新型有源机房式地箱组建广播电视网络的方案与分析

旧机房空间不够,新机房选址困难、建设难度大,建设周期长,郊区的新楼盘离机房距离远,如何低成本快速提供高带宽的双向网络是运营商共同关心的问题。根据广州有线电视的经验,介绍有源机房式地箱与CCMTS相结合的建设方案,可快速搭建网络,提供高带宽的互动高清电视业务和宽带业务。

北京老城区煤市街东侧迁改工程供配电设计

北京老城区改造是京津冀协同发展、适应首都定位和总体规划要求的重要工作。通过梳理前门大栅栏煤市街供配电现状,结合改造目标的要求,充分考虑改造区域的功能定位,确保改造后的供配电系统满足发展需求,将供配电设施融入改造后的整体环境,以创建和谐宜居的环境。

高等测绘教育在土地管理学科的现状与发展

介绍了中国土地管理学科的建设和课程设置概况，论述了该学科中的测绘教育基本情况和教学改革的进展。侧重介绍了该专业的地形、地籍、房产为一体的测量学教学改革之进展与体会。并对２１世纪的土地测量学的知识结构和教材建设提出了初步设想和展望。

Seismic facies response of tectonics and direction of block movement in the northeastern South China Sea

The close relationship between the structure,evolution,and resources environment of the South China Sea is a current research focus and also a focal point of our study.In this paper,we use regional seismic sections to analyze the relationship between seismic facies and the structure and tectonic evolution of the northeastern South China Sea and propose new points about the structure and the direction of block（land mass） motion.First,the tectonic features are clear and can be divided into five different structural units which are both linked and independent of each other.Second,it doesn＇t matter if the South China Sea basin pattern is extensional,weakly compressive,or strongly compressive,the regional tectonic stress field is unified.For the first time we find that two shallow subduction zones are recognized in the seismic profiles.All the tectonic blocks have accordion-fold-style structures,converging in the east,and the South China Sea exhibits different stages of basin development：growth, maturity,end,and termination.The block subduction and regional block dip directions are all aligned with the regional stress field.

A Comparative Study of Fish Assemblages Near Aquaculture, Artificial and Natural Habitats

Habitat plays a critical role in regulating fish community structure. Using the data collected from a monthly trammel net survey in Ma'an archipelago off the east coast of China, we evaluated impacts of five different habitats(artificial reefs, mussel farms, cage aquaculture, rocky reefs and soft bottom) on fish assemblages. This study suggests that artificial reefs(AR) have significantly higher species richness, abundance and diversity than mussel farms(MF) or soft bottom(SB) habitats during most seasons, and that fish taxa in the AR habitats are similar to those in the rocky reef(RR) habitats. Two different fish assemblage patterns were revealed in the study area using non-metric multidimensional scaling ordination: an assemblage dominated by reef fishes(especially by Scorpaenidae species) in AR, RR and cage aquaculture(CA) habitats and an assemblage dominated by Sciaenidae species in MF and SB habitats. We suggest that reef fishes play a key role in differentiating fish community structures in the study area. Although few differences in fish abundance and diversity were found between the CA and SB habitats, a more diverse age structure was observed in the CA habitats. A much more complex fish assemblage and enhanced population of local species were established as a result of the presence of both floating and fixed artificial structures, probably through improved survival rates.

On-site tests to estimate aquifer permeability of drainage area of south caisson anchorage construction of Taizhou Bridge

During the construction of the south caisson anchorage of Taizhou Bridge, the drainage area is located in the lower reaches of the Yangtze River and the permeability of stratums there is considerable. In order to maintain progress and guarantee safety during the sinking of the caisson, water should be drained in the initial period. Subsequently, detailed information about the aquifer permeability is required to make sure that the drainage will proceed successfully, which consequently necessitates the on-site estimation of the aquifer permeability in the drainage area. Therefore, the traditional pumping test and slug test are implemented respectively on site. The comparison of computational results of these two tests indicates that they are consistent overall. Notwithstanding, as slug test can be conducted with portable facilities in a short time and the manipulation is easy and few people need to be involved, the advantages of slug test is conspicuous compared with the traditional pumping test. It could be speculated that slug test will gain a prevalent application in the measurement of aquifer permeability in the future.

Centrifugal model test and numerical simulation of vertical earth pressure on soft foundation box culvert

To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and the comparisons with the current methods to determine the load on a culvert were completed. The results of the model test and numerical analysis are in satisfactory agreement, which shows that the direction of the shear stress between the culvert and the adjacent embankment depends on the differential settlement between them. A vertical earth pressure concentration appears on the culvert with a rigid piles foundation because of a downward shear stress. The ratio of the load on a soft foundation culvert and the overburden pressure above the culvert raises first and then decreases as the backfill height increases. In order to reduce the load on a culvert, it is suggested to limit the stiffness difference of the foundations under the culvert and embankment and to use a light backfill over the culvert.

