最新刊期
卷 30 ， 期 5 ， 2008
- 摘要：City images are tending toward the similar features. The solution to the problem of losing city characteristics is based on geographic nature and historic humanities. The unique natural landscape of the QinghaiTibet Plateau provides us with plenty of material. I discuss creating a city characteristic of Xining based on a plateau landscape conception with traditional Chinese artistic methods. Only by constructing a plateau garden city and making full use of local image characteristics can we solve the impact of identity crisis facing Xining.573|1494|0更新时间：2023-11-28
- 摘要：Research on carrying capacity as an important indicator describing the state of regional urbanrural systems is quite important. Based on an analysis of urbanrural system elements characteristics and mechanism, mathematical models were established to evaluate regional comprehensive carrying capacity and development expenditure level. These models were applied to a case study of Hainan Province, P. R. China, using statistical data from 1995 to 2005. The conclusions are as follows: (1) During this period, the carrying capacity of the regional urbanrural system in Hainan fluctuated, and the capacity was overloaded from 1995 to 1998, under loaded from 1999 to 2001, and overloaded again from 2002 to 2005. (2) The degree of coordination between the regional natural and socioeconomic carrying systems is 0.60, three times the regional multiple carrying capacity. Both the socioeconomic and natural carrying capacities rose unsteadily, averaging 0.30 and 0.11, respectively. (3) The contribution of various carrying factors to regional multiple carrying capacity is quite different. Carrying capacity factors include socioeconomic development, human resources, imports, environmental and resource possession. Their average rates of contribution were 31.40%, 22.71%, 18.79%, 13.64% and 13.45%, respectively. (4) From 1995 to 2004, economic development expenditures were the principal part of all regional expenditures, the contributing 61.88%. In 2005, export expenditures exceeded economic development expenditures, becoming an important part of the all regional expenditures.741|626|0更新时间：2023-11-28
- 摘要：Chongqing was the temporary Chinese capital during the War of Resistance against Japan. The historic sites related to this war are regionally valuable. They not only continue Chongqings historical arrangement with their historical, cultural and tourism values, but also enrich the urban humanities landscape. However, with the rapid urbanization of Chongqing, the current preservation and use of these sites is quite worrisome. It is important to harmonize the relationship between the preservation and use of these sites. Based on an analysis of the value and preservation status of these sites, some measures and strategies are offered to preserve and reuse these valuable historic sites.769|1044|0更新时间：2023-11-28
- 摘要：Through analysis of an investigation of the cultural environment, I point out that historic sites and traditional culture are the end-results of cities. I advance a method for conservation and continuance of the cultural environment and architectural characteristics of cities. I suggest that only by maintaining a citys root system can a city be full of vitality.406|428|0更新时间：2023-11-28
- 摘要：Summarizing building damage in all previous large earthquakes is an important approach to promote the development of structural seismic design. We conducted a statistical analysis of the earthquake damage to various buildings in Mianyang city, Sichuan province, P. R. China. This analysis was based on the emergency assessment and investigation of building damage in Mianyang city caused by the large earthquake that occurred on May 12, 2008 in Wenchuan. We also summarize the damage characteristics of different buildings and the lessons learned. We present the following findings and suggestions for structural seismic design:(1)Buildings in Mianyang designed according to current seismic code withstood the rare earthquake.(2)Different structural systems have obviously varied seismic behaviors. (3)Old buildings always have been the weak links in earthquakes, and should be evaluated and strengthened selectively after an earthquake.(4)Studies of anticracking measures for masonry walls should be conducted. (5)Effective measures should be taken to reduce earthquake damage to nonstructural components, for example, infill walls in frames.(6)Seismic design methods and construction measures for stairs should be studied.1147|617|0更新时间：2023-11-28
- 摘要：We address damage detection based on dead loads in monitoring the health of beams and bridges. We discuss the damage characteristics of statically indeterminate beams under dead loads and analyze monitoring parameters and sensor placement in monitoring. We used an amended genetic algorithm to solve the optimization problem under constrained parameters. Damage in a beam was detected successfully based on dead loads with limited sensor allocations. We present a way to detect damage based on dead loads in bridge health monitoring.392|500|0更新时间：2023-11-28
