Using the generalized interpolation material point method for fluid-solid interactions induced by surface tension

This thesis is devoted to the development of new, Generalized Interpolation Material Point Method (GIMP)-based algorithms for handling surface tension and contact (wetting) in fluid-solid interaction (FSI) problems at small scales. In these problems, surface tension becomes so dominant that its influence on both fluids and solids must be considered. Since analytical solutions for most engineering problems are usually unavailable, numerical methods are needed to describe and predict complicated time-dependent states in the solid and fluid involved due to surface tension effects. Traditional computational methods for handling fluid-solid interactions may not be effective due to their weakness in solving large-deformation problems and the complicated coupling of two different types of computational frameworks: one for solid, and the other for fluid. On the contrary, GIMP, a mesh-free algorithm for solid mechanics problems, is numerically effective in handling problems involving large deformations and fracture. Here we extend the capability of GIMP to handle fluid dynamics problems with surface tension, and to develop a new contact algorithm to deal with the wetting boundary conditions that include the modeling of contact angle and slip near the triple points where the three phases -- fluid, solid, and vapor -- meet. The error of the new GIMP algorithm for FSI problems at small scales, as verified by various benchmark problems, generally falls within the 5% range. In this thesis, we have successfully extended the capability of GIMP for handling FSI problems under surface tension in a one-solver numerical framework, a unique and innovative approach.Chapter 1. Introduction -- Chapter 2. Using the generalized interpolation material point method for fluid dynamics at low reynolds numbers -- Chapter 3. On the modeling of surface tension and its applications by the generalized interpolation material point method -- Chapter 4. Using the generalized interpolation material point method for fluid-solid interactions induced by surface tension -- Chapter 5. Conclusions

Fiscal Decentralization,Corporate Investment Efficiency and Capital Allocation

文章从财政分权的角度出发,实证检验了财政分权、企业投资效率和资本配置的关系。研究发现:总体上,上市公司所在地财政分权度越高,企业过度投资或投资不足程度越低,即企业投资效率越高;相对于民营企业,地方财政分权程度对国有企业的投资和资本配置效率影响更显著,国有企业过度投资或投资不足程度越低;相对于中央国有企业,地方国有企业过度投资或投资不足程度越低。财政分权制下能有效降低企业过度投资或投资不足对公司价值造成的损害,使得企业投资更符合市场需求。进一步研究发现,财政分权制下形成有效的市场机制所带来融资约束的缓解和企业内部第一类、第二类代理成本的降低,是促进地方上市公司投资效率提高的重要原因。From the perspective of fiscal decentralization,this paper empirically tests the relationship of fiscal decentraliza-tion,corporate investment efficiency and capital allocation. The study shows that:In general,the higher the degree of fiscaldecentralization in the location of the listed company,the lower the degree of corporate overinvestment or underinvestment,and the higher the corporate investment efficiency;Compared with private enterprises,the degree of local fiscal decentraliza-tion has a more significant impact on investment and capital allocation efficiency of state-owned enterprises,the level of over-investment or underinvestment of state-owned enterprises is lower;Compared with central state-owned enterprises,the levelof overinvestment or underinvestment of local state-owned enterprises is lower. The fiscal decentralization system can effec-tively reduce the damage of corporate overinvestment or underinvestment to corporate value,and make corporate investmentmore to meet the market demand. The further study indicates that the effective market mechanism under the fiscal decentraliza-tion system,which brings about the mitigation of financing constraints and reduces the first and second types of agency costsinside enterprises,is an important reason for promoting the improvement of investment efficiency of local listed companies.厦门大学社会科学基金项目(10zd&036

