基于数控张拉技术的预应力张拉数据远程管理平台的开发与应用

在预应力工程的施工当中,预应力张拉施工是一个非常重要的部分,建筑结构预应力的施工情况,对于整个工程的安全性、耐久性都有着重要的影响。对于预应力的情况,应当进行详细的了解和掌握,才能够及时的发现其中存在的问题,并采取有效的措施进行解决。对此,可以基于数控张拉技术,积极开发预应力张拉数据远程管理平台,并在实际施工中对其进行充分的应用,从而更好的对工程结构预应力进行控制。

钢材拉伸试验数据的同质性判别

具有同质性的拉伸试验数据是确定钢材机械性能指标的依据,判别试验数据的同质性,剔除无效数据,是分析拉伸试验数据具有同质性的前提。应用数理统计理论,建立了试验数据同质性的判别方法。基于桥梁用Q420NHY中厚板拉伸试验数据,在双侧置信度为99%时,判别了试验数据的同质性,确定了Q420NHY钢的机械性能指标。研究表明:拉伸试验数据的同质性对钢材机械性能指标的影响不可忽视。

P2P模式下协同软件数据传输方式的分析与研究

本文主要是对P2P模式下的协同软件关于数据处理的一些研究。针对GK-Star模型协作区存在的问题,就数据传输方面提出了具体的改进方案,改变传统的"推数据"方式为"推、拉数据"相结合的方式。通过方案的实施,大大提高了系统性能。

奥氏体不锈钢预应变效果评价

对奥氏体不锈钢进行预应变是为了获得良好的机械性能,预应变效果评价是改进钢材生产工艺的基础。应用概率论与数理统计知识,建立了预应变效果的评价体系:用F分布评价预应变对机械性能参数标准差的改变效果,用t分布评价预应变对机械性能参数均值的改变效果。以奥氏体不锈钢S30408的预应变效果评价为例,基于液氮温度下的有效拉伸试验数据,在双侧置信度为99%时,评价了S30408钢的9%预应变效果:(1) 9%预应变明显提高S30408钢屈服强度均值,其标准差基本不变;(2) 9%预应变对于S30408钢抗拉强度的均值与标准差基本无影响。

Glacier Fluctuations between 1975 and 2008 in the Greater Himalaya Range of Zanskar,Southern Ladakh

Glaciers in the Himalaya are often heavily covered with supraglacial debris,making them difficult to study with remotely-sensed imagery alone.Various methods such as band ratios can be used effectively to map clean-ice glaciers;however,a thicker layer of debris often makes it impossible to distinguish between supraglacial debris and the surrounding terrain.Previously,a morphometric mapping approach employing an ASTER-derived digital elevation model has been used to map glaciers in the Khumbu Himal and the Tien Shan.This study on glaciers in the Greater Himalaya Range in Zanskar,southern Ladakh,aims (i) to use the morphometric approach to map large debris-covered glaciers;and (ii) to use Landsat and ASTER data and GPS and field measurements to document glacier change over the past four decades.Field work was carried out in the summers of 2008.For clean ice,band ratios from the ASTER dataset were used to distinguish glacial features.For debris-covered glaciers,topographic features such as slope were combined with thermal imagery and supervised classifiers to map glacial margins.The method is promising for large glaciers,although problems occurred in the distal and lateral parts and in the fore field of the glaciers.A multi-temporal analysis of glaciers in Zanskar showed that in general they have receded since at least the mid-to late-1970s.However,some few glaciers that advanced or oscillated - probably because of specific local environmental conditions - do exist.

