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When the hydrostatic thrust bearings operate under conditions of high speed and heavy load, the oil film will be strongly sheared and squeezed, which will increase the temperature of the hydrostatic oil film, resulting in uneven deformation of the workbench and tribology in serious cases. The deformation of the friction pair greatly affects the stability of the workbench during operation, and then affects the machining accuracy. Taking the hydrostatic thrust bearings as the research object, the model of hydrostatic thrust bearings was established based on the fluid–thermosolid coupling theory, and the influencing factors of the deformation of the hydrostatic thrust bearings are analyzed using ANSYS Workbench software, and the influencing laws are discussed. Finally, the correctness of the simulation method is verified by experiments. The results show that the larger the lubricating oil viscosity, the greater the deformation of the guide surface and the oil pad. With the increase in the rotation rate, the deformation of the guide surface and the oil pad increases continuously. With the increase in the inlet flow rate, the deformation of the guide surface and the oil pad is continuously reduced. In engineering practice, on the premise of ensuring the bearings capacity, low-viscosity lubricating oil should be used as much as possible, the rotation rate should be lower, or the inlet flow rate should be increased.

Greenhouse gases (GHGs) emissions from high-cold terrestrial ecosystems underlain by permafrost on the Qinghai–Tibet Plateau (QTP) have received widespread attention. However, the dominant factors regulating ecosystem respiration (Re) and its components (soil respiration Rsand heterotrophic respiration Rh) and how the differences in carbon emissions from different ecotypes and seasons remain are still unclear. We conducted a 2-year field investigation (August 2018 to October 2020) and applied the structural equation model (SEM) to clarify the changes in the factors controlling the respiration components during different seasons. The results indicate that the Reand its controlling factors in three alpine grassland ecosystems (alpine steppe, alpine meadow, and swamp meadow) vary with seasons. Furthermore, autotrophic respiration (Ra) contributes the most to the seasonal changes in Re. The Regradually increases in the early growing season and rapidly decreases in the late growing season. Rhremains relatively stable during the year. Under these seasonal variations in the respiration components, the dominant factors controlling Rein the nongrowing season are the temperature of the atmosphere–soil interface (heat flux, atmospheric temperature, and soil temperature at 5 cm depth) and microbial activity (microbial carbon and pH) with the variable importance projections >1.5. During the growing season, the dominant factors regulating Re, Rs, and Rhare the soil temperature with a standardized direct effect (SDE) of 0.424, soil nutrient conditions (total nitrogen and pH) with SDEs of 0.570–0.614, and microbial activity (microbial carbon) with a SDE of 0.591, respectively. In addition, meteorological conditions have an important impact on the respiration components during the growing season. Specifically, the atmospheric vapor pressure is the dominant factor regulating the three respiration components (standardized total effects = 0.44−0.53, p < 0.001). The optimal soil water contents during the growing season (water content at which Rereaches the maximum) are 10% in the alpine steppe, 13%–15% in the alpine meadow, and 40%–43% in the swamp meadow, respectively. The effect of the soil water content on Reis more important in arid ecosystems (alpine steppe and alpine meadow) than in wet ecosystem (swamp meadow). The alleviation of water limitations in arid ecosystems may potentially increase Re.

ABSTRACTThis paper uses the principles of polarisation to calculate the Stokes component of the polarisation image. It designs the spatial weighted fusion algorithm, focusing on the research and evaluation of the accuracy and time complexity of the spatial weighted fusion algorithm in the polarisation image fusion processing. The spatial weighted image fusion algorithm is used to fuse the polarisation degree image, the polarisation angle image, and the light intensity image. Finally, the algorithm function is realised through software programming to verify the effect and accuracy of the algorithm. Experimental results show that the spatial weighted fusion algorithm can keep the pixel value of the polarisation source image unchanged, avoid image distortion, artefacts and ringing effects algorithm is stable and efficient, with low time complexity.

