Search

Characteristics and forming causes of the cracks in welded joint of 15Cr1Mo1V steel serviced 70000h are investigated by mechanical and chemical testing and crack morphology observation. Results show that the cracks initiate from welded metal or coarse grain heat affect zone (CGHAZ) near fusion line, and there are three kinds of defects observed in the crack region, which are macrocracks, microcracks and voids. According to the forming position, process and morphology of the cracks, it is estimated that the cracks are a kind of stress relief crack (SRC). The main reasons of the cracking are because of residual stress caused by improper temperature field during post welding heat treatment, strong stress concentration caused by welding structure, additional stress caused by abnormal hangers & supports and decreased ductility of welded joint in service. The SRC in welded joint can be avoided through optimizing the welding process and postweld heat treatment(PWHT) process to ensure enough critical ductility deformation ability εc and avoiding and reducing stress concentration and additional stress to decrease ductility deformation εP of welded joint which make εc>εp consistently.

Dujiangyan Irrigation Project promotes the sustainable development of economy and society in Chengdu plain, which plays an important ecological role and has great historical, cultural and social values. As an significant infrastructure, Dujiangyan project not only optimizes the river system distribution in Chengdu plain and improves the ecological living environment of Chengdu plain, but also grants Chengdu plain a rich connotation of water cultures, such as scientific concept of water management, advanced water-control techniques and the customs of loving water and protecting water. These are all the ecological wisdom of ancient urban construction. This essay summarizes the ecological and cultural wisdom of Dujiangyan irrigation project, its influences on the development and living environment of Chengdu plain. It not only provides some pretty enlightenment for rationality and moderation of urban infrastructure construction, also is an important reference of sustainable development. At the same time, this paper puts forward the importance of cultural relics in the process of sustainable development, which provides a new idea about the research on the future urban infrastructure.

Fatigue failure analysis on key components of bladder accumulators was conducted. Failure fracture of the key components, which included the shell, the support ring and the oil inlet valve body in the accumulators, was investigated by optical microscope (OM) scanning electron microscope (SEM). According to the metallographic analysis and micro-hardness determination at the crack profile, crack initiation and propagation direction was confirmed. By simulation using the finite element method, it was detected that the peak stress of the key components applied on the contact surfaces. Obvious plastic deformation was observed at the region with high stress. However, the fatigue crack did not initiate at the contact surface, but occurred on the second high stress area without contact.

This paper presents the design of a 10 bit 2GHz digital to analog converter circuit. The digital to analog converter circuit adopts the design simulation of HBT process, able to work at a sampling frequency of 2 GHz, the highest sampling frequency can reach about 4 GHz. The SFDR of the digital to analog converter circuit can reach 62dB (simulation work at 2 GHz), the SFDR can reach 45 dB (simulation work at 4 GHz). Early product parameters of the digital to analog converter circuit (working in 1 GHz sampling frequency) are as follows: the narrowband SFDR parameter can be achieved 81 dB, broadband SFDR parameters can reach 46 dB.

An analog-digital clock delay locked loop (DLL) control circuit is proposed to detect and adjust the analog-digital clock phase difference in real time in a 14-bit 2GSPS digital-to-analog converter (DAC). To achieve a reasonable analog-digital clock phase difference, a digitally controlled delay line (DCDL) should be able to provide a total clock delay up to 1024ps. Such fine control is realized by a control block tracking and maintaining the precise phase relationship between analog and digital clock domains. The control circuit is realized by designing a digital finite state machine (FSM) carefully. The proposed circuit is implemented in 0.18μm CMOS technology. Simulation results show that the proposed circuit performs well in various conditions in high speed data transmission applications.

The IC technology of adjustable delay is simply presented. Then aim at the engineering application forms a kind of segmented Digitally Controlled Delay Line (DCDL) which has overcame the tradeoff between adjustable delay resolution and dynamic range, benefited from small die area, high resolution and large adjustable range. Finally presented is the performance of the segmented DCDL which is fabricated by 0.18μm CMOS technology. From the test result, the DCDL’s resolution is 12ps and the dynamic range is 4ns.

