盖挖逆作法钢管混凝土柱高精度调垂技术研究

竖向支撑钢管混凝土柱的调垂技术是盖挖逆作法施工的关键。以北京城市副中心站综合交通枢纽工程为例,进行了盖挖逆作法工况下钢管混凝土柱高精度调垂技术的研究。通过应用先进的传感测垂技术、优化施工工艺和精确的过程控制,成功保证了钢管混凝土柱高精度垂直度的设计要求,且施工质量可靠、数据波动范围小。

极寒条件下输电线路弧垂在线监测技术研究应用

文章研究现有接触式和非接触式弧垂传感技术,对比图像特征提取式、超声波测距式、激光测距式等三种传感器的低温运行性能,试验结果显示激光测距式弧垂传感器在各温度下具有较小的测量误差,在极寒条件下优势更突出。在此基础上,研制极寒条件下输电线路弧垂在线监测系统,并在呼伦贝尔根河、海纳尔、满洲里等地应用,通过监测数据对比,文章研制的在线监测系统整体无故障率高于通用型输电线路弧垂在线监测系统,且监测数据未出现中断和丢包,装置整体稳定性好。文中研究成果为我国输电线路监测装置在极寒条件下的运行设计提供依据,有效预防、减少输电线路事故的发生,具有广泛的社会效益和明显的经济效益。

纺织面料特点对服装设计的影响分析

合理的面料选择,既可以让服装的外观和舒适度得到提升,也能对服装的整体气质产生十分重要的影响。因此,站在设计师角度,其开展服装设计阶段掌握纺织面料的特点,同时掌握其对服装设计效果的影响,对设计出成功的产品有着重要意义。对此,文章就纺织面料特点对服装设计的影响展开分析。首先对纺织面料的分类加以分析,然后探讨纺织面料特点对服装设计带来的影响,最后从多维度探讨如何在充分考虑纺织面料特点的背景下开展服装设计,供服装设计师、服装企业参考,旨在使设计成果满足社会公众对服装产品的多样化需求。

Observation and modeling of vertical carbon dioxide distribution in a heavily polluted suburban environment

The vertical distribution of carbon dioxide(CO2)is important for the calibration and validation of transport models and remote sensing measurements.Due to the large mass and volume of traditional instruments as well as supporting systems,in-situ measurements of the CO2 vertical profile within the boundary layer are rare.This study used a miniaturized CO2 monitoring instrument based on a low-cost non-dispersive infrared(NDIR)sensor to measure the CO2 vertical profile and meteorological parameters of the lower troposphere(0–1000 m)in southwestern Shijiazhuang,Hebei Province,China.The sensors were onboard a tethered balloon with two processes:the ascending process and the descending process.The results showed that the overall trend of CO2 concentration decreased with height.Weather conditions and CO2 emission sources caused fluctuations in CO2 concentrations.The CO2 concentration varied from morning to afternoon due mainly to the faster spread of air mass during daytime,with strong convections and the accumulation of emissions at night.The low-cost sensor produced results consistent with the traditional gas chromatography method.The Weather Research and Forecasting model could not capture the CO2 profiles well due mainly to the bad performances in boundary layer height and the potential outdated fossil fuel emissions around the experimental site.This experiment is the first successful attempt to observe the CO2 vertical distribution in the lower troposphere by using lowcost NDIR sensors.The results help us to understand the vertical structure of CO2 in the boundary layer,and provide data for calibrating and validating transport models.

FY-4 Meteorological Satellite

FY-4 is the second generation of Chinese geostationary satellite for quantitative remote sensing meteorological application. The detection efficiency, spectral bands, spatial and time resolution have been greatly improved with respect to those of first generation, as well as the radiometric calibration and sensitivity. The combination of multichannel detection and vertical sounding was first realized on FY-4, because both the Advanced Geostationary Radiation Imager(AGRI) and Geostationary Interferometric Infrared Sounder(GIIRS) are on the same spacecraft. The main performance of the payloads including AGRI, GIIRS and Lightning Mapping Imager, and the spacecraft bus are presented, the performance being equivalent to the level of the third generation meteorological satellites in Europe and USA. The acquiring methods of remote sensing data including multichannel and high precision quantitative observing, imaging collection of the ground and cloud, vertical observation of atmospheric temperature and moisture, lightning imaging observation and space environment detection are shown. Several innovative technologies including high accuracy rotation angle detection and scanning control, high precision calibration, micro vibration suppression, unified reference of platform and payload and on-orbit measurement, real-time image navigation and registration on-orbit were applied in FY-4.

