微波加热对叶绿素水溶液的影响

本文通过对叶绿素水溶液进行微波加热,分析微波加热对叶绿素水溶液的温度、色度、叶绿素含量的影响。结果表明,微波加热处理的水溶液温度显著高于对照沸水浴,1~2 min时,1000 W功率下的水溶液温度显著高于200 W(P<0.05)。与沸水浴相比,微波加热显著降低了叶绿素水溶液的绿色程度,且高功率微波加热显著加剧了水溶液亮度的变化。200 W微波加热使水溶液中叶绿素a、b含量降低,但1000 W微波加热则提高了水溶液中叶绿素a、b含量。     

Internal habits formation and optimality

In a very influential model with internal habits, Carroll et al., (2017, 2000), establish that an increase in economic growth may cause a positive change in savings. The optimality of this result, and of many other contributions using a similar framework, has been questioned by some authors who have observed that the parametrization used in these models always implies a utility function not jointly concave in consumption and habits. In this paper, we revisit the optimality issue and, using advanced techniques in Dynamic Programming, we answer the following long-standing open questions: (i) Is the solution found in Carroll et al., (2017, 2000) optimal? (ii) Is it also unique or do other optimal solutions exist?     

NTRU格上高效的身份基线性同态签名方案

针对现有的格上身份基线性同态签名方案密钥存储量大、结构复杂导致方案实际运行效率相对偏低的问题，提出了一个NTRU（Number Theory Research Unit）格上高效的身份基线性同态签名方案。首先在密钥生成阶段利用NTRU密钥生成算法产生主密钥，接着采用格基委派算法给出身份签名私钥，最后运行NTRU格上原像抽样算法产生出线性同态签名。对方案的安全性证明与性能分析结果表明，新方案满足正确性，具有弱内容隐私性。在随机预言机模型下，该方案在小整数解问题困难性条件下满足适应性选择身份和选择消息的存在性不可伪造性。同时，由于采用NTRU格的特殊结构，新方案在密钥量与运行效率方面与已有方案相比较均具有显著的优势，这对于计算资源受限环境的同态认证中具有重要的应用价值。     

新一代车险“理赔难”

保险作为现代服务行业之一,服务质量问题始终贯穿其中。其中,“理赔难”的现象层出不穷。从1929年11月在中国上海成立第一家保险公司太平保险,到目前保险行业已发展90余年,中国的车险理赔还难吗?依然难,只是难点变了,老矛盾得到部分解决,新矛盾层出不穷,唯独对理赔服务质量的评价参差不齐是永恒的。     

中小规模民营经济体提高理财能力解决方案探讨--基于转型中的民营企业提高理财能力的必要性以其“系统工程”模式的解决方案

在深化改革、开放的总体思路下,市场逐步迈向国际化。众多中小型民营资本普遍存在的理财管理能力不足问题,成为制约其成功转型调整和进入国际化市场的障碍。带着这一问题,通过大深度社会调研活动,汲取被调查企业理财经营成功经验,并借助他们从理论到实践的丰富积累,把脉中小民营企业会计理财能力方面的先天不足如：家族化、创业者强势经营模式等和后天营养不良方面典型问题成因,经过整理分析,总结归纳适合民营经济体特点兼顾当前经济调整环境具备新意特征的理财方法三个、管理理念一个、理财概念一个、系统性理财模式一个。旨在针对普遍性问题,结合中小民企会计实际专业知识教育程度,侧重借鉴社会上其他企业类型会计理财方面成功经验,从实用学术角度加以转化探讨。     

电源SPD检测中连接线问题的解决方法

在日常SPD检测过程中,经常会遇到SPD两端连接线问题而达不到国家规范要求的情况。本文针对现场检测SPD遇到的问题,分析SPD接线方式对防雷效果的影响,提出解决方法。     

Optimal harvesting of a spatial renewable resource

In this paper we investigate the optimal harvesting of a renewable natural resource. While in most standard approaches the resource is located at a single point, we allow the resource to be distributed spatially. Consequently, an agent who exploits the resource has to travel from one location to another. For a fixed planning horizon, we investigate the speed and the path of harvesting chosen by the agent. We show that the agent adjusts this speed so as to visit each location only once, even in the absence of travelling cost. Since the agent does not return to any location for a second harvest, it is optimal to fully deplete the resource upon arrival. A similar type of bang–bang solution results when we drop the assumption of a constant harvesting rate: allowing for a variable harvesting rate, the agent chooses to fully exploit the resource either in the last or in the first travelling period. A society interested in conserving some of the resource thus has to take measures to limit the exploitative behaviour of the agent.     

Complex Network of Aviation E-Services in the Belt and Road Initiative: A Heuristic Study of Small Data based on Block Modeling

ABSTRACT

The aviation e-service system is an important part of support for business communication in regions covered by Belt and Road initiative. In exploring the role of airline companies in this system, we examine the structure of the network, which consists of airlines interconnections based on small data of individual attributes of aviation companies in aviation e-services, and study these interconnections across different groups using block modeling. The heuristic solution of airline companies in development of international communication and cooperation is further discussed. Among our policy implications for global managers, we suggest the enhancement of cross-regional cooperation among airlines.     

EMPIRICAL PERFORMANCE OF GARCH MODELS WITH HEAVY‐TAILED INNOVATIONS

We introduce a new type of heavy‐tailed distribution, the normal reciprocal inverse Gaussian distribution (NRIG), to the GARCH and Glosten‐Jagannathan‐Runkle (1993) GARCH models, and compare its empirical performance with two other popular types of heavy‐tailed distribution, the Student's t distribution and the normal inverse Gaussian distribution (NIG), using a variety of asset return series. Our results illustrate that there is no overwhelmingly dominant distribution in fitting the data under the GARCH framework, although the NRIG distribution performs slightly better than the other two types of distribution. For market indexes series, it is important to introduce both GJR‐terms and the NRIG distribution to improve the models’ performance, but it is ambiguous for individual stock prices series. Our results also show the GJR‐GARCH NRIG model has practical advantages in quantitative risk management. Finally, the convergence of numerical solutions in maximum‐likelihood estimation of GARCH and GJR‐GARCH models with the three types of heavy‐tailed distribution is investigated.     

Identifying R&D partners through Subject-Action-Object semantic analysis in a problem & solution pattern

Today’s companies still rely heavily on expert knowledge rather than quantitative data with a systematic approach to effectively identify and choose Research and Development (R&D) partners. It is advantageous to identify and select potential R&D partners using a Problem & Solution (P&S) pattern. This paper presents a novel process for identifying R&D partners on the basis of solution similarities that assist technology managers in understanding the relationships between research targets. First, we choose a thematic dataset that contains problems and quantitative data with relative topic terms. Then, we extract Subject-Action-Object semantic structures in a P&S pattern from the dataset, and identify various solutions to a technical problem, with each as a subject. In addition, we provide correlation mapping to visualise the text characters and identify R&D partners. Finally, we validate the proposed method through a case study of the dye-sensitized solar cells sector.