Construction In Beijing Research Articles

Development and tests of the 499.8 MHz srf cryomodules for HEPS

A 499.8 MHz single-cell superconducting cavity has been proposed as the active third-harmonic cavity for the High Energy Photon Source (HEPS), a 6 GeV diffraction-limited synchrotron light source currently under construction in Beijing. Two 499.8 MHz cryomodules are required to provide a total of 3.5 MV of rf voltage and 400 kW of beam power. A mechanically enhanced cavity design, based on the original KEKB-type cavity, was developed to meet the specifications of HEPS. Three cryomodules have been assembled and subjected to horizontal tests. A comprehensive clean-assembly procedure was developed, resulting in excellent rf performance maintained from vertical tests to horizontal tests at cryogenic temperatures. The unloaded quality factors of all three modules exceeded 2.45×109 at 1.75 MV, significantly surpassing the design goal. No field emissions were observed throughout the tests. These are the highest-performing 500 MHz modules treated by buffered chemical polishing, also outperforming the average performance of their electropolished counterparts. Following dedicated analyses and multiple road tests, one cryomodule was successfully transported in its entirety from the test platform to the HEPS tunnel, with well-controlled accelerations on delicate components. Vacuum integrity and performance were well maintained. The module has been accelerating electron beams since August 2024 for the HEPS commissioning. This paper presents the design, fabrication, assembly, cryogenic tests, and transportation of the mechanically improved 499.8 MHz single-cell srf cryomodule.

Building green infrastructure for mitigating urban flood risk in Beijing, China

Due to climate change and accelerated urbanization, urban flooding has an increasing impact on the sustainable development of metropolitan areas. Since the 1990s, green infrastructure has developed as an alternative and sustainable approach to the mitigation of flood disaster in urban areas. To improve the resilience of urban ecological flood control and build a green infrastructure network, we provide quantitative measures of flood risk assessment to generate a grid-scale (1 ×1 km) flood risk assessment results and analyze its spatiotemporal heterogeneity. Then, we propose a GIS-based multi-criteria assessment method to determine the priority areas of green infrastructure according to four criteria, generating a distribution map of green infrastructure priorities in Beijing at the township scale. From the perspective of urban flood risk mitigation, the research proposes a new method to determine the priority areas of green infrastructure, thus establishing suggestions for future green infrastructure construction in Beijing.

Compact design of the 166.6 MHz superconducting cavity and its beamline elements for HEPS

The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited synchrotron light source under construction in Beijing. It will use five 166.6 MHz superconducting radio frequency (rf) cavities to accelerate the 200 mA electron beam in the storage ring. In the current lattice design, each straight section is 6 meters long to accommodate two 166.6 MHz cavities. The cavity adopts β=1 quarter-wave geometry, and the damping of the higher order modes is realized by using an enlarged cavity beam pipe to 505 mm and a ferrite absorber installed on the beam pipe. The low rf frequency, as well as the large beam aperture, added great challenges to the design of the 166.6 MHz cavity module to fit into a strictly limited longitudinal space. In addition, heat load optimization for the transition from room temperature to the cryogenic temperature, smooth tapering from the 505 mm beam aperture to the small diameter of the gate valves for impedance control, proper collimation of the synchrotron light to prevent thermal damage of delicate components, are also demanding requirements for a compact design. Accessibilities are also preserved for tuners and vacuum components to enable online maintenance. Finally, rf field leakage in the vacuum seal groove of the cavity is carefully examined to prevent overheating on the superconducting flange, which, in the worst scenario, may cause a thermal runaway, thus limiting the achievable accelerating gradient of the cavity. This paper presents the first compact design of the 166.6 MHz srf section for HEPS.