Preliminary Estimation of Torsion of Curved Bridges Subjected to Earthquake Loading

This paper focuses on the seismic response of the curved and post-tensioned concrete box girder bridges. More specifically, it investigates how the curvature influences the response of a bridge subjected to earthquake. Parametric analysis of different radius of curvature is performed and the internal forces, torsion moment, axial and shear along the bridge are calculated. Two types of connections are investigated, the monolithic connection and deck connection with bents and abutments with rubber bearing. The response spectrum seismic analysis was performed. The models were designed, according to the provisions of EC8-part 2, EC2 and the Greek regulations E39/99. Diagrams relating the curvature with the torsion moment have been obtained from the results of parametric analysis. These diagrams could be used by engineers for preliminary design of such kind of bridges.

Analysis of the Competition of Ports in the Middle East Container Ports Using HHI

The market concentration of selected 24 container port/terminal in the Middle East region was evaluated. Data collected for 6 years （2009-2014）, HHI （Herfindahl-Hirschman index technique） was used to analyse the market behaviour and the movement of the market towards monopoly or to lead to PPC （pure and perfect competition）. Based on the above, by analyzing the defined market data, it was found to be a promising market and tends to competition. Of course, this serves the interest of the client, which is the efficiency and speed of cargo handling safely and at the lowest cost.

An Opinion Poll for the Establishment of a Bioethanol Plant Utilizing Local Resources and a Fuzzy Inference System

The cultivation of sweet sorghum （sorghum bicolor） is still one of the new promising energy crops for bioethanol production nowadays. An opinion poll for the establishment of a bioethanol plant utilizing local resources such as the cultivation of sweet sorghum and the zeolite deposits was held. Data were collected by heads of selected households of the Municipality of Trigono （Evros, Greece）. The simple random sampling was applied and a face-to-face interviewing and filling in of the forms of a questionnaire was conducted. It was estimated that some 44,778-55,971 acres of land should be cultivated with sweet sorghum for a satisfactory production of bioethanol in a bioethanol plant in the order of 120,000-150,000 tons/year. Furthermore, in this paper an optimum solution was estimated by using of the Fuzzy Logic Toolbox of Matlab （Intelligent system） which is formulated as follows ＂the bioethanol plant absorbing the sweet sorghum＇s production of a cultivating area of 46,600 acres and operating 12 hours/day would produce 125,000 tons of bioethanol annually＂. Such a vast area of land would offer occupation to a significant number of young farmers for the cultivation of sweet sorghum.

Container Cargo Simulation Modeling for Measuring Impacts of Infrastructure Investment Projects in Pearl River Delta

In the Pearl River Delta (PRD), there is severe competition between container ports, particularly those in Hong Kong, Shenzhen, and Guangzhou, for collecting international maritime container cargo. In addition, the second phase of the Nansha terminal in Guangzhou’s port and the first phase of the Da Chang Bay container terminal in Shenzhen opened last year. Under these circumstances, there is an increasing need to quantitatively measure the impact these infrastructure investments have on regional cargo flows. The analysis should include the effects of container terminal construction, berth deepening, and access road construction. The authors have been developing a model for international cargo simulation (MICS) which can simulate the movement of cargo. The volume of origin-destination (OD) container cargo in the East Asian region was used as an input, in order to evaluate the effects of international freight transportation policies. This paper focuses on the PRD area and, by incorporating a more detailed network, evaluates the impact of several infrastructure investment projects on freight movement.

Response of Plant Community Carbon and Nitrogen Stoichiometry to Experimental Warming on the Qinghai-Tibet Plateau

Low temperature is an important limiting factor for alpine ecosystems on the Tibetan Plateau. This study is based on data from on-site experimental warming platforms(open top chambers, OTC) at three elevations(4300 m, 4500 m, 4700 m) on the Qinghai-Tibet Plateau. The carbon and nitrogen stoichiometry characteristics of plant communities, both above-ground and below-ground, were observed in three alpine meadow ecosystems in August and September of 2011 and August of 2012. Experimental warming significantly increased above-ground nitrogen content by 21.4% in September 2011 at 4500 m, and reduced above-ground carbon content by 3.9% in August 2012 at 4300 m. Experimental warming significantly increased below-ground carbon content by 5.5% in August 2011 at 4500 m, and the below-ground ratio of carbon to nitrogen by 28.0% in September 2011 at 4300 m, but reduced below-ground nitrogen content by 15.7% in September 2011 at 4700 m, below-ground carbon content by 34.3% in August 2012 at 4700 m, and the below-ground ratio of carbon to nitrogen by 37.9% in August 2012 at 4700 m. Experimental warming had no significant effect on the characteristics of community carbon and nitrogen stoichiometry under other conditions. Therefore, experimental warming had inconsistent effects on the carbon and nitrogen stoichiometry of plant communities at different elevations and during different months. Soil ammonium nitrogen and nitrate nitrogen content were the main factors affecting plant community carbon and nitrogen stoichiometry.