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In this paper, a method to realize the reliable operation of the variable frequency drive(VFD)is proposed: Hot Backup switching, and the electrical design, software design and test results are given. And meanwhile, also state the switching control principle, clearly indicate the distinctive difference and improved performance between traditional switching mode and Hot Backup switching mode. At the end, gain the conclusion based on test results and extend to bigger size of motor.

This paper analyses the multi-objective design requirements of UAV with high timeliness, high manoeuvrability and long-endurance long-range flight capability. Then put forward an aerodynamic configuration conception of wide flight envelope that can perform multi-tasks, such as fast approach, long endurance patrol and critical maneuvering. By means of wind tunnel test, the aerodynamic characteristics regularities of this configuration changed by shape parameters, component combination and spatial relationships are studied. Base on analysing the flow coupling efficiency of canard vortex and wing vortex, proposed the principle of relative position matching between canard and wing. The results show that when the canard was higher than the wing, the canard vortex provided additional vortex lift on the upper surface of the wing, which could provide a favorable influence in the cruise phase. Further more, using the trapped vortex of variable curvature lip on nose which was similar to the influence mechanism of canard vortex, a stable favorable interference vortex system in a wide envelope could be obtained, and the components and controlling complexity of this aircraft configuration would be simplified.

The damage effect characteristics of GaAs pseudomorphic high electron mobility transistor (pHEMT) under the irradiation of C band high-power microwave (HPM) is investigated in this paper. Based on the theoretical analysis, the thermoelectric coupling model is established, and the key damage parameters of the device under typical pulse conditions are predicted, including the damage location, damage power, etc. By the injection effect test and device microanatomy analysis through using scanning electron microscope (SEM) and energy dispersive spectrometer (EDS), it is concluded that the gate metal in the first stage of the device is the vulnerable to HPM damage, especially the side below the gate near the source. The damage power in the injection test is about 40 dBm and in good agreement with the simulation result. This work has a certain reference value for microwave damage assessment of pHEMT.

Different switching frequencies are required when SiC metal–oxide–semiconductor field-effect transistors (MOSFETs) are switching in a space environment. In this study, the total ionizing dose (TID) responses of SiC power MOSFETs are investigated under different switching frequencies from 1 kHz to 10 MHz. A significant shift was observed in the threshold voltage as the frequency increased, which resulted in premature failure of the drain–source breakdown voltage and drain–source leakage current. The degradation is attributed to the high activation and low recovery rates of traps at high frequencies. The results of this study suggest that a targeted TID irradiation test evaluation method can be developed according to the actual switching frequency of SiC power MOSFETs.

Based on the comparison and analysis of bus topology, star topology, tree topology, ring topology and network topology, the tree topology of low voltage station area is established according to the correlation between output line and input line of each distribution box. Experiments show the realizability of this method.

In recent years, the oil-infused slippery surfaces inspired by Nepenthes pitcher have potential applications in domestic and industrial fields due to their excellent water repellence. However, the current preparation methods of the oil-infused slippery surfaces have the disadvantages of time-consuming, expensive equipment and complex processes. In our research, we reported an approach to prepare the oil-infused slippery surface with multi-functional applications by simple chemical etching. First, Al plates were etched by hydrochloric acid solution and modification with lower surface energy. Then, the as-prepared samples were immersed into the lubricant oil. After that, the oil-infused slippery surface with a water slide-off angle of 3° was obtained. The freezing rain tests, chemical stability tests, and self-cleaning tests were conducted on original Al plate and the as-prepared sample. This work will enrich the preparation methods of the oil-infused slippery surfaces.

The superhydrophobic surface on 30Cr2NiWVA aeronautic steel is fabricated via electrochemical etching and FAS modification. The results of scanning electron microscopy (SEM) show that, after electrochemically etching, the aeronautic surface is covered with rough coralloid-structure film. This surface demonstrates excellent corrosion protection, anti-icing and self-cleaning property. Additionally, this surface shows outstanding superhydrophobicity after anti-icing, self-cleaning test, and even after exposure to the air in the normal ambient environment for two years, proving the durability property of superhydrophobic aeronautic surface. The proposed method is simple and has great potential applications for large-scale applications in aircraft.