Analysis of atmospheric turbulence in the upper layers of sea fog

Atmospheric turbulence plays a vital role in the formation and dissipation of fog. However,studies of such turbulence are typically limited to observations with ultrasonic anemometers less than 100 m above ground. Thus,the turbulence characteristics of upper fog layers are poorly known. In this paper,we present 4-layers of data,measured by ultrasonic anemometers on a wind tower about 400 m above the sea surface; we use these data to characterize atmospheric turbulence atop a heavy sea fog. Large differences in turbulence during the sea fog episode were recorded. Results showed that the kinetic energy,momentum flux,and sensible heat flux of turbulence increased rapidly during the onset of fog. After onset,high turbulence was observed within the uppermost fog layer. As long as this turbulence did not exceed a critical threshold,it was crucial to enhancing the cooling rate,and maintaining the fog. Vertical momentum flux and sensible heat flux generated by this turbulence weakened wind speed and decreased air temperature during the fog. Towards the end of the fog episode,the vertical distribution of sensible heat flux reversed,contributing to a downward momentum flux in all upper layers. Spatial and temporal scales of the turbulence eddy were greater before and after the fog,than during the fog episode. Turbulence energy was greatest in upper levels,around 430 m and 450 m above mean sea level(AMSL),than in lower levels of the fog(390 m and 410 m AMSL); turbulence energy peaked along the mean wind direction. Our results show that the status of turbulence was complicated within the fog; turbulence caused fluxes of momentum and sensible heat atop the fog layer,affecting the underlying fog by decreasing or increasing average wind speed,as well as promoting or demoting air temperature stratification.

Investigation on the Maternal-Infantile Infection with Human Parvovirus B19

To investigate the maternal-infantile infection with human parvovirus B19, the IgG and IgM antibodies against human parvovirus and the B19-DNA in serum and peripheral blood mononuclear cells (PBMC) of pregnant women as well as the serum IgM antibody against B19 and the B19-DNA in serum and cord blood nucleated cells (CBNC) of newborns were determined by ELISA and nested PCR respectively. It was found that the positive rate of the IgG antibody against human parvovirus B19 in sera of 92 pregnant women was 38.04% (35/92), and that of the IgM antibody in 720 pregnant women was 9.03% (65/720). However, the IgM antibody against human parvovirus B19 was negative in the cord blood sera of 95 newborns. As to the human parvovirus B19 DNA, none of 720 pregnant women and 95 newborns was proved to be positive in their sera. Nevertheless, the positive rate of the parvovirus B19 DNA in PBMC was 3.06% (3/98) in 98 pregnant women and 1.12% (1/89) in CBNC of 89 newborns. It is concluded that the history of infection with human parvovirus B19 exists in certain pregnant women with a small percentage of pregnant women infected with recent or acute infections of B19 virus. The detection rates of the B19 viral DNA in PBMC of pregnant women and CBNC of newborns were higher than those in sera, indicating that the risk for vertical transmission is very low.

Stress sensitivity of coal samples in terms of anisotropy

The permeability and porosity of coal seams are anisotropic, and the variation of confining stress may induce deformation in coal samples. In order to study these characteristics, experiments and model analyses were conducted to understand the behaviors of anisotropic stress sensitivity of lean coal samples. The results showed as the closure of cleats and the generation of micro-cracks, the strong stress sensitivity of coal samples and the discrete changes in porosity were caused by confining pressure changes. In the compression period, the anisotropy trend first increased, and then decreased. In the direction perpendicular to the bedding plane, the permeability decrease rate and the irreversible damage rate were the highest. In the direction parallel to the cleats, permeability recovery rate was higher and the irreversible damage rate was lower along butt cleats. Compared to the cube root of permeability to porosity, a 1/6 power relationship was proved to be closer to the experiment results, the new relationship had the highest fit level in the face cleat direction, and the lowest fit level in the vertical direction

Sensitivity Study of Design Parameters of a Railway Route under Vertical Deformations

Studying the interaction of components is basic for a railroad project, which is also very important for creating maintenance procedures based on predictions from a model that assumes adequate performance. To determine these interactions, which can have a great number of combinations, the use of a computational model is of vital importance, in this case, the program FERROVIA 1.0 （RAILROAD 1.0） was used. A critical study developed the program FERROVIA 1.0, and its variables were characterized based on values observed in the literature. After initial characterization was carried out, a comparative study was performed on the sensitivity between these variables and the indications of significant behavior for a railway deformed by the known load of a wheel. A statistical program was used to correlate the elements. The intention was to launch the program FERROVIA 1.0 and later use it for 2,187 combinations. The data used in these correlations corresponded to the normal values for the elements used in railroad engineering practice. Our main goal is to understand the behavior of the track vertical deflection according to the variation of the scaling of the various elements of the railway,

Simultaneous sensing of displacement and temperature with a single FBG

A novel fiber Bragg grating(FBG) sensor with simultaneous sensing of displacement and temperature is presented.The FBG is affixed on the cantilever inclinedly.The midpoint of FBG exactly coincides with the zero strain layer of a rectangular beam.The vertical displacement can be measured by the broadened bandwidth of FBG as the bandwidth is insensitive to temperature,while the temperature can be measured by the center wavelength shift as the wavelength shift is insensitive to vertical displacement.With 0.1 nm spectral resolution of the analyzer,sensitivities of bandwidth-displacement and center wavelength-temperature are 0.48 nm/mm and 0.05 nm/℃,resolutions are 0.2 mm and 2.0 ℃,and sensing ranges of displacement and temperature are up to 8.5 mm and 45℃ respectively.Experimental results match theoretical analyses very well.