Modeling of seasonal soil cold storage using natural cold energy

To reduce energy consumption on summer air conditioning,a novel seasonal soil cold storage mode using natural energy is presented and two-dimensional transient heat transfer model of U-tube is developed. The three processes of cold storage in winter,shut-down in transition season and cold extraction in summer are simulated by using sensitive heat capacity method with variable time step. The changing of U-tube outlet water temperature in different periods,daily cold storage and cold extraction are estimated. The temperature field of the U-tube and soil around the tube is investigated. Simulations show that seasonal soil cold storage using natural cold energy is feasible in the north to Changchun,which provides theoretical support for seasonal soil cold storage application.     

Rutile TiO2 nanorod arrays directly grown on Ti foil substrates towards lithium-ion micro-batteries

Nanosized rutile TiO₂ is one of the most promising candidates for anode material in lithium-ion micro-batteries owing to their smaller dimension in ab-plane resulting in an enhanced performance for area capacity. However, few reports have yet emerged up to date of rutile TiO₂ nanorod arrays growing along c-axis for Li-ion battery electrode application. In this study, single-crystalline rutile TiO₂ nanorod arrays growing directly on Ti foil substrates have been fabricated using a template-free method. These nanorods can significantly improve the electrochemical performance of rutile TiO₂ in Li-ion batteries. The capacity increase is about 10 times in comparison with rutile TiO₂ compact layer.     

The analysis of core promoter sequences based on their chemical features

The biochemical behaviors of promoter sequences are closely associated with their chemical properties and structures. In this study, an approach to the analysis of promoter sequences was developed based on the chemical features in DNA sequences. Utilizing the chemical parameters of nucleotides, a string of character sequence was translated into numerical sequences, and then the profiles of chemical properties in the sequence can be observed, which are helpful to better understanding for the behaviors of the sequence. The proposed approach was applied to the analysis of core promoter sequences of Escherichia coli K-12. Apart from the validation of the motifs at the − 35 and − 10 regions, several possible functional sites were observed, and the interaction mechanism between promoter sequence and RNA Polymerase holoenzyme was explored. The obtained results indicate that the consensus of important chemical features is higher than that of the characters in sequences, and our study could provide biologists some valuable hints.     

建筑文脉的延续、再生与创造

本文由讨论文脉理论与现代建筑的关系开始,然后分别从文脉的延续、再生与创造等三个方面针对现代城市、建筑单体中对文脉的忽视所产生的问题加以探讨并提出了相应的应对原则,最后提出了文脉应该来源于历史并在发展中创造历史的观点。     

管道支吊架的设置及选用

通过对同一管系的3种支吊架设计方案的计算,比较了不同方案对管系的影响并分析了其中的原因。认为在管道应力分析过程中,合理设置支吊架．能改善管系中的应力分布和端点受力及力矩状况。