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Quantitative assessment of livability within a city facilitates the identification of urban problems and targeted improvements to the environment. Available studies are mostly limited to static analysis of a particular phase. It is difficult to reveal the dynamic development state of cities at the micro level. Taking Sino-Singapore Tianjin Eco-city as an example, we established an evaluation index system for the livability of the eco-city from five dimensions, including environmental health, transportation convenience, urban security, facility convenience, and economic prosperity. Multi-source data from 2016 to 2020, including the remote sensing images, points of interest, and planning data, combined with the entropy method and the TOPSIS method were used to dynamically monitor the livability of the eco-city in a long-term series. The results showed that during the study period, the livability levels of different areas in the eco-city had strong spatial and temporal variations. Spatially, with the southern part of the Sino-Singapore Eco-city Cooperation Zone as the core, the overall livability was characterized by a high center and a low edge. The convenience of facilities, traffic convenience, and economic prosperity were characterized by a high center and a low edge. Urban security and environmental health showed the characteristics of low center and high edge. From 2016 to 2020, the livability improvement rate of the eco-city had gradually accelerated, with the the most obvious improvement in the southern part of the China-Singapore Cooperation Zone.定量评估城市内部宜居性便于发现城市问题从而针对性改善环境。现有研究多囿于单一时相的静态分析,难以在微观层面揭示城市动态发展状态。本研究以中新天津生态城为例,从环境健康性、交通便捷性、城市安全性、设施便利性和经济繁荣性5个维度创建生态城宜居性评估指标体系,利用研究区2016—2020年的遥感影像、兴趣点、控制性详细规划数据等多源数据,结合熵值法和优劣解距离法从居住地块尺度对生态城内部宜居情况进行长时间序列的动态监测。结果表明: 研究期间,生态城内不同片区宜居水平有较强的时空差异性。空间上,以生态城中新合作区南部为核心,宜居性整体呈现出中心高、边缘低的特点,设施便利性、交通便捷性和经济繁荣性呈现出中心高、边缘低的特点,而环境健康性和城市安全性则呈现出中心低、边缘高的特点。2016—2020年间,生态城宜居性提升速度逐步加快,中新合作区南部的宜居性整体提升最明显。.

The solvent-free fast-curing coating for repairing is prepared using polyurea as matrix and graphite nanoplatelets (GNPs) as fillers. The effects of GNPs on the coating are studied. The coating is prepared by HDI tripolymer and polyetheramine. The GNPs is functionalized (f-GNPs) by aminopro-pyltriethoxysilane (APTES) in mixture of water and ethanol. The performances of the coatings are tested by salt spray time, polarization curves and electrochemical impedance. The coating presents solvent-free and fast-curing characteristics and is suitable for repairing. The f-GNPs provide both physical barrier and coulomb block for the coating. When the f-GNPs added amount is 0.6 wt%, the salt spray resistance time of the coating is more than 420 h, and the corrosion potential is –0.6428 V. The effects of GNPs on coating are investigated. The results can provide a new idea for preparation of anticorrosive coating used for repairing, and can benefit in-depth understanding of the influence of f-GNPs on the coatings. The coating for repairing is prepared by adding f-GNP as fillers. The anticorrosive mechanism and performance of the coating are discussed in detail.

The objective evaluation of human settlement in cities helps find the problems exposed in urban development and make targeted adjustments to improve urban environment. Taking the downtown of Fuzhou as the research area, the residential area as the research unit, using multi-source data such as meteorological monitoring data, remote sensing imagery, map points of interest data (POI), and land planning data, we constructed monitoring system of urban human settlement from four aspects: environmental health and comfort, traffic convenience, city safety, and life conve-nience. The TOPSIS method was used to conduct a comprehensive evaluation of human settlement. The results showed that the human settlement level of downtown Fuzhou was quite different, which was high in the central area and low in the peripheral areas. The human settlement index was high in the middle of the urban area, low in the eastern and southern areas, with mixed high and low values in the western and northern areas. In each index layer, the characteristics of high-high agglomeration and low-low agglomeration of traffic convenience and life convenience were consistent with the distribution of high and low value clusters of the human settlement. Convenient transportation and complete service facilities had a greater impact on human settlement. The environmental health and comfort were characterized by interior low and edge high of the city, while city safety was characterized by interior high and edge low.城市内部居住环境的客观性评价有助于发现城市发展中暴露出的问题,有针对性地进行调整进而改善城市环境。以福州市中心城区为研究区,居住区为研究单元,利用气象监测数据、遥感影像数据、地图兴趣点数据、国土规划数据等多源数据,从环境健康舒适性、交通便捷性、城市安全性和生活方便性4方面构建城市人居环境监测体系,并使用优劣解距离法进行人居环境质量综合评价。结果表明: 福州市中心城区人居环境水平差异性较大,整体上呈现出中心区域高、边缘地区低的特点。城区中部人居环境指数较高,东部和南部区域较低,西部和北部区域人居环境高值与低值混杂分布。各指标层中,交通便捷性和生活方便性的高-高集聚以及低-低集聚特征与人居环境高低值聚类分布较为一致,便捷的交通以及完备的服务设施对人居环境评价的影响较大;环境健康舒适性呈现城市内部低、边缘高的特点,而城市安全性呈现内部高、边缘低的特点。.

