Saving copper by using aluminum is the international trend now, but the development is progress step by step and every country has a different processes. There is an obvious difference among China and other countries on the application of aluminum and aluminum alloy in electric cables. There is a wide development space for the aluminum alloy conductors using for overhead line. There is a little development for application of copper clad aluminum conductors and the related standards are being approved as well as written; we expect progressive test in use. Now we also expect to find good technic economic efficient means to separate the copper and aluminum during recycling processing. The market of aluminum clad steel wires is also expanding in recent years, with the maturity of manufacturing technology. The amount of aluminum enameled wire is also rising recently. It is no doubt that there is more fiber and less copper in the communication field continuously. There is a substantial progress of saving copper by using aluminum on airplanes. It is very important for saving energy and protecting environment through recycling copper and aluminum scrap directly. It is imperative under the situation to set up the recoverable networks of scrap wires of copper and aluminum.
An ensemble platform on generalized source tracking of urban air pollutants and an emission source assimilation with application of satellite remote sensing has been proposed. The ensemble platform of generalized urban air pollutant source tracking is built on principal factor analysis of aerosol emissions, aerosol variation spectrum analysis, feature analysis on aerosol changes with phase within urban canopy layer, wind vectors correlating with remote pollutant transport, back forward trajectories and boundary layers affecting the foot mark methods. Also, in order to reduce the emission source uncertainties, which is a key difficulty in air quality modeling, the Newton approximation nudging technology has been applied in the air pollutant modeling based on the seasonal or monthly SO2 and NO2 emissions, and the remote sensing data of air pollutants have been applied on the data assimilation in air pollutant modeling. The integration approach with remote sensing and ground based observations could be used in the research on urban air pollutant tracking, urban haze and heat island. The comprehensive analysis of land water air cycles is attempted as an exploratory study on water pollutant source tracking.
The rapid development of economy and the continuous improvement of technical level form a growing voice to enhance our influence on the international standardization activities. ISO 18186∶2011 Freight Container-RFID Shipment Tag System was officially released in 2011 by International Standardization Organization (ISO), which is the first International Standard launched, drafted and led by Chinese experts in the field of the logistics and the internet of things, since China began to participate in ISO activities. The international standard, with “building a complete industrial chain including platform construction, hardware and software design, commercial mode, and system applications” as the technical support and along the route of “technique patented, patent standardized and standard internationalized”, firstly formed the national standard GB/T 23678—2009 and proceeded with the formulation of relevant international standards. This paper describes the development process and method of this International Standard and shares some experience in order to provide some useful help on how to raise our Chinese innovation up to an international standard.
In this paper, a systematic review was made on the rainstorm flood early warning research and operation in the Yangtze River basin in four aspects, namely, the meso scale rainstorm field observation experiment, the heavy rainfall meso scale system formation mechanism research, the heavy rainfall numerical model forecast technology and the hydro meteorological coupling model. Then, the main factors on restricting heavy rainfall forecast and flood early warning ability and level over the Yangtze River basin were analyzed. Lastly, the main problems of science and technology and its countermeasures were put forward.
Based on the current situation and development plan of marine meteorological observation, it is recognized that there is a need to develop appropriate data assimilation technology for enhancing the efficiency of data utilization. Only in that way, there is a chance to overcome the lack of observation, and to improve numerical weather prediction. In this paper, the multi scale/block batch wise data assimilation is suggested to perform the test of tropical cyclone data assimilation. The results show: the multi scale/block batch wise data assimilation can be appropriate for the data assimilation of tropical cyclone multi scale circulation, satisfy with the flow dependent background error covariance required by tropical cyclone data assimilation, also can use effectively the marine meteorological observation. By means of the multi scale/block batch wise data assimilation, to amplify the utilization of marine meteorological observation, it is an effective approach to obtain high quality tropical cyclone initial circulation.
The method of satellite infrared and passive microwave remote sensing for precipitation were briefly introduced firstly. The instruments onboard the tropical rainfall measurement mission (TRMM) satellite and the application of their measurements were discussed . As for example, precipitation structure, relationship among altitude of cloud top and rain top with surface rain rate for a summer hot convective precipitation system were brought forth together with analyzing of long time dataset of the TRMM precipitation radar on precipitation climatology in Asia.At last, the prospect of the satellite active and passive remote sensing of precipitation in the near future were given.
The Urumqi Institute of Desert Meteorology of China Meteorological Administration (CMA) carried out an atmospheric scientific experiment on the detection of dust weather using a wind profiler radar in the hinterland of the Taklimakan Desert in April 2010. Based on the wind profiler radar data obtained from this experiment, this paper analyzes the characteristics of the horizontal wind field and vertical velocity of a breaking dust weather in a desert hinterland, calculates and gives the radar echo intensity and vertical distribution of a dust storm, blowing sand and floating dust weather, and discusses the atmospheric dust counts/concentration derived from the wind profiler radar data. Studies show that a wind profiler radar is an upper air atmospheric remote sensing system that effectively detects and monitors dust. It captures the beginning and ending of a dust weather process as well as monitors the sand and dust being transported in the air in terms of height, thickness and vertical intensity. The echo intensity of a blowing sand and dust storm weather episode in Taklimakan is about -3~10dBZ while that of floating dustis -15~-3 dBZ, indicating that the dust echo intensity is significantly weaker than that of precipitation while stronger than that of clear air.