Pressure-induced magnetic phase transitions are attracting interest as a means to detect superconducting behaviour at high pressures in diamond anvil cells, but determining the local magnetic properties of samples is a challenge due to the small volumes of sample chambers. Optically detected magnetic resonance of nitrogen vacancy centres in diamond has recently been used for the in situ detection of pressure-induced phase transitions. However, owing to their four orientation axes and temperature-dependent zero-field splitting, interpreting these optically detected magnetic resonance spectra remains challenging. Here we study the optical and spin properties of implanted silicon vacancy defects in 4H-silicon carbide that exhibit single-axis and temperature-independent zero-field splitting. Using this technique, we observe the magnetic phase transition of Nd2Fe14B at about 7 GPa and map the critical temperature–pressure phase diagram of the superconductor YBa2Cu3O6.6. These results highlight the potential of silicon vacancy-based quantum sensors for in situ magnetic detection at high pressures.

As a promising enhanced gas recovery technique, CO2huff-n-puff has attracted great attention recently. However, hydraulic fracture deformation hysteresis is rarely considered, and its effect on CO2huff-n-puff performance is not well understood. In this study, we present a fully coupled multi-component flow and geomechanics model for simulating CO2huff-n-puff in shale gas reservoirs considering hydraulic fracture deformation hysteresis. Specifically, a shale gas reservoir after hydraulic fracturing is modeled using an efficient hybrid model incorporating an embedded discrete fracture model (EDFM), multiple porosity model, and single porosity model. In flow equations, Fick’s law, extended Langmuir isotherms, and the Peng-Robinson equation of state are used to describe the molecular diffusion, multi-component adsorption, and gas properties, respectively. In relation to geomechanics, a path-dependent constitutive law is applied for the hydraulic fracture deformation hysteresis. The finite volume method (FVM) and the stabilized extended finite element method (XFEM) are applied to discretize the flow and geomechanics equations, respectively. We then solve the coupled model using the fixed-stress split iterative method. Finally, we verify the presented method using several numerical examples, and apply it to investigate the effect of hydraulic fracture deformation hysteresis on CO2huff-n-puff performance in a 3D shale gas reservoir. Numerical results show that hydraulic fracture deformation hysteresis has some negative effects on CO2huff-n-puff performance. The effects are sensitive to the initial conductivity of hydraulic fracture, production pressure, starting time of huff-n-puff, injection pressure, and huff-n-puff cycle number.

The full alumina dissolution process in aluminum electrolysis cells was investigated using an improved computational fluid dynamics (CFD) model based on the previous researches by consideration of agglomerate formation. The results show that the total mass of alumina agglomerate and its maximum size are mainly dependent on the feeding amount and increase with increasing it. Higher superheat can effectively inhibit the agglomerate formation and thus promote the full alumina dissolution behavior. The full alumina dissolution process mainly includes a fast stage and a slow stage, with an average dissolution rate of 17.24 kg/min and 1.53 kg/min, respectively. About 50% (mass percentage) of the total alumina particles, almost all of which are the well-dispersed alumina fine grains, dissolve within the fast dissolution stage of about 10 s. The maximum values of the average dissolution rate and final percentage of the cumulative dissolved alumina mass are obtained with a feeding amount of 1.8 kg for a superheat of 12 °C. The formation of the alumina agglomerates and slow dissolution characteristics play a dominant role in the full dissolution of alumina particles.

Moisture is one of the important factors affecting coal spontaneous combustion. Coal with different moisture contents was prepared to obtain oxidized coal samples at different temperatures through temperature programming. In situFourier Transform Spectrometer was used to determine content of active functional groups in different oxidized coal samples, and to study influence of moisture form on formation and transformation of microscopic functional groups during coal spontaneous combustion. Nitrogen adsorber was used to study specific surface area of different oxidized coal samples and influence of form moisture on changes of micro-pore structure during coal spontaneous combustion. Combined with the change law of functional groups and specific surface area, microscopic action of different form moisture on coal spontaneous combustion process was discussed. The action regime of outside moisture varies with the development of coal spontaneous combustion. Different forms of moisture can promote formation of phenols, alcohols, hydroxyl groups, and carbonyl-containing compounds. Effects of moisture form and its content on change of micro-specific surface area, and on evolution of aliphatic C–H components, hydroxyl-containing compounds and carbonyl-containing compounds during spontaneous combustion of coal are different. While effect of moisture form and its content on formation and transformation of hydroxyl-containing compounds and carboxylic acid compounds are similar.