Paddy rice agriculture plays an important role in food security and has a considerable influence on natural systems. In the context of climate change, understanding the nature and drivers of shifts in the northern limit of paddy rice (NLPR) is crucial for adaptation strategies and food security. However, quantitative studies on the effect of climate change on paddy rice distribution shifts have not been well performed. Here, we mapped the NLPR in China using Landsat imagery from 1984 to 2013, analyzed the latitudinal and elevational dynamics of the NLPR using Fishnet analysis, and explored the factors driving the changes in rice area across the NLPR regions using a linear regression model. Our results show that between 1984 and 2013, the NLPR shifted 24.93 km northward (the greatest movement was 88.01 km occurring at approximately 133° E) and elevational limits increased by 39.15 m (the greatest movement was 117.08 m occurring at approximately 129° E). While socioeconomic factors (e.g. benefits, policies, irrigation, and mulch) played significant roles in rice area changes, the changes in rice area across the NLPR regions had the strongest positive association with the increase in the previous temperature, indicating that rice cultivation in the NLPR regions has moved to higher latitudes over the 30 year study period to adapt to climate change. Our study highlighted that quantifying the interactions between climate change and crop production systems can facilitate a better understanding of the human responses to changes in the growing conditions in the face of climate change and ensuring regional and global food security.

With the advent of the Internet, big data has penetrated into all aspects of life. In such an environment, Chinese medicine needs not only inheritance, but also advance with the times, innovative thinking and technology. This article takes big data processing and analysis as the goal, and analyzes the application scenarios of big data in Chinese medicine analysis. The model adopts APRIORI algorithm and text clustering, which improves the application of big data technology in the analysis of information extraction of traditional Chinese medicine. The test results of traditional Chinese medicines show that the use of basic big data to process the data, combined with the K-Means text clustering calculation method, the scientific conclusions obtained in the medical and health industry application rate has increased by 18%, these conclusions provide a certain degree for Chinese medicine manufacturers Help to improve production efficiency and product quality. However, the basic large database of Chinese medicine in my country has not been established, which makes the use of big data unable to be fully implemented.

In this paper, the test site is the working surface hollowing area of Luling Coal Mine 8, coal seam III 811, and the distributed fiber temperature measurement is carried out. Distributed temperature measuring fibers and beam tubes are arranged in the inlet and return wind lanes of the work surface for continuous monitoring. After analyzing the data such as measuring temperature and gas concentration, the remote monitoring technology of the temperature field in the mining area is expanded. Finally, combined with the self-ignition characteristics of the Luling coal seam and the classification criteria of the “three zones” in the mining area, the range of the self-ignition hazard area of the III 811 mining area is accurately determined. This paper provides theoretical and technical support for the development of targeted fire prevention measures and remote monitoring.

This paper introduces the design and construction process of a bilingual machine translation auxiliary tool between Chinese and Kazakh languages. The tool uses the Jieba word segmentation tool to segment the input sentence, and then translates it according to the two language correspondence and rule-based dictionary method. This paper introduces the development and implementation process and overall framework of said auxiliary tool, and the role of some functional modules of it.

The aerodynamic shape optimization design of the aircraft is to combine the aerodynamic performance analysis of the aircraft with the optimization method, by constantly changing the design shape of the aircraft, its aerodynamic performance is improved to achieve optimal aerodynamic performance under certain constraints. Aircraft aerodynamic shape optimization is a comprehensive design platform that integrates geometric parameterization, moving grid, CFD calculation and optimization algorithms. With the development of computational fluid dynamics (CFD) and the maturity of calculation methods, the role of aerodynamic shape optimization in modern aircraft design becomes more and more important. To this end, an aerodynamic shape optimization design platform based on non-uniform rational B-spline (NURBS) was established. In the optimization process, a mesh deformation method based on radial basis functions is used, and an arbitrary Lagrangian Eulerian method (ALE) is used to describe the unsteady process of the wing. The optimization analysis of the large aspect ratio wing under subsonic conditions has certain reference value for the deformation problem in the aerodynamic shape optimization design.