For avoid the perforation accident, oil perforating urgent need to calculate accurately shaped charge detonation parameters to guide the design and construction of perforation. According to the charge type and characteristics of shaped charge, based on traditional detonation theory and detonation parameters calculated method, this paper first determining shaped explosive detonation reaction equation, then analysis the shaped charge detonation heat, detonation temperature, detonation tolerance and detonation pressure and detonating velocity, extract the analytical methods of shaped charges detonation parameters suitable for oil at last. The specific practices: determined the reaction equation of shaped charges explosive with a maximum heat release rule; determined detonation heat, detonation temperature and detonation tolerance with law of Hess, internal energy value method and Avogadro law; calculated detonation velocity and pressure by Kamlet law; use engineering calculation method to analyze the detonating velocity as to the non-C-H-N-O composition shaped charges which containing feeling agent, bonding agent, flammable agent, plasticizer and other active agent; by revision Kamlet formula, get detonation pressure calculation formula.

Understanding rules of the distribution of fiber is important to control the mechanical properties of composite material performance. Fiber orientation in dumbbell-shaped injection cavity is different from that in regular cuboids because of its complex shape. Fiber orientation equation, Fokker - Planck equation was solved by the finite volume method and the errors brought by approximate method were avoided. The calculation results verified demonstrated that the shape of injection cavity affected the fiber orientation. In the flow direction, fiber of the shrinkage zone oriented along the flow direction and of the dilation zone oriented along tensile direction which is vertical to the flow. In cavity thickness direction, fiber orientation was layered.

As the electric vehicles usually run under complex conditions of city road, there always exists parameter perturbation of motor, which will affect the vehicle performance. To solve the problem, an improved sliding mode variable structure control (SMC) method which combines continuous function and reaching law has been proposed in this paper. Then the improved vector control algorithm’s codes are generated automatically in the MMC (Model-based Motor Control) platform. The results show that the improved SMC algorithm has small chattering and strong robustness to the parameter perturbation and the external disturbances.

In the situation that energy is increasingly grim, how to use high-sulfur fuel effectively and reasonably is a big problem for high-energy consumption cement industry. But high-sulfur fuel will also brought up crusting problem because of higher concentration of circulating and accumulating volatile components. By-pass system can resolve this problem. Rapid-cooling mixer is key equipment for by-pass system. The thermal flow field inside the mixer determines the performance of rapid-cooling mixer directly. CFD method is used to simulate the flow field and temperature field inside mixer. The simulation result help to guide and test the improvement of mixer structure design. After optimization structure design, the mixing of hot gas and cooling air is full and strong inside mixer that leads to excellent cooling effect and good protection for equipment from crusting.

Aspheric lens of Zinc sulfide is widely used in infrared, but it is always formed by polishing with low efficiency, ductile regime grinding aspheric surface of hot-pressed zinc sulfide is studied to reduce time-consuming of polishing. The results of orthogonal grinding experiments demonstrate that the depth of grinding is the main influencing factor on ductile regime removal mechanisms and surface roughness Ra values which decrease with decreasing depth of grinding, and the optimal value is 7.6nm, the steady ductile regime removal mechanisms appears when depth of grinding is below 0.4μm. With diamond wheel by grain size of D20/30, machining parameters on the basis of orthogonal grinding experiments, the aspheric surface cross grinding experiments show that ductile regime removal is obtained only in little center areas of aspheric surface, most of aspheric surface is in brittle regime. Then, the ductile regime aspheric surface with roughness of 20.1nm is observed by cross grinding of diamond wheel with grain size of D4/8.

Dynamic characteristics of the structure have a significant effect on the performance of the structure. Modal test is a common method to obtain structural dynamic characteristics. However, due to the mass effect of the transducer, the measured results of lightweight structure are inaccurate. This paper proposes using strain gauges to test the mode of lightweight structures, and we take the cantilever beam as an example. The paper derived strain modal expressions. We use the strain gauges, the accelerometers and the finite element simulation to test the modal of the cantilever. To compare and analyze the experimental data, it illustrates that the strain modal test methods can measure the bending mode of the beam effectively.