Spherical copper particles with diameter ranging from 120.6 to 437.0 μm were prepared by the pulsated orifice ejection method (termed “POEM”). These spherical copper particles exhibit a good spherical shape and a narrow size distribution, suggesting that the liquid copper can completely break the balance between the surface tension and the liquid static pressure in the crucible micropores and accurately control the volume of the droplets. Furthermore, the relationship between cooling rate and microstructures of spherical copper particles was carried out with a specific focus on different cooling atmosphere and particle diameter during the rapid solidification. The cooling rate of spherical copper particles is evaluated by a Newton’s cooling model. It is revealed that the cooling rate was depended on cooling medium and particle diameter. The cooling rate decreases and the grain size increases with the increase of particle diameter during the rapid solidification, while the grain boundary of same particle diameter with larger cooling rate in argon gas is smaller, while the grain boundary of particles with smaller cooling rate in helium gas is larger. When the particle diameter is larger than 100 μm, the cooling rate of the cooper droplet in argon gas achieves 1.0×104 K/s. Meanwhile, the cooling rate decreases rapidly when the particle diameter increased between 70.6 and 149.6 μm. It is an effective route for fabrication of high-quality spherical copper particles.

Graphical Abstract:

Spherical mono-sized Sn-1.0Ag-0.5Cu (wt.%) particles with diameter ranging from 124.0 to 337.4μm were prepared by the pulsated orifice ejection method (termed “POEM”).These spherical Sn-1.0Ag-0.5Cu particles exhibit a good spherical shape and a narrow size distribution, suggesting that liquid Sn-1.0Ag-0.5Cu can completely break the balance between the surface tension and the liquid static pressure in the crucible micropores and accurately control the volume of the droplets. Furthermore, the relationship between cooling rate and microstructures of spherical Sn-1.0Ag-0.5Cu particles was studied with a specific focus on different particle diameter during the rapid solidification. The cooling rate of spherical Sn-1.0Ag-0.5Cu particles with different diameter was evaluated by the Newton’s cooling model. It is revealed that the cooling rate decreases gradually with the increase of particle size during the rapidly solidified process. When the particle diameter is equal to 75 μm, the cooling rate of the Sn-1.0Ag-0.5Cu particle achieves 4.30×103 K/s which indicates that smaller particles can rapidly solidified due to their higher cooling rate. Meanwhile, the cooling rate decreases rapidly when the particle diameter increases between 75 and 100 μm. Furthermore, the different particle diameter with different cooling rate has a great influence on the solidification microstructure of Sn-1.0Ag-0.5Cu particles. The cooling rate and grain boundary size decreases with the increase of particle diameter during the rapid solidification. In addition, the phase size of βSn increases with the decrease of particle size. Smaller particles have relatively high cooling rate and it gives less solidification time as compared to larger particles. It is an effective route for fabrication of high-quality spherical Sn-1.0Ag-0.5Cu particles. Keywords: Spherical Sn-1.0Ag-0.5Cu particles; Rapid solidification; Structural; Cooling rate