Necessity of treating subclinical hypothyroidism in early pregnant women

目的评估早孕妇女亚临床甲状腺功能减退症(subclinical hypothyroidism,SCH)对妊娠结局的影响及药物治疗的必要性。方法收集18 243例在厦门大学附属第一医院产前检查直至分娩的病例,诊断标准为妊娠10~12周产前检查时TT4与FT4正常而TSH≥2.5 m IU/L为SCH,甲状腺过氧化物酶抗体(thyroid peroxidase antibody,TPOAb)≥34 U/L为阳性。根据TSH的升高程度不同、TPOAb情况、能否遵医嘱按时按量服用L-T4使TSH控制在正常范围内进行分组:2.5 m IU/L≤TSH≤5.0 m IU/L且TPOAb阳性且能遵医嘱者为A组,不能遵医嘱者为B组;TSH>5 m IU/L且TPOAb阳性且能遵医嘱者为C组,不能遵医嘱者为D组;2.5 m IU/L≤TSH≤5.0 m IU/L且TPOAb阴性且能遵医嘱者为F组,不能遵医嘱者为G组;TSH>5 m IU/L且TPOAb阴性且能遵医嘱者为H组,不能遵医嘱者为K组。并随机抽取200例同期甲状腺功能正常的病例作为对照组(E组),回顾分析早孕妇女甲状腺功能异常的发生率、SCH对妊娠结局的影响、早孕妇女SCH行左旋甲状腺素片(L-T4)替代治疗的剂量及影响因素。结果早孕妇女SCH检出率为5.20%,甲状腺功能正常率为79.00%。A组早产3.31%(8/242)、妊娠期高血压7.02%(17/242)、胎儿生长受限7.02%(17/242)、出生低体质量儿6.61%(16/242)的发生率均低于B组的8.79%(8/91)、14.29%(13/91)、15.38(14/91)、14.29(13/91)(P均 5 m IU / L,TPOAb was positive and had good compliance; Group D: TSH and TPOAb as Group C but not have good compliance; Group F: 2. 5 m IU / L≤TSH≤5. 0 m IU / L,TPOAb was negative and had good compliance; Group G: as Group F,but not have good compliance; Group H: TSH > 5 m IU / L,TPOAb was negative and had good compliance; Group K: as Group H,but not have good compliance. Randomly selected 200 cases with normal thyroid function at the same period as the control group( Group E). Retrospective analysis the occurrence rate of thyroid gland dysfunction,the influence of SCH to pregnancy outcome,the doses and influencing factors of replacement therapy by L-T4 to SCH of early pregnant women. Results Relevance ratio of SCH in early pregnant women was5. 20%,the ratio of normal thyroid function was 79. 00%. In group A,premature birth 3. 31%( 8 /242),gestational hypertension 7. 02%( 17 /242),fetal growth restriction 7. 02%( 17 /242),low birth weight infant 6. 61%( 16 /242),were lower than that in group B 8. 79%( 8 /91),14. 29%( 13 /91),15. 38( 14 /91),14. 29( 13 /91) respectively( P < 0. 05). In group C,spontaneous abortion 3. 31%( 6 /181),premature birth 3. 89%( 7 /181),gestational hypertension 8. 29%( 15 /181),gestational diabetes mellitus 3. 89%( 7 /181),fetal growth restriction 7. 73%( 14 /181),low birth weight infant 6. 63%( 12 /181),were lower than that in group D 11. 54%( 6 /52),11. 54%( 6 /52),19. 23%( 10 /52),11. 54%( 6 /52),17. 31( 9 /52),15. 38( 8 /52)( P < 0. 05). No significant statistical difference were found in multiple comparison of the above six indexes of group A,B,C. And just the same as the multiple comparison of group F,G,H,K,E. When TSH reach the standard,the dosage of L-T4 in group A and C had significant difference [( 0. 757 ± 0. 378 vs. 1. 106 ± 0. 454) μg / kg,t = 8. 39,P < 0. 001]. There were also significant differences of group F compared with group H[( 0. 443 ± 0. 198 vs. 0. 813 ± 0. 378) μg/kg,t = 8. 22,P < 0. 001],group( A + F) compared with group( C + H) [( 0. 634 ± 0. 358 and 1. 017 ±0. 427) μg / kg,t = 11. 77,P < 0. 001],group A compared with group F [( 0. 757 ± 0. 378 vs. 0. 443 ± 0. 198) μg / kg,t = 9. 85,P < 0. 001 ],group C compared with group H [( 1. 106 ± 0. 45 vs. 0. 813 ± 0. 378) μg / kg,t = 5. 59,P < 0. 001],group( A + C) compared with group( F + H) [( 0. 932 ±0. 463 vs. 0. 693 ± 0. 388) μg / kg,t = 6. 53,P < 0. 001]. Conclusion The early pregnant women with SCH and TPOAb positive could increase the occurrence rate of spontaneous abortion,premature birth,gestational hypertension,gestational diabetes mellitus,fetal growth restriction and low birth weight infant. The early intervening treatment of L-T4 could efficiently decrease the adverse event occurrence ratio of pregnant woman with SCH and positive TPOAb,but no effect for that with SCH and TPOAb negative. The TSH level and condition of TPOAb could affect the replacement therapy dosage of early pregnancy with SCH