In order to solve the negative problems of environment and energy caused by fuel vehicles, the application of new energy sources in the field of automobiles has gradually become the focus of attention. A hybrid energy system of electric vehicle was studied, which is composed of ultracapacitors(UCs), solar panel (namely PV) and lead-acid battery set. Through the research, it was found that the maximum power tracker can track the maximum power point of the solar panel, and the ultracapacitors with high power density and the battery with high energy density can be complementary by each other, shorten the discharge time of high current and improve the dynamic performance of the vehicle.

Objective: To optimize the preparation technology and matrix ratio of Sanqi hemostatic spongia. Methods: The effects of Twain 80, formaldehyde and twelve sodium alkyl sulfate on the matrix formability of the spongia were investigated by the L9 (33) orthogonal test, and the optimum ratio of the matrix was optimized through the water absorption, the thickness uniformity, the softness and the color degree. The orthogonal test results showed that the matrix ratio was Twain 80 1.4g, formaldehyde 1.6 mL, sodium dodecyl sulfate 1.0 g, and Sanqi hemostatic spongia was superior when the proportion of other substrates was fixed. Conclusion: Sanqi hemostatic spongia was produced by orthogonal test and matrix ratio is stable, uniform in thickness and good in quality.

Link prediction has been attached more attention in recent years. In this paper, we develop a link prediction method which has a unique perspective on using network structures. The key idea is to exploit the relationship information based on Graphical Markov models (GMM) for designing similarity indices. Specifically, networks with GMM were modeled to capture the relational influence of nodes by taking multi-hop neighbors into consideration. Then, link ties are measured for supporting relationship prediction based on the theory of weak and strong ties. Moreover, the proposed method can be used to predict the emergence of future relationships between the nodes. Finally, empirical studies on real-world dataset demonstrate that the benchmark of the proposed method improves with a significant margin compared with other methods.

Objective: The dosage form of Sanqi Shangyao tablets was reformed and made smeared films. Methods: PVA-124 was used as film forming material, glycerol as plasticizer, Twain 80 as surfactant and azone as penetration enhancer. On the basis of the single factor test, the orthogonal test L9 (34) was used to screen the matrix prescription, and the optimum matrix ratio was obtained by investigating the fluidity, color, flexibility, film forming time and the appearance uniformity of the coating agent. Results: The best substrate ratio was Twain 80 0.5 g, PVA-124 4.0 g, glycerol 2.0 g, azone 0.3 g. Conclusion: The proportion of the smeared films prepared by orthogonal test is stable. The film forming time is short, and the preparation process is simple and feasible.

Self-propelling micro devices, which means moving spontaneously without traditional motor, have been widely studied in recent years. We proposed a new kind of self-rotating micro device based on water droplet, which can achieve rotating without any external energy. It can transform surface energy of the water droplet into kinetic energy of the micro device. And the feasibility experiment showed that the micro device work well, the numerical analysis of the micro device about the rotating velocity varied with the different center distance and number of the inclined pores provided us an empirical equation to predict the rotating property of the micro device, and an application model in micro generator field was proposed. The self-rotating micro device is a totally original self-propelling device with a green propelling mechanism to the environment.

Groundwater near the Qilu petrochemical plant in Zibo City is polluted by oil for over thirty years, which seriously threaten the local ecological environment. The results of GC-MS analysis of water samples show that benzene was the most abundant and toxic organic pollutant. The adsorption-desorption behaviour of benzene in soil was studied through batch experiments. The results indicated that the adsorption amount of benzene in the local soil showed a trend of increasing first and then decreasing with the increasing of the initial concentration of benzene. There existed an optimal initial concentration of benzene in the adsorption experiments. The desorption concentration of benzene was proportional to the initial concentration of benzene. Particle size of the soil was inversely related to adsorption and desorption concentration of benzene. The soil with the average particle size of 0.08 mm had the largest adsorption capacity for benzene, which could reach 376.39 mg/kg. The results could provide a theoretical basis for the local groundwater remediation.