- 摘要：Because high material strength and composite load-bearing are emphasized in constructing members for high-rise steel frame structures, in a composite connection, steel strength has a dramatic influence on both the bearing performance and the composite action of the concrete slab. Based on a finite element analysis, we discuss the composite effect and the connection breaking mode, focusing on the performance change of the composite effect in adopting high strength steel. It can be found from the results that, along with the improvement of the steel strength, the elastic and plastic ultimate strength of the composite connection will increase, the ductility will decrease to a certain extent, and the composite effect of the concrete slab will diminish. The collapse of the concrete in a positive moment side contacting the column flange is viewed as the limiting state of the connection.431|491|0更新时间：2023-11-28
- 摘要：In order to solve the problem that the choice of acoustic emission (AE) parameters in concrete detection are determined only by experience, several tests were conducted. Through lead-breaking and stimulant loading tests, the reasonable value of threshold at which noise can be efficiently insulated was obtained. Through lead-breaking tests, time parameters (PDT, HDT, HLT) which fit concrete samples were obtained. The velocity and attenuation of AE signals in concrete also were measured through lead-breaking tests. This method of ascertaining detection parameters by testing is practical for AE detection in concrete structures.703|780|0更新时间：2023-11-28
- 摘要：Based on the large scale conceptual model theory of similar material, a physical model of metro station tunnel excavation was simulated. The excavation process of metro station tunnel between existing double tubes also was simulated. Ground settling, soil deformation and displacement of specific points around tunnels were studied. The influence of a castinplace pile on reducing soil displacement was simulated. The dynamic mechanical behavior and deformation laws of the soil were obtained along with some useful conclusions. The conclusions are beneficial for guiding the construction and expanded excavation of metro station spaces between existing double tubes.478|633|0更新时间：2023-11-28
- 摘要：Steelconcrete composite slim floors with the steel beam encased in concrete floor slabs have many advantages, including low structural height, high fire resistance and rapid construction times. These features make such floors a promising for use in multistorey steel buildings. We established a 3D finite element model of a monolithic composite slim floor using the ANSYS software package. We analyzed the loading capacity, deformation behavior, natural vibration frequency, the influence of reinforcement, and the concrete in the floor rib under a uniformly distributed vertical load. We calculated the effective width of midgirder and secondary beams. The following conclusions can be drawn from the analysis results: First, monolithic composite slim floors possess high loading capacity for common buildings. Second, the concrete rib and reinforcement ratio in the rib have significant effects on floor loading capacity. Third, calculation of effective primary beam width should be based on analysis of monolithic floors rather than single beams.1195|945|0更新时间：2023-11-28
- 摘要：It has been established that a pavement slab will curl up if a temperature gradient exists across the depth of a slab. A negative temperature gradient causes the slab edge to curl up while a positive temperature gradient curls up the slab center. Temperature stress in slabs is induced by self-weight and other slab constraints. At present in P. R. China, the total stress considered in cement concrete pavement design includes the load stress plus the temperature stress, and only transverse cracking from bottom to top is considered for concrete pavement. Slab responses under axial loads and temperature gradient coupling are not included. We modeled a single slab with a frictionless interface between the slab and foundation using the finite element method. Slab deflection and stress were calculated under axial loads at different slab positions and negative or positive temperature gradient coupling. The calculated results show that the different conditions of axial loads and temperature gradient coupling will change the maximum tension and cause various types of cracks in a slab.519|10|0更新时间：2023-11-28
- 摘要：Pavement structures will be damaged by subgrade soil movement around the pipes introduced by extrashallowundergroundpipe jacking. Soil layer deformation with shallow deposits on pipes during extrashallowundergroundpipe jacking is analyzed using 3D FEM. The effects on pavement deformation created by the friction between shield and soil, injection slurry, jacking forces and the vehicle loads are studied with a practical project. The analytical results show that the ground surface deformation is an uplift first followed by settling with the lower part of the cover moving faster than the upper layers. It is demonstrated by comparing computational results of FEM simulation and the observed data from the insitu test that these FEM models can be applied to realworld engineering. Subgrade soil settling on extrashallowundergroundpipe jacking in a crosssection will be stable when the shield has passed through a section with a length twice the diameter of the pipe. Horizontal surface subsidence along the lateral distribution is similar to a normal distribution curve, with the primary affected areas on both sides of the axis approximately 1.5 times the diameter of the pipe.633|9|0更新时间：2023-11-28