The high level applications for the HEPS Linac

The High Energy Photon Source (HEPS) is a 6 GeV diffraction-limited storage ring based light source, which is under construction in Beijing, China. The HEPS accelerator consists of a Linac, a booster, a storage ring and three transfer lines. Installation and high-power conditioning of the Linac has been completed. For beam commissioning and measurements of the HEPS Linac, it is necessary to develop high level applications (HLAs). The development of the Linac HLAs, based on the framework named Python accelerator physics application set(Pyapas), has been completed. All the applications are physics quantity based, including measurement applications, control applications and monitoring applications. All the applications have been tested and verified on virtual accelerator. The results show the validity of the algorithm and indicate that the developed applications could meet the requirements of Linac commissioning. All the applications have been deployed to the actual machine environment and communication and control test with hardware system have been completed.

Analysis on the Development of Smart City of Big Cities in China and Its Effect to Economic Structure Based on Entropy Method

This work aims to analyze the construction of smart cities in China’s large cities and its impact on the economic structure. Some developed countries, such as the United States and Europe, have established mature smart city evaluation systems. Therefore, this work draws on the evaluation system of smart cities in developed countries to study the development status of smart cities in large cities in China. An extend linear system evaluation model is established. Besides, five first-level indicators and 24 second-level indicators are established from the five aspects: urban infrastructure, technological innovation, smart economy, human services, and intelligent environment to evaluate the development status of the city. In addition, a susceptible infected system model has been established to study the impact of smart city construction on the industrial structure. The research results demonstrate that the development level of smart cities and smart industries in eastern China is relatively high, and the comprehensive scores of smart city construction in Beijing, Shanghai, Guangzhou, Shenzhen, and Chongqing all exceed 0.082. However, the development level of smart cities and smart industries in the central and western regions is relatively low. The comprehensive evaluation scores of smart cities such as Tianjin, Hangzhou, and Wuhan are between 0.35 and 0.8, and technological innovation still needs to be further developed. In conclusion, the development gap between eastern, central, and western China has further widened with time. This work provides possible research experience for China’s smart city construction and industrial construction.

Research on Optimization of the Thermal Performance of Composite Rammed Earth Construction

Rammed earth (RE) is a low-tech recyclable building material with good heat storage and moisture absorption performance that can better maintain the stability of the indoor thermal environment and improve indoor comfort. With innovations in and the development of new technology, the field of rammed earth construction technology is gradually expanding. However, deficiencies in the thermal insulation of traditional rammed earth structures make it impossible for them to meet China’s building energy codes in cold regions. This study constructs a comprehensive evaluation index of the thermal performance of rammed earth walls that is based on the heat transfer mechanism, optimizing the thickness of the boundary conditions of the building interior’s design temperature, as well as the energy demand and economic efficiency. This research also offers a new design for the thermal insulation of rammed earth construction by combining the building energy savings design code with WUFI Pro software. This study demonstrates that the optimum thickness of rammed earth construction in Beijing is about 360 mm, the thickness of extruded polystyrene board (XPS) is 50 mm (for public buildings) and 70 mm (for residential buildings), and the structural form of external insulation offers the highest performance benefit. In addition, this work also evaluates the risk of condensation inside composite rammed earth construction, finding that there is a risk of condensation on the exterior side of the wall and at the interface between the insulation panels and rammed earth wall, thus requiring an additional moisture-proof layer. In this study, thermal mass and insulation are fully considered and a design strategy for rammed earth construction given quantitatively, providing a theoretical basis for the application of rammed earth materials in cold regions.

