Emerging low-density polyethylene/paraffin wax/aluminum composite as a form-stable phase change thermal interface material

Thermal interface materials(TIMs) play a vital role in the thermal management of electronic devices and can significantly reduce thermal contact resistance(TCR). The TCR between the solid–liquid contact surface is much smaller than that of the solid–solid contact surface, but conventional solid–liquid phase change materials are likely to cause serious leakage. Therefore, this work has prepared a new formstable phase change thermal interface material. Through the melt blending of paraffin wax(PW) and low-density polyethylene(LDPE), the stability is improved and it has an excellent coating effect on PW. The addition of aluminum(Al) powder improves the low thermal conductivity of PW/LDPE, and the addition of 15wt% Al powder improves the thermal conductivity of the internal structure of the matrix by 67%. In addition, the influence of the addition of Al powder on the internal structure, thermal properties, and phase change behavior of the PW/LDPE matrix was systematically studied. The results confirmed that the addition of Al powder improved the thermal conductivity of the material without a significant impact on other properties, and the thermal conductivity increased with the increase of Al addition. Therefore, morphologically stable PW/LDPE/Al is an important development direction for TIMs.

Everlasting Beauty of Dunhuang:The Exhibition of Chang Shuhong and Chang Shana's Art Works

In 1946,Chang Shuhong and his 15-year-older daughter Chang Shana held a joint exhibition in Lanzhou.After 73 years,they were known as"Patron Saint of Dunhuang"and"Decrypter of Dunhuang Patterns"respectively.

Application of psychological intervention in intensive care unit nursing for patients with severe acute pancreatitis

BACKGROUND Severe acute pancreatitis(SAP)is a familiar critical disease in the intensive care unit(ICU)patients.Nursing staff are important spiritual pillars during the treatment of patients,and in addition to routine nursing,more attention needs be paid to the patient’s psychological changes.AIM To investigate the effects of psychological intervention in ICU patients with SAP.METHODS One hundred ICU patients with SAP were hospitalized in the authors’hospital between 2020 and 2023 were selected,and divided into observation and control groups per the hospitalization order.The control and observation groups received routine nursing and psychological interventions,respectively.Two groups are being compared,using the Self-rating Anxiety Scale(SAS),Self-Determination Scale(SDS),Acute Physiology and Chronic Health Evaluation(APACHE)Ⅱ,and 36-item Short Form Health Survey(SF-36)scores;nursing satisfaction of patients;ICU care duration;length of stay;hospitalization expenses;and the incidence of complications.RESULTS After nursing,the SDS,SAS,and APACHEⅡ scores in the experimental group were significantly lower than in the control group(P<0.05).The SF-36 scores in the observation group were significantly higher than those in the control group(P<0.05).The nursing satisfaction of patients in the experimental group was 94.5%,considerably higher than that of 75.6% in the control group(P<0.05).The ICU care duration,length of stay,and hospitalization expenses in the observation group were significantly lower than those in the control group,and the incidence of complications was lower(P<0.05).CONCLUSION For patients with SAP,the implementation of standardized psychological intervention measures can effectively alleviate adverse psychological conditions.

THE CHANGE OF THE GENERAL FORM AND THE TRANSPORT OF THE WATER， LOAD AND SALT ABOUT THE NORTH－BRANCH OF THE CHANGJIANG RIVER MOUTH

陈宝冲ＴＨＥＣＨＡＮＧＥＯＦＴＨＥＧＥＮＥＲＡＬＦＯＲＭＡＮＤＴＨＥＴＲＡＮＳＰＯＲＴＯＦＴＨＥＷＡＴＥＲ，ＬＯＡＤＡＮＤＳＡＬＴＡＢＯＵＴＴＨＥＮＯＲＴＨ－ＢＲＡＮＣＨＯＦＴＨＥＣＨＡＮＧＪＩＡＮＧＲＩＶＥＲＭＯＵＴＨ￥ＣｈｅｎＢａｏｃｈｏｎｇ（Ｎ...

