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As the number of doubly fed induction generator (DFIG)- based wind-turbine systems continues to increase, wind turbines are required to provide Low Voltage Ride-Through (LVRT) capability, especially under the condition of grid voltage dips. This paper, depending on the operating characteristics of doubly-fed induction generator during grid faults ,deals with a protection and control strategy on rotor-side converter (RSC) to enhance the low voltage ride through capability of a wind turbine driven doubly fed induction generator (DFIG). The simulation and experiment studies demonstrate the correctness of the developed model and the effectiveness of the control strategy for DFIG-based wind-turbine systems under such adverse grid conditions.

The finite-time neural network adaptive control of under-actuated robot is investigated, and a kind of multistep control strategy is used. First the transformation of dynamics model is made, and the passive joints are driven to desire positions by the coupling among joints, then the passive joints are locked. When the passive joints are locked to other operating point, the system becomes the one with structure uncertain. Combining the theory of finite-time control with neural network adaptive control, a finite-time neural network adaptive controller is got which can make the position tracking of joint rapidly. The simulation shows the effectiveness of the controller.

The fracture samples of spring steel stabilizer bars in 60Si2Mn were researched in this paper. Through the methods such as macro-and micro-fracture analysis, SEM fracture morphology observation, microstructure observation (surface and internal organization), and macro-hardness testing to analysis the failure causes for earlier fracture of the stabilizer bars. The results were showed that the fatigue crack source for the non-stress stabilizer bar was on the surface. The earlier fracture cause was due to the decarburized layer on the surface and the uneven organization in the internal, which lead to the fatigue resistance at the non-severe stress, was greatly decreased. And the fatigue crack of stabilizer bar in the normal stress was originated at the deformation on the surface in the processing.

The purpose of the modern product design is to provide users with a good living environment, making a great combination between art and life then conferred it practical function, is to design in a relationship. We should design in a relationship. Fengxiang clay sculpture has novel shape, fine craft, contrast color , so it is very valuable to study traditional culture. So that the local design have been given a form of traditional culture and symbolic semantics, thus product is not only a product, but the new soil of traditional culture.The combination of traditional culture and modern products, not only can enhance the artistic quality of the product, also can make the traditional culture to get the most convenient, the cheapest and most convenient route of transmission.

The development of sportswear is closely related to the development of scientific and technological,the improvement of the communitys civilization.As the professional sportswear design and production are close to new material,high-tech sportswear will not only help the athletes improve performance and raise campaign skills,but also more advantageous in protecting athletes safety.

Distinguished quadrotor , the research of tricopter is still in undeveloped state. This paper focuses on torque analysis and mathematical modeling for attitude control of the tricopter aircraft. The simulation of controller shows that the PID method can not achieve the desired states, so the research of building the mathematical model provides some theoretical foundation for controlling the tricopter.

The existing Extensible Authentication Protocol (EAP) based handover authentication schemes have show robust security features especially the Qi Jing et al.'s design, which not only meets the essential security requirements in handover authentication but also achieves privacy preservation. However, it still suffers pitfalls in the process of authentication. The main idea of this paper is to extend the work by Qi Jing et al. and particularly focus on the formal analysis using extending BAN logic which is more concise yet practical to use on PKI-based protocols.

Dissemination is a data dissemination protocol for wireless sensor network based on TinyOS. The purpose of it is that we can send data to every node reliably Dissemination can reconfigure,query and reprogram nodes easily This article briefs the mechanism of Dissemination,and analyzes its principle. At last, it is applied in practice. Practice shows that, when network traffic is small, Dissemination has good performance, and reliable, simple to deploy, with high practicability and value. But when network is large, its performance is poor. So, based on the specific practice, Dissemination is improved.

Collection Tree Protocol is a data collection protocol for wireless sensor network, which is based on an embedded operating system --TinyOS. This article briefs the mechanism of Collection Tree Protocol, analyzes the principle of data transmission. Especially, when mass of data must be transferred, it solves the reliability of Collection Tree Protocol. This improves its performance and has wide development prospects.

With the enhancement of safety factor in civil aviation, simulation technology has been paid more and more attention and got comprehensive application. We describe the application of simulation technology in the field of civil aviation security, such as runway generation, terrain reproduction, data import and export, and flight path computing and so on. We propose a method for computing flight path in simulation and reconstruction, and analyze the solving process in detail. We perform the calculation results of the simulation reproduction with CEFA software and Google earth.

Cultural gene pool provides necessary support for design platform which is based on the cultural gene. It is also the most basic part of gene engineering. Based on the tourist souvenirs, a new design methodpan-ethnic-group is put forward. Take tourist souvenirs actual project development of Hanyangling Museum as an example, Xi'an cultural gene pool has been built. Through pan-ethnic-group, cultural tourist souvenir sales were increased.

Travel souvenir industry is driven by the rapid development of the tourism industry. In the product development process, researching and developing (R&D) strategy needs to be studied in order to obtain the corresponding policy of market positioning, research and development cycle and the development number. According to the survey data, scientific and rational calculations are carried out to maximize the ratio of benefits and costs, the allocation of resources are improve effectively, and market demands and customer needs can be satisfied in a better way.

Based on the status of modern cultural tourism souvenir market survey and research, the consumption preferences in the market of cultural tourism souvenirs are studied, the driving factors of production and cost and pricing constraint are analyzed, the production information database and the type of product configuration database are established in order to realize rational allocation of product type. By the scientific thinking method, the selection theory and application system over development of culture tourist souvenirs are improved and perfected. And it is of a certain degree of reference and guidance to develop cultural tourism souvenirs.