First order least squares method with weakly imposed boundary condition for convection dominated diffusion problems

We present and analyze a first order least squares method for convection dominated diffusion problems, which provides robust L2 a priori error estimate for the scalar variable even if the given data f in L2 space. The novel theoretical approach is to rewrite the method in the framework of discontinuous Petrov - Galerkin (DPG) method, and then show numerical stability by using a key equation discovered by J. Gopalakrishnan and W. Qiu [Math. Comp. 83(2014), pp. 537-552]. This new approach gives an alternative way to do numerical analysis for least squares methods for a large class of differential equations. We also show that the condition number of the global matrix is independent of the diffusion coefficient. A key feature of the method is that there is no stabilization parameter chosen empirically. In addition, Dirichlet boundary condition is weakly imposed. Numerical experiments verify our theoretical results and, in particular, show our way of weakly imposing Dirichlet boundary condition is essential to the design of least squares methods - numerical solutions on subdomains away from interior layers or boundary layers have remarkable accuracy even on coarse meshes, which are unstructured quasi-uniform

Making and identifying optical superposition of very high orbital angular momenta

We report the experimental preparation of optical superpositions of high orbital angular momenta(OAM). Our method is based on the use of spatial light modulator to modify the standard Laguerre-Gaussian beams to bear excessive phase helices. We demonstrate the surprising performance of a traditional Mach-Zehnder interferometer with one inserted Dove prism to identify these superposed twisted lights, where the high OAM numbers as well as their possible superpositions can be inferred directly from the interfered bright multiring lattices. The possibility of present scheme working at photon-count level is also shown using an electron multiplier CCD camera. Our results hold promise in high-dimensional quantum information applications when high quanta are beneficial.Comment: Submitted for publication consideration (4 figures

“僵尸企业”问题研究

关于\"僵尸企业\"的识别尚未有统一权威的方法,既有学术标准,也有国内定义。总体来看,\"僵尸企业\"的普遍特征是企业生产经营持续不景气、企业融资风险高、企业外部依赖性强。许多理论模型从银行的微观行为解释了\"僵尸企业\"的形成原因。本文从宏观层面,首先对\"僵尸企业\"的定义进行了界定,并基于\"僵尸企业\"的普遍特征,测算了我国上市公司的\"僵尸企业\"规模情况。结果显示,采矿业、交通运输业、农林牧渔业、批发零售业、制造业、住宿餐饮业等传统行业的\"僵尸企业\"占比较高。从省份来看,一些资源型省份和中西部省份的\"僵尸企业\"占比较高,均高于10%。最后,本文通过研究日本处置\"僵尸企业\"的经验,提出有关我国处置\"僵尸企业\"的政策建议。国家自然科学基金青年项目(项目批准号:71703165)的资

港珠澳大桥对香港、澳门、珠海房地产业的影响分析

港珠澳大桥的建成贯通,对于粤港澳大湾区的建设及香港、澳门、珠海房地产业的发展,是一个极大的推动。通过以房地产业为对象进行研究,将香港、澳门、珠海分为两两一组,引入空间引力模型,通过构建香港&mdash;澳门,香港&mdash;珠海与澳门&mdash;珠海的房地产业空间相互作用模型,分别分析两城市间房地产业的相互影响力。分析结果表明:港珠澳大桥开通后,香港、澳门和珠海两两城市间房地产业的空间相互影响力大大增强。对于香港&mdash;澳门和香港&mdash;珠海而言,港珠澳大桥对澳门、珠海房地产业的影响力大于香港,澳门、珠海的房地产业辐射范围会更大,对香港居民的吸引力更强