国土空间生态修复与保护空间识别——以北京市为例

PDF HTML阅读 XML下载 导出引用 引用提醒 国土空间生态修复与保护空间识别——以北京市为例 DOI: 10.5846/stxb202103150692 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金重点项目（71533005）；中国科学院青年创新促进会（2013030） Spatial identification of territory space ecological conservation and restoration: A case study of Beijing Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:构建国土空间修复与保护识别体系可以有效实现区域生态系统修复与保护，然而，当前国土空间生态修复与保护研究和规划缺乏从系统性和完整性的角度识别关键生态修复与保护区。因此构建了系统的生态修复与保护空间识别方法，以实现区域协调发展、保障区域生态安全。基于该方法，以北京市为例，通过评估生态系统服务、生态系统质量和生态问题，构建生态修复与保护空间格局。研究结果表明：① 2000-2015年生态系统服务和质量退化区主要集中在平原区和密云水库北部，面积为760.4 km2；生态系统质量低下区主要分布在西南部山区和东北部山区，面积为4925 km2；水土流失问题区零星分布在山区，面积为130.1 km2；基于以上三者的北京生态修复建议区总面积5606 km2。②建议北京生态保护区6391 km2，主要分布在北部山区和西南部山区，保护了79.63%的水源涵养功能，74.97%的土壤保持功能，58.79%的洪水调蓄功能和60.3%的自然栖息地。本研究构建的生态修复与保护空间识别方法体系，为北京生态修复和保护规划与生态安全格局构建提供科学依据，还可以为其他地区的生态修复与保护规划提供参考。 Abstract:A robust identification system of territory space ecological restoration and conservation can make effective contribution to regional ecosystem restoration and conservation. However, current research and planning lack the identification of key ecological restoration and conservation areas from the perspective of systematicness and integrity. This study established a systematic spatial identification method for ecological restoration and conservation to provide basis for regional coordinated development and regional ecological security. On the basis of the method, taking Beijing as a case, the spatial pattern of ecosystem restoration and conservation was explored through assessing of ecosystem services, ecosystem quality and ecological problems. The results showed that:(1) the ecosystem quality and ecosystem services increased generally in Beijing from 2000 to 2015. Ecosystem quality of forest, shrub and grassland improved by 39%. Correspondingly, water retention service, soil conservation service and flood mitigation service increased by 11%, 3% and 10%, respectively. However, ecological degradation occurred in some regions because of nature or human activities impact. The degraded areas of ecosystem services and ecosystem quality from 2000 to 2015 were mainly concentrated in the plain and the north of Miyun Reservoir, covering a total area of 760.4 km2 dominated by farmland and urban land. The areas with low ecosystem quality were mainly distributed in the mountainous areas of southwest and northeast, covering an area of about 4925 km2 dominated by forest and shrub ecosystems. The areas with severe soil erosion were scattered in mountainous areas, covering an area of about 130.1 km2 dominated by farmland and shrub. The suggested ecological restoration regions in Beijing consisted of the above mentioned three, with a total area of about 5606 km2., accounting for 34.16% of the total area of Beijing. (2) The area of ecological conservation suggested was 6391 km2, accounting for 38.95% of the total area of Beijing, mainly distributed in the northern and southwestern mountainous areas. The forest, shrub, grassland and wetland accounted for 54.81%, 34.38%, 6.53% and 4.27% of the total area of the ecological conservation space, respectively. The ecological conservation areas of Beijing could conserve 79.63% of Beijing's water retention service, 74.97% of soil conservation, 58.79% of flood regulation and storage, and 60.3% of Beijing's natural habitat. The spatial identification system of ecological restoration and conservation constructed in this study could not only serve as scientific basis for ecological restoration and conservation planning and ecological security pattern construction in Beijing, but also provide references for ecological restoration and conservation in other areas. 参考文献 相似文献 引证文献

Theoretical analysis and experimental evaluation of vibration isolation system with broadband characteristic for laser tracker