When the Cassini spacecraft finally plunged into the Saturnian atmosphere on 2017 September 15, China’s deep space telescope pointed to Saturn to observe Cassini and study the Saturnian upper neutral atmosphere. In this first Chinese Saturnian radio science experiment, X band Doppler velocity radio science data between the deep space telescope and the Cassini spacecraft were obtained. After removing Saturnian and solar gravity effects, Earth rotation effect, the remaining Saturnian atmosphere drag information was retrieved in the Cassini final plunge progress. Saturn’s upper neutral atmosphere mass density profile is approximately estimated based on atmosphere mass density derived principally by real orbit measurement data. Saturn’s upper neutral atmospheremass density from76 000 km to 1400 km is estimated fromthe orbit measurement data, the mass density results are about from 1.4 × 10−15 kg cm−3 to 2.5 × 10−14 kg cm−3.

In order to measure the Universal Time (UT1) in real time, National Time Service Center (NTSC) has built a VGOS-like (VLBI Global Observing System) broadband VLBI network, which includes three 13-m radio telescopes located in Jilin, Sanya and Kashi, and a data analysis center in Xi’an. Each station is equipped with a highly stable hydrogen atomic clock and a self-developed VLBI backend, and is colocated with two GPS receivers. This VGOS-like VLBI network may play an important role in improving the Chinese broadband VLBI technology and making valuable contributions to domestic VLBI measurements of UT1. In this paper, we introduce the specifications of this VLBI network, and present the UT1 measurements at C-band conducted in 2018 using the Jilin-Kashi baseline of this network. The comparisons between our UT1 estimates and those provided by IERS suggest that the NTSC VLBI network is capable to determine UT1 accurate at the level of 58.8 μs.

Nerve tissues contain hierarchically ordered nerve fibers, while each of the nerve fibers has nano-oriented fibrous extracellular matrix and a core-shell structure of tubular myelin sheath with elongated axons encapsulated. Here, we report, for the first time, a ready approach to fabricate biomimetic nerve fibers which are oriented and have a core-shell structure to spatially encapsulate two types of cells, neurons and Schwann cells. A microfluidic system was designed and assembled, which contained a coaxial triple-channel chip and a stretching loading device. Alginate was used first to assist the fabrication, which was washed away afterwards. The orientation of the biomimetic nerve fibers was optimized by the control of the compositions of methacrylate hyaluronan and fibrin, together with the parameters of microfluidic shearing and external stretching. Also, neurons and Schwann cells, which were respectively located in the core and shell of the fibers, displayed advanced biologic functions, including neurogenesis and myelinating maturation. We demonstrate that the neural performance is relatively good, compared to that resulted from individually encapsulated in single-layer microfibers. The present study brings insights to fabricate biomimetic nerve fibers for their potential in neuroscience research and nerve regeneration. Moreover, the present methodology on the fabrication of oriented fibers with different types of cells separately encapsulated should be applicable to biomimetic constructions of various tissues.

The increasing of car ownership makes the problem of parking difficult to become more and more prominent. The application of three-dimensional garage is one of the most effective solutions at present, which saves both cost and space. Based on the traditional three-dimensional garage, this paper designs a cylindrical three-dimensional garage system. The lifting device of the vehicle is composed of screw, parking platform, and transmission track. The control system of the garage is designed with the single-chip microcomputer as the control core. Finally, the control circuit of the software simulation system realizes the function of automatic exit storage of vehicles, which verifies the feasibility of the design.

We investigate the synergism effect of total ionizing dose (TID) on single-event burnout (SEB) for commercial enhancement-mode AlGaN/GaN high-electron mobility transistors. Our experimental results show that the slight degradation of devices caused by gamma rays can affect the stability of the devices during the impact of high energy particles. During heavy ion irradiation, the safe working values of drain voltage are significantly reduced for devices which have already been irradiated by 60 Co gamma rays before. This could be attributed to more charges trapped caused by 60 Co gamma rays, which make GaN devices more vulnerable to SEB. Moreover, the electrical parameters of GaN devices after 60 Co gamma and heavy-ion irradiations are presented, such as the output characteristic curve, effective threshold voltages, and leakage current of drain. These results demonstrate that the synergistic effect of TID on SEB for GaN power devices does in fact exist.