Dynamic changes of ocular biometric parameters:a modified form-deprivation myopia model of young guinea pigs

AIM: To evaluate the dynamic ocular biometric changes of a modified form-deprivation myopia model in young guinea pigs. METHODS: The animals were randomly assigned to two groups: the monocularly deprived facemask group (MDF, with all the right eyes covered, n=24) and the normal control group(free of facemask, n=24). Each group was then equally divided into four subgroups which were followed up for 2, 4, 6 and 8 weeks, respectively. Parameters measured from every eye included refraction, corneal curvature, axial length and the dry weight of sclera at the posterior pole. RESULTS: All the facemasks remained in place during the follow-up. The covered eyes developed myopia with the vitreous chamber lengthening and the dry weight of posterior sclera reduced at each time point compared with the contralateral uncovered (P<0.05 at all time points). The changes had a linear correlation with the deprivation time (P<0.05). There were no significant differences in all the parameters between the uncovered eyes of MDF group and the normal control group (P>0.05 at all time points). CONCLUSION: Monocular form deprivation with the facemask is highly effective and non-invasive in inducing axial myopia in guinea pigs. The axial myopia is mainly caused by the increased vitreous chamber length and the weakened posterior sclera rigidity. The form-deprivation eye didn't interfere with the natural development of the contralateral eye.

Artificial Intelligence and the Future of Education： Big Promises -Bigger Challenges

The history of educational technology in the last 50 years contains few instances of dramatic improvements in learning based on the adoption of a particular technology.An example involving artificial intelligence occurred in the 1990s with the development of intelligent tutoring systems( ITSs). What happened with ITSs was that their success was limited to well-defined and relatively simple declarative and procedural learning tasks(e. g.,learning how to write a recursive function in LISP; doing multi-column addition),and improvements that were observed tended to be more limited than promised(e. g.,one standard deviation improvement at best rather than the promised standard deviation improvement).Still,there was some progress in terms of how to conceptualize learning. A seldom documented limitation was the notion of only viewing learning from only content and cognitive perspectives( i. e.,in terms of memory limitations,prior knowledge,bug libraries,learning hierarchies and sequences etc.). Little attention was paid to education conceived more broadly than developing specific cognitive skills with highly constrained problems. New technologies offer the potential to create dynamic and multi-dimensional models of a particular learner,and to track large data sets of learning activities,resources,interventions,and outcomes over a great many learners. Using those data to personalize learning for a particular learner developing knowledge,competence and understanding in a specific domain of inquiry is finally a real possibility. While the potential to make significant progress is clearly possible,the reality is less not so promising. There are many as yet unmet challenging some of which will be mentioned in this paper. A persistent worry is that educational technologists and computer scientists will again promise too much,too soon at too little cost and with too little effort and attention to the realities in schools and universities.

Impact of Ethnic Migration on the Form of Settlement: A Case Study of Tulou of South Fujian and the Hakkas

Traditional Chinese settlements show gradual changes of the form from south to north, and such a tendency of change in different dimensions is demonstrated as the integration of traditional Chinese folk dwellings(quadrangle and post-and-lintel building) and ethnic folk dwellings(terraced house and column-and-tie construction) in different degrees. There are also mutations in some peculiar regions, such as Minnan Tulou and the Hakka Tulou in Fujian Province(Tulou: earth building). These phenomena are all related to the migration of Han people, integration of Han people and ethnic groups, and the formation of sub-nations. This paper focused on the inheritance and evolution of settlement form under the influence of the above three factors, and also subtle relations formed in this process.

Combined Effects of Temperature and Nutrient Availability on Growth and Phlorotannin Concentration of the Brown Alga <i>Sargassum patens</i>(Fucales;Phaeophyceae)