High-energy synchrotron radiation source, as a large scientific device, is under construction in Beijing, China. This device is one of the fourth-generation synchrotron radiation sources with the highest brightness in the world. It will provide an important support platform for basic science and engineering science. As a kind of high-precision large-scale measurement equipment, laser tracker is used mainly in high-energy particle accelerator equipment installation, precision poses dynamic measurement and antenna feed dynamic motion precision engineering measurement field. At the construction site of high energy synchrotron radiation source, the laser tracker is often used to calibrate and pre-collimate the high energy source magnet equipment and carry on the tunnel measurement . However, the laser tracker is easily affected by the vibration of the surrounding environment, and the adverse vibration seriously affects its measurement accuracy and even causes the equipment to damage. In order to effectively control the influence of environmental vibration and ensure good static bearing capacity, a broadband vibration isolator for laser tracker is proposed. It is installed in the leg position of the triangular bracket of the laser tracker, which ensures the vibration isolation performance and good bearing capacity. For the above system, the equivalent single freedom nonlinear dynamic differential equation is established, and the steady-state response solution of the broadband isolator is obtained by using the complex variable-average method. The numerical finite element method is used to verify the correctness of the theoretical model and corresponding calculation results. On this basis, the stability of a nonlinear system is analyzed by harmonic balance method, and the influence of key designing parameter <i>K</i><sub>3</sub> on vibration isolation performance is considered. Combined with the complexity of the actual working environment of laser tracker, a variety of typical working conditions are set up for test, including long time static pressure test, vertical impact excitation and lateral displacement excitation tests, to evaluate the static stability and vibration control effect of broadband isolator. The experimental results show that the maximum static displacement of the laser tracker is about 2×10<sup>–5</sup> m under static pressure in a long time, and the maximum static load is within the allowable error range. When the occasional impacting is triggered, the installation of broadband isolator can make the combination quickly restore stability in about 2.95 s, exhibiting better vibration isolation performance. Under different dynamic loads, by comparing the acceleration frequency response curves of the laser tracker with and without the isolator, in the frequency band below the fundamental frequency of the laser tracker, the attenuation rate of the combined system can be up to about 97% with and without the vibration isolator. In the frequency band above the fundamental frequency, the attenuation rate of the combined system with and without the vibration isolation system can reach up to about 88%, and the effective vibration isolation frequency band is extended. The broadband vibration isolator meets all technical requirements.

Addressing the macroeconomic and hedonic determinants of housing prices in Beijing Metropolitan Area, China

This paper examined both the macroeconomic and hedonic determinants of housing prices in Beijing. The vector autoregression (VAR) model was used to explain the dynamic impacts of macroeconomic indicators on housing prices, and the geographical weighted regression (GWR) model was used to reveal the spatial variations in the effects of hedonic attributes on housing prices. The VAR results suggest that shocks to the macroeconomic indicators produce different dynamic changes in housing prices. Both an increase in the money supply and a decrease in the mortgage rates lead a rise in housing prices in the long term. Therefore, monetary policies and mortgage rates could be used as long-term financial tools to regulate the dynamics of housing prices. The GWR results show that the effects of hedonic attributes vary spatially. The size of a house has a negative impact on housing prices, especially in the downtown areas. The age of a house also has a negative impact on housing prices, especially in the suburbs. The effect of the number of bedrooms changes from positive in the downtown areas to negative in the suburbs. Furthermore, convenient accessibilities to critical amenities such as commercial centers, metro stations and high-quality schools contribute greatly to high housing prices in the downtown areas. The hedonic analysis of housing prices provides great implications for forming policy on urban planning, building design and public services construction. The core problem concerning urban planning, building design and public services construction in Beijing is the mismatch between working and living spaces. Therefore, relevant policy makings should focus on reducing the mismatch between working and living spaces, which is conductive to alleviating the spatial imbalance between housing supply and demand, narrowing the development gap within the city, and solving the urban diseases. Therefore, one important policy suggestion is that urban planning and public services construction should be upgraded to introduce more governmental offices, job opportunities, high-quality schools, commercial facilities and infrastructures into the suburbs. Another important policy suggestion is that the design for the floor area ratio and internal structures of new residential buildings should be planned to accommodate more residents and form better living environment in the downtown areas. Those suggestions can provide some guidance for solving urban problems in China and in other countries.