The construction of the excavation and support of the subsea tunnel is very difficult, and safety risk is also very high. Relying on the construction of a fault and crush zone of the second subsea tunnel inland, using the method of geologic survey, TSP, flank holes, and analyzing the data, predicting basis geology condition within 45 meters ahead of working face. Combining long term geology prediction with short term geology prediction, comprehensive pre geology prediction is reported. According to its geological property, adopting full sectional grouting upper section in the fault and crush zone in order to strengthen stratum, bench excavation method, and strong support. At the same time, monitoring and measuring convergence, subsidence of crown, and pressure of surrounding rock, by processing of data, and to the construction, is called the information construction of the subsea tunnel in a fault and crush zone. The method is applied to the construction, produces a satisfactory effect.
In view of the first underwater railway shield tunnel, Guangzhou Zhujiang River Shiziyang shield tunnel, the prototype test is carried out against its segmental lining structure by using “Multi function Shield Tunnel Structure Test System”. And the mechanical characteristics of segmental lining structure using straight assembling and staggered assembling are studied deeply. The results show that the mechanical characteristics of segmental lining structure vary from different water pressure. Especially after cracking, the high water pressure plays a significant role in slowing down the growing inner force and deformation. It is also testified that the failure characteristic varies between straight assembling structure and staggered assembling structure. Shear failure often occurs nearby longitudinal seam when using straight assembling.
Full scale model tests were carried out on a 30 m span prestressed concrete box girder and a 20 m span prestressed concrete hollow slab. Failure models were prestressed reinforcement tensile failure and crushing of roof concrete, respectively. The ductility indexes of the box girder and hollow slab were 1.99, 1.23, respectively according to the energy viewpoint. Based on the horizontal section hypothesis, the nonlinear computation procedure was established using the limited banding law, and it could carry out the entire performance analysis including the unloading, mainly focusing on how to achieve the unloading curves computation through stress-strain, moment-curvature and load-displacement curves. Through the procedure, parameters that influence on the bearing capacity, deformation performance and ductility of the structures were analyzed. Those parameters were quantity of prestressed reinforcement and tension coefficients of prestressed reinforcement.
The absorption characteristics of cationic polyelectrolyte PDADMAC and anionic polyelectrolyte PSS on benzoguanamine formaldehyde (BGF) particles are investigated. The charging characteristics of BGF particles are changed and controlled using electrostatic self assembly method. A variety of PEi BGF/SiO2 composite abrasives are obtained. The as prepared samples are analyzed by Zeta potential analysis, transmission electron microscope (TEM) and thermogravimetric (TG) analysis. The composite abrasives slurries are prepared for copper polishing. The polishing results indicate that it is SiO2 abrasives, not only coated SiO2 abrasive on polymer particles but also free SiO2 abrasive in slurry, that offer the polishing action. The material removal rates of copper polishing are 264 nm/min, 348 nm/min and 476 nm/min using single SiO2 abrasive slurry, PE0 BGF/SiO2 mixed abrasives slurry and PE3 BGF/SiO2 composite abrasives slurry respectively. The surface roughness Ra of copper wafer (with 5 μm×5 μm district) is decreased from 0.166 μm to 3.7 nm, 2.6 nm and 1.5 nm, and the surface peak valley values Rpv are less than 20 nm, 14 nm and 10 nm using these kinds of slurries respectively.
Actually, when an eccentric cam rotates around a fixed axis, it is the geometric center of eccentric cam that moves in simple harmonic motion (sine/cosine motion), under certain conditions, the components (such as piston) driven by the eccentric cam do not move in the same simple harmonic motion, therefore some problems, such as the change in pressure, can be caused when double eccentric cams are applied in some process equipment. Therefore, on the basis of analysis of the motions of the double eccentric cams used in process intensification equipment, the causes that the motions of the two pistons driven by the eccentric cams are not completely symmetrical and this may cause the pressure in the equipment to change is found out, and the relevant solutions are proposed.
Based on the theory of system dynamics, the paper analyzes the mechanism of socio economic benefits of highway projects and establishes the system dynamic model of regional economic－public road transportation. Then taking Jinji highway project of Tianjin as an example, the error of system simulation tested and the system dynamic model built are verified to be quite stable, which have a high performance. Through the comparison of simulation results of Jinji highway being built or not, the paper simulates and predicts the socio economic benefit of each year from 2003 to 2013. Thus the quantification evaluation of socio economic benefit of highway project is realized and it will provide the theory instructions for similar projects in the future.
There are some problems of easy damage and arduous maintenance in the expansion joints at abutment, and a new type of single expansion joint bridge (SEJB) is herein proposed to deal with them. To investigate the mechanical characteristics of SEJB under temperature load, simplified calculation model is proposed in this paper. Considering the distribution and development rule of cracks in approach pavement, theoretical formulas for internal force and deformation were derived, and calculation programs were compiled. For example, under the effect of temperature drop of 20 ℃, the maximum steel stress was 148 MPa, and the maximum crack width was 0.185 mm for a 280 m length SEJB, which met the requirement of criterion; the additional stress of beam was 0.105 MPa, which could be ignored. Moreover, taking the different temperatures into account, parameter analysis was performed. The results show that the 30 m length pavement can well meet the needs for use. Internal force is reduced by using bearing and cushion materials with low surface friction coefficient, and a biaxial geogrids is recommended.