Water impurity is the essential factor of reducing the insulation performance of transformer oil, which directly determines the operating safety and life of a transformer. Molecular dynamics simulations and first-principles electronic-structure calculations are employed to study the diffusion behavior of water molecules and the electrical breakdown mechanism of transformer oil containing water impurities. The molecular dynamics of an oil-water micro-system model demonstrates that the increase of aging acid concentration will exponentially expedite thermal diffusion of water molecules. Density of states (DOS) for a local region model of transformer oil containing water molecules indicates that water molecules can introduce unoccupied localized electron-states with energy levels close to the conduction band minimum of transformer oil, which makes water molecules capable of capturing electrons and transforming them into water ions during thermal diffusion. Subsequently, under a high electric field, water ions collide and impact on oil molecules to break the molecular chain of transformer oil, engendering carbonized components that introduce a conduction electronic-band in the band-gap of oil molecules as a manifestation of forming a conductive region in transformer oil. The conduction channel composed of carbonized components will be eventually formed, connecting two electrodes, with the carbonized components developing rapidly under the impact of water ions, based on which a large number of electron carriers will be produced similar to &ldquo, avalanche&rdquo, discharge, leading to an electrical breakdown of transformer oil insulation. The water impurity in oil, as the key factor for forming the carbonized conducting channel, initiates the electric breakdown process of transformer oil, which is dominated by thermal diffusion of water molecules. The increase of aging acid concentration will significantly promote the thermal diffusion of water impurities and the formation of an initial conducting channel, accounting for the degradation in dielectric strength of insulating oil containing water impurities after long-term operation of the transformer.

Foam concrete products had high absorption rate due to a large number of bubbles dispersion in it.which has serious effects upon the overall thermal performance of material and the durability of construction.Three methods were studied which includes Organic Silicon hydrophobic agent、High fatty acids hydrophobic agent and hydrophobic agent F in order to reduce the water absorption rate.Results show that the water absorption rate was reduced significantly with mixed High fatty acids. The water absorption rate drops of 68.2%, and the organic silicon is in a second place , and the hydrophobic agent F is the worst.

Electro optical techniques including EOFM (Electro Optical Frequency Mapping) and EOP (Electro Optical Probe) are common dynamic optical probing techniques used during failure analysis. This paper demonstrated two real cases to show the application of these techniques on the fault isolation of high resistive vias.

In order to solve the problem of non-uniform electric field distribution in converter transformer barrier system caused by conductivity difference between the transformer oil and pressboard, the SiC(silicon carbide) modified pressboard was developed by nano doping method. The conductivity of modified pressboard was measured. The measuring results show that the conductivity of modified pressboard increases exponentially with the increase of nano SiC doping ratio. The electric field strength has obvious influence on conductivity at high nano doping ratio, which shows great nonlinear characteristic. Based on the nonlinear conductivity characteristic of modified pressboard, the homogenizing effect of the nano modified pressboard on electric field distribution was verified by simulation. The simulation results show that the electric field distribution under DC and polarity reversal voltage in barrier system can be well homogenized by using the nonlinear characteristic of nano modified pressboard.

In high voltage direct current (HVDC) cable accessories, there is a large difference of conductivity between crosses linked polyethylene (XLPE) and liquid silicone rubber (LSR), especially considering the presence of temperature gradient and the changing of operating temperature. In this paper, nano silicon carbide (SiC) was adopted to prepare five kinds of nanocomposites with filler fractions of 1%, 2%, 3%, 4% and 5%, respectively. The conductivity and DC breakdown strength of SiC/LSR nanocomposites were measured under different temperatures. The results show that the nano SiC doping does not has the great influence on LSR DC breakdown strength, and the nano SiC doping can improve the conductivity of LSR effectively, which can realize the conductivity matching between the LSR and XLPE to homogenize the electric field distribution in cable accessory.