The earthquake resistance detection method for high-rise residence is researched in this paper. Traditional earthquake resistance detection does not take into account the non-fixity of high-rise residence materials, resulting in easy deformation when residential material is borne the large impact force, thus affecting the earthquake resistance of high-rise residence. To solve this problem, an earthquake resistance detection method for high-rise residence based on maximum entropy algorithm is proposed. According to the strength of impact force that the residential building materials can be borne, the pressure-bearing detection model of residential building materials is established. Using the maximum entropy method can calculate the deformation rule of fixed high-rise building materials caused by pressure-bearing. Thus, the earthquake resistance detection of high-rise residence can be completed.

In this paper, the complementary and selective characteristics of ECL (Emitter-Coupled Logic) circuit are fully taken advantage to implement various logic gates including MUX, XOR, AND, NAND, OR, and so on. From the analysis, we find that one ECL circuit can realize many relative logic functions, which is more flexible than CMOS logic. We conclude that if the characteristics of ECL circuit are fully taken advantages, the design of logic functions can be very easy.

To realize video surveillance at any time and any place, a kind of video surveillance platform based on 3G smart phone was designed. In this paper, the general design scheme of video surveillance system was firstly introduced. Then, the surveillance software development method of smart phone client, the transmission mode and transmission protocol of surveillance video were also emphatically described. This system used SVAC which is kind of specifying surveillance video to meet security-monitoring demand. It used multi-image display to realized multi-channel video surveillance, and also used multi-thread to increase the running speed of software. Experimental results demonstrate that it can obtain stable real-time surveillance video.

The selection of suppliers is very important in the purchase of decision support systems. In this paper, firstly the complicated factors of supplier selection which existed in the course of purchase inviting bid are analyzed systemically, Then an comprehensive evaluation index system for picking up the ideal bidders is put forward, Based on the hierarchy-gray theory, a multi-attribute decision mathematics model of purchase inviting bid is constructed, Finally feasibility and effectiveness of the model is testified by a example.

This paper aims at the phenomenon of uneven wear of working roll and the work-side wear is much higher than the drive-side of an acid rolling mill tension leveler for dynamics simulation analysis, analyzes the vibration characteristics of working roll in different process parameters and different bias conditions of rolls and vibration test is carried out to test the rolls by Donghua5920 test-collection system, and combined with the field vibration data of bending roll, points that unilateral severe wear of bending roll is mainly the zero problems of tension leveler.

This paper takes Yuanjiang 20MWp Grid-connected PV Station in Yunnan as an example, introduces the Grid-connected PV station configuration and engineering research in Plateau and analyzes and discusses its actual operating data. This research also studies the PV array operation mode and inclination angle combined with the terrain and the amount of solar radiation, and summarizes the designs and equipment selection of Grid-connected PV Station’s electrical system to accumulate design experience for future large-scale Grid-connected PV Station.

The PEEK/PEI/PES plastic alloys were processed by twin-screw extruder at 370°C separately with five mass ratios of 70/30, 70/25/5, 65/30/5, 60/30/10. The flame retardant of plastic alloys were investigated by experiments, their results showed that, the oxygen index declines when PES was added, the oxygen index of plastic alloy with mass ratios of 70/30 is higher than that of pure PEEK or PES, lower than that of pure PEI, which the oxygen index is 37.1%. The volume resistivity plastic alloy with mass ratios of 60/30/10 is 3.72×1017Ω·cm, which is higher than that of pure PEEK and PES for two orders of magnitude, and the insulation performance of PEEK is improved significantly by alloying.

Combining with both working condition of working roll in tension leveler and wear classification, this paper maintains that abrasive wear is the main type of working roll’s abrasion, and states that shape defects of hot rolled strip is the main cause of the abnormal abrasion of working roll, and concludes that to reduce the wear of working roll relying solely on technology of tension leveling has its limits. So, combining with the materials of working roll in tension leveler and rolling mill, the surface hardness and the wear rates of different materials after heat treatment are experimentally analyzed to provide a theoretical guidance for the further improvement of working roll’s materials.

Wind power has become one of the most potential and vital green energy sources. Location of the wind farm has a better wind resource，and it is also relatively open. Lightning accident in the wind farm happened occasionally, in order to avoid the situation, which impulse current damages the wind turbine, in the accident, lightning protection grounding system of wind turbine is essential .In this paper, according to the experience of Dongshan wind farm project , the method of how to design the wind turbines and booster station grounding grid as required, the calculation of ground resistance and specific measures to reduce grounding resistance of wind turbine grounding device are discussed.