Toxic effects C60 fullerene derivatives on zebrafish embryos and molecular mechanisms

纳米科技已经成为21世纪前沿科学技术的代表领域之一，纳米材料应用日益普遍。富勒烯及其衍生物又因为它们特有的物理化学性质，在各个领域,特别是在生物医药领域的应用越来越广泛，环境中暴露几率的提高使得富勒烯衍生物潜在的毒理学效应评价十分必要。本论文以斑马鱼为模式生物，研究不同功能基团修饰的富勒烯衍生物暴露下斑马鱼胚胎的毒性效应，并阐明了不同功能基团修饰的C60衍生物诱导斑马鱼胚胎毒性的机制较全面的评估了不同富勒烯衍生物的胚胎毒性，为今后合理设计具有较好生物相容性的富勒烯衍生物，拓展其生物学应用提供科学理论依据。主要研究内容和实验结果如下： 1.合成了三种富勒烯衍生物：羟基C60衍生物，乙二胺C60...Nanotechnology has become one of the frontier of the science and technology in the 21st century, nanomaterials have exhibited a wide and increasing range of applications. The most extensively used nanoparticles among these engineered nanomaterials are fullerenes and its derivatives, due to their unique physical and chemical properties. The environmental exposure risk of fullerene derivatives makes...学位：理学硕士院系专业：材料学院_生物医学工程学号：3142012115006

A Study on the Practical Issues of the Chinese Criminal Pretrial Conference System

刑事庭前会议作为新刑事诉讼法的突破点，旨在通过庭审中断问题的解决，较大程度地提高庭审效率。制度实行以来，各地法院都积极探索实践，许多司法机关也联合出台了相关工作机制性文件，但不规范不统一地适用使实务中有诸多困惑。目前我国刑诉法及司法解释中对刑事庭前会议制度的规定较粗陋，仅有寥寥数语。作为一个新设立的制度，它的相关规定和适用的确存在很多问题，需要不断完善。本文拟在对刑事庭前会议法律规定和实践运作分析的基础上，探讨庭前会议适用范围、主体、内容、效力等相关方面的完善。 文章主要分四部分对刑事庭前会议制度做探讨。 第一部分概括了刑事庭前会议制度。文章首先介绍了刑事庭前会议的立法背景。然后对刑事庭前...The criminal pretrial conference as the new breakthrough of criminal procedure law, designed to solve the problem of trial interrupt for greatly improving the efficiency of the trial. Many courts actively practice the criminal pretrial conference. Many judicial organs jointly issued relevant working mechanism files. The application without specification makes a lot of confusion in practice. At pre...学位：法律硕士院系专业：法学院_法律硕士学号：X201112003

Design and Implementation of OA System for aGrassroots Geological Team

改革开放以来，我国的IT技术、网络通讯技术、多媒体技术等信息技术呈现出跨越式发展的良好态势，信息化已然成为企业最为重要的竞争力要素。作为企业信息化过程中不可或缺的OA系统建设同样越发受到重视，其开发的前景性和紧迫性日益突显。研究如何利用一系列的现代化办公设备和先进的网络通讯技术，基于工作流概念，建成全面、高效、安全的信息处理和使用系统（即OA系统），打破“信息孤岛”模式引发的内部协同管理的瓶颈，帮助企业切实提高科学管理和决策服务的效率，有着十分重要的现实意义。 本文基于某基层地质勘查单位内部管理及业务发展需要，在可行性分析的基础上，应用成熟的计算机技术和Internet技术，为该单位开发OA...Since the reform and opening up,China's IT technology, network communication technology, and multimedia technology were surging forward with great momentum. Informatization has become the most importantfactor of enterprises’ competitiveness. As an essential part of enterprises’ informatization process, the OA system construction also gets more and more attention. The prospect of its development an...学位：工程硕士院系专业：软件学院_工程硕士(软件工程)学号：X201323049