A1Ⅱ离子3snp^1p1序列能级辐射寿命的非单调变化

本文考虑了一价铝离子双激发干扰态３ｐ４ｓ＾１ｐ１＾０对ｓｎｐ＾１Ｐ１＾０Ｒｙｄｂｅｒｇ序列的强相互作用，多组态ＨＦＲ自洽场方法计算了Ａ１Ⅱ３ｓｎｐ＾１Ｐ１０（ｎ＝３－１０）序列能级的辐射寿命，与已有的实验和理论计算结果进行了比较，结果表明该序列能级寿命随主量子数ｎ呈现非单调变化。     

一类随机利率模型下的年金精算现值

年金在日常生活中被广泛应用,但已往大多研究的是固定年金以及随机利率下的确定年金.本文在前人研究成果的基础上考虑了利率随机波动对生命年金的影响,运用随机利率模型,得出年金精算现值较为简单的递推关系式,并举例说明利率的随机波动对年金精算现值的影响程度,结果表明利率的波动对年金的定价影响非常大,绝对不容忽视.     

Life—a complex polymer system

After a discussion of the different levels of macromolecules, the phenomenon of life is regarded as a complex polymer system. The thermodynamic basis of general system theory is explained as well as the character of system laws. The important notion of emergent system properties is stressed, and life is explained as a system property of a sufficiently complex system. The general applicability of the systemic approach is pointed out, and some examples are provided. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 471–478, 2004     

运动对小白鼠乳酸脱氢酶(LDH)同工酶的影响初探

经总酶活性测定和凝胶电泳图谱分析发现:剧烈运动后,小白鼠六种组织LDH总酶活性,骨骼肌有显著升高,(p<0.05),其余五种组织均变化不显著;心肌、骨骼肌、肾脏的M型LDH相对活性显著升高(P<0.05),而H型LDH相对活性显著下降(p<0.05);相应地,A亚基比例显著升高,B亚基比例显著下降,这种变化似能反应剧烈运动对小白鼠厌氧代谢的明显影响.     

某型激光测距系统可靠性预计

在试验数据有限的情况下，通过分析激光测距系统工作模式和建立系统可靠性模型解决了小批量、复杂的某型激光测距系统可靠性评价问题。根据以前相似产品的试验数据，采用相似电路法对系统可靠性进行预计。根据激光晶体、染料片、全反射镜、聚光腔等元器件的寿命，对激光器寿命进行预计，并在实际使用中得到了验证。这对系统设计和使用具有重要参考作用。     

芯片封装焊球连接疲劳寿命预测分析--能量法和有效应变法之比较

研究了目前常用的两种芯片封装焊球连接的寿命预测方法一能量法和有效应变法。对焊球连接的材料本构关系进行了对比分析，并利用FORTRAN语言编制了相应的材料本构模型子程序，将其与有限元仿真工具ANSYS耦合，实现了将焊球连接的材料本构模型用户子程序导入到ANSYS的材料库。在此基础上模拟了三维芯片叠层球栅阵列尺寸封装的焊球结构，在热循环条件下(-40～ 125℃的工作状态，并分别利用能量法和有效应变法对焊球连接的寿命预测进行了比较分析，最后对两种方法作出了评价。     

OPTIMUM GROWTH AND REPRODUCTION SCHEDULES FOR FOREST TREES

A control theory optimization of iteroparous life histories indicates that if growth and reproduction are nonlinear functions of energy allocations, graded allocations of energy to potential reproduction can be optimal.     

各向异性损伤力学在螺纹疲劳寿命预估中的应用

引用损伤力学方法研究金属构件疲劳问题。在微结构力学模型基础上建立轴对称的各向异性疲劳损伤本构关系,通过有限元-附加力解法编制考虑各向异性损伤的有限元程序。应用引入门槛条件的损伤演化方程,并以损伤划分步长预估了构件疲劳裂纹形成与扩展寿命。用这一方法预估30CrMnSiNi2Aφ5和φ8螺栓全寿命。结果表明,理论S-N曲线与试验S-N曲线吻合良好并且门槛条件对修正低应力下疲劳寿命有很好的效果。本方法所需机时较少,可用于工程实际构件的高周疲劳寿命预估及抗疲劳优化设计。     

A High‐Voltage and Ultralong‐Life Sodium Full Cell for Stationary Energy Storage

Recently, there has been great interest in developing advanced sodium‐ion batteries for large‐scale application. Most efforts have concentrated on the search for high‐performance electrode materials only in sodium half‐cells. Research on sodium full cells for practical application has encountered many problems, such as insufficient cycles with rapid capacity decay, low safety, and low operating voltage. Herein, we present a layered P2‐Na_0.66Ni_0.17Co_0.17Ti_0.66O₂, as both an anode (ca. 0.69 V versus Na⁺/Na) and as a high‐voltage cathode (ca. 3.74 V versus Na⁺/Na). The full cell based on this bipolar electrode exhibits well‐defined voltage plateaus near 3.10 V, which is the highest average voltage in the symmetric cells. It also shows the longest cycle life (75.9 % capacity retention after 1000 cycles) in all sodium full cells, a usable capacity of 92 mAh g^?1, and superior rate capability (65 mAh g^?1 at a high rate of 2C).     

Modeling mechanical properties of polyhydroxyalkanoate during degradation in animal tissue

Polyhydroxyalkanoates (PHAs) are a family of biodegradable and biocompatible polymers produced by several species microorganisms that possess favorable mechanical properties (e.g. strength and elongation properties). Different types of PHA polymers have been used in medical applications. However, in order to better understand the use of this polymer in the different applications, a thorough understanding of the kinetics of in vivo degradation is one of the major requirements. In this study, poly(3‐hydroxybutyrate) (PHB) was subcutaneously implanted in mice and incubated for 2, 4, 8, or 16 weeks. After removal from the animal, the strength, elongation, mass loss, and enthalpy of the PHB were tested for each time point. From these data, a mathematical model was generated by Rayleigh's method of dimensional analysis, where polymer strength over tissue contact time could be predicted. To prove the model, previous data obtained by our group were used: poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) [P(HB‐co‐HHx)] incubation in the presence of human embryonic kidney cells (HEK). It was found that the developed model was aligned with experimental results, could predict the strength of the polymer when in contact with cells, and the predicted strength follows the trend of the experimental data. Also, the dimensionless constant (K) value associated with the model is different for both experiments, where this constant, produced via experimental data, is used for construction of a homogeneous equation. Copyright © 2017 John Wiley & Sons, Ltd.