Search

This article through the research of industrial current situation in Changchun, recalling the development history of industrial buildings in Changchun and the industrial legacy building's formation reasons, analyzes industrial legacy building's renovation, reuse of the meaning and value, finally, based on Changchun City's territorial, proposed industrial legacy building renovation, reuse of methods and principles.

Based on the concept of cleaner production, the feasibility of application of the flue gas in mine mouth power to fire prevention and extinguishing in goaf was numerically studied by taking the mechanized caving mining face 11-214 of Caocun coal mine as the example. The heterogeneity porosity and multi-component gas transport equations were introduced into the mathematical model. The calculated results showed that the area of “spontaneous combustion zone” turn small obviously in goaf and the maximum width of “spontaneous combustion zone” in goaf decreased from 78m to 9.5m after injecting the flue gas. At the same time, the sink terms of oxygen consumption was formed in the port of gas injection. The migration law of flue gas showed that the numerical calculation of goaf should select the different computation model based on the judgment basis of Reynolds number. Through the continuous monitoring of the migration of flue gas at different locations in goaf, the reasonable parameters of flue gas injection was obtained for high efficient fire prevention .

In this work, Al-10.8Zn-2.8Mg-1.9Cu alloy was manufactured by the spray forming technique. The microstructure of the spray-formed alloy was investigated by optical microscopy and field emission scanning electron microscopy. The results indicated that the porosity in the spray-deposited alloy was mainly composed of interstices, interconnected pores and gas pores. The distribution and types of porous defects were different, responding to position of the preform.

Compared to conventional mesophilic anaerobic digestion, thermophilic anaerobic digestion may offer attractive advantages such as higher volatile solid destruction efficiency, higher biogas generation, and higher disinfection effect and better dewater ability. In this study, two experiments of waste activated sludge were conducted to evaluate the influence of total solid and inoculums ratio on the biogas production and thermophilic (55±1°C) anaerobic process stability. In first experiment, the biogas production of 4 reactors with solid concentration of 6%, 8%, 10% and 12% respectively was observed. The biogas productions in 4 reactors were 4444 mL, 4891 mL, 5573 mL and 6327 mL respectively, the biogas productions per unit VS digested of each group were all above 360 mL/g and the methane content in biogas of each reactor was kept about 70%. During the operation, pH value in the reactor was kept between 6.5 and 8.4. In second experiment, the biogas production of 4 reactors with inoculums ratio of 20%, 30%, 40% and 50% respectively was observed. The biogas productions in 4 reactors were 4730 mL, 6630 mL, 6820 mL and 7175 mL respectively, the biogas productions per unit VS digested of each group were all above 340 mL/g and the methane content in biogas of each reactor was kept about 70%. During the operation, pH value in the reactor was kept between 6.4 and 8.6. Putting into consideration, the shortening of anaerobic digestion cycle, costs saving, and increasing economic benefits; choosing TS within the scope of 8-10%and inoculums ratio within the scope of 30-40% are more recommended. And the results showed that thermophilic anaerobic digestion process for waste activated sludge could be operated steadily.

A bacterial strain S5-1capable of degrading chlorimuron-ethyl was isolated from paddy soil using enrichment technique. On the basis of traditional culture characteristics, colony and cell morphology, physiological and biochemical characteristics, type of internal photosynthetic membrane and combined with 16S rRNA gene sequence analysis, the strain was identified as aRhodopseudomonassp.. The optimal temperature and pH for biodegradation of chlorimuron-ethyl byRhodopseudomonassp. strain S5-1were 35°Cand pH 7.0, and the degradation rate reached 87.8% within 10 days under the optimal conditions. The results revealed that strain S5-1could degrade chlorimuron-ethyl efficiently and for further study it could potentially be used as a biological agent for the remediation of soil, water or crops, contaminated by chlorimuron-ethyl herbicide.

With the development of component technology, component granularity plays a very import role on the complexity of component composition. How to assemble the component of big granularity? How to make the component in the same domain integrated? Application framework brings the new era of software-reused technology. But how to construct application framework to make it higher reuse? According to the current research of application framework, the paper gives a hierarchy model; The model divides application framework into several layers. Different application framework in different layer has different solutions and the higher the application framework stands in, the lower the probability of change is.

