检索结果-南通市图书馆

冲击点火反应过程中RDX基PBX炸药的热辐射特性

在线全文

学校读者我要写书评

暂无评论

高压物理学报 2025年第1期39卷 011301-1-011301-9页

作者：施鑫辉杨雷杨雪康洪亮袁文硕刘福生西南交通大学物理科学与技术学院高温高压物理研究所四川成都　610031

研究冲击波流场中聚合物黏结炸药的热辐射特性可能是获取相关物质组分温度数据的重要途径。利用二级轻气炮加载技术、瞬态辐射测温方法及粒子速度剖面测量技术，探讨了聚合物黏结炸药/氟化锂窗口界面的热辐射特性及其与界面压力之间的... 详细信息

研究冲击波流场中聚合物黏结炸药的热辐射特性可能是获取相关物质组分温度数据的重要途径。利用二级轻气炮加载技术、瞬态辐射测温方法及粒子速度剖面测量技术，探讨了聚合物黏结炸药/氟化锂窗口界面的热辐射特性及其与界面压力之间的相关性;同时，还优化了聚合物黏结炸药样品制备方法，显著抑制了包裹气体和界面间隙发光背景，给出了界面辐亮度数据及界面温度数据。结果表明，在连续2次冲击加载过程中，界面温度随时间衰减特征与反应产物的等熵膨胀行为密切相关，界面温度反映了界面处产物温度的演化行为，为直接观测点火反应和起爆释能期间非均质复合炸药的反应产物温度数据提供了一种可行的技术途径。

关键词：聚合物黏结炸药冲击加载界面热辐射点火反应等熵膨胀界面温度

Equidistribution of Expanding Translates of Curves in Homogeneous Spaces with the Action of(SO(n,1))^(k)

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2022年第1期38卷 205-224页

作者： lei yang College of Mathematics Sichuan UniversityChengdu 610000P.R.China

Let X=G/Γbe a homogeneous space with ambient group G containing the group H=(SO(n,1))^(k)and x∈X be such that Hx is dense in *** an analytic curve?:I=[a,b]→H,we will show that ifφsatisfies certain geometric condition,then for a typical diagonal subgroup A={a(t):t∈R}■H the translates{a(t)?(I)x:t>0}of the curve?(I)x will tend to be equidistributed in X as t→+∞.The proof is based on Ratner's theorem and linearization technique.

关键词： Equidistribution homogeneous spaces Ratner's theorem

An Inner Product Formula on Two-dimensional Complex Hyperbolic Space

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2011年第11期27卷 2285-2300页

作者： lei yang Department of Mathematics Peking University Beijing 100871 P. R. China

We study the Eisenstein series for a convex cocompact discrete subgroup on a two-dimen- sional complex hyperbolic space Hc^2. We find an inner product formula which gives the connection between Eisenstein series and automorphic Green functions on a two-dimensional complex hyperbolic space HC^2. As an application of our inner product formula, we obtain the functional equations of Eisenstein series.

关键词： Eisenstein series automorphic Green functions functional equations

New concept for ADS spallation target: Gravity-driven dense granular flow target

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第10期58卷 1705-1711页

作者： yang lei ZHAN WenLong Institute of Modern Physics Chinese Academy of Sciences

For the Chinese-ADS project, to provide enough neutrons to drive the subcritical system, tens of MW spallation targets for the C-ADS are necessary. This is not an easy task. Here we propose a new concept for a gravity-driven dense granular flow target, in which heavy metal grains are chosen as the spallation target material. Compared with currently widely used targets, this conceptual design has advantages with regard to heat removal, thermal shock protection, neutron yield, radiotoxicity reduction, and convenient operation. The gravity-driven dense granular flow target has the potential to easily deal with these issues and to form a foundation for tens of MW spallation targets for cost-effective facilities. Preliminary simulations and experiments have been completed to support this conceptual design.

关键词： accelerator driven system spailation target dense granular flow

经皮椎体成形联合椎弓根强化治疗重度骨质疏松性椎体骨折的有限元分析

在线全文

学校读者我要写书评

暂无评论

中国组织工程研究 2025年第15期29卷 3089-3094页

作者：李红桃潘泓宇雷杨肖常明西南医科大学附属中医医院脊柱外科四川省泸州市646000

背景:椎弓根内骨水泥灌注联合椎体成形已被用于治疗Kummell病和椎弓根溶骨性转移瘤等疾病,但该手术方式对相邻椎体及椎间盘的影响尚不明确。目的:应用三维有限元模型探讨经皮椎体成形联合椎弓根强化术治疗重度骨质疏松性椎体骨折对邻近... 详细信息