焊后热处理对P92钢焊接接头显微组织和力学性能的影响研究

P92钢是在P91钢的基础上微调元素成分得到的美标马氏体耐热钢。该种金属材料在各类高压蒸汽管道中有广泛应用。相较P91钢,P92钢增加了钨元素和硼元素,同时在元素成分比例方面提升了钨元素和钼元素含量。通过元素比例的调整P92钢在耐高温以及耐腐蚀性上优于P91钢。在加工过程中,由于进行了元素比例调整,因此其高温蠕变断裂强度获得提升。以超超临界压发电机组主蒸汽管道为例,使用P92钢能够在保障强度、耐高温性、耐腐蚀性的基础上降低管道整体重量,在不改变基础结构设计的前提下有效提升整体应用效果。合金材料显微组织情况及其力学性能直接影响该材料在实践应用中的整体效果。P92钢在加工处理过程中,需要应用到焊后热处理技术,对该材料进行研究时应重点分析,经焊后热处理后P92钢在焊缝部位的纤维组织以及力学性能情况。

Improvement of Glacial Lakes Detection under Shadow Environment Using ASTER Data in Himalayas, Nepal

The detection of glacial lake change in the Himalayas, Nepal is extremely significant since the glacial lake change is one of the crucial indicators of global climate change in this area, where is the most sensitive area of the global climate changes. In the Hima- layas, some of glacial lakes are covered by the dark mountains＇ shadow because of their location. Therefore, these lakes can not be de- tected by conventional method such as Normalized Difference Water Index （NDWI）, because the reflectance feature of shadowed glacial lake is different comparing to the ones which are located in the open flat area. The shadow causes two major problems： 1） glacial lakes which are covered by shadow completely result in underestimation of the number of glacial lakes; 2） glacial lakes which are partly iden- tified are considered to undervalue the area of glacial lakes. The aim of this study is to develop a new model, named Detection of Shadowed Glacial Lakes （DSGL） model, to identify glacial lakes under the shadow environment by using Advanced Space-borne Ther- mal Emission and Reflection Radiometer （ASTER） data in the Himalayas, Nepal. The DSGL model is based on integration of two dif- ferent modifications of NDWI, namely NDWls model and NDWIshe model. NDWI~ is defined as integration of the NDWI and slope analysis and used for detecting non-shadowed lake in the mountain area. The NDWIshe is proposed as a new methodology to overcome the weakness of NDWI~ on identifying shadowed lakes in highly elevated mountainous area such as the Himalayas. The first step of the NDWIshe is to enhance the data from ASTER 1B using the histogram equalization （HE） method, and its outcome product is named AS- TERho. We used the ASTERhe for calculating the NDWIhc and the NDWIshe. Integrated with terrain analysis using Digital Elevation Model （DEM） data, the NDWIshe can be used to identify the shadowed glacial lakes in the Himalayas. NDWIs value of 0.41 is used to identify the glacier lake （NDWI~ 〉 0.41）, and 0.3 of NDWIshe is used to identify the shadowed glacier lake （NDWIsho 〈 0.3）. The DSGL model was proved to be able to classify the glacial lakes more accurately, while the NDWI model had tendency to underestimate the presence of actual glacial lakes. Correct classification rate regarding the products from NDWI model and DSGL model were 57% and 99%, respectively. The results of this paper demonstrated that the DSGL model is promising to detect glacial lakes in the shadowed en- vironment at high mountains.

Contemporary Crustal Motion and Deformation of South America Plate

This paper presents the contemporary motion and active deformation of South America plate and relative motion of Nazca-South America plate using space geodetic data. The South America plate is moving at average 14.5 mm/a with an azimuth of 15.2° and shrinking in the west-east at 10.9 mm/a. The geodetic deformations of sites with respect to the South America plate are in quite good agreement with the estimated deformations from NNR-NUVEL1A, but the deformation of the western South America regions is very large.

Solubility of Ammonia in Ethylene Glycol Between 303K and 323K under Low Pressure from 0.030 to 0.101 MPa

The solubility of ammonia in ethylene glycol is measured by an isothermal solubility equilibrium method at temperatures of （303.2, 308.2, 313.2, 318.2 and 323.2） K and total pressures of （0.030, 0.040, 0.050, 0.060, 0.070, 0.080, 9.090 and 0.101） MPa. The molality of ammonia in ethylene glycol ranges from 1.925 mol·kg-1 to 8.265 mol·kg-1. The experimental results are used to determine Henry＇s law constant of ammonia in ethylene glycol Furthermore, experimental data are correlated by applying the thermodynamic model on the basis of extended Raoult＇s law, extended Henry＇s law, corresponding-states correlations and Pitzer＇s molality scale based equation. The overall average relative deviation between the calculated data and the experimental data of Henry＇s law constant and ammonia solubility are 2.029% and 2.164% respectively.

