中国古建筑的斗拱及其建筑模数价值分析

阐述了斗拱在中国建筑中的历史渊源、组合、称谓及其作用,具体介绍中国古建筑中的材分制、口分制,并对现代建筑模数与古代建筑模数的关系进行价值分析。

CFD analysis of sound pressure in tank gun muzzle silencer

The high pressure waves generated due to muzzle blast flow of tank gun during firing is a critical issue to examine. The impulsive noise from the gun has various negative effects such as damage of human bodies, damage of structures, creating an environmental, social problem and also military problems such as exposure of location of troops. This high pressure impulsive sound, generated during the blast flow, was studied and attenuated. An axisymmetric computational domain was constructed by employing Spalart Allmaras turbulence model. Approximately 90% of pressure and 20 dB of sound level are reduced due to the use of the three baffle silencer at the muzzle end of the gun barrel, in comparison with the tank gun without silencer. Also, the sound pressure level at different points in the ambient region shows the same attenuation in results. This study will be helpful to understand the blast wave characteristics and also to get a good idea to design silencer for large caliber weapon system.

Studies of Oral Preparation of Low Molecular Weight Heparin

ＳｔｕｄｉｅｓｏｆＯｒａｌＰｒｅｐａｒａｔｉｏｎｏｆＬｏｗＭｏｌｅｃｕｌａｒＷｅｉｇｈｔＨｅｐａｒｉｎＦｏｒＭａｓｔｅｒ＇ｓＤｅｇｒｅｅ：Ｈｕｉ－ＦｅｉＣｕｉＳｕｐｅｒｖｉｓｏｒ：Ｐｒｏｆ．Ｔｉａｎ－ＭｉｎＺｈａｎｇＤｅｐａｒｔｍｅｎｔｏｆＢｉｏｃｈ...

Distribution and mechanism of gently dipping fractures subjected to river incision: A case study from Nujiang River, China

Gently dipping fractures subjected to river incision are widely distributed on rock slopes.In this paper,a rock slope on the Nujiang River(China)is investigated to study the role of gently dipping fractures in the rock slopes evolution.Detailed field surveys indicate that gentle fractures are concentrated in four main zones.Moreover,the kinematics of the fracture system suggest that the genesis of these fractures can be synthesized into a progressive evolution model.This model indicates that the joints begin with the formation of an array of en echelon cracks that are subjected to continued crack elongation and shearing before ultimately approaching one another and interacting to form a complex joint system.Geomechanical analysis is performed to reveal the mechanisms of this genesis,and three main fracture patterns are identified based on the slope stress and are classified with respect to the slope evolution.Based on the detail field investigations and the evolutionary history of the river valley,we propose that intermittent incision by the river was the main factor contributing to the concentrated distribution of gently dipping joints.

The Demographic Impact on Credit Scores＂ Evidence From Statistical Methods and Geographic Information Systems （GIS） Mapping

Average credit scores for people in the United States （US） differ from state to state. Some states have high, and some states have low average credit scores. Since lenders and employers use credit scores to make loan and employment decisions, people living in states where average credit scores are high should experience the benefits of living where credit scores tend to allow more favorable loan and employment decisions. Although credit scores are the direct result of credit histories, credit histories may be impacted by demographic factors. If the demographic factors that impact credit histories are identified, ways to improve credit scores are likely to be discovered and available to people and state government policymakers. This study looks for demographic factors to indirectly explain the average credit scores for people living in each state of the US. The methodology includes statistical analyses and geographic information systems （GIS） mapping. Statistical analyses provide evidence to suggest that state average credit scores are explained by the demographic factors of education, family, income, and health. GIS mapping reveals clusters of states with similar demographics and credit scores.

Application of PID Controller Based on BP Neural Network in Export Steam’s Temperature Control System

By combining the Back-Propagation （BP） neural network with conventional proportional Integral Derivative （PID） controller, a new temperature control strategy of the export steam in supercritical electric power plant is put forward. This scheme can effectively overcome the large time delay, inertia of the export steam and the influencee of object in varying operational parameters. Thus excellent control quality is obtaitud. The present paper describes the development and application of neural network based controller to control the temperature of the boiler＇s export steam. Through simulation in various situations, it validates that the control quality of this control system is apparently superior to the conventional PID control system.

How “Made-in-China” Boosts U.S.Employment-An Empirical Analysis of “U.S.Content” in China’s Exports of Manufactured Goods

This paper aims to examine the specific ways in which China＇s exports of manufactured goods to the United States boost the U.S. job market. Using the OECD STAN Bilateral Trade Database by Industry and End-use Category to calculate the share of U.S. intermediate products used in the manufactured goods China exports to the U.S., this paper finds that the ＂U.S. content＂ in China＇s exports of manufactured goods to the U.S. increases with the technology content of the goods and shows a decreasing trend over time. From 2006 to 2010, the average ＂US. content＂ in China＇s exports of manufactured goods to the U.S. was 1%, and such content in China＇s exports of high-end manufactured goods was 1.6%. On this basis and using the employment-output ratio in the U.S. Employment Demand Matrix, this paper concludes that as many as 1.71 million jobs have been created by the U.S. intermediate products used in China＇s exports of manufactured goods to the U.S. during the same period. Thus, the development of Sino-U.S. trade has a positive impact on the job market in the U.S.. By contrast, instead of improving the employment situation in the U.S., the RMB appreciation proposed by the U.S. might even have a negative effect.