Design Optimization of a Mechanically Improved 499.8-MHz Single-Cell Superconducting Cavity for HEPS

Superconducting 499.8-MHz radio frequency (rf) cavities have been proposed for the High Energy Photon Source (HEPS), a 6-GeV diffraction-limited synchrotron light source currently under construction in Beijing. Being an active third-harmonic system, two cavities shall provide 3.5-MV rf voltage and 400 kW of beam power to enable a complex rf gymnastics required by a novel injection scheme. Adopting the veteran KEKB-type 500-MHz single-cell geometry, the cavity design has been focused on optimizing its mechanical properties. Various cavity wall thickness and external stiffening mechanisms were investigated to reinforce the cavity to ensure compliance to the pressure vessel codes under different working conditions from a bare cavity to a dressed cavity in the cryomodule. Small margins on operational pressure previously reported on this type of cavity have been largely improved with slightly reduced yet acceptable frequency tunability. Extensive design optimizations have been conducted aiming for lower stress, larger elastic buckling pressure, and higher frequencies of mechanical modes to cause microphonics, while the frequency tunability, pressure sensitivity, and Lorentz force detuning were being carefully monitored. In view of the HEPS’s lifetime, cavity fatigue was examined. This constitutes a comprehensive design optimization of the 499.8-MHz single-cell superconducting cavity with improved mechanical properties.

Beam-ion instability and its mitigation with feedback system

The beam-ion interaction is a potential limitation of beam performance in electron accelerators, especially where the beam emittance is of a great concern in future ultra-low emittance light source. "Conventionally", the beam instability due to beam-ion interaction is attributed to two types of effects: ion trapping effect and fast ion effect, which emphasize the beam-ion dynamics in different time scales. Whereas, in accelerators, the beam suffers from a mixture of ion trapping effect and fast ion effect, leading to a more complicated process and requiring a self-consistent treatment. To evaluate the beam characteristics, as emittance growth under the influence from beam-ion effect, a new numerical simulation code based on the "quasi-strong-strong" model has been developed, including modules of ionization, beam-ion interaction, synchrotron radiation damping, quantum excitation, bunch-by-bunch feedback, etc. In the study, we do not regularly distinguish the ion trapping effect and the fast ion effect, but treat beam-ion interaction more generally and consistently. The lattice of High Energy Photon Source, a diffraction limit ring under construction in Beijing, is used as an example to show the beam-ion effect. It is found that in this low emittance ring, the beam-ion instability is not a dominant mechanism in operation mode with a high beam current, but seriously occurs in a lower beam current region. When the beam-ion instability were significantly driven and can not be damped by the synchrotron radiation damping, the simulations show the bunch-by-bunch feedback system based on the Finite Impulse Response filter technique can be adopted to mitigate it effectively.

Development of fundamental power couplers for 166.6 MHz superconducting quarter-wave beta = 1 proof-of-principle cavities.

Superconducting 166.6 MHz β = 1 cavities of quarter-wave geometry have been chosen for a high energy photon source, a 6 GeV diffraction-limited synchrotron light source currently under construction in Beijing. Five cavities will provide the required 5.4 MV radio frequency (rf) voltage and 900 kW beam power. Each cavity will be equipped with one fundamental power coupler (FPC), delivering a minimum rf power of 180 kW to the beam. A 50 Ω coaxial structure with one planar warm window was employed. Its location was carefully selected to avoid electron bombardments on the ceramic window due to potential cavity field emission while preserving the required strong coupling. Focusing on optimized heat loads, a compact geometry was pursued to allow assembly with the cavity in a class 10 clean room, thus minimizing contamination. Two prototype FPCs have been fabricated and examined with high power on room-temperature test stands. The couplers were tested up to 50 kW continuous wave (cw) limited by the available solid-state amplifier. The rf conditioning was conducted initially in travelling-wave mode and later in a standing-wave setup with the variable phase of the reverse wave. All rf surfaces were thus exposed to a high field equivalent to 200 kW cw traveling wave. Being the most critical component, the window-inner-conductor assembly was conditioned up to 150 kW at 650 MHz on a hybrid test stand. Multipacting barriers were encountered as predicted and can be processed by rf conditioning. The design, fabrication, and high-power tests of the first 166.6 MHz FPCs are presented.