With the change of business model, market competition has gradually changed from product competition to service competition, and service design has been paid more and more attention by various industries. The ultimate goal of service design is tantamount to bring users a better experience and maximize the interests of stakeholders. Therefore, this paper will create a service design method based on service dominant logic and more emphasis on user experience. This paper sorts and summarizes the concept, content and characteristics of service design and product service system, and then find out the future development direction of service design and product service system. In this paper, various design methods are analyzed and compared, and one of the best design methods is associated with the product service system to form a new design method. After that, this new design method will be applied to the service design of children’s design thinking education as a practice.

Expanding tube separation device is a commonly used linear separation device, whose energy resource is a shielded mild detonation cord (SMDC). In this research, the SMDC is a mild detonation cord sheathed in flat polyethylene. Two experiments were achieved to discuss the energy output efficiency of the SMDC. In the first experiment, the SMDC was inserted into 1060 aluminum cylinder directly. While in the other experiment, the SMDC was insert into aluminum cylinder after contained within a flat steel tube. The velocity and displacement of the characteristic points on the outer surface of the aluminum cylinder during explosion were measured by photonic Doppler velocimetry (PDV). The simulation results with Ls-dyna fluid-solid coupling algorithm correspond well with the experimental results. According to the simulation analysis, the distribution of total energy of explosives were obtained. The plastic strain energy of the aluminum cylinder corresponds to the ability of the SMDC to do external work. The result shows that, 39.3% of the total energy in the explosive is output to aluminum cylinder with SMDC acting on it directly, while the energy output efficiency turns to 20.8% after passing through the flat tube.

Te-doped GaSb single crystal grown by the liquid encapsulated Czochralski (LEC) method exhibits a lag of compensating progress and a maximum carrier concentration around 8×1017 cm−3. The reason for this phenomenon has been investigated by a quantity concentration evaluation of the Te donor and native acceptor. The results of glow discharge mass spectrometry (GDMS) and Hall measurement suggest that the acceptor concentration increases with the increase of Te doping concentration, resulting in the enhancement of electrical compensation and free electron concentration reduction. The acceptor concentration variation is further demonstrated by photoluminescence spectra and explained by the principle of Fermi level dependent defect formation energy.

Novel type of multifunctional polymeric micelles (PMs) designated as HM-PMss/CTX micelles were developed in the present study for tumor-targeted and glutathione (GSH)-responsive delivery of cabazitaxel (CTX). The surface of the vehicles was modified with piloting molecules (HM-3 peptide), which targets α v β 3 integrin overexpressed on cancer cells, and the micelle core was cross-linked by GSH-disintegrable disulfide linkages for controlled drug release. HM-PMss/CTX micelles were prepared using a mixture of two functionalized amphiphilic block copolymers and found to physically encapsulate CTX with excellent entrapment efficiency (93.94 ± 4.19%), drug-loading capacity (8.39 ± 2.28%), and a narrow size distribution. In vitro release profiles showed that CTX remained stably entrapped in the micelles in a release medium without GSH or with GSH of low concentration, while undergoing a rapid release in a highly reductive environment. Cellular uptake experiments showed that the conjugation of the targeting peptide, containing an arginine-glycine-aspartate sequence, enhanced the cellular uptake of HM-PMss/CTX micelles via α v β 3 integrin-mediated endocytosis. In vitro cell viability measurements revealed that blank micelles were biocompatible, while HM-PMss/CTX micelles, owing to their tumor-targeting ability and GSH sensitivity, effectively inhibited the proliferation of MDA-MB-231 breast cancer cells. These results indicate that HM-PMss/CTX micelles could be a promising platform for future intelligent drug delivery in cancer therapy.

