资金约束下三层供应链的融资和定价决策研究

实际生活中,供应链的资金管理是极其复杂多变的,现有学者关于供应链定价问题研究多以简单的二层供应链为基础,脱离了实际可用性。本文将二层供应链拓展成三层供应链,以单一供应商、单一生产商和单一零售商组成的三层供应链为研究对象,在市场风险中性的假设条件下,探究在供应商拥有不同初始资金约束情形下的供应链融资与最优定价决策,弥补了原先模型使用范围的狭隘性。通过模型的建立与数值分析显示,当供应商存在资金约束时,供应链融资能够使整条供应链上参与者的最优利润增加,从而创造价值。     

新型带宽调制型Mott化合物的高压合成及其金属化相变

利用高温高压条件，制备了（SrCa）CrO3系列带宽可调型的钙钛矿Mort化合物。在10 GPa的外加压力下，观察到SrCrO3的绝缘体-金属化相变。原位高压x射线衍射实验表明，Sr／CaCrO3晶体结构在0-9 GPa压力范围内保持稳定。但SrCrO3在4 GPa时存在着电子结构变化所引起的等结构相变，表现为体弹性模量的反常软化。此外，由于电子关联效应，磁性和热输运性质的测试结果表明了材料的奇异电子态特征。     

基于以太网的分布式数据采集与双模式管理系统

针对HL-2M装置诊断设备中采集系统布局分散、信号容易衰减和被干扰的问题,提出了一种新颖的以太网分布式数据采集系统和管理方案。采集模块具有以太网接口,能够容易远距离分布式放置和接入局域网。集中管理系统运用多线程Socket网络通信技术,采用客户端/服务端双模式,分不同级别管理采集系统,实现数据采集、存储、上传与集中管理功能。在真实放电实验中测试表明,采集系统具有测量准确,抗干扰性能强,数据传输速度快,方便部署和管理的特点,能够满足等离子物理诊断系统的数据需求。     

High pressure synthesis and characterization of the pyrochlore Dy_2Pt_2O_7:A new spin ice material

The cubic pyrochlore Dy2Pt2O7 was synthesized under 4 GPa and 1000℃ and its magnetic and thermodynamic properties were characterized by DC and AC magnetic susceptibility and specific heat down to 0.1 K.We found that Dy2Pt2O7 does not form long-range magnetic order,but displays characteristics of canonical spin ice such as Dy2Pt2O7,including(1)a large effective moment 9.64μB close to the theoretical value and a small positive Curie-Weiss temperatureθCW=+0.77 K signaling a dominant ferromagnetic interaction among the Ising spins;(2)a saturation moment ~4.5μB being half of the total moment due to the local<111>Ising anisotropy;(3)thermally activated spin relaxation behaviors in the low(~1 K)and high(~20 K)temperature regions with different energy barriers and characteristic relaxation time;and most importantly,(4)the presence of a residual entropy close to Pauling’s estimation for water ice.     

Light scattering effect of submicro-textured Ag/Al composite films prepared at lower substrate temperatures

We present a new and practical approach for preparing submicro-textured silver and aluminum (Ag/Al) double-structured layers at low substrate temperatures. The surface texturing of silver and aluminum double-structured layers was performed by increasing the deposition temperature of the Al layers to 270℃. The highly submicro-textured silver and aluminum double-structured layers were prepared by thermal evaporation on quartz glasses and their surface microstructure, light scattering properties, and thermal stability were investigated. Results showed that the highly submicro-textured Ag/Al composite films prepared at low substrate temperatures used as back reflectors not only can enhance the light scattering and have good thermal stability, but also have good adhesion properties. In addition, their fabrication is low cost and readily carried out.     

英国化学思想史家大卫·奈特

随着化学史的逐步成熟,相应地,其研究内容日益丰富。其中,关于化学思想史的研究近年来在我国化学史界方兴未艾。在西方,由于化学史的成熟和化学史与社会学相联系的研究趋势,化学思想史已经成为化学史研究的一门重要分     

基于在险价值的物流网络规划模糊两阶段模型与精确求解方法

针对物流网络规划问题中顾客需求和运输成本的不确定性,使用在险价值量化投资风险,建立了以投资损失的在险价值最小化为目标的模糊两阶段物流网络规划模型。对于模型中不确定参数均为规则模糊数的这一类模糊两阶段规划模型,本文通过理论分析和证明将其转化为等价的确定一阶段规划模型进行求解,从而将无穷维的优化问题转化为有限维的经典优化问题,降低了计算难度且得到了模型的精确解。不同规模的数值实验证实了所提出模型及其求解方法的有效性。     

Synthesis, Crystal Structures and Characterization of Ba5LiTiNb9O30

A new niobate compound with the chemical composition of Ba5LiTiNb9O30 was synthesized by doping Li^ into the system BaO-TiO2-Nb2O5 in conventional solid state reaction method. The crystalline structure was determined by X-ray diffraction analysis (XRD). The results showed that crystal structure of Ba5LiTiNb9O30 belongs to tetragonal tungsten bronze structure with space group P4bm and its unit cell parameters: a=b=1.2512(2) nm, c=0.4008(5)nm. The microstructure of reaction products was observed by scanning electron microscopy (SEM).     

Highly sensitive torsion sensor based on Mach–Zehnder interference in helical seven-core fiber taper

We propose a high-sensitivity bidirectional torsion sensor using a helical seven-core fiber taper embedded in multimode fiber(MHSTM).Sensors with different taper waists and helical pitches are fabricated,and their transmission spectra are obtained and analyzed.The waist and length of the sandwiched seven-core fiber are finally determined to be 68 μm and3 mm,respectively.The experimental results show that the clockwise and counterclockwise torsion sensitivities of the proposed sensor are 2.253 nm...     

赣南清溪离子吸附型稀土矿元素迁移富集特征研究

离子吸附型稀土矿床是中国特有的稀土资源。对这一类型矿床及周边的地质环境,风化壳中稀土进行研究具有较高的产学研价值。本文通过对中国赣南典型稀土矿区花岗岩风化壳进行元素地球化学分析,并结合相关地球化学参数与图解,结果表明：研究区成矿花岗岩风化壳形成于强化学风化条件,发育成熟度高,处于晚期去Si阶段;稀土元素地球化学参数显示,风化壳整体的稀土配分特征主要继承于成矿母岩;稀土元素主要以离子交换态在风化剖面中迁移,并受pH值、微生物活动、氧化还原条件等多种因素控制。