Chemodynamic therapy (CDT) employs Fenton catalysts to kill cancer cells by converting intracellular H2O2into hydroxyl radical (•OH), but endogenous H2O2is insufficient to achieve satisfactory anticancer efficacy. Despite tremendous efforts, engineering CDT agents with specific and efficient H2O2self-supplying ability remains a great challenge. Here, we report the fabrication of copper peroxide (CP) nanodot, which is the first example of a Fenton-type metal peroxide nanomaterial, and its use as an activatable agent for enhanced CDT by self-supplying H2O2. The CP nanodots were prepared through coordination of H2O2to Cu2+with the aid of hydroxide ion, which could be reversed by acid treatment. After endocytosis into tumor cells, acidic environment of endo/lysosomes accelerated the dissociation of CP nanodots, allowing simultaneous release of Fenton catalytic Cu2+and H2O2accompanied by a Fenton-type reaction between them. The resulting •OH induced lysosomal membrane permeabilization through lipid peroxidation and thus caused cell death via a lysosome-associated pathway. In addition to pH-dependent •OH generation property, CP nanodots with small particle size showed high tumor accumulation after intravenous administration, which enabled effective tumor growth inhibition with minimal side effects in vivo. Our work not only provides the first paradigm for fabricating Fenton-type metal peroxide nanomaterials, but also presents a new strategy to improve CDT efficacy.

The recent experimental progress in parity-time (PT) symmetry has attracted great interest. However, compared with PT symmetry, there are only a few reported results on its counterpart, anti-PT symmetry, which would lead to new insights and applications. Experimentally simulating and demonstrating the properties of anti-PT symmetry is of particular interest. Here, we present experimental research for simulating the dynamics of bosonic Bogoliubov quasi-particles with anti-PT symmetry based on single photons generated from a point defect in a gallium nitride film. The dynamical evolution under a non-unitary operator is a continuous complex Lorentz transformation in a complex Minkowski space. The evolved states are located on hyperbolic curves, depending on the values of the new defined inner product, which remain invariant during the evolution. Three types of state, space-like, light-like, and time-like, which are analogous to those predicted by the special relativity, are demonstrated. The results of our work could be helpful to investigate the dynamics of quasi-particles in diverse systems and promote deep understanding of non-Hermitian quantum mechanics in open systems.

ABSTRACTObjective: To evaluate the effects of combined Rex-bypass shunt and pericardial devascularization on prehepatic portal hypertension secondary to cavernomatous transformation of portal vein (CTPV).Methods: Forty-two patients aged from 3 years to 49 years (divided into 3 groups), 26 cases male and 16 female, with prehepatic vascular hepertention were treated with Rex-bypass shunt combined with pericardial devascularization. In each patient, preoperative assessment included ultrasound and computed tomographic angiography of the portal vein and blood analysis. The procedure was Rex-bypass shunt (with or without graft), and patients with moderate or severe gastroesophageal varices required additional paraesophagogastric devascularization. Splenectomy or subtotal splenectomy was performed if combined hypersplenism co-existed. All data were analyzed retrospectively.Results: No intraoperative death occurred, blood routine analysis improved (P < 0.05), the blood flow velocity (P < 0.05) and diameter (P < 0.05) of the left portal vein (LPV) significantly increased, the esophageal and gastric varices significantly relieved in 34 patients (P < 0.05), and better effects of earlier operations were demonstrated than the delayed ones (P < 0.05). During the period of follow-up from 6 to 64 months, the overall patency rate was 85.7% and the younger the age the better of the effect.Conclusion: Rex-bypass shunt combined with pericardial devascularization is a safe and effective procedure for prehepatic portal hypertension caused by CTPV.

Six new meroterpenoids, chrodrimanins K–N (1–4), including two uncommon chlorinated ones (1and 2), and verruculides B2 (5) and B3 (6), as well as seven known ones (7–13), were isolated from the fermentation broth of Penicilliumsp. SCS-KFD09 isolated from a marine worm, Sipunculus nudus, from Haikou Bay, China. The structures including the absolute configurations of the new compounds were unambiguously elucidated by spectroscopic data, X-ray diffraction analysis, and ECD spectra analysis along with quantum ECD calculations. In addition, the X-ray crystal structures and absolute configurations of two previously reported meroterpenoids, chrodrimanins F (9) and A (11), are described for the first time. Compounds 1, 4, and 7displayed anti-H1N1 activity with IC50values of 74, 58, and 34 μM, respectively, while compound 5showed weak inhibitory activity against Staphylococcus aureuswith an MIC of 32 μg/mL.