Statistical Characteristics of ENSO Events in CMIP5 Models

By applying the historical-run outputs from 24 Coupled Model Intercomparison Project Phase 5(CMIP5) models and the NOAA Extended Reconstructed SST V3 b dataset(ERSST), the characteristics of different types of ENSO in the selected CMIP5 models, including cold-season-matured Eastern Pacific(C-EP) ENSO, warmseason-matured EP(W-EP) ENSO, cold-season-matured Central Pacific(C-CP) ENSO, and warm-season-matured CP(W-CP) ENSO, were examined in comparison with those in the ERSST dataset. The results showed that, in general, consistent with observations, EP ENSO events in most of the model runs were relatively much stronger than CP ENSO events, and cold-season-matured ENSO events were relatively much more frequent than warm-season-matured ENSO events for both EP and CP ENSO events. The composite amplitudes of ENSO events in most of the models were generally weaker than in observations, particularly for EP El Ni?o and CP La Ni?a. Moreover, most of the models successfully reproduced the amplitude asymmetries between El Ni?o and La Ni?a for cold-season-matured EP and CP ENSO events, exhibiting an average stronger/weaker EP El Ni?o/La Ni?a regime and a weaker/stronger CP El Ni?o/La Ni?a regime. Most of the models, however, failed to reproduce the observed regimes of stronger/weaker W-EP El Ni?o/ La Ni?a and weaker/stronger W-CP El Ni?o/La Ni?a.

Fabrication characteristics and tensile strength of novel Al2024/SiC/red mud composites processed via stir casting route

The stir casting technique was used to fabricate aluminum2024matrix hybrid composites reinforced with SiC(5%,mass fraction)and red mud(5%-20%,mass fraction)particles.The developed composites were characterized by using scanning electron microscopy(SEM)and electron dispersive spectrum(EDS)techniques.Further,Taguchi’s approach of experimental design was used to examine the tensile strength of the hybrid composites(with minimum number of experiments).It was found that the reinforcing particles were well dispersed and adequately bonded in the hybrid composites.The density and porosity of the hybrid composites were reduced with the increase in reinforcement content.The tensile strength of the composites increased with the increase in the red mud content and the ageing time.The developed model indicated that the red mud content had the highest influence on the tensile strength response followed by the ageing time.Overall,it was found that Al2024/SiC/red mud composites exhibited superior tensile strength(about34%higher)in comparison to the Al2024alloy under optimized conditions.

Research development of digital maintenance and management system for long-span cable-stayed bridges

Digital cable-stayed bridge maintenance and management system （DCBMS） was developed for the need of maintenance and management of long-span cable-stayed bridges. In this paper, the major functions and theoretical application of eight modules were systematically stated with the background of Harbin Songhua River cable-stayed bridge, which include data management module, inspection and measurement module, assessment module, finite dement analysis module, disease diagnosis and prediction module, maintenance module, query module and help module. By analyzing and calculating the data from manual inspection database, basic database and health monitoring subsystem, DCBMS can accomplish the functions like life prediction, disease diagnosis, comprehensive assessment, maintenance and management of bridges. Therefore, the maintenance and management of long-span cable-stayed bridges can be made digital, professional and scientific. By running this system, a real-time and specific technical guidance can be provided for the maintainers and managers of long- span cable-stayed bridges.