In order to solve the practical issues that the management of container inventory is difficult, time-consuming and overuse of manpower in manufacturing enterprises.A method is presented for the material container inventory management, that is, through radio frequency identification technology to achieve positioning and quantity of material containers. Then, the traditional manual inventory becomes automatic inventory which occurs at each container’s transfer process. The material container inventory management based on RFID is designed in the paper through the introduction of the applied RFID technology, architecture system design, hardware selection and software design. At last the practicability and superiority of the system is tested by run the system in a factory.

In this study, a novel two-phase image segmentation algorithm (TPIS) by using nonlocal mean filter and kernel evolutionary clustering in local learning is proposed. Currently, the difficulties for image segmentation lie in its vast pixels with overlapping characteristic and the noise in the different process of imaging. Here, we want to use nonlocal mean filter to remove different types of noise in the image, and then, two kernel clustering indices are designed in evolutionary optimization. Besides, the local learning strategy is designed using local coefficient of variation of each local pixels or image patch is employed to update the quality of the local segments. The new algorithm is used to solve different image segmentation tasks. The experimental results show that TPIS is competent for segmenting majority of the test images with high quality.

This paper presents a quickly locate the query methods in the face of huge amounts of data. The method by analyzing the data relationship, split the database, the formation of cross-database quickly Hash positioning table, and by analyzing the query cost to build double weighted graph and weight table. Each query is given based on the node weight table fast cross-database query path, and quickly locate the target from the cross-database positioning Hash table Hash calculation, in order to achieve fast positioning method.

This paper analyzes the effect of stable behaviors when amplitude, phase of sine voltage compensation signal are added in the system, reveals that the dynamical behaviors mechanism that sine voltage compensation signal changes feedback voltage-mode controlled buck converter lies in changing the duty cycle without impacting the system stable error via analyzing the change of period multiplier in Monodromy matrix and conditions of period bifurcation, and finally achieves stabilization control for bifurcation and chaotic behaviors. The simulation and experimental results prove the correctness of the theoretical analysis.

LF16 aluminum alloy and Q235 steel were brazed by Zn-Al solder and the Al-Si-Cu solder. Metallographic microscope and scanning electron microscope were used to observe the microstructure of weld joint. The result shows that the strength of the joints, which were welded with Zn-Al solder reached 133.6Mpa. Zn-rich solid solution phase and Al-rich solid solution phase existed in Zn-based solder brazing seam. The Fe element trend was gradual changed, while Al element trended more gently, and generated Fe2Al5 intermetallic compounds in the joints in both the brazing joint of Zn-based and Al-based solder.

This paper introduces the test and analysis of shear lag effect of a vast scale model of a continuous box girder with variable depth under symmetric lateral varying concentric loads. The strain distribution of the top plates and bottom ones of three cross-sections is tested, while the concentric loads respectively forced on the middle section and the quartile ones. Those sections are: the root-section of the cantilever, mid-section and one quartile section. Test shear lag coefficients of feature points were got through dividing the test strains to those calculated by elementary beam theory. They are compared with those soluted by method of energy variational calculus. The comparing result shows that the shear lag coefficients of the top plate shift from positive to negative accompanying with the load position from ribs to mid point of top plate. At the same time, the overall shear lag coefficient level increases. Meanwhile that of the corresponding bottom plate distribution character finely changes, but its overall shear lag coefficient declines that means that the contribution to bending resisting of bottom weakens. Lateral position of concentric loads has fine influence on shear lag of those sections relatively far from the loads.

This paper takes the monitoring data sample from the top of fractionation tower system of one petrochemical company and uses prediction model which is constructed by BP neural network to study the corrosion prediction of catalytic fractionation tower top system. It uses min-max and z-score standardized method to deal with the original data and compare the impacts. The result shows that the BP neural constructing prediction model can provide basis of corrosion control for refinery. It also shows that better accuracy can be achieved by using min-max standardized method and when the number of training data quantity is over 20, the prediction result is more accurate and stable.