Export Value-Added of China’s Manufacturing Sector:Estimation and Mechanism Analysis

Estimation of domestic and overseas value-added of manufacturing sector is an important and difficult subject for the science-based evaluation of a country＇s trade interests under global value chain. Traditional HIY approach overestimates the domestic value- added of export. Although Koopman＇s method made certain improvements, it cannot utilize traditional I/O matrix and direct input coefficient matrix under the condition of incomplete information. By creating GAMS model, this paper addresses the above-mentioned problems and employs an improved model for the estimation of variations in domestic and overseas value-added of Chinese exports between 2002 and 2012. Our results indicate that by neglecting the export of processing trade, HIY approach overestimates the domestic value- added ratio of Chinese exports. As more imported intermediate inputs have been used in the export of processing trade, the estimation result of this paper have corrected deviations in the forecast of overseas value-added ratio and its tendencies based on HIY method Further analysis of specific factors of domestic value-added of export led to the discovery that the domestic value-added of export of processing trade and mixed trade is highly vulnerable to the impact of international capital inflow. It can be seen that the improved method for the estimation of value-added has indeed corrected the deviations in the estimation of China＇s value-added. In conclusion, China should accelerate the development of export of non- processing trade and trade in high-end services, and balance the relationship of export between local firms and foreign-funded firms, with a view to improving trade dependence and increasing the trade status of Chinese manufaeturing firms in global value chain.

Does hukou still matter？ The household registration system and its impact on social stratification and mobility in China

The household registration system has been a basic institutional arrangement in Chinese society. Under this system, registered residence （hukou） plays an important role in resource allocation and interest distribution, and thus exerts a significant impact on social stratification and mobility. After nearly three decades of reform and opening up, does it still play a role, and, if so, what is this role？ Drawing on data from the China General Social Survey, we find that China＇s social stratification is characterized by the simultaneous existence of differentiation between urban and rural hukou and hierarchy within urban hukou; furthermore, there is a positive correlation between one＇s opportunities for social mobility and the possibility of changing and transferring one＇s hukou. Despite the increasing social mobility ensuing from market-oriented transformation, the hukou hierarchy and its structural influence on mobility within the institutional framework persist. The strongly conglutinative nature of the household registration system has given rise to social disparities. The basic direction for reform of the system should be unification ofhukou and free choice of movement from one place to another.

Recognition on the forming-vanishing process and underlying mechanisms of the hypoxia off the Yangtze River estuary

On the basis of compiled multidisciplinary historical data in 2006-2007 and incorporation of relevant simulation results and re- mote sensing data, we performed an in-depth study of the generation and dissipation process of the hypoxic zone and its distribu- tion morphology and structure off the Yangtze River estuary, Based on the hydrological circulation dynamics, reproduction of phytoplankton （leading to the decomposition of organic matter）, and other factors, we comprehensively and systematically inves- tigated the generation and dissipation of the hypoxic zone and underlying mechanisms for the seasonal variation in its position, explored the multi-factorial synergistic reactions during the generation and dissipation process of the hypoxic zone, and revealed the controlled mechanism for the morphology and structure of the hypoxic zone＇s distribution. Our studies indicate that in the winter and spring seasons, the hydrological environment off the Yangtze River estuary provides a water body with relatively low contents of dissolved oxygen （DO）, which is the background for the formation of a hypoxic zone. After entering into the summer season, the hypoxic zone gradually develops towards the north and becomes mature. Because of the impact of the terrain, local decomposition of organic matter, and upwelling of the Kuroshio subsurface water in July-August, the bypoxic zone off the Yang- tze River estuary exhibits the characteristics of discontinuous distribution in space and has a south and north ＂dual-core＂ structure in the inner continental shelf. In addition, there is a hypoxic core in the eastern outer continental shelf. The degrees of hypoxia vary for different areas; they are strongest overall in the north, next strongest in the south; they are weakest on the outer continen- tal shelf. In summer, the hypoxic zone in the north is related to the northward differentiation of the southern hypoxic zone and re- sults from local development and intensification. In August, the hypoxic zone in the north reaches its peak, and after September, it rapidly retreats southward and disappears because of weakening stratification. In the fall, there is hypoxic zone along the coast of Zhejiang in the south, and there is also a low-DO area to the southwest of Jeju Island, with both zones disappearing rapidly. In addition, the change of dynamic environment also causes the low-DO area of the outer continental shelf to move outward in the fall. The variation in the intensity of the stratification and its cumulative effects as a barrier of vertical DO transportation over long pe- riods of time have a significant impact on the degree of hypoxia in the hypoxic zone. In addition, the seasonal variations in the size of the stratified region, intensity of each current system/water mass, upwelling, front, and high-value area of phytoplankton biomass jointly restrict the extension of the hypoxic zone in the inner continental shelf and latitudinal （south-north direction） movement of its location off the Yangtze River estuary. The combined effect of dynamic factors, such as that of the Kuroshio subsurface water, causes a low-DO core in the outer continental shelI： The bottom cold water to the north of the East China Sea is the dynamic basis for the formation of the low-DO area to the southwest of Jeju Island during the fall season. The special seabed to- pography and mud area distribution off the Yangtze River estuary have a certain degree of influence on the development of the hypoxic zone. The generation and dissipation of the hypoxic zone and its distribution morphology off the Yangtze River estuary, and seasonal variation of its structure and position are a result of the synergistic effects of various factors.

