新型地震结构保护系统的大跨径桥梁抗震分析

吉林龙华松花江特大桥抗震设计方案中拟使用近年来新出现的lock up装置和液体黏滞阻尼器.建立了大跨度桥梁使用lock up装置和液体黏滞阻尼器在桥梁地震反应中的分析模型及方程,采用动态时程分析法,对龙华松花江特大桥在多点一致激励作用下的地震反应进行了分析,探讨了使用新型地震结构保护装置对大跨度连续箱梁桥地震响应的影响.

高层建筑结构中粘滞阻尼器的新型安装方式

在建筑结构中,一般粘滞阻尼器均布置在层间,但在有些情况下较小的层间位移差在一定程度上制约了阻尼器性能的充分发挥。系统回顾了为解决这一问题,目前最新的一些解决方案:改进层间阻尼器的连接方式,如基于连杆结构、杠杆原理与齿轮机构的位移放大系统,及大对角支撑;新型结构保护系统,如利用结构构件竖向振动位移及框架核心筒结构的加强层阻尼系统等,并重点分析了加强层阻尼系统。

佛山市公共文化综合体坊塔消防系统设计问题探讨

介绍了佛山市新地标工程佛山市公共文化综合体——坊塔的消防系统设计。该工程造型独特,集剧院、城市规划展馆、观光塔等多功能为一体,消防系统设计有独特性,可供同类工程参考。

大型低温LNG储罐的安全系统设计

针对大型低温液化天然气(LNG)储罐存在的安全问题,结合石油化工厂或装置典型多保护层结构模型,逐层分析了大型低温LNG储罐在设计、运行过程中应采取的安全性措施,详细阐述了基本过程控制系统、储罐仪表系统、可燃气体检测系统、安全仪表系统等监控、防护系统,以及安全阀、消防灭火系统等物理保护措施在各保护层中的作用.实践证明:基于石油化工厂或装置的典型多保护层结构的大型低温LNG储罐安全系统设计,满足了储罐的安全稳定运行要求,对大型低温LNG储罐及其他介质低温储罐的安全设计有一定的借鉴意义.

Effect of TYLCV Infection on Leaf Anatomical Structure and Protective Enzyme System of Tomato

[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.

Trust Model Based on Structured Protection for High Level Security System

In order to ensure the security of information systems, it's essential to make sure that system behaviors are trusted. By analyzing threats that exist in executing procedures, a trust model based on structured protection is proposed. We consider that functional components, system actions and message flows between components are three key factors of information systems. Structured protection requirements on components, connections and action parameters are also provided. Four trusted properties of the model are deducted through formal analysis, and trusted system behavior is defined based on these properties. Furthermore, decision theorem of trusted system behavior is proved. The developed prototype system indicates the model is practical. It is a general theory model built on logic deduction and independent on specific environment and the behaviors of the system designed and implemented following the model are trusted.

Vegetation Composition and Structure of Some NeotropicaMountain Grasslands in Brazil

The description and understanding of plant communities is fundamental for the implementation of conservation or restoration programs, especially when these communities are highly threatened and need to be restored.Campos rupestres, some Neotropical mountain grasslands located in central Brazil and part of the Cerrado biome(covering 2 million km2) host unique plant communities, currently threatened by quarrying and mining.The grassy matrix of campos rupestres, has long been considered a rich mosaic under the control of local topography and the nature of substrate, but this affirmation has not been well studied.We analyzed whether plant communities varied in relation to edaphic factors within the stony substrate and the sandy substrate of this grassy matrix.We selected 5 sites where occur both grasslands on stony substrate and on sandy substrate, and we carried out vegetation surveys and soil analyses.We counted 222 plant species within our communities, among which38.6% are exclusively found on campos rupestres.Our results show that both soil-types are strongly acidic, nutrient poor and exhibit a seasonal variation.Phosphorus increases and p H and organic carbon decrease during the dry season.Stony soils areslightly richer in nutrients than sandy soils and differences in soil granulometry and composition have led to the formation of distinct plant communities.Some species are confined to either one or the other grassland-type, which makes the plant composition of each community unique.Variations in edaphic factors generate heterogeneous grasslands favorable to a high plant diversity.Conservation programs and restoration actions have to maintain or recreate this heterogeneity.The presence of distinct plant communities implies that different strategies might be adopted to improve the restoration of these ecosystems.