The study determined the biogas production potential of different concentrations of biogas slurry co-digested with cornstalk at the TS of 8%. It turned out that pure biogas slurry mixed with cornstalk had the best performance. Besides, using biogas slurry without adding any water could keep the pH of the system at 6.9-7.2, while acidification happened when using other concentrations of biogas slurry and the pH went below 6.4.

As an important commercial application, E-commerce is widely used with the development of Internet technology. However credit disks block the progress of E-commerce in the non-standard market environment, Analyzing credit management modes such as eBay and Taobao, this paper proposed a new credit calculation formula and construct a credit evaluation framework, in order to improve trading success rate, to avoid commercial fraud, and to contribut information construction of China.

An efficient method for functionalizing carbon nanotubes (CNTs) is reported, which combined HF corrosion with sulfuric acid and nitric acid for further oxidation. The X-ray diffraction and transmission electron microscopy are employed to investigate the physic-properties of the prepared catalysts. Cyclic voltammetry and chronoamperometry methods are used to study the performance of the prepared catalysts. CNTs further treated with H2SO4 and HNO3 mixed solutions with the volume ratio of 1 to 3, heating at 100 oC for 2 h, used as catalysts supports exhibit significantly improved performance towards ethanol oxidation in alkaline solutions in comparison with other decorated CNTs. The reason could be attributed to the oxygen-contain functional groups on CNTs surface can efficiently improve the interaction between CNTs and metallic particles in catalysts.

Hierarchical ZrO2 nanorods have recently received considerable attention due to their special physical and chemical properties. However, traditional preparation methods are involved in expensive equipment, complicated process and high production cost. Here we report a simple hydrothermal approach to prepare hierarchical ZrO2 nanorod. The results show that as-synthesized products are composed of many nanorods with 80~150 nm in diameter and 15~20 μm in length. After annealing, the final product was involved into hierarchical monoclinic ZrO2 (m-ZrO2) nanorods, namely, the big nanorod was made up of many small nanorods with 20~30 nm in diameter and 300~500 nm in length. The possible formation mechanism was proposed based on a series of chemical reactions and the natural properties of zirconium.

Pre-stressed concrete continuous rigid frame bridges have been widely used for modern long-span bridges due to its advantages, such as comfortable for travelling, easy to be constructed and maintained etc. However, cracks and excessive mid-span sag of box girders generally exist in many built bridges of this kind during service, and because of its large size and the complex natural environment, it is particularly important to study the long-term performance based on the long-term field measurements. In this paper, a high-pier & long-span pre-stressed concrete continuous rigid-frame bridges, with five-spans (106m+3×200m+106m), was taken as the research object, by pre-embedding strain sensors in mid-span sections and root sections on box girders, field-tests for stress variation were conducted in extreme weather conditions (ie, the hottest and coldest in one year) after its completion in two years, providing tested data for studying long-term performance of bridges similar to the same kind.

Three-dimensional (3D) lower limb kinematic and kinetic analysis based on ambulatory measurements is introduced in this paper. We developed a wireless sensor system composed of a mobile force plate system, 3D motion sensor units and a wireless data logger. 3D motions of body segment and triaxial ground reaction force (GRF) could be simultaneously measured using the system, and the data obtained from sensor units on thighs, shanks and feet could be transferred to a personal computer by wireless local area network (LAN). An inverse dynamics method was adopted to calculate triaxial joint moments. The accuracy of kinematics and kinetics (joint moments) assessment is validated against results obtained from the stationary measurement system based on camera movement analysis and force plates.

The technology of mining without coal pillar is popular in many mine, though it can improve the recovery rate, it aggravate the air leakage of gob. Because of the ignorance about oxidation in gob, so it is very difficult to know the true value. When we make the test, we find computer can do it that simulation is consistent with reality overall. The article simulate the velocity field and oxygen concentration by finite element method, so divide the ‘three zones’ of gob and analysis the differences before and after plugging, we can see the huge impact of air leakage. So if we want to prevent the Spontaneous Combustion in mining without coal pillar, it is necessary to use the plugging technology.

Experimental work for the compressive strength of recycled aggregate concrete was designed. The results indicated that the recycled coarse aggregate (RCA) re-placement ratio has a remarkable influence on the compressive strength of recycled aggregate concrete.the relationships between the compressive strength and themw/mcratio are also different for differentRCA replacement ratios and the developments for the compressive strength of recycled aggregate concrete are not exactly the same as that of normal concrete.