背景:椎弓根内骨水泥灌注联合椎体成形已被用于治疗Kummell病和椎弓根溶骨性转移瘤等疾病,但该手术方式对相邻椎体及椎间盘的影响尚不明确。目的:应用三维有限元模型探讨经皮椎体成形联合椎弓根强化术治疗重度骨质疏松性椎体骨折对邻近节段椎体以及椎间盘相关生物力学的影响。方法:选择1位已完成经皮椎体成形联合椎弓根强化术的重度骨质疏松性椎体骨折(L1)女性患者,并提取其术前及术后的CT文件,研究范围为T_(12)-L_(2)(包括伤椎、邻近椎体和椎间盘)。通过Mimics、SolidWorks和Geomagic等软件分别建立了术前、术后三维脊柱功能单元的有限元模型。在T_(12)上终板垂直方向加载500 N力矩和10 N·m旋转力矩,模拟前屈、后伸、侧屈和旋转等运动方位,分析手术前后相邻节段椎体终板和椎间盘的应力变化情况。结果与结论:①成功建立了术前和术后脊柱功能单元的三维有限元模型;②通过计算得出,在模拟载荷下,术后T_(12)下终板应力分布更均匀且最大应力值减小,与术前相比无显著差异(P>0.05);术后L_(2)上终板应力分布更均匀且最大应力与术前无显著差异(P>0.05);同样,术后T_(12)/L_(1)、L_(1)/L_(2)椎间盘应力分布也更均匀且最大应力值均显著减小(P<0.05);③因此,经皮椎体成形联合椎弓根强化能够有效改善术后相邻椎体终板和椎间盘的应力分布,并能够减小应力,最终降低术后再骨折风险以及显著延缓椎间盘退变。

关键词：椎弓根强化骨质疏松性椎体骨折椎体成形应力有限元模型骨水泥

Extended finite element-based cohesive zone method for modeling simultaneous hydraulic fracture height growth in layered reservoirs

在线全文

学校读者我要写书评

暂无评论

Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2960-2981页

作者： lei yang Baixi Chen Hopkins Extreme Materials Institute Johns Hopkins UniversityBaltimoreMD21218USA School of Civil Engineering The University of SydneyNSW2006Australia Department of Mechanical Engineering University of Wisconsin-Madison1513 University AvenueMadisonWI53706-1572USA Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

In this study,a fully coupled hydromechanical model within the extended finite element method(XFEM)-based cohesive zone method(CZM)is employed to investigate the simultaneous height growth behavior of multi-cluster hydraulic fractures in layered porous reservoirs with modulus *** coupled hydromechanical model is first verified against an analytical solution and a laboratory ***,the fracture geometry(***,aperture,and area)and fluid pressure evolutions of multiple hydraulic fractures placed in a porous reservoir interbedded with alternating stiff and soft layers are investigated using the *** stress and pore pressure distributions within the layered reservoir during fluid injection are also *** simulation results reveal that stress umbrellas are easily to form among multiple hydraulic fractures’tips when propagating in soft layers,which impedes the simultaneous height *** is also observed that the impediment effect of soft layer is much more significant in the fractures suppressed by the preferential growth of adjoining *** that,the combined effect of in situ stress ratio and fracturing spacing on the multi-fracture height growth is presented,and the results elucidate the influence of in situ stress ratio on the height growth behavior depending on the fracture ***,it is found that the inclusion of soft layers changes the aperture distribution of outmost and interior hydraulic *** results obtained from this study may provide some insights on the understanding of hydraulic fracture height containment observed in filed.

关键词： Hydraulic fracturing Layered reservoir Simultaneous height growth In situ stress Fracture spacing Extended finite element method(XFEM) Cohesive zone method(CZM)

A closed nuclear energy system by accelerator-driven ceramic reactor and extend AIROX reprocessing

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2017年第11期60卷 1702-1706页

作者： yang lei ZHAN WenLong Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China

For the future energy system, we propose a new closed nuclear energy cycle system, which consists of an accelerator-driven external neutron source, a ceramic reactor and an extend AIROX reprocessing. The attractive features of this system are as follows. （l） The operating mode of the reactor is a combination of subcritical mode and critical mode. initially, the reactor would be driven by the accelerator external neutron source in subcritical mode. A few years later, the reactor would reach the critical mode, and then would operate for a long time. （2） Nuclear fuels, coolants, and structure materials in the ceramic reactor core are made up of ceramic with excellent thermodynamics properties and neutron performance. Therefore, the ceramic reactor has extremely inherent safety, good breeding performance and high power generation efficiency. （3） Fuel reprocessing uses an extend AIROX reprocessing, which is a simple high-temperature dry process and rarely involved in chemical process. In this reprocessing, only most of fission products are separated. Other isotopes, including uranium isotopes, transuranic nuclides and long-lived fission products, would re-enter the reactor as new fuels. Therefore, this closed nuclear energy system could be known as ADANES, short for Accelerator-Driven Advanced Nuclear Energy System, which can greatly improve the utilization rate of nuclear fuels, enhance the nuclear safety, reduce the nuclear proliferation and become a sustainable and low-carbon energy supply for thousands of years.