Home courtyard agriculture is an important model of agricultural production on the Tibetan plateau. Because of the sensitive and fragile plateau environment, it needs to have optimal performance characteristics, including high sustainability, low environmental pressure, and high economic benefit. Emergy analysis is a promising tool for evaluation of the environmental-economic performance of these production systems. In this study, emergy analysis was used to evaluate three courtyard agricultural production models: Raising Geese in Corn Fields (RGICF), Conventional Corn Planting (CCP), and Pea-Wheat Rotation (PWR). The results showed that the RGICF model produced greater economic benefits, and had higher sustainability, lower environmental pressure, and higher product safety than the CCP and PWR models. The emergy yield ratio (EYR) and emergy self-support ratio (ESR) of RGICF were 0.66 and 0.11, respectively, lower than those of the CCP production model, and 0.99 and 0.08, respectively, lower than those of the PWR production model. The impact of RGICF (1.45) on the environment was lower than that of CCP (2.26) and PWR (2.46). The emergy sustainable indices (ESIs) of RGICF were 1.07 and 1.02 times higher than those of CCP and PWR, respectively. With regard to the emergy index of product safety (EIPS), RGICF had a higher safety index than those of CCP and PWR. Overall, our results suggest that the RGICF model is advantageous and provides higher environmental benefits than the CCP and PWR systems.

It has been previously demonstrated that loss‐of‐function mutations in the coding sequence of the betaine aldehyde dehydrogenase 2 (BADH2) gene result in the accumulation of 2‐acetyl‐1‐pyrroline (2‐AP), the key component of fragrance in most rice cultivars. In this work, a novel allele of the BADH2 gene, badh2‐p‐5′UTR, found in a new fragrant rice cultivar Nankai 138 was studied. In Nankai 138, mutations in the non‐coding sequence of the BADH2 gene result in downregulation of the mRNA. This makes the specific activity of the BADH2 protein in the Nankai 138 decline from 50 to 40% of the value observed in Nipponbare from 12 to 20 d after flowering, and subsequently leading an increase of 2‐AP content to 47.8 ng g–1in brown rice. In conclusion, the mutations in non‐coding region of BADH2 gene in Nankai 138 weaken transcription of the gene thereby reducing the accumulation of the functional protein and conferring fragrance to rice. These results add to the current knowledge of molecular mechanism of fragrance in rice.

The purpose of this paper is to propose a mixed integer programming model of service restoration reconfiguration considering the minimum switching frequency and power losses. The recovery after the service failure of distribution network is a multi-objective optimization problem with constraints. This paper also discusses the reconfiguration algorithms for power restoration and load balancing in the real-time operation environment of distribution network, which can make the problem solving easy to handle and control. The methods and measures for service auto restoration in distribution automation system are analyzed by examples.

The chronic stress model was developed on the basis of the stress–diathesis hypothesis of depression. However, these behavioural responses associated with different stress paradigms are quite complex. This study examined the effects of two chronic stress regimens on anxiety-like and depressive behaviours. C57BL6 mice were subjected to unpredictable chronic mild stress or to chronic restraint stress for 4 weeks. Subsequently, both anxiety-like behaviours (open field, elevated plus maze and novelty suppressed feeding) and depression-like behaviours (tail suspension, forced swim and sucrose preference) were evaluated. Both chronic stress models generated anxiety-like behaviours, whereas only unpredictable chronic mild stress could induce depressive behaviours such as increased immobility and decreased sucrose consumption. These results of the present study provide additional evidence on how chronic stress affects behavioural responses and point to the importance of the validity of animal models of chronic stress in studying depression.

Since 2012, known as the first year of "massive open online Courses (MOOCs)", its development speed beyond our imagination, only Courses one company registered online learners reached more than 4.1million people (up to July 21, 2013). MOOCs will be bring what challenge for distance education development in China, how to deal with these challenges, is our reality problem need to concerned. We hope through the above question discussion to accelerate the change of distance education in our country, to adapt to the trend of the internationalization of higher education, promoting its healthy development..

