Numerical investigation on heat transfer characterization of liquid lithium metal in pipe

Liquid Li metal is a promising nuclear reactor coolant; however, relevant research regarding its heat transfer characteristics remains insufficient. In this study, a steady-state two-dimensional mathematical model is established to describe the heat transfer process of liquid Li in a straight pipe. A numerical analysis is conducted to investigate the effects of inlet velocity, inlet temperature, and wall heat flux on heat transfer in liquid Li. The results indicate the advantage of using liquid Li for improving heat transfer at high inlet temperatures (> 1000 K) compared with using liquid sodium and lead–bismuth eutectic. Considering the mechanism of the outlet radial heat flow model, the ratio of turbulent to molecular diffusion coefficients presents a parabolic distribution along the radius of the pipe. Increasing the inlet velocity, decreasing the inlet temperature, and decreasing the wall heat flux can effectively weaken the dominant role of molecular heat transfer owing to the low Prandtl number of liquid Li. The heat transfer of liquid Li is investigated comprehensively in this study, and the results provide a basis for the practical application of liquid Li as a promising coolant.     

Comparison of Travel Mode Choice Between Taxi and Subway Regarding Traveling Convenience

In this study, we investigate travel mode choice behavior between taxi and subway with an emphasis on the influence of traveling convenience. In the first stage, we examine the Origin-Destination(OD) points of Beijing taxi trips and compare these locations with the respective nearest subway station. Statistics reveal several interesting conclusions. First, for approximately 24.89% of all trips, no convenient subway connections exist between the OD pairs. As such, a taxi becomes the only viable choice. Second, for 80.23% of the remaining 75.11%of trips(equivalent to 60.26% of all trips), access distance from either the origin or the destination to the nearest subway station is greater than 500 meters. This phenomenon indicates that walking distance plays an important role in travel mode choice. In the second stage, we examine groups of taxi trips with similar travel distances and travel times to reveal common features. We establish a preference rule in terms of travel distance and travel time.This determines whether an individual driver will take a taxi or the subway, using a pairwise comparison-based preference regression model. Tests indicate that more than 95% of taxi trips can be correctly predicted by this preference rule. This conclusion reveals that traveling convenience dominates the travel model choice between taxi and subway. All these findings shed light on the factors that influence travel mode choice behavior.     

统一碳税和差异化碳税下的再制造绩效评价

分别在无碳税、统一碳税和差异化碳税三种政策下,构建了垄断制造商的利润最大化决策模型,研究实施不同碳税政策对制造商的再制造生产决策、碳排放和社会福利的影响.研究表明:相比于无碳税政策,政府征收碳税减少了制造商的利润和碳排放,在一定条件下有利于提高社会福利;实施碳税政策有利于鼓励更多类型的制造商参与再制造,并且差异化碳税比统一碳税具有更大的灵活性.进一步地,结合理论比较和数值试验,研究了政府在统一碳税的基础上分别做单向和双向差异化碳税调整后的绩效变化情况,结论表明:统一碳税与差异化碳税不存在绝对占优的碳税形式.政府应根据再制造品特点、单位环境污染损失、统一碳税基准水平和调整幅度等特点,采取合理的碳税调整方式以优化社会福利.     

明清时代的鄱阳商业与商人

文章利用方志与墓志中的商业与商人史料,分析了明清时代鄱阳县本地商业状况与外来商帮构成,以及鄱阳商人的经营行业和商贸地域.透过商人的传记资料,可以看到士人为商人写传,大力肯定商人的志业,商人则高度认同士人所代表的儒学主流价值观;方志为商人立传,商人为桑梓与国家效力,体现的是士商之间、商人与国家和社会之间相得益彰、"美美与共"的良性互动.     

儿童最大利益原则与我国儿童权益保护制度的完善——从婚姻家庭法的角度

儿童最大利益原则作为一项国际通行保护儿童利益的原则不同于我国现存的儿童优先原则。我国作为《儿童权利公约》的缔约国,相关法律中不乏保护儿童利益的规定,但至今没有确立"儿童最大利益原则",同时,对儿童权益保护在制度上的缺陷也较为明显。我国保护儿童利益应该确立儿童最大利益原则,取消非婚生子女的称谓,建立收养监督制度并完善探望权制度,实现亲权由"亲"向"子"之转变。     

Nest structure and all stages of the long-cheeked yellow jacket Dolichovespula intermedia Birula (Hymenoptera: Vespidae)

Nest structure, morphology of all stages and behaviour have contributed to the phylogenetic and taxonomic studies of social vespids. Two aerial nests of Dolichovespula intermedia were discovered in China. The morphology of the three castes, the five larval instars, and the nest structure of D. intermedia Birula, are described in detail and illustrated. The presence of only one campaniform sensillum above each labial palp and the dense minute spicules on the posterior gena found in D. intermedia larvae are mentioned here for the first time for Dolichovespula. The identification characters between D. intermedia and Dolichovespula sylvestris are briefly discussed.     

Incorporating textual and management factors into financial distress prediction: A comparative study of machine learning methods

Financial distress prediction (FDP) has been widely considered as a promising approach to reducing financial losses. While financial information comprises the traditional factors involved in FDP, nonfinancial factors have also been examined in recent studies. In light of this, the purpose of this study is to explore the integrated factors and multiple models that can improve the predictive performance of FDP models. This study proposes an FDP framework to reveal the financial distress features of listed Chinese companies, incorporating financial, management, and textual factors, and evaluating the prediction performance of multiple models in different time spans. To develop this framework, this study employs the wrapper-based feature selection method to extract valuable features, and then constructs multiple single classifiers, ensemble classifiers, and deep learning models in order to predict financial distress. The experiment results indicate that management and textual factors can supplement traditional financial factors in FDP, especially textual ones. This study also discovers that integrated factors collected 4 years prior to the predicted benchmark year enable a more accurate prediction, and the ensemble classifiers and deep learning models developed can achieve satisfactory FDP performance. This study makes a novel contribution as it expands the predictive factors of financial distress and provides new findings that can have important implications for providing early warning signals of financial risk.     

高校图书馆古籍保护的问题与建议

介绍了高校图书馆古籍保护的现状，分析了高校图书馆古籍保护中所存在的问题，提出了做好高校图书馆古籍保护的建议。     

Inconsistent idealizations and inferentialism about scientific representation

Inferentialists about scientific representation hold that an apparatus's representing a target system consists in the apparatus allowing “surrogative inferences” about the target. I argue that a serious problem for inferentialism arises from the fact that many scientific theories and models contain internal inconsistencies. Inferentialism, left unamended, implies that inconsistent scientific models have unlimited representational power, since an inconsistency permits any conclusion to be inferred. I consider a number of ways that inferentialists can respond to this challenge before suggesting my own solution. I develop an analogy to exploitable glitches in a game. Even though inconsistent representational apparatuses may in some sense allow for contradictions to be generated within them, doing so violates the intended function of the apparatus's parts and hence violates representational “gameplay”.