Cobalt additive was added into the Al2O3-TiC composite to improve the mechanical properties. The microstructure and fracture mode of composite tool materials Al2O3-TiC and Al2O3-TiC-Co were investigated, emphasizing on the difference of thermal residual stress distribution with added cobalt. The interfacial thermal stress and the stress distribution in each phase were worked out according to thermoelasticity theory. The results demonstrated that cobalt could strengthen the interfacial bonding strength of ceramic grains and influence the residual stress distribution in Al2O3 matrix, which change the fracture mode and lead to the flexural and irregular crack propagation path.

Removal of hydrogen sulfide from waste and energy-rich gases is required not only because of environmental health and safety reasons, but also because of operational reasons. Biotrickling filter is one of the most promising clean technologies for removing H2S. This study attempted to remove H2S in biogas using a laboratory-scale biotrickling filter. The performance and the influence caused by different concentrations of pH, CODCr, sulfate, external nitrate source in the nutrient solution were systematically analyzed. Optimal operating conditions were obtained by the following: pH 2.0~8.0, COD 400~500mg/L, cumulative sulfate concentration 250mg/L, external nitrogen concentration 7.5mg /L.

Virtual learning community has become the main online learning place for learners, and cloud computing provides new tools for the development of virtual learning community. Based on the Google APP Engine (GAE) cloud computing platform provided by Google Company, the article explained the construction of the virtual learning community in cloud computing environment.

Mobile learning is a new way of application of mobile communications technology. As a new way of learning mode and technology it must be pay much attention. It is severely affected by network technology. Cloud computing, a new computing model, is proposed based on a distributed system, grid computing, etc. It is a new way of sharing infrastructure. Cloud computing will develop a new environment of learning space, information sharing, collaboration and learning to the field of education. This article explores the impact of Cloud computing to mobile learning from several factors of the mobile learning environment.

The key of intelligent learning support system lied in providing personalized service according to different students. Based on cognitive student model, the article designed an intelligent learning support system based on machine learning, which automatically diagnosed students’ cognitive abilities in order to make students in different levels get different depth’s answers, and appropriate level skills training. This would stimulate students' interest in learning and improve students' cognitive ability.

A bacterial strain S9-1 capable of degrading sulfonylurea herbicide pyrazosulfuron-ethyl (PSE) was isolated from contaminated soil through the enrichment incubation method. Based on morphology, colony and cultural properties, physiological and biochemical characteristics, living-cell absorption spectra, internal photosynthetic membrane, and phylogenetics of its 16S rRNA gene sequence, S9-1 was preliminarily identified as belonging to the genus Rhodopseudomonas, a group of photosynthetic bacteria (PSB). The effects of PSE concentration, pH, and temperature on biodegradation were examined. The degradation rate was found to decrease with increasing PSE concentration. Optimal growth pH and temperature were found to be 7.0 and 30°C, respectively. The strain was able to degrade 47.51% of PSE at a concentration of 100 mg ml-1 after 7 days of incubation at 30°C and could tolerate 800 mg ml-1 PSE. S9-1 was also able to completely co-metabolically transform 100 mg ml-1 PSE at 30°C, pH 7.0, and 7500 lux in 15 days. As the concentration of PSE increased, the degradation process took longer to complete. The fragment encoding acetolactate synthase (ALS) gene from S9-1 was cloned and sequenced. Comparison of deduced amino acid sequences was implemented, and the conserved sites were analyzed. To our knowledge, this is the first report of PSB in PSE biodegradation. These results highlight the potential of this bacterium as a detoxifying agent for use with PSE-contaminated soil and wastewater.

In order to improve the machining efficiency of high strength steel 2.25Cr1Mo0.25V and tool life, intermittent turning performance of 2.25Cr1Mo0.25V with common carbide tools and advanced coated carbide tools was experimentally studied, cutting parameters and tool types were optimized. The results showed that the machining efficiency and tool life of advanced coated carbide tools were remarkably higher than that of common carbide tool; the tool life of quadrate coated tool was longer than that of circular tool. The cutting tool failure mechanisms were also discussed.