Global warming is predicted to affect plant-herbivore interactions. However, little is known about the effects of temperature on marine plant secondary chemistry and how these effects may impact plant-herbivore interactions. As marine macroalgae can become physiologically stressed due to warm water temperatures and nutrient-poor conditions during summer, we conducted a culture experiment to test the combined effects of temperature (10°C, 20°C, 30°C) and nutrient availability (seawater enriched with 25% PESI medium and non-enriched seawater) on relative growth rate (RGR) and concentration of phlorotannins (i.e., defensive compounds) in the upper and lower parts of shoots of the brown alga Sargassum patens. RGR was affected by temperature but not by nutrient availability. Phlorotannnin concentration was affected by nutrient availability but not by temperature, although there was a significant interaction between temperature and part of the shoots. Correlations between RGR and phlorotannin concentration were significant for the upper part of the shoots but not for the lower part. These correlations were slightly positive in the nutrient-enriched medium but negative in the non-enriched medium. These results suggest that temperature affects phlorotannin concentration of S. patens indirectly via changes in the growth rate and that its effect depends on the part of the shoot and nutrient availability.

Previous ITU Exhibitions Reflect Tremendous Changes in China's Telecom Industry——Houlin Zhao, Deputy Secretary-General of ITU

The long-awaited ITU Telecom World 2006 is to open in Hong Kong. It is no doubt that the hosting of this pageant in Hong Kong proves the praise and recognition of the rapid development of China's telecom industry as well as the favor and support to Hong Kong, a world-class trade metropolis. At this opportunity, I'd like to extend my warm congratulations to the event together with readers of China Telecommunications Trade.

Fundamental Laws of Structure and Form Changing of Palladium Loading with Hydrogen

There are reviewed some experimental results on metal-hydrogen and PdH x -hydrogen interaction. There is experimentally shown that penetration of hydrogen in palladium is accompanied with strong and micro structural effects, as well as grain shifts, etc. Moreover, the hydrogen saturation of palladium causes form-changing (bending) of palladium plate. These effects, undoubtedly, must be taken in account in technologies of low-temperature diffusion membrane apparatus exploitation.

D^(+)→π^(+)v■decay process within the QCDSR approach

In this paper,we investigate the charmed meson rare decay process D^(+)→π^(+)v■using an approach based on QCD sum rules.First,the pion twist-2,3 distribution amplitude(DA)moments<ξ_(2)^(n);|μand<ξ3;π(p,σ),n>|μ,are calculated up to the tenth and fourth orders,respectively,in the QCD sum rules according to the background field theory.After constructing the light-cone harmonic oscillator model for the pion twist-2,3 D As,we obtain their behaviors by matching the calculatedξ-moments.Then,the D→πtransition form factors(TFFs)are calculated using an approach based on QCD light-cone sum rules.The vector form factor at the large recoil region is f_(+)^(D)→^(π)(0)=0.627_(-0.080)^(+0.120).Using the rapidly converging simplified series expansion of z(q^(2),t),we present the TFFs and corresponding angular coefficients in the whole squared momentum transfer physical region.Based on nonstandard neutrino interactions,the■^(0)→π^(+)e■_(e)decay can be related to the■^(0)→π^(+)e■_(e)decay indirectly.Thus,we first describe the semileptonic decay process■^(0)→π^(+)e■_(e),differential decay widths,and branching fraction with B(■^(0)→π^(+)e■_(e))=0.308_(-0.066)^(+0.155)×10^(2).The■^(0)→π^(+)e■_(e)differential/total predictions for forward-backward asymmetry,q^(2)-differential flat terms,and lepton polarization asymmetry are also reported.The prediction for the D^(+)→π^(+)v■branching fraction isB(D^(+)→π^(+)v■)=1.85_(-0.46)+^(0.93)×10^(-8).

PRICING CATASTROPHE OPTIONS WITH COUNTERPARTY CREDIT RISK IN A REDUCED FORM MODEL

In this paper, we study the price of catastrophe Options with counterparty credit risk in a reduced form model. We assume that the loss process is generated by a doubly stochastic Poisson process, the share price process is modeled through a jump-diffusion process which is correlated to the loss process, the interest rate process and the default intensity process are modeled through the Vasicek model： We derive the closed form formulae for pricing catastrophe options in a reduced form model. Furthermore, we make some numerical analysis on the explicit formulae.