- 摘要：As the real estate industry in P. R. China developed rapidly in recent years and the housing price constantly rose, the Tail Part of Real Estate (TPRE) became a new investment option for shrewd investors due to its huge profit possibilities. We appraise the investment values of different TPREs and provide the investor with scientific decisionmaking support regarding the selection of TPREs. We introduce the TPRE concept and analyze the causes and factors influencing TPRE formation. We construct a mathematical fuzzy comprehensive evaluation model to analyze the investment options for TPREs. We provide an example showing how to analyze the TPRE investment choices using our method provided herein. It could be a good reference for the investors in choosing a TPRE for investment.510|16|0更新时间：2023-11-28
- 摘要：The degree of centralization indicates the concentration of production management in a particular industry and is an important indicator to reflect industry and market structures. We use the concentration rate ( ) to analyze the concentration of the construction industry from 2000 to 2005 in P. R. China and compare that industry with others in the country. We also use a Lorenz curve to analyze the industrial structure of P. R. China based on data from P. R. China and developed countries. We conclude that the concentration of the Chinese construction industry definitely has developed; there still exist, however, considerable gaps when it is compared with counterparts in developed countries. We therefore discuss ways to improve the degree of centralization of the Chinese construction industry, based on the laws and regulatory system, market order, and industrial and enterprise structures.652|9|0更新时间：2023-11-28
- 摘要：Due to very large scale of general contract projects, the scope of projects is always uncertain when the contractor bids and the difference between the planned and actual volumes of projects is very large. If a lump sum contract is used to establish the price, contractors thus must take high risks. The contract price is always high, and both owners and contractors show unwillingness to optimize technology under lump sum contract conditions. Owners are inclined to extend the norm and scope of projects. Such situations may result in additional costs. As a new pricing contract, a target contract fits the situation when project scope is not fully defined or the forecasting risks are high. Such a contract can bring both sides enthusiasm for technology optimization and substantially reduces project cost. Therefore, a target contract is suitable for EPC general contract pricing.539|25|0更新时间：2023-11-28
- 摘要：Crack propagation of control fissures in perilous rock under loads is a key process in the failure of perilous rock. Based on the loading mechanism, the control fissures are classified into compressionshear and tensionshear types. By introducing a model of seepage stress, the calculating principle of the stress intensity factor and the propagation orientation of control fissure under seepage stress are put forward using fracture mechanics methods. Using Shoulishan perilous rock in the Wanzhou district of Chongqing, P. R. China, as an example, the calculated results show that there is an obvious increase of the stress intensity factor. The influence of hydrostatic pressure and hydrodynamic pressure also are analyzed.404|8|0更新时间：2023-11-28
- 摘要：There are many risks that influence freeway project financing and the influence of these risks differ by project stage. However, it is impossible to analyze the total risk of project financing objectively and accurately merely using the fuzzy or grey evaluation methods. These methods cannot reflect the dynamic characteristics of financing risks during freeway project construction. A dynamically grey fuzzy comprehensive evaluation method was established and used to evaluate the financing risks of a freeway project. The results indicate that this method can not only make full use of the rich experience of the experts, but also reduce the influence of subjective factors. In addition, this method can reflect the dynamic characteristics of the financing risks during freeway project construction. Investors therefore can pertinently prevent and control financing risks based on the results of the evaluation of financing risks in every stage of the project. A demonstration shows that the method is suitable for comprehensive evaluation of financing risks of infrastructure projects such as freeways.515|10|0更新时间：2023-11-28
- 摘要：A construction project letter of guarantee is used as financial credit to insure the smooth project execution. The construction project letter of guarantee system developed over one hundred years in the United States where a comprehensive system has been established. It is proven that the system played a vital role in controlling construction industry risk in the U.S. In contrast, the system developed later in P. R. China but has played an increasing role in the Chinese construction industry. Based on a discussion of the structure, meaning and condition of the letter of guarantee system in the U.S., a suitable framework is sought to promote development of the letter of guarantee system in the Chinese construction industry.390|11|0更新时间：2023-11-28
- 摘要：Based on characteristics of transportation infrastructure projects under a PPP model, an early warning risk index system for the private sector was put forward. The system is comprised of 15 indexes from five aspects, including risks associated with politics and law, economics, credit, construction and operation. An early warning risk model was constructed by applying fuzzy set theory and matterelement theory. The fuzzy set method helps calculate the weight and evaluation values for qualitative indexes, thereby avoiding the limitations of individual decisions. The matterelement method can evaluate comprehensive risks by using the comprehensive relations, is easy to use, and directly gives results. Further empirical research was conducted that verifies this method is scientific and applicable.468|10|0更新时间：2023-11-28