In this paper, a passive snake-like arm based on wire-driven mechanism is proposed, which can be connected with remote center of motion (RCM) mechanism to form a laparoscope-holder robot and be used in laparoscopic surgery. The purpose of the snake-like arm is to replace traditional multi-joint manipulator, making it possible for the robot to assist the surgeon in the best position in a surgery. The snake-like arm consists of a main body composed of four arm units and a wire locking device with 12 wire locking units. The arm units are connected by hook hinges. Four classes force amplificatory structure is adopted in the wire locking unit. The detail structure and working principle of the wire locking device are proposed in this paper. The wire tensioning and guiding mechanism as well as the layout of wires are also introduced in this paper. Mechanical calculation of the force amplicatory structure is proposed in this paper to ensure that sufficient locking force can be provided. The workspace of the snake-like arm is drawn by simulation, and the large workspace allows the snake-like arm to be used in most laparoscopic surgeries.

By means of the UGD function extracted from an AdS/CFT inspired saturation model, the charm and bottom structure functions are studied in fixed-order perturbation theory. It is shown that the theoretical results are in good agreement with the recent HERA data. Then, this UGD function is also used to investigate net-kaon rapidity distribution in Au+Au collisions at RHIC energies and the theoretical results fit well to the BRAHMS data. In the end of this paper, we give the predicted results for nuclear charm structure function at very small x where the popular shadowing parameterizations are invalid.

In this paper, the gluon distribution is extracted from the KLR-AdS/CFT saturation model and used to investigate net-baryon and net-kaon rapidity distributions in ultrarelativistic heavy-ion collisions. With the same parameters of the saturation model fitting to HERA data and an ?2 analysis of the overall constant C, the theoretical results are in good agreement with RHIC data in Au+Au collisions at ?s?=?0.2?TeV. Then, we present the predictive results for net-baryon rapidity distributions in central Pb+Pb collisions at LHC energies of ?s?=?2.76, 3.94, and 5.52 TeV, and give the corresponding values of dN/dy for net-baryon at y = 0.

The BEPC II Luminosity Monitor (BLM) monitors relative luminosity per bunch. The counting rates of gamma photons, which are proportional to the luminosities from the BLM at the center of mass system energy of the psi(3770) resonance, are obtained with a statistical error of 0.01% and a systematic error of 4.1%. Absolute luminosities are also determined by the BESIII End-cap Electro-Magnetic Calorimeter (EEMC) using Bhabha events with a statistical error of 2.3% and a systematic error of 3.5%. The calibration constant between the luminosities obtained with the EEMC and the counting rates of the BLM are found to be 0.84 +/- 0.03 (x10(26) cm(-2).count(-1)). With the calibration constant, the counting rates of the BLM can be scaled up to absolute luminosities.

The synergism effect of total ionizing dose (TID) on a single event transient (SET) in a bipolar comparator is investigated. Experimental results show that the shapes of the SET are considerably influenced by the TID accumulated in low dose rates. The variation tendency of SET shapes can be accurately simulated by temperature switching irradiation. The mechanism of this synergism effect is also analyzed in brief via the operating schematic of a comparator. After the accumulation of 100 krad(Si), the lower tendency of negative SET can be attributed to the degeneration of beta. The change tendency of a positive SET, either lower or higher, is dependent on the load condition that limits the output range of the comparator.

In this paper, the approximate expressions of the solitary wave solutions for a class of nonlinear disturbed long-wave system are constructed using the homotopic mapping method.

The mechanisms occurring when the switched temperature technique is applied, as an accelerated enhanced low dose rate sensitivity (ELDRS) test technique, are investigated in terms of a specially designed gate-controlled lateral PNP transistor (GLPNP) that used to extract the interface traps (Nit) and oxide trapped charges (Not). Electrical characteristics in GLPNP transistors induced by Co-60 gamma irradiation are measured in situ as a function of total dose, showing that generation of Nit in the oxide is the primary cause of base current variations for the GLPNP. Based on the analysis of the variations of Nit and Not, with switching the temperature, the properties of accelerated protons release and suppressed protons loss play critical roles in determining the increased Nit formation leading to the base current degradation with dose accumulation. Simultaneously the hydrogen cracking mechanisms responsible for additional protons release are related to the neutralization of Not extending enhanced Nit buildup. In this study the switched temperature irradiation has been employed to conservatively estimate the ELDRS of GLPNP, which provides us with a new insight into the test technique for ELDRS.