Analysis of land subsidence changes on the Beijing Plain from 2004 to 2015

Abstract. Land subsidence, as a surface response to the development, utilization and evolution of underground space, has become a global and multidisciplinary complex geological environment problem. Since the 1960s, land subsidence has been developing rapidly in the Beijing Plain area. Against the backdrop of the integration of Beijing, Tianjin and Hebei in addition to “southern water” (South-to-North Water Diversion Project, SNWDP) entering Beijing, the systematic study of the evolution mechanism of land subsidence is of great significance for the sustainable development of the regional economy. Firstly, this study used ENVISAT ASAR and RADARSAT-2 data to obtain surface deformation information for the Beijing Plain area from 2004 to 2015 and then verified the results. Secondly, the study area was divided into units using a 960 m×960 m grid, and the ground settlement rate of each grid unit from 2004 to 2015 was obtained. Finally, the Mann–Kendall test was performed on the grid to obtain the mutation information for each grid unit. Combined with hydrogeology and basic geological conditions, we have attempted to analyze the causes of the mutations in the grid. The results show that 2347 grid cells were mutated in a single year, with most of these distributed across the Yongding River alluvial fan and the middle and lower parts of the Chaobai River alluvial fan. A total of 1128 grid cells were mutated in multiple years, with the majority of these cells mainly distributed across the upper-middle area of the alluvial fan, near the emergency water source and at the edge of the groundwater funnel. This study aims to provide favorable technical support and a scientific basis for urban construction in Beijing.

Comparison of the suitability of plant species for greenbelt construction based on particulate matter capture capacity, air pollution tolerance index, and antioxidant system

Particulate matter (PM) pollution is an urgent urban environmental problem. However, plants can mitigate this pollution by filtering the air. Combining the PM capture capacity with the air pollution tolerance could be better evaluate the suitability of greenbelt plants. We selected nine dominant roadside plants growing at two sites in Beijing, and compared their PM capture capacity, morphological characteristics, biochemical characteristics, and air pollution tolerance index (APTI). Sophora japonica had the highest PM capture capacity (362.98 μg cm−2), and its wax layers could trap large amounts of PM2.5; this high efficiency is important for successful phytoremediation. Sophora japonica. Sabina chinensis, Ulmus pumila, and Euonymus japonicus also showed relatively high PM capture capacity. This is due to their complex cuticular wax layers, short petioles, rough surfaces, high stomata density, and dense canopy structures which reduce the possibility of resuspension of captured PM. Amount of PM captured per unit leaf area had a significant positive effect on the degree of membrane lipid peroxidation, indicating that species with high PM capture capacity suffered higher oxidative stresses. Air pollution showed the strongest negative effect size on chlorophyll contents of E. japonicas. While, S. japonica, S. chinensis, and U. pumila could prevent chlorophyll content decline under severe oxidative stress. Sophora japonica also had the highest APTI at both sites, indicating this species had the greatest tolerance to air pollution. Our findings suggest that S. japonica would be the most suitable species for greenbelt construction in Beijing, followed by S. chinensis, E. japonicus, and U. pumila.

Research on Surface Settlement of Subway Station Construction Using Pile-Beam-Arch Approach

The pile-beam-arch (PBA) approach is illustrated as a creative construction method in shallow-buried tunneling excavation of subway construction. Attentions have been paid to this method due to its unique advantages of construction technology. Subway station construction by using PBA approach will make disturbance to the ground surface. Research on surface deformation caused by PBA approach is of great significance to the surrounding environment and its structure. The example of subway construction in Beijing is presented as the research background, a three-dimensional model is established by using the Midas-GTS finite element numerical simulation software to simulate the practical excavation support conditions, and to analyze the surface settlement, the initial support structure settlement and crustal stress caused by PBA construction method.