Change Detection of Desert Sand Dunes: A Remote Sensing Approach

Deserts are one of the major landforms on the Earth. While deserts occupy about one-fifth of Earth’s land surface, they have been studied to a much lesser extent. All over the world, desert landforms are expanding ever rapidly and more and more human settlements are finding place in desert regions for habitation. Thus, quantifying and monitoring dunes becomes more relevant from a managerial perspective. Analyzing desert areas using satellite imagery is a challenging task due to weak textural differences and nearly homogeneous spectral responses in most parts of the terrain. In this paper, a post-clustering methodology for change detection of desert sand dunes is proposed. Features based on Radon spectrum are used to cluster dunes of various orientations. These clustered boundaries are used to detect if there are any changes occurring in the dune regions. In the experiments, remote sensing data covering various dune regions of the world are observed for possible changes in dune orientations. In all the cases, it is seen that there are no major changes in desert dune orientations since three decades.

Finslerian Ricci Deformation and Conformal Metrics

In this paper, a new Ricci flow is canonically introduced in Finsler Geometry and, under the variance of Finsler-Ehresmann form, conformal changes of Finsler metrics are studied. Some existence conditions of this Finslerian Ricci flow on a compact manifold which preserves the conformal class of the initial metric are obtained as an application.

Stability of elliptic Harnack inequalities Dedicated to Professor Jia-an Yan on the Occasion of His 80th Birthday

We survey some recent progress in the study of stability of elliptic Harnack inequalities under form-bounded perturbations for strongly local Dirichlet forms on complete locally compact separable metric spaces.

基于六水氯化钙的单相变材料热二极管的实验研究

基于相反传热方向上相变程度不同引起的传热形式和系数差异设计的相变材料热二极管被认为是有潜力的热管理器件.然而多种材料的使用或仅依靠数值模拟的研究使其结构复杂或理想化,降低了其实际应用的可能性.因此,本文结合材料固液相变和自然对流过程的传热形式和传热系数变化,提出了一个仅含有CaCl_(2)·6H_(2)O单相变材料的简单热二极管结构,并制备了相应的器件,搭建了稳态热通量测试系统用于实验研究,其测量结果与文献记载值相近,具有良好的准确度,实验研究了冷热端温差和正反传热方向对热二极管热整流效果的影响规律.结果表明:热二极管的热通量随冷热源温差的减小而降低,正向和反向分别沿逆重力和重力方向时,热整流比最高可达1.58,最佳冷源温度范围为20-25℃,接近室温,所提出的相变材料热二极管结构在建筑节能和热管理等方面具有一定的应用潜力.

成都人民公园空间的层积分析及变迁动因研究

成都人民公园是中国重要的近现代城市公园遗产之一,是见证城市发展与公共需求变化的重要城市历史公园,具有不可忽视的城市历史景观遗产价值。采用历史层积分析对成都人民公园发展脉络进行梳理,将其空间历史变迁分为普通游园初创、传统公园转型、现代公园建设、现代公园完善和公园城市营造5个时期,整理各时期形态与功能变迁,探寻其变迁的内在动力。将公园的层积关系分为反复、重建、共存和成长4种主要模式,探索公园建设的层积变化:基于自然条件,综合历史事件、治园观念、文化活动和人群变化等因素,公园空间形态由封闭、单一和无序转向开放、多元和有序,承担职能从功能杂乱的小游园转化为集休闲、文化、健身和爱国教育为一体的综合性园林。分析成都人民公园空间的历史变迁动因与机制,能够为中国近现代城市公园遗产保护与发展补充实证,为当代城市公园文脉与底蕴的探寻提供参考。

A New Interpretation in Urban Form of the Wards of Tang Chang'an

By comparing the gridiron plans of ancient western cities with that of Tang Chang'an in the same scale,the authors find that a residential ward of Tang Chang'an was about the same size as an ancient western city.Thus the paper puts forward a hypothesis that Tang Chang'an was not a single city,but a cluster of hundreds of small towns with rigid layout.This theory is then proved by comparing a ward of Tang Chang'an with a typical small town in China from the perspectives of town scale,spatial layout,residential density,and land-use.The authors further explain the main cause for this unique urban form of Tang Chang'an,which was the compulsory migration policy.