Aiming at the features of complexity, poor real-time and Low-accuracy of single-phase Active Power Filter (APF), and the problem of impossible parallel computation in the traditional DSP software realization, new design method of APF Based on FPGA is proposed, This paper focuses on the study of the harmonic current detecting method and improves control method of compensate current, it builds an experimental platform with FPGA EP1C12Q240C8 as the controller, the experimental results all support the effectiveness and correctness of the control methods and design methods of APF.

Wireless sensor networks can real-time sense, acquire and process the environmental information. Based on the research of the sensor node in grain storage temperature monitoring, the hardware circuit of the node is designed. And according to the feature of DS18B20 , multi-point temperature acquisition of grain storage is designed too. What’s more, based on the TinyOS operating system ,we design the temperature acquisition system for the grain storage monitoring.

With the rapid development of wireless sensor network, the request of granary monitoring is pointed out to connect wireless sensor network with Internet. The gateway is one of the most important parts. By analyzing the interconnection between wireless sensor network and Ethernet, combining with the granary monitoring needs, a gateway solution based on high-performance network processors and embedded real-time operating system is designed. And transparent transfer of data between the wireless sensor networks and the Internet is realized.

Cost-effective technologies to remove arsenic from high arsenic groundwater are urgently needed for safe water supply in many countries. In this study, a new sorbent of nanoscale iron-manganese binary oxides (NIM) was prepared by an improved co-precipitation method. The as-synthesized adsorbent is amorphous with 280 m2/g surface area and particle size of 10-20nm. For the adsorption of 2 mg/L As(III), the aqueous concentration quickly decreases to less than 10 μg/L within 30 min. During the adsorption of As(III), low concentration of As(V) is measured in aqueous solution in the initial stage and disappeared afterwards, whereas the fraction of As(V) on NIM surface gradually proving the oxidative transformation of As(III) to As(V). Its batch experiment data followed pseudo-second-order kinetics.

Large amounts of chromite ore processing residues (COPR) containing hexavalent chromium (Cr(VI)) discharged from the production processes of sodium chromate and dichromate need to be treated since Cr(VI) has been recognized as a carcinogen internationally and has posed a great threat to the environment and human health. Remediation of COPR containing Cr(VI) with bacteria, biomass and ferrous sulfate was studied in this work. A strain of Cr(VI)-reducing bacteria (CRB), a strain of sulfate-reducing bacteria (SRB), orange peels and ferrous sulfate were used as antidotes to reduce Cr(VI) to Cr(III). The experimental design methodologies — Uniform Design and Orthogonal Experimental Design were adopted to investigate the effects of the reductants on the reduction of the Cr(VI) in COPR. The results show that orange peels and CRB can reduce Cr(VI) in COPR over 95% in 30 days. Together using the four stuff can reduce Cr(VI) over 97% in 12 days. However, it seems that presence of the SRB is not beneficial to Cr(VI) reduction because it might refrains the action of CRB. Therefore, it is not surely beneficial to apply multiple microorganisms simultaneously to the reduction of Cr(VI) in COPR.

The straightness error was measured from a certain part surface by CMM. The paper expounded the principle of error separation technique, and separated the straightness error into deterministic error and random error. It proved strictly an opinion that random error is obedient to normal distribution. Extraction point of random error far outweighs the extraction point which is obtained from deterministic error. Based on the principle of sampling signal, a conclusion can be pointed out that utilizing the characteristic of random error to recover the signal of straightness error without distortion is feasible and normal distribution model can be used in the computer simulation to study the problem of extraction point.

Green Manufacturing and Recycling Economy is the basis for the sustainable development of human society, is also the direction for the future development of manufacturing industry. This article describes the concept of Green Manufacturing and Recycling Economy, analyses the work of Green Manufacturing processes, from product design, production, recycling-oriented three-pronged explained, and presents three suggestions of Green Manufacturing for circular economy, including extending the product life cycle, establishing enterprise's return goods processing center and strengthening cooperation with relevant manufacturers. Through these methods can enable enterprises to achieve the recycling of materials and energy, and enable enterprises to reduce production costs, improve core competitiveness.

A large number of macroscopic pores were introduced into commercially pure aluminum (Al) and Zn-Al eutectoid alloy by air pressure infiltration process to comparatively study the influence of macroscopic pores on the damping behaviors of the materials. Macroscopic pores size are on the order of a millimetre (0.5~1.4mm) and in large proportions, typically high 76vol.%. The damping behavior of the materials is characterized by internal friction (IF). The IF was measured on a multifunction internal friction apparatus (MFIFA) at frequencies of 0.5, 1.0 and 3.0 Hz over the temperature range of 25 to 400 °C, while continuously changing temperature. The damping capacity of the metal materials is shown to increase with introducing macroscopic pores. Finally, the operative damping mechanisms in the metal materials with macroscopic pores were discussed in light of IF measurements.

This paper presents an experimental investigation of the machining characteristics of sintered NdFeB permanent magnet using a combination process of electro-discharge machining (EDM) with ultrasonic machining (USM). Concentration of abrasive in the dielectric fluid is changed to explore its effect on the material removal rate (MRR). MRR of EDM /USM, conventional EDM are compared, machined surface characteristics are also compared between them. It is concluded that the combination EDM/USM process can increase the MRR and decrease the thickness of the recast layer. In the combination process, an appropriate abrasive concentration can improve its machining efficiency.