Slope Reinforcement for Housing in Three Gorges Reservoir Area

The Three Gorges Project of the Yangtze River is the largest hydropower-complex project under construction in the world. Under the largescale relocation projects, 2874 engineered slopes are formed along with the construction of new towns. In this paper, the cutting slopes are mainly soil slopes and rock slopes. Soil slopes include residual soil slopes, colluvial accumulation slopes, swelling soil slopes, and artificial earth fill slopes, etc. Rock slopes include blocky structure rock slopes, layer structure rock slopes, and clastic structure rock slopes, etc. Varied protection measures have been used for slope protection in the reservoir area including shotcrete concrete-anchor bars, frame beams, retaining walls, slope stabilizing piles, sheet-pile walls, anchorage anti-shear tunnels, flexible protection grids, and drainage, etc. Besides, slope deformation monitoring systems have been set up to monitor deformation failure and the stability state of slopes. The protection measures have guaranteed slope safety and maintained a harmony with the urban environment and surrounding landscape.

Construction of Circular Economy Industrial System

It is difficult to realize the transformation from traditional economy industrial system to circular economy industrial system. Regarding primary raw materials as the indicators, the industrial system has been specified according to the divergence among the indicators and the circular utilization modes. In comparison with the association among industrial systems, the relationship among industrial sub-systems is named as industrial cross-linking in this paper. The industrial system which could completely utiLize and recycle the indicators shouM be increased and strengthened, and the circular economy industrial system with complete industrial association and industrial cross-linking should also be constructed. Taking the development of circular agricultural system basing on the traditional agricultural system as an example, the traditional agricultural products are regarded as the indicators which have been divided into foodstuff and crop straws which are used to produce food and articles for use, Like fertilizer, energy and papers etc. The way to construct the circular agricultural industrial system is to increase the industrial systems that could utilize the products generated from crop straws, feces and other castoffs and transform the wastewater and other trucks into environmental friendly products. It has also been pointed out that the construction of circular economy industrial system is conducive to the foundation of circular industrial economics and the establishment of the construction layout of circular economy and the application schemes. Suggestions to the theoretical and practical work of the next step have also been brought forward in this paper.

A Critical Examination of the European Standard EN 1504 ＂Products and Systems for Protection and Repair of Concrete Structures＂

The European Standard EN 1504 ＂Products and systems for protection and repair of concrete structures -- Definitions, requirements, quality control and evaluation of conformity＂ can be considered a real milestone for the companies involved in the rehabilitation of buildings, bridges, piers, pipelines, and other civil or industrial concrete structures. However in some cases the examination and, even more, the practical application of the proposed guidelines are made difficult by a complicated sub-division in principles and methods, and by a confusing and repetitive layout. The paper deals in particular with the principles and methods for the rehabilitation of concrete damage due to reinforcement corrosion, often strictly connected, anyway, to those adopted in order to rehabilitate the concrete itself. Suggestions are given for a possible future update of the Standard, based on the personal experience of the Authors.

Design and heat transfer analysis of a compound multi-layer insulations for use in high temperature cylinder thermal protection systems

Thermal protection systems are very essential for high temperature thermal conductivity measurement system to reduce the heat loss to environment at the range of 600-1800 K. A compound multi-layer insulations structure which composed of inner carbon fibrous materials and outer alternately arranged alumina fibrous materials and high reflectivity foils is proposed for use in high temperature cylinder thermal protection systems. A coupled conductive and radiation governing equations is presented for heat transfer analysis of the structure. The finite volume method and the discrete ordinate method are used to solve the goveming equations. The optimization structure of the compound multi-layer insulations is investigated by considering the pressure of the gas, the density of the carbon fibrous materials, the density of the alumina fibrous materials, the number of reflective foil layers and the emissivity of reflective foils. The results show that the compound structure has the best thermal insulation performance when the pressure of the gas is below 0.01 kPa, the density of carbon fibrous materials is 180 kg m^-3, the density of alumina fibrous materials is 256 kg m^-3 and the number of reflective foil layers is 39. In addition, the thermal insulation performance is much better when the emissivity of reflective foils is lower.