STUDY OF SOURCES OF SCORE VARIABILITY IN PERFORMANCE ASSESSMENT USING MFRM:A CASE OF SPEAKING TEST IN PETS BAND3

As direct measure of learners' communicative language ability, performance assessment (typically writing and speaking assessment) claims construct validity and a strong power for predictive utility of test scores. However, it is also of common concern that the subjectivity of rating process and the potential unfairness for test takers who encounter different writing prompts and speaking tasks would constitute threats to reliability and validity of test scores, especially in those large-scale and high-stakes tests. Therefore, appropriate means for quality control of subjective scoring should be held essential in test administration and validation. Based upon raw scores from one administration of speaking test in PETS Band3 held in Hangzhou, the present study investigates and models possible sources of score variability within the framework of Many-Facet Rasch Model (MFRM). MFRM conceptualizes the possibility of a examinee being awarded a certain score as a function of several facets — examinee ability, rater severity, domain difficulty and step difficulty between the adjacent score categories and provides estimates of the extent to which the examinee's test score is influenced by those facets. Model construction and data analysis was carried out in FACETS Version 3.58, computer program for conducting MFRM analysis. The results demonstrate statistically significant differences within each facet. Despite the generally acceptable rater consistency across examinees and rating domains, fit statistics indicate some unexpected rating patterns in certain raters such as inconsistency and central tendency, to be avoided through future rater training. Fair scores for each examinee are also provided, minimizing the variability due to facets other than examinees' ability. MFRM manifests itself as effective in detecting whether each test method facet functions as intended in performance assessment and providing useful feedback for quality control of subjective scoring.

Changes of multiple cropping in Huang-Huai-Hai agricultural region,China

Multiple cropping index （MCI） is the ratio of total sown area and cropland area in a region, which represents the regional time intensity of planting crops. Multiple cropping systems have effectively improved the utilization efficiency and production of cropland by increasing cropping frequency in one year. Meanwhile, it has also significantly altered biogeochemical cycles. Therefore, exploring the spatio-temporal dynamics of multiple cropping intensity is of great significance for ensuring food and ecological security. In this study, MCI of Huang-Huai-Hai agricultural region with intensive cropping practices was extracted based on a cropping intensity mapping algorithm using MODIS Enhanced Vegetation Index （EVI） time series at 500-m spatial resolution and 8-day time intervals. Then the physical characteristics and landscape pattern of MCI trends were analyzed from 2000-2012. Results showed that MCI in Huang-Huai-Hai agricultural region has increased from 152% to 156% in the 12 years. Topography is a primary factor in determining more stable in hilly area than in plain area. An the spatial pattern dynamics of MCI, which is increase from 158% to 164% of MCI occurred irplain area while there was almost no change in hilly area with single cropping. The most active region of MCI change was the intersection zone between the hilly area and plain area. In spatial patterns, landscape of multiple cropping systems tended to be homogenized reflected by a reduction in the degree of fragmentation and an increase in the degree of concentration of cropland with the same cropping system.

A multi-modular shunt active power filter system and its novel fault-tolerant strategy based on split-phase control and real-time bus communication

We first present a new multi-modular shunt active power filter system suitable for large-capacity compensation. Each module in the system has the same circuit topology, system functionality, and controller design, to achieve coordination control among the modules. The module＇s reference signals are obtained by multiplying the total reference signal by the respective distribution coefficient. Next, a novel fault-tolerant approach is proposed based on split-phase control in the a-b-c frame and real-time bus communication. When a phase fault occurs, instead of halting the whole module, the proposed strategy isolates only the faulted bridge arm, and then recalculates the distribution coefficients and transfers the compensation capacity to the same phases of the other normal modules, resulting in a continuous operation of the faulted module and optimization of the remaining usable power devices. Through steady-state analysis of the post-fault circuit, the system stability and control reliability are proven to be high enough to guarantee its engineering application value. Finally, a prototype is established and experimental results show the validity and feasibility of the proposed multi-modular system and its fault-tolerant control strategy.