Under the background that solid wastes have been produced and increased continuously, how to change waste into treasure has become an important research topic to achieve sustainable development. Based on a cooperating project with an enterprise, the production technology and key equipments for ceramsite produced from coal fly ash and clay have been studied which is of great significance not only to carry out the industrial solid waste disposal and make best use of resource but also to guide the running of the production line.

The compensation effect of expansive agent on shrinkage of self-compacting concrete (SCC) are studied. The deformation of Concrete was tested by concrete comparator, and the qualitative and quantitative analysis of hydration products were done by X-ray diffractometer (XRD). The results show that the dosages of mineral admixture and curing conditions affect the application results of expansive agents markedly. SCC samples containing expansive agent cured in the water are expanding within the test time. In the case of watering condition and natural curing condition, the samples are always shrinkage within test time, but mineral admixtures have a good effect to resist the shrinkage of SCC. Microstructure analysis show that ettringite content is reduced slightly due to the reduction of the alkalinity of SCC resulted by more mineral admixture. However, when at water curing condition, humidity inside SCC is much higher, which makes ettringite content larger even though with more mineral admixture. So, curing is the most important factors for the micro-expansion of SCC containing expansive agent.

Based on the fundamental assumption of the stretch-bending straightening theory and applying the elastoplastic theory, the paper analyzes and deduces the distribution and change of stress and strain of strip in the bending springback, raising that bending unloading will increase the elongation of the neutral layer of the strip. Then, through the conditions set-up of the finite element simulation model and results of data analysis, we found the effect of different tension and bending degree on the elongation for the neutral layer of the cold strip in process of unloading, and this kind of influence is described quantitatively.

For tension roller skidding and motor alarm phenomenon often appeared in the process of straightening. This paper take electromechanical hybrid drive system of tension leveler as example, analysis the control system, focusing on the dynamic tension load distribution, points out that the above situation can be avoid effectively by setting the parameter of tension reasonably. And the same time, speed control and torque control are analyzed in this paper, and it provides a reference for the further study of electromechanical hybrid transmission control system.

In order to know the corrosion behavior of 16MnR in the circulating water system and determine the influential sequence of factors, such as chloride ion concentration, temperature of circulating water, pH value and calcium ions concentration, to the corrosion of 16MnR. In this article, the electrochemical impedance test of 16MnR was conducted with electrochemical test system of CS310. The orthogonal test is adopted and the influential sequence of each factor to the corrosion of 16MnR is obtained by range analysis. The result shows that the impedance spectroscopy of 16MnR in the circulating water is a single capacitive reactance arc; the parameter which controls the corrosion process is the solution resistance RP and with the increasing of RP, the impedance value increases thus slowing down the corrosion velocity of 16MnR; the greatest impact on the corrosion of 16MnR are chloride ion and the temperature.

Based on examples of the application of e-government, this paper aims to provide a theoretical study on how the Information and Communication Technology (ICT) helps to increase the innovation dynamics of the regional systems. According to the literature review, we understand the innovation dynamic of a regional system is generated from the interplay of the knowledge production between different actors such as government, university and industry. ICT can be viewed as the stimulus of facilitating the e-government to develop the innovation dynamics. Accordingly, some examples of the application of e-governments around the world will be provided for a deep understanding the link between ICT and innovation dynamics.

This paper aims to emphasize the necessity of introducing Project-Based Learning (PBL) to design enterprises in order to foster designers creativity and facilitate innovation of design enterprises. According to the literature review, creativity can be viewed as the first stage of innovation; PBL has at least two elements including solving real problems and group work that can provide conditions of creativity development. Moreover, creativity techniques such as brainstorming, mind mapping, checklist and morphological analysis are suggested to be integrated into PBL in the design enterprises.

The army's existing preparation system, maintenance task allocation problem is missing quantitative analysis method, Research on Materiel readiness rate and the talented person growing law of task allocation model, This method has guiding significance for the Army equipment maintenance tasks assigned, At the same time which has important effect on improving the combat effectiveness of our armed forces and cultivate high-quality constructive. finally, test the feasibility of the method with examples.