关键词： accelerator-driven neutron source ceramic reactor extend AIROX reprocessing closed nuclear energy system future energy system

Numerical Analysis on Nanoparticles-laden Gas Film Thrust Bearing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2013年第4期26卷 675-679页

作者： yang Zhiru DIAO Dongfeng yang lei Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi'an Jiaotong University Institute of Nanosurface Science and Engineering (INSE) Shenzhen University

Nanoparticles can be taken as additives and added into various fluids to improve their lubricating performances. At present, researches in this area are mainly concentrated on the improvement effects of nanoparticles on the lubricating performances of liquid such as oil and water. Nanoparticles will also affect gas lubrication, but few related studies have been reported. Nanoparticles-laden gas film (NLGF) is formed when adding nanoparticles into gas bearing. Then, the lubricating performances of gas bearing including pressure distribution and load-carrying capacity will change. The variations of pressure distribution and load-carrying capacity in nanoparticles-laden gas film thrust bearing are investigated by numerical method. Taking account of the compressibility of gas and the interactions between gas and nanoparticles, a computational fluid dynamics model based on Navier-Stokes equations is applied to simulate the NLGF flow. The effects of inlet nanoparticles volume fraction and orifice radius on film pressure distribution and load-carrying capacity of the NLGF are calculated. The numerical calculation results show that both of the film land pressure and the maximum film pressure both increase when the nanoparticles are added into gas bearing, and the film pressures increase with the rising of the inlet nanoparticles volume fraction. The nanoparticles have an enhancement effect on load-carrying capacity of the studied bearing, and the enhancement effect becomes greater as the film thickness decrease. Therefore, nanoparticles can effectively improve the lubricating performance of gas bearing. The proposed research provides a theoretical basis for the design of new-type nanoparticles-laden gas film bearings.

关键词： load-carrying capacity pressure distribution nanoparticles-laden gas film computational fluid dynamics

The Short-Duration Heavy Rainfall in Different Quadrants of Northeast China Cold Vortices

在线全文

学校读者我要写书评

暂无评论

Journal of Meteorological Research 2024年第2期38卷 321-338页

作者： lei yang Yongguang ZHENG Liaoning Meteorological Disaster Monitoring and Early Warning Center Shenyang 110166 National Meteorological Centre China Meteorological AdministrationBeijing 100081 China Meteorological Administration Tornado Key Laboratory Foshan 528315

The Northeast China cold vortex(NCCV)is one of the main synoptic-scale systems causing short-duration heavy rainfall(SDHR)in Northeast *** conditions(e.g.,water vapor,instability,and vertical wind shear)are known to be distinctly different over the four quadrants of NCCVs,rendering prediction of the SDHR related to NCCVs(NCCV_SDHR)more *** on 5-yr hourly rainfall observations from 3196 automatic weather stations and ERA5 reanalysis data,10,232 NCCV_SDHR events were identified and divided into four quadrant groups according to their relative position to the center of the NCCV(CVC).The results show that the southeast quadrant features the highest frequency of SDHR,with stronger intensity,longer duration,and wider coverage;and the SDHR in different quadrants presents different formation mechanisms and varied temporal evolution.A new coordinate system is established relative to the CVC that uses the CVC as the origin and the radius of the NCCV(r CV)as the unit *** this new coordinate system,all of the NCCV_SDHR events in the 5-yr study period are *** is found that the occurrence frequency of NCCV_SDHR initially increases and then decreases with increasing distance from the *** highest frequency occurs mainly between 0.8 and 2.5 times r CV from the CVC in the southeast *** can be attributed to the favorable conditions,such as convergence of the low-level shear line and abundant water vapor,which are concentrated in this ***,high-frequency NCCV_SDHR larger than 50 mm(NCCV_SDHR50)is observed to be closer to the *** NCCV_SDHR50occurs,the NCCV is in closer proximity to the subtropical high,resulting in stronger low-level convergence and more abundant water ***,there are lower lifting condensation levels and stronger 0-6-and 0-1-km vertical wind shears in these *** findings provide a valuable reference for more accurate prediction of NCCV_SDHR.

关键词： Northeast China cold vortex short-duration heavy rainfall statistical characteristics environmental conditions