异地宽带线上和线下两种受理模式的数字化应用

宽带业务作为电信行业的基础服务,直接影响通信企业的发展和收入,因此其用户规模和服务质量至关重要。随着互联网业务的发展和客户需求的转变,客户在非宽带资源归属地区受理异地宽带的诉求日益凸显。传统的异地宽带受理需客户到宽带资源归属地受理和开通,无法规避地域限制完成随时随地的受理和开通,客户受理十分不便。因此,打破传统异地宽带受理的系统支撑模式,以客户为中心重塑异地宽带业务办理的数字化流程十分必要。本文在分析异地宽带受理存在问题的基础上,提出了基于实体渠道和线上渠道的数字化解决方案。通过关键技术和手段,如数据拉通、流程拉通和中台赋能,实现了异地宽带随时随地自主化、快捷化的受理和全流程可视化跟踪,提升了客户的便利性和满意度。

Study on high speed tension property of B-grade bulletproof steel

In this paper, the high speed tension experiments have been performed on ultra high strength bulletproof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thickness of 2.3 mm. The mechanical properties at strain rates of 0.001 s^-1, 0.01 s^-1, 0.1 s^-1 and 1 s^-1 were carried out on MTSS10, while those at higher strain rates of 200 s^-1, 500 s^-1 and i 000 s^-1 were tested on HTM5020 high speed tension tester and Hopkinson bar. The data from the high speed tension experiments were fitted via Johnson-Cook constitutive equation, and the fracture surface of each specimen was analyzed by scanning electron microscope （SEM）. The results indicate that, the shoot resistance capability of bulletproof steel is closely related to its strength, thickness and flow behaviors under high strain rate. The shoot resistance will be improved in the case of higher strength and better matching between strength and elongation. The Johnson-Cook constitutive equation fitted via experimental data provides fundament to numerical simulation. With the increase of strain rate, the size and depth of dimple trend to decrease and the depth of dimple changes less in steel with lower strength and higher elongation. The SEM analysis of fracture aspect is of benefit for further understanding of deformation and fracture mode under high strain rate.

Faster Focus Group Interviews--CurroCus Groups--An Improved Faster Approach to Collect Consumer Data

There is a need for cost-efficient methods in consumer research. Existing qualitative methods are expensive to conduct. This paper aims to improve the focus group method. The objective was to improve focus groups with different aims： shorter time conducting interviews, interview greater number of respondents, deliver results faster than traditionally analysis of data, and lower total cost. CurroCus groups of 15-45 minutes duration were tested in five different experiments, including 70 to 160 respondents in groups of 7-11 respondents. The name of the new method is formed from the word ＂Curro＂ in Latin that means speed in English, and ＂Cus＂ that is the last syllable of the word ＂focus＂, thereby forming a new word： CurroCus~ on the method. The results from testing of the CurroCus~ group method at different cases showed that trained moderators and observers could collect relevant responses in a given time for each group. It was possible to process a number of 6 to 10 respondents for each group. By conducting several successive groups, saturation of information was reached after an adequate number of CurroCus~ groups. Therefore, the total number of respondents can be optimized and results can be more precise, with reduced risk of inaccuracy. At the same time, the cost for each case can be lowered substantially, in our cases to approximately 1/10 of a traditional focus group cost. The role （skills） of the moderator is important. A disadvantage is the risk that some of the respondents are not able to express their thoughts in due time when time is limited. There is a need for more research on all parts of the CurroCus group process.

Analysis and Study on the Change of the Observed Geo-electric Field Data at Lhasa Geomagnetic Station before and after the Nepal MS8.1 Earthquake

In this paper,the main purpose is to analyze and research the characteristics of the geoelectric field observed data with a long time span and large amplitude abnormal change,at the Lhasa geomagnetic station( hereafter referred to as "Lhasa station "),before and after the Nepal M_S8. 1 strong earthquake,which occurred on April 25,2015. Based on the observation conditions,the observation system,and the observed data of Lhasa station preliminary discussed,the main characteristics of the abnormal change and evolution process are analyzed and studied,using the following two methods; the "synthesis energy accumulation"and the "power as MSA spectrum"analysis,from the two aspects of the"Time Domain"and"Frequency Domain. "The results show that the abnormal change of the geo-electric field observation of Lhasa station experienced a development stage following the process of "trend change- disturbance change- earthquake period-recovery period",and an evolution process of "low frequency change- high frequency change- smooth change- high frequency change ",before and after the Nepal M_S8. 1strong earthquake. Comprehensive analysis shows that the variation characteristics and evolution process of the geo-electric field at Lhasa station are basically consistent with the results of the relevant mechanism and phenomenon research. So far,this is valuable information with certain objectivity,which is typical and representative to reflect the whole process of the gestation, occurrence and complete development of such strongearthquakes.