HEPS-BPIX2: The hybrid pixel detector upgrade for high energy photon source in China

The High Energy Photon Source (HEPS) is a new research facility currently under construction in Beijing, China. HEPS-BPIX2 is the second prototype of photon counting pixel detector developed at Institute of High Energy Physics (IHEP) to comply with the requirements of the HEPS. It follows the first prototype, HEPS-BPIX, with a pixel size of 150μm x 150μm and frame rate up to 1.2 kHz at 20-bit dynamic range, but upgrades with transmission control protocol (TCP) hardware stack on 10 Gigabit Ethernet (10 GbE) for large-area multi-modules system. One million-pixel detector with 16 modules, covering an area of 16.32 cm x 18.3 cm, is integrated, and it has demonstrated the basic functionality with X-ray and synchrotron light. The readout system is organized in parallel with groups and in daisy-chain in each group, achieving 23 Gbps data at full 1.2 kHz frame rate.

Reflections on Beijing Rural Energy Policies and New Rural Construction ——Using Digital Information Means

In recent years, the Beijing construction in accordance with the philosophy of environmental protection, solid depth to carry out a series of policies and measures, such as rural energy structure optimization and adjustment; rural residential seismic energy-saving; village green landscaping. If displaying and recording movement states and regulars of the beautiful countryside construction through this information process, It will greatly strengthen regulation of the relationship between new rural people, to realize system optimization, make urban and rural become conducive to human survival and sustainable development of space.

Coordination of Economic Development and Ecological Compensation in Miyun Reservoir

Miyun reservoir, the most important water conservation in Beijing, is of great importance to ecological conservation area. However,the current Eco-compensation mechanism is not perfect and economy of the reservoir area is still not well resolved.In order to achieve the coordination of ecological protection and economic development, first we need to perfect the ecological compensation mechanism, establish reasonable compensation standards and promote diversification of compensation method. Also we need to reposition the area function, optimize the industrial structure of the district, speeding up the integration of urban and rural construction in Beijing.

Analysis on the Carbon Emission (CE) Arising from the Direct Energy Consumption (EC) of Beijing's Construction Industry

Taking the construction industry of Beijing as an example, we, first, accounted the energy consumption (EC) and carbon emission (CE) in 1990-2012. Then, we used the Partial Least Squares (PLS) method to analyze the drivers of the CE. It was found the EC and the CE of Beijings construction industry in 1990 was 8.1 PJ and 0.99 Mt, respectively. They grew up to 30.6 PJ and 4.52 Mt in 2012. The increasing number was 22.5 PJ and 3.53 Mt with an average annual growth rate of 6.23% and 7.15%. The sources of CE were mainly arising from electricity, diesel, gasoline and raw coal. The driver's size of GDP per capita (A) was bigger than population (P). The 1% increase of A or P would make the CE increase 1.758% or 0.105%, respectively. The classical hypothesis of Environmental Kuznet's curve did exist in the CE of Beijing's construction industry. The urbanization rate increased 1%, to some extent, would make the CE decrease 0.421%. The improvement of scientific study itself cannot make the CE decrease. Only when the gotten achievements were transformed into the concrete technology and used in real life, the CE might decrease. So, it was necessary to speed up the new-type urbanization strategies, the development pattern's upgrade and transformation of economy and to continue to carry out national relevant policies on controlling population growth.

An Effective Method of Evaluating Safety of Adjacent Buildings Influenced by Metro Construction in Beijing

With the growing demand for public transportation in big cities, metro construction is developed rapidly. It is much important to keep the adjacent buildings safe in the course of metro construction. In this paper, an effective method of evaluating safety of adjacent buildings influenced by metro construction in Beijing is suggested. It is composed with collection of related data, analysis of geotechnical condition, detection of building appearance quality, measurement of existing building, control standard of subgrade deformation and numerical prediction. Finally, an example is given to explain this method in detail.