Magnetic Barkhausen noise (MBN) is a new technique on non-destructive testing of residual stress. The testing system based on virtual instrument was explored. It can achieve the MBN and deal with it in time. The technique is applied to analyze residual stress in the welding line of iron materials back and forth the heat treatment. Through comparing with the data of blind-hole method, the corresponding change between Barkhausen signals and residual stress is verified.

This paper deals with an experimental investigation on the performance of a novel pulverized coal burner, featuring the introduction of an outer secondary air without swirling, as applied to an industrial boiler. Both cold air and combustion tests were conducted to investigate the effects of the secondary air on flow, combustion, and NOx emission from this novel burner. The measured flow fields, temperature distributions, and gas concentrations were presented. It was shown that, due to the presence of the outer secondary air, slagging in the adiabatic combustion chamber could be avoided and a NOx emission level of 600 mg/Nm3 was realized. In addition, the operating efficiency of the boiler was found to be greater than 89.50%, which was higher than that of the conventional industrial boilers.

Experiment research on the air flow rate measurement using tracer gas method in a 300mm internal diameter and 90° elbow duct are presented, which CO and air are selected as tracer gas and gas stream. Results show that the relative errors between the flow rate measured by tracer gas method and turbine flowmeter are varied in the range of -2.15%~1.69% when the injection point is upstream of the elbow on 7D~13D (D is the internal diameter of the duct), and the sampling point is downstream of the elbow on 10D~14D. The further distances of the injection point and sampling point are apart, the less relative errors of the gas flow rate measured by tracer gas method and turbine flowmeter are made. The injection flow rate of tracer gas should be matched with the gas flow rate in the duct. It is a simple and effective method that gas flowmeter online calibration with tracer gas method on the large diameter industrial gas pipeline transportation.

To investigate the mixing uniformity between tracer gas and gas stream in the duct, numerical simulations of the CO tracer gas and air mixing in a 300mm diameter and 90 degree elbow duct were performed on the commercial CFD software FLUENT, and the comparisons between the simulation results and experimental data were analyzed. Tracer gas is injected by 5-point discharge, the mixing uniformity between tracer gas and air is better than that of 1-point discharge. The results indicated that the tracer gas concentrations of simulations were agreed with the experimental data. Simulation results could provide a valuable guidance for gas flow rate measurement and online calibration for gas flowmeter with tracer gas technique.

Three treatments consisting of 0%, 15%, and 30% seawater were investigated to analyse the ecotypic variabilities among five populations of Jerusalem artichoke (Helianthus tuberosus) regarding their responses to seawater stress under a hydroponic culture system. Analyses were done 2, 4, and 6 days after treatments. The 15% and 30% seawater treatments reduced the growth rates of roots and shoots of H. tuberosus populations. The activities of superoxide dismutase, peroxidase, and catalase majored in the leaves were stimulated under the seawater stress. The electrolyte leakage and malondialdehyde contents of the leaves were also stimulated owing to seawater stress. The contents of proline and soluble-sugars in the leaves increased significantly with increasing seawater concentrations. The concentrations of Na+, K+, and Cl−in the aerial parts and roots increased with an increase in the seawater concentration throughout the experimental period. There were ecotypic differences among the five populations of H. tuberosus as evidenced by the analyses of the above items in both aerial parts and roots under seawater treatment. The magnitude of the ecotypic variance components indicated that a substantial proportion of the total variation for these physiological and biochemical responses were owing to ecotype, indicating the possibility of improvement through hybridization and selection.

According to preliminary statistics, there are 9.4×106ha of mire, 8.0×106ha of lake, 2.1×106ha of salt marsh, 2.7×107ha of shallow sea (0–5m), and 3.8×107ha of paddyfield, their total area amounts to 8.45×107ha. Wetland consists of natural wetland system and man-made wetland system. According to hydrology, landform, soil and vegetation etc., natural wetland can be divided into the following types: marine, esturine, riverine, lacustrine, palustrine subsystems. On the basis of the wetland bottom compound, waterlogged state and vegetation forms, it can be subdivided into 26 wetland classes. Man-made wetland can be subdivided into 4 wetland classes. Wetland is a unique landscape in the earth and one of the most important living environment with rich resources and many functions. At present, 262 different types of Wetland Natural Reserves have been established in China, in which 7 Wetland Nature Reserves have been listed in international important wetlands of “The Wetland Convention”.