- 摘要：We developed a model of timedependent resistance for a steel structure project and discuss herein the expression and the primary value of many parameters in the model. On the basis of the APDL language furnished by universal finite element program, we united the functions of structural and statistic analyses. A timedependent reliability analysis was implemented. The result of the timedependent reliability analysis was compared with that of the no timedependent reliability analysis. Through testing a calculated example, we saw that when the timedependent resistance was considered, the factor of time greatly influences structural reliability. In addition, we found that the model of timedependent resistance for a steel structure is reasonable and feasible.657|7|0更新时间：2023-11-28
- 摘要：The balance principle of the straingauge arrays observation is analyzed in detail according to the first invariant of the stress. A partly damaged straingauge arrays' strain conversion is discussed. The stress computation through the strain gauge arrays under different condition is confirmed. A method for determining the validity of the straingauge arrays is studied and summarized. A collection procedure containing the straingauge arrays' validity judgment, strain conversion, and stress computation is established based on the causal relation model.453|748|0更新时间：2023-11-28
- 摘要：We point out the weak points of oxidation ditch excess activated sludge thickening by cavitation air floatation process. out in this paper and the reasons for such weak points are analyzed, and some advanced measures are put forward and. a mModified cavitation air flotation (MCAF) equipment MCAF10 for oxidation ditch sludge thickening has been developed. The flocculant FO4440SH with 1.0 kg/tDS was added with 1.0 kg/tDS and the 0.2kg/tDS of the surfactant 1227 were adopted with addition of 0.2kg/tDS. When the CAF5 was employed to thicken oxidation ditch excess sludge, the optimal solid loading was 230kgMLSS/m3·d, and the hydraulic loading was 90 m2/m3·d, and the SS in the effluent was 200～250mg/L;. When the MCAF10 was used to thicken oxidation ditch excess activated sludge, the optimal solid loading was 270kgMLSS/m3·d, hydraulic loading was 110 m2/m3·d, and the SS of the effluent was 100～150mg/L. The experimental results indicate that the modified cavitation air flotation (MCAF) equipment is more suitable for sludge thickening.634|1024|0更新时间：2023-11-28
- 摘要：The wet bulb globe temperature (WBGT) is difficult to measure and calculate in field observation and numerical simulation. To solve this problem, the air dry bulb temperature, wet bulb temperature, globe temperature, relative humidity, mean air velocity, solar radiation and wet bulb globe temperature in Guangzhou, P. R. China, first were collected during the summer (July). Next, correlation and regression analyses were used to derive a simplified model for calculating WBGT. The results show that dry bulb temperature, relative humidity, solar radiation, mean air velocity and WBGT were interrelated to some extent. These four parameters with high linear correlation can be used to predict WBGT in a simplified model with high precision. The simplified WBGT model can be used in field observation and simulation research regarding urban thermal environments.1003|1819|0更新时间：2023-11-28
- 摘要：The annual energy consumption of representative office buildings in Guangzhou, P. R. China, was surveyed over a three year period. Among the modern office buildings surveyed, two largescale office buildings were chosen to analyze the energy consumption features and monthly energy consumption trends. Based on the actual occupied area calculation, the total annual energy consumption of the two office buildings was 149.3 kWh/m2 and 115 kWh/m2, respectively. The airconditioning energy consumption in two office buildings accounted for 49.2% and 38.5% of the total energy consumption. The research results could be used as energy consumption subdatabases or references for largescale public buildings in Guangzhou due to the accurate survey technique and representativeness of the survey objects. In addition, energy consumption in these office buildings was compared with levels described in other studies. Energy saving methods are proposed for buildings located in hot summer/warm winter climate zones.700|1549|0更新时间：2023-11-28
- 摘要：The structure and energy conservation characteristics of hybrid desiccant cooling system with condensation heat recovery are introduced briefly. Based on the first and second law of thermodynamics, a system thermodynamic model is established and the solution process given in a diagram. The dehumidification capacity is calculated under different exergy efficiency and indoor sensible heat conditions. The calculation results show that the desiccant wheel barely can compensate for the humidity load of outdoor air under with a ventilation rate of providing fresh air once per hour; when the fresh air rate of ventilation is limited to 0.5 times per hour, however, the desiccant wheel possess sufficient capacity under relatively large wheel exergy efficiency and high sensible heat load.466|945|0更新时间：2023-11-28
