₂–air flames. With increasing V_coflow the NO_x emission index decreases, while with increasing V_fuel it decreases and then increases due to the recirculation of burned gas and the reduced radiant heat losses, respectively. Given V_coflow/V_fuel the flame length increases with enhanced NH₃ substitution since more air is needed for reaction stoichiometry. The predicted flame structure shows that NH₃ is consumed more upstream than H₂ due to the difference between their diffusivities in air.     

应变梯度塑性理论模拟晶粒尺寸对铝多晶体强度的影响

采用经典塑性理论与基于微观机制的应变梯度（MSG）塑性理论对不同晶粒尺寸铝多晶的应力-应变关系进行了模拟分析,结果表明：基于微观机制的应变梯度本构方程所得的应力-应变曲线中,随着晶粒尺寸的减小,塑性应变功明显增加．晶粒直径为20μm的应力-应变曲线稍高于经典塑性理论得到的曲线,这进一步说明随着晶粒尺寸的增大,应变梯度的贡献逐渐减小,同时计算所得的屈服强度与晶粒尺度关系拟合的直线与铝晶体的Hall-Petch直线比较吻合。     

承重横墙上异常裂缝及成因分析

以某院一幢学生楼承重横墙上出现的异常裂缝为例,描述该种裂缝现象、特征及危害,分析论证温度应力是这种裂缝发生的主要原因,进而解释有关问题,为设计、施工和使用管理人员在处理类似问题时提供参考。     

对中国古典园林与英国自然风景园之综合分析比较

英国自然风景园与中国古典园林具有相似之处,但是区别无疑是巨大的。该文试从哲学基础及审美差异、设计观念和关于“自然”概念的理解等几方面比较深入地阐释两者的本质不同。     

“问渠哪得清如许,为有源头活水来”——中国古典园林理水的现代意义

中国古典园林理水有着独特的理念理法和丰富的文化哲理内涵,它所塑造的水景优美而富有意境。文章分析了古典园林理水对水形、水色、水声、动与静的塑造,对融于物和意境的表达,并结合现代城市景观的特点和创作实践,阐述了中国古典园林理水的继承与发展,以期探索既符合当代城市发展理念,又具有中国传统文化底蕴的现代水景设计方法。