Evidence of Invariance of Time Scale at Critical Point in Ising Meanfield Equilibrium Equation of State

We solve the equilibrium meanfield equation of state of Ising ferromagnet （obtained from Bragg-Williams theory） by Newton-Raphson method. The number of iterations required to get a convergent solution （within a specified accuracy） of equilibrium magnetisation, at any particular temperature, is observed to diverge in a power law fashion as the temperature approaches the critical value. This is identified as the critical slowing down. The exponent is also estimated. This value of the exponent is compared with that obtained from analytic solution. Besides this, the numerical results are also compared with some experimental results exhibiting satisfactory degree of agreement. It is observed from this study that the information of the invariance of time scale at the critical point is present in the meanfield equilibrium equation of state of Ising ferromagnet.

Inflatable rock bolt bond strength versus rock mass rating (RMR)： A comparative analysis of pull-out testing data from underground mines in Nevada

The purpose of this paper is to establish confidence in anticipated minimum bond strength for inflatable rock bolts by comparing the bond strength to variable geotechnical conditions using the rock mass rating （RMR） system. To investigate a correlation between these parameters, the minimum bond strength of pull-out tested inflatable rock bolts was compared to the RMR of the rock in which these bolts were placed. Bond strength vs. RMR plots indicate that expected minimum bond strength is positively corre- lated with RMR; however, the correlation is not strong. Cumulative percent graphs indicate that 97~; of pull-out tests result in a minimum bond strength of 3.3 and 1.7 ton/m in RMR/〉 45 and 〈45, respectively. Although lower bond strengths are more commonly encountered in low RMR ground, high bond strengths are possible as well, yielding higher variability in bond strengths in low RMR ground. Bond strength of friction bolts relies on contact between the rock bolt and drill hole. Experience in Nevada indicates that RMR is known to affect both the quality and consistency of drill holes which likely affects bond strength. Drilling and bolting in low RMR ground is more sensitive to drilling and bolting practices, and strategies for maximizing bond strength in these conditions are discussed.

A New Approach to Estimating the T-Year Return-Period Wave Height

The paper introduces a new approach to estimating the T-year return-period wave height (TRPW), i.e. the wave height expected to occur in T-year, from two sets of observed extreme data and on the basis of the maximum entropy principle. The main points of the approach are as follows. 1) A maximum entropy probability density function (PDF) for the extreme wave height H is derived from a Euler equation subject to some necessary and rational constraints. 2) The parameters in the function are expressed in terms of the mth moment of H. 3) This PDF is convenient to theoretical and practical applications as it is simple and its four parameters are easy to be determined from observed extreme data. An example is given for estimating the TRPW in 50 and 100 years by the present approach and by some currently used methods using observed data at two hydrographic stations.The comparison of the estimated results shows that the present approach is quite similar to the Pearson-Ⅲ and Gumbel methods.

Testing Point of Care Portable Data Capture in a Hospital HIV Transmission Prevention Programme and Experience from Computerized Patient Management in a Sub-Saharan Clinic Setting

Clinicians involved in HIV/AIDS （Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome） prevention of mother to child transmission （PMTCT） programme and research activities can benefit from the advantages that computerized systems add to medical practice even in resource constrained sub-Saharan clinic settings. Their continued use of paper based systems presents clinical data management and patient care challenges. A portable point of care data capture electronic system and a computerized clinic patient management system （CCPMS） were implemented to remedy these challenges. PMTCT report compilation was easier with the portable data collection system whose data were found to be more complete and accurate with a 0.83% error rate compared to a 4.1% error rate in the paper registers. A resounding majority of clinicians preferred using the new CCPMS with many of the view that it improved drug inventory and general clinic management with a positive effect on patient care.