带延迟索赔和随机收入的离散风险模型的Gerber-Shiu分析（英）

破产理论是保险数学中的重要问题，它可以为保险公司决策者提供一个非常有用的早期风险预警手段．本文研究了一个带潜在延迟索赔和随机保费收入的复合二项风险模型．利用矩母函数的技巧，得到了 Gerber-Shiu 期望折罚函数的递推公式．特别地，还得到了贴现因子为 1 的特殊情形下的 Gerber-Shiu 期望折罚函数的解析表达式．最后还得到了实际应用中的一些重要的破产特征量，包括破产概率，破产时赤字的密度函数，破产前盈余与破产时赤字的联合密度函数，以及导致破产的索赔密度函数等．     

不同有机物对硝酸盐氮测试的影响

研究了红糖、葡萄糖、乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸、混合有机溶剂等10种不同有机物对麝香草酚光谱法和离子色谱法测试硝酸盐氮的影响。结果表明,溶液中含有红糖或葡萄糖时,均会对麝香草酚法测试硝酸盐氮造成影响,使得测试结果偏大;在无硝酸根离子存在时,红糖和葡萄糖的质量浓度与硝酸盐氮的测试浓度非线性相关;而乙酸钠、甲醇、乙醇、乙酸、丙酸、丁酸、正戊酸和混合有机溶剂则对麝香草酚法测试硝酸盐氮没有影响。实验发现,红糖和葡萄糖在浓硫酸的作用下与麝香草酚发生Molisch反应,形成有色复合物和红棕色不溶性沉淀。实验采用离子色谱法测试硝酸盐氮时,红糖和葡萄糖等糖类有机物对测试结果均无影响。     

Triglyceride-based thermosetting resins with different reactive diluents and fiber reinforced composite applications

Recently, there has been a growing research interest on renewable composite due to sustainability concerns. This work demonstrates the possibilities of bio-based reactive diluents and thermoset resin systems in composite applications from an engineering point of view. Formulating bio-based resins and monomers with different reactive diluents can tailor the physical and mechanical properties of the polymer system, allowing them to be suitable for different applications. In addition to the traditional reactive diluents, bio-based methacrylated fatty acid (MFA) was used in the formulations. Increasing the MFA content increases the toughness and the bio-based content of thermosetting polymers while reducing the hazardous air pollutant emissions. Composites panels with fiber glass and natural fiber reinforcement using selected bio-based resin formulations showed good mechanical properties and exhibited similar physical performance to parts made with commercial petroleum derived resins.     

A highly efficient nanostructured quinary photocatalyst for hydrogen production

Semiconductor photocatalysts play a crucial role when it comes to environmental issues such as global warming, pollutant degradation, fuel shortage, and energy crisis. In this paper, three nanostructured compound (3‐, 4‐, and 5‐component) semiconductor materials were synthesized through a facile one‐pot hydrothermal method, and were applied as alloy photocatalysts to generate hydrogen fuel via a water photo‐splitting process. Nitrogen adsorption–desorption isotherms revealed that the synthesized materials were all mesoporous and the highest surface area was witnessed for Ag‐doped quinary photocatalyst, viz. Cd_0.1Zn_0.87Sn_0.01Ag_0.01S (CZTSS). This heterogeneous photocatalyst exhibited a maximum performance in evolving hydrogen gas. The superiority of CZTSS was justified in terms of its greater surface area, higher conduction band and its silver plasmon resonance, enhancing the light absorption at long wavelengths. Field emission scanning electron microscopy revealed a spectacular nanostructure for this photocatalyst that was comprised of nanoparticles, platelets, and microspheres attached together. Energy dispersive X‐ray (EDX) analyses of the CZTSS also proved the synthesis of the quinary photocatalyst, having different compositions in distinct zones. Copyright © 2014 John Wiley & Sons, Ltd.     

改性防护蜡对轮胎胎侧胶性能的影响

研究改性防护蜡对轮胎胎侧胶性能的影响。结果表明,与传统防护蜡相比,改性防护蜡异构烷烃质量分数较小,结晶尺寸小且致密程度高。改性防护蜡可在不影响胎侧胶硫化特性和物理性能的前提下,大幅提高胎侧胶抗喷霜性能,保证轮胎表面不受臭氧侵蚀,在防止裂纹产生的同时明显改善成品轮胎外观。     

端盖双滑块+斜顶3次复合抽芯机构注射模设计

针对塑件注射成型自动化实施困难问题， 设计了一副单点潜浇口、两板式2次开模注射模来解决这一难题。模具布局为1模2腔。模具中单腔的机构设置情况为：（1）定模侧，设计了一个油缸驱动的定模顶出机构；动模侧，设置了2个特殊的斜顶+滑块复合机构、1个万能斜顶机构、1个隧道滑块机构、及1个顶针顶出机构；（2）定模顶出机构由油缸驱动定模顶出板以驱动6根斜顶杆来对6个倒扣特征进行自动脱模；（3）2个特殊的复合机构分别为：双滑块+斜顶3次复合抽芯机构、单滑块斜顶两次抽芯机构；此2个机构的作用是，通过斜导柱驱动滑块，从而2次驱动滑块内的斜顶实施2次抽芯，来到达塑件局部区域多次多向抽芯的目的；（4）机构中，使用万能斜顶机构能有效减小模具高度尺寸；使用隧道滑块斜抽芯机构，动模一侧增加1次模板开模打开来驱动隧道滑块实施斜抽芯，能有效利用模具开模动力，降低模具制造成本。     

Pt-based trimetallic nanocrystals with high proportions of M (M=Fe,Ni) metals for catalyzing oxygen reduction reaction

For boosting oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs), a new type of multi-functional catalyst with high activity, high stability, and low cost has been designed and prepared by introducing high proportions of M (M = Fe, Ni) metals in Pt-based nanoparticles through a microwave-assisted polyol method, followed by thermal annealing process. A uniform dispersion of nanoparticles (5 nm) and a face-centered tetragonal (fct) phase improve the activity and stability of the Pt–Fe–Ni/C catalyst. Owing to differences in the surface energies of the alloying elements, Pt atoms with low surface energy have a tendency to segregate from the subsurface to the surface during the annealing. This tendency exposes the internal Pt atoms to the surface of the nanoparticles in the existence of high proportions of M metals, significantly improving the utilization of Pt. As a cathode catalyst, the Pt–Fe–Ni/C catalyst annealed at 675 °C with a mass activity of 0.73 A/mg_Pt, which is 3.5 times higher than that of the commercial Pt/C catalyst, exhibits an excellent half-cell performance. An accelerated durability test demonstrates that the prepared Pt–Fe–Ni/C-675 catalyst is more stable than the commercial Pt/C. The proposed multi-functional catalyst has great potential for PEMFCs and other applications.     

薄膜铂电阻元件稳定性测试与分析

高端军事应用环境对测温传感器提出了小结构、高精度、良好的长期稳定性等要求,采用溅射方式制备的薄膜铂电阻元件成为了首选。通过分析薄膜铂电阻元件的结构、工艺,探讨影响稳定性的主要因素,包括薄膜缺陷、杂质、电迁移、结构封装应用与温度应力等。选择薄膜铂电阻在水三相点下的电阻值作为稳定性的比较基准,设计了一款不大于3mK的高精度测试系统。通过对薄膜铂电阻元件进行高温电寿命试验和温度冲击试验,评估得出薄膜铂电阻元件长期稳定性达到10mK,满足设计需求。