N-doped meso/macroporous carbon materials were synthesized by using melamine-formaldehyde resin as carbon precursor and silica spheres as a removable template. Scanning electron microscopy images reveal that the macropores of carbon materials can be modulated by changing the diameter of template. While the BET results verify that the template had no obvious effect to the mesopores of the materials. The as-synthesized carbon materials with a bimodal pores structure display a high surface nitrogen content of 30wt%. XPS analysis reveals that N atoms are mostly bound to the graphitic network in two forms, i.e. pyridinic and pyrrolic nitrogen.

With the lack of the water source, the accurate metering is more and more important. This paper designs and realizes a kind of water meter auto calibration system, which can calibrate the water meter within a short time by image recognition technology . Shown by practical application, the system not only improves the testing efficiency, but also save the man-hour.

To overcome disadvantages of complex wiring and difficult maintenance for traditional wired sensor networks, a data acquisition system for chemical equipment monitoring based on wireless sensor network has been put forward. The proposed data acquisition system has functions of real-time data acquisition, transmission, storage, query and remote sharing of history data, and provides favorable technical supports for real-time chemical equipment monitoring. First, the system framework, EMBV210 hardware are introduced. Then, in the LabVIEW platform, the data acquisition system is developed, and the remote sharing of equipment operating status by DataSocket is realized. Finally, the proposed data acquisition system is simulated and verified. The work provides a feasible way for chemical equipment monitoring and useful references for the development of other similar integrated measurement and control systems.

Corrosion type, reasons and influential factors of the tail heated surface tube of the low carbon steel under the flue gas medium in LNG(Liquefied Natural Gas) power station HRSG(Heat Recovery Steam Generator) were researched through cracks morphology observation, corrosion products analysis, corrosion elements measurement and tube wall temperature field FEM calculation. Results showed that the crack initiated from the outer wall of the tube and propagated toward the inner wall with the arborescent morphology. Intergranular embrittlement ruptured. Rock type feature and secondary crack were observed on the fracture. Mud pattern and polygonal figure of the corrosion products were present. According to these morphology characteristics, the crack was identified as stress corrosion crack, and corrosion type was SCC(Stress Corrosion Cracking). Reasons of SCC were that low feed water or flue gas temperature during a certain period of the unit startup and shutdown for peaking operation brought about the temperature of the outer wall of tube below the flue gas dew point, and the flue gas became dew and corrosion solution emerged on the outer wall of tube. The SCC component was CO2 solution according to the corrosion products. S and Cl elements were found in the outer wall of tube, but their effects on SCC are still needed more researches.

so-parametric trajectory generation and tool orientation determination for the 5-axis machining of an impeller are developed in this paper. Firstly, u direction of the surface is selected as the feed direction, and v direction is set as the step interval direction for the iso-parametric trajectory generation. Secondly, tool orientations are determined by the vector starting from the guide curve point and ending at the CL point. The guide curve is located between neighbor blades and fitted by the middle points with the least square method. Thirdly, a program is developed and the AIsopara Trajectory menu is added to the main menu bar by UG MenuScript. Finally, the generated trajectories and tool orientations are demonstrated with their tool swept volume.

In reverse engineering, data pre-processing has played an increasingly important role for rebuilding the original 3D model. However, it is usually complex, time-consuming, and difficult to realize, as there are huge amounts of redundant 3D data existed in the gained point cloud. To find a solution for this issue, point cloud data processing and streamlining technologies are reviewed firstly. Secondly, a novel pre-processing approach is proposed in three steps: point cloud registration, regional 3D triangular mesh construction and point cloud filtering. And then, the projected hexagonal area and the closest projected point are defined. At last, a parabolic antenna model is employed as a case study. After pre-processing, the number of points are decreased from 4,066,282 to 449,806 under the constraint of triangular grid size h equaling to 2mm, i.e. about 1/9 size of the original point cloud. The result demonstrates its feasibility and efficiency.

With macrographic examination, SEM observation and fracture quantitative analysis technology, the fracture fractography of a spray tube with both the mechanical stress and the thermal stress in a boiler desuperheater of a power plant was interpreted, and the failure mode and the cause were researched. Results showed that rupture of the spray tube was due to the fatigue, and further, the thermal mechanical fatigue. The alternating bending stress and thermal stress were main factors of the fracture failure. The shallow surface thermal fatigue cracks in tube inner wall were induced by thermal stress. When the thermal mechanical fatigue crack grew up steadily to the shallow surface cracks zone, fast growth occurred and the local fast fracture zone generated which had different fractographies with final fast fracture zone of the normal fatigue fracture.