In this paper, we consider performance assessment method in integrated test. Test and evaluation (T&E) is defined as the demonstration, measurement and analysis of the performance of a system, and the assessment of the results. The importance of system performance assessment model in T&E is illuminated through mathematical description of integrated test. In order to solve the problems that conventional regression analysis can not deal with nonlinear performance output and complex interactions between different factors in T&E of hightech weaponry, a metamodel-based performance assessment method is put forward. Taking Kriging and radial basis function as examples, contrastive analysis for fitting performances of metamodel and conventional polynomial regression is made. Simulation results show the superiority of metamodel in performance assessment for integrated test.

In order to study the breakdown characteristics of oil-paper insulation under compound electric field, the typical oil-pressboard insulation model was adopted according to the insulation structure in converter transformer. The electric field in oil and oil-impregnated pressboard was simulated according to the equivalent circuit for the above model, and the breakdown characteristic test for typical oil-pressboard insulation, oil and oil-impregnated pressboard was carried out separately under compound electric field. To analyze the relationship between the breakdown strength and electric field, the electric field expressions for oil gap and the oil-impregnated pressboard were derived under compound voltage with different AC content. The test result shows that breakdown voltage of oil-pressboard insulation rises first and falls later under compound voltage. According to the characteristics the electric field distribution and breakdown strength of oil gap and oil-impregnated pressboard, it can be found that the breakdown strength of oil-pressboard insulation mainly depends on electric field distribution and breakdown characteristics of oil and oil-impregnated pressboard under compound voltage.

Compared with the traditional space-borne and aviation synthetic aperture radar (SAR synthetic aperture radar) which can only make limited time sampling analysis after the event for large oil spill, the ship-borne x-band radar has the real-time navigation superiority which may real-time detect the accident at the initial stage and can provide emergency treatment references for the Marine environmental protection department in order to take emergency reflect strive for the time. Given the domestic and foreign research achievement on oil spill at sea, the study based on maritime radar is still rarely. In this paper, the authors has summarized the predecessor oil spill study by the SAR and comprehend maritime radar characteristics, worked out a technical route using of maritime radar for oil spill monitor who provides the theoretical foundation for further research and system development.

Under the concept of SOA, a new platform structure is present using RIA technology as the presentation layer. Contrast to the traditional E-Government GIS platform, this new mode improves in three fields: the integration of graphics and form, the visualization of structured data and the diversification of thematic map. From the standpoint of technical advantage, platform frame and function realization, this paper prove that the new model can effectively solve the three problems above.

First, an analysis of the status of the military power station (MPS) and its measure-control system (MCS) in the weapon system and modern war were presented. Then presentation of construction and principle of distributed MCS, types of the measured signal, characteristics of simulative load and its switch-control signal were discussed. Finally, a discussion of the main technical issues and solutions in this distributed MCS system were given.

The minimum mean-squared error (MMSE) linear detector has been used for demodulation of the direct-sequence code-division multiple access signals. The blind MMSE linear detector can be implemented by the Griffiths' adaptation algorithm. However, its convergence speed is limited by the wide eigenvalue spread of the correlation matrix associated with the received signal vectors. In this paper, the transform domain Griffiths' adaptation algorithm is proposed to improve the convergence properties. Computer simulations show that, by using orthonormal transforms, the adaptation speed can be improved, especially in the presence of strong interference.

Cu-Mn-Dy resistive thin films were prepared on glass and Al2O3 substrates, which was achieved by co-sputtering the Cu-Mn alloy and dysprosium targets. The effects of the addition of dysprosium on the electrical properties and microstructures of annealed Cu-Mn alloy films were investigated. The composition, microstructural and phase evolution of Cu-Mn-Dy films were characterized using field emission scanning electron microscopy, transmission electron microscopy and X-ray diffraction. All Cu-Mn-Dy films showed an amorphous structure when the annealing temperature was set at 300 degrees C. After the annealing temperature was increased to 350 degrees C, the MnO and Cu phases had a significant presence in the Cu-Mn films. However, no MnO phases were observed in Cu-Mn-Dy films at 350 degrees C. Even Cu-Mn-Dy films annealed at 450 degrees C showed no MnO phases. This is because Dy addition can suppress MnO formation. Cu-Mn alloy films with 40% dysprosium addition that were annealed at 300 degrees C exhibited a higher resistivity of 2100 cm with a temperature coefficient of resistance of -85 ppm/degrees C.