- 摘要：City expansion is a major driving force altering local and regional hydrology and increasing nonpoint source (NPS) pollution. To explore these environmental consequences of urbanization, longterm runoff and NPS pollution were assessed in Beijing, P. R. China. The assessment was based on landuse types, soil hydrology, and long term precipitation data. The environmental impact model LTHIA was used. The outcomes indicate that the area likely would be subjected to impacts from urbanization on runoff and some types of NPS pollution. Urban sprawl will increase runoff volume considerably and significantly increase losses of COD and certain heavy metals such as Pb, Zn in runoff. The results of this study have significant implications for urban planning and decision making efforts to protect and remediate water and habitat quality in the Beijing area. The techniques described herein can be used in other areas.456|388|0更新时间：2023-11-28
- 摘要：The application of existing formulas to determine solar altitude and azimuth angles is inconvenient and inadequate. To improve the existing formulas, a new timing system named the Radiation Calendar was established. In this system the angles' ranges were redefined, making the angles calculated from the improved formulas singlevalued and varying with hour angle. Representative curves of solar altitude and azimuth angles varying with hour angle were plotted. The mathematical distinctions of these curves astronomically and geographically describe some rules of solar position varying with time, which proves the validity and generality of the improved formulas. The results calculated using the improved formulas show simply and clearly the daily and annual variation of solar altitude and azimuth angles, which are valuable in the work of sunlight distribution analysis related to the design of buildings, airconditioning systems and structures.768|2345|0更新时间：2023-11-28
- 摘要：Based on a study of the timeprocess of individual evacuees in highrise building fires, we found that the lowsecurity influencing factor will affect the possibility of successful evacuation severely. The traditional grey relational grade cannot reflect the effect of the grey relational coefficient fluctuation. Moreover, the single weight calculation with a subjective or objective weight will also directly affect the evaluation result of safe evacuation during highrise building fires. Based on these analyses, the grey Euclid relative grade was applied to indicate the effect of the grey relational coefficient fluctuation. The Spearman correlative rating coefficient was used to combine the subjective and objective weights to eliminate the deficiency of the single weight case. We discuss the possibility of applying the improved grey relational evaluation. Comparing the evaluation results, we found that the weight combination and grey Euclid relation applied in a safety evaluation model can improve evaluation result accuracy. The evaluation model thus corresponds to the characteristics of highrise building fires and the weight set substantially affects the evaluation result.377|881|0更新时间：2023-11-28
- 摘要：Utilizing a combined velocityvariable biofilter，a fullscale experiment was carried out on advanced treatment of secondary effluent from an oxidation ditch wastewater plant．The study was made on the performance of the biofilter at three different hydraulic loadings．The results showed that the highest average removal rate of CODcr reached 21.42%,which increased with hydraulic loadings rise; the highest of those of NH3N and turbidity was 43.19% and 60.40%.respectively.The study shows that this biofilter technology is an good process for advanced treatment of secondary effluent which is characterized by deficiency of nutrition and low biodegradability．338|1017|0更新时间：2023-11-28
- 摘要：We studied the effect of a new kind of retarder, hydroxy carboxyl compound (KHPT), on setting time and 28d strength of building gypsum. We used a noncontacting electrical resistance device and a scanning electric microscope to study the change of the hydration process and the crystal morphology of the gypsum. The results indicate the following: With increasing addition of new retarder, gypsum setting time extends. A new retarder content of 0.05% not only affects gypsum setting but also enhances gypsum strength. At a retarder content of 0.10%, the retarding effect is quite good with the setting time nearly reaching 1 hour. With increased new retarder content, the abrupt change stage of hydration resistivity of building gypsum is delayed, the resistivity stabilization stage decreases, the crystal enlarges, and the ratio of length to diameter decreases.504|1293|0更新时间：2023-11-28
- 摘要：The content of calcic minerals in fly ash is an important factor affecting the properties and application of fly ash. We reviewed information about and analyzed the formation of calcic minerals in fly ash and the negative effects of calcic minerals on fly ash properties. We found that the content of SO3 versus CaO is a linear relationship. Fly ash morphology and degree of silicate polymerization vary as the calcic minerals content in fly ash increases. Higher levels of calcic minerals in fly ash may cause poor soundness of cement and concrete added with fly ash; high content calcic minerals in fly ash may become an advantage, however, when the volume of fly ash used in concrete is limited and the fly ash is pretreated.676|10|0更新时间：2023-11-28
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