The averaging method has been applied to calculate the critical conditions of parametric resonance instability of the first order mode shape of clamped-clamped and pinned-pinned pipes conveying fluid. The influence of gravity factor on parametric resonance of pipe conveying fluid, with different supporting forms and different flow velocity, has been studied based on the comparison results of gravity factor being considered and neglected. It is concluded that gravity factor has a greater influence on parametric resonance region of pinned-pinned pipe than the one of clamped-clamped pipe, and, at a higher flow velocity, gravity factor is more influential to both pinned-pinned pipe and clamped- clamped one.

The treatment efficiency of domestic sewage by the SBR filled with humus soil was investigated and compared with that by the conventional SBR. The results show that the removal rates of organic matters, NH4+-N and TP by the SBR filled with humus soil reach 85%, 83% and 72% respectively. Compared with the conventional SBR, the degradation rate of organic matters is improved, and the addition of humus soil contributes to occurrence of SND, thus the removal rate of NH4+-N is increased. The addition of humus soil shortens the oxidation time of organic matters and the nitrification time of NH4+-N, which can improve the treatment efficiency and reduce the operation cost.

Design Expression course is a very important basic course of Industrial Design to the students who learn this major, as it involves the expression and scheme of design idea. It will help students to develop design thinking and improve the professional quality that instruct students in understanding the importance of design expression correctly in the process of personnel training.

Hand painted of product design is not a pure creation of art painting. It is a technique method to organize and visual the product design which meets with consumer’s needs with guidance of design thinking and methods. It can rapid expresses design ideas, and examine design project and convey the true effect of the product design. As a designer the basic language of expression, hand painted run through the design process. It plays an important role to enhance the designer thinking. The using of hand painted in product design include enrich the accumulation of design, Inspire design, communication design, depiction of real emotion. It plays an important role to enhance the designer thinking.

In this paper, a novel approach of linear octree is employed to represent discrete tools and build their swept volumes along machining trajectories. Firstly, a data structure of linear octree is defined as the base of geometrical transformations. The linear octree can be extended into leaf nodes in the deepest level for simplifying homogeneous transformations, and all leaf nodes in the deepest level can also be concentrated into a linear octree for saving storage capacity inversely. Secondly, tool trajectories are interpolated as short lines, and swept volumes between neighbor interpolation points are defined as the Minkowski sum of their cell sets at both locations. Thirdly, equations of the rotation matrix for local coordinate system, roll, pitch and yaw angles of tool orientations are established to define the global rotation motions. Finally, a case of discrete sphere tool and its swept volume modeling are studied to validate the proposed approach.

In order to explore the application methods and development potential of solar energy technology in facility agriculture, and to seek a solution to resolve problems existing in greenhouse production, such as high heating cost and serious environment pollution etc. , an experimental study was carried out on a solar energy combined coal-fired boiler heating system used for greenhouse. In this paper, with Kunming Trifecta Orchid Nursery Co. Ltd of Yunnan Flower Demonstration Garden for experimental research object, the general design and operation method for the system were introduced, and an experiment on operation performance and heating effect of the system was tested in Kunming. The results showed that whether it was sunny or cloudy, the system could make full use of solar energy, make the water temperature of heat preservation tank reach a certain expectation, and ensure the temperature requirements on different growing stages of phalaenopsis in greenhouse. So a theoretical basis is provided for the study on solar energy combined with coal-fired boiler heating system for greenhouse. Through economic analysis of the system, the results showed that this system had high economic value, energy saving and environmental protection performance.

On condition that the surface of 304 stainless steel has formed passive film, we have done research on the impact that the change of concentration of Cl- and Na+, the temperature, pH of Na+, on 304 stainless steel properties. This experiment is preceded studied with electrochemical method. The results show that along with the increase of temperature, pH improves the repairing capacity of passive film on the surface of 304 stainless steel. However, its stability decreases. Meantime, the pitting corrosion will happen become easier, when the repairing capacity of passive film and stability have been weakened because of the concentration of Na+, Cl- increases.