Energy Supply and demand, and carbon emission constraints are the problems that must be considered in the process of rapid economic development by national and every province. Under the constraints of energy supply and demand, and carbon emissions, there has practical significance to rational allocate regional energy utilization. With carbon pinch method, this paper research the energy allocation of Tianjin, establish analysis model. Considering the overall and regional energy demand and carbon emission constraints, to determine the usage amount of every kind of fossil energy and clean energy, in order to achieve the best energy structure and optimal balance between energy supply and demand. To provide scientific evidence for local government to make reasonable energy supply and carbon emission constraint index.

The paper presents a numerical algorithm for simulating the trajectories of charged dust particles moving horizontally in the vicinity of an oppositely charged droplet. With taking the air drag, electrical and gravitational into account, the trajectories of charged dust particles are traced by solving the Newton equation. Calculation results show that the dust particles deposit in the whole surface of charged droplet by the effect of electrical force. Electrical force becomes the main factor for dust deposition at low Stokes.

With the extensive application and continuous growth of big data, new challenges are imposed into network design. Without enough consideration of big data in traditional design, bottleneck problems will occur frequently in such IT infrastructure. SDN (Software Defined Network) is one of the solutions to conquer such problems. However, most current SDN applications are limited to pure SDN structure or internal data centers. Differently, we focus on the traffic transmission between data centers in this paper. We construct the WAN links between data centers through VPN based on SDN architecture and traditional network. Both theoretical analysis and experiment results show that SDN had advantage over traditional network. Our work also suggested SDN architecture and traditional network could coexist in the real condition.

Hub-and-Spoke network that originated from the aircraft industry of USA has aroused the extensive concern from the business and academic circles. The range of Hub-and-Spoke network application extended to other scopes such as transportation and tourisms. On account of the obvious advantages of scale merit, agglomeration economies and space efficiency. Hub-and-Spoke network has been testified the effective organizational forms in the actual operation from the freights transportation to the production organization. Many research results about the Hub-and-Spoke network have been received presently, but there is rarely research on the applications of logistics industry, the formative mechanism, the combination with the regional economic policy etc under the special regional environment.

In order to study the heat conduction, convection and heat flux density of blood for blood pump rotor system,and established the three-dimensional model of the blood pump rotor system in Solidworks, and then will establish a model to lead the finite element analysis in ANSYS Workbench, thermal analysis, the result of analysis is temperature distribution and heat flux distribution and temperature deformation figure of the blood pump rotor system. Through the study, the rise of temperature of the blood pump rotor system meets the requirements, and The structure design is reasonable;the blood pump rotor system overall deformation is small,but it’s not affect the normal work of the blood pump, It could provided data to support the optimization design of the blood pump rotor system.

In order to study the impact of external forces of the influence of the structural characteristics of axial flow blood pump rotor system.Using the blood pump rotor system as the research object,use ANSYS software,Use the method of static structure.the stress and strain analysis nephogram of the blood pump rotor system was obtained under the external load.through the study: The deformation of the blood pump rotor system which under the action of external load was mainly concentrated in the external contact of blade wheel rotor and ceramic shaft,but the deformation is small.So the blood pump rotor system design is reasonable. The vulnerability part of the blood pump rotor system was obtained.it provide date support for the further optimization of the blood pump rotor system and it also lay the foundations for the subsequent dynamic analysis.

Because we did not consider the dynamic characteristics of system components in static voltage stability analysis, the reliability of the static analysis of the results is reduced. So if we want to explain the mechanism of the voltage instability fundamentally, we must adopt the method of the dynamic analysis. This paper discuss the small disturbance analysis method and the continuation algorithm analysis method of the dynamic analysis method, then research the mechanism of voltage collapse and the results of the dynamic analysis. A load model and the dynamic system for the voltage stability studies is the key of the voltage stability to the maturity.

This paper presents a feasible approach for modeling and locating of assembly\disassembly tools in the virtual scene: First, a novel point-vector model for tool is presented by means of abstracting the locating constraints of tools; Then, the mapping relationship for locating constraints between tools and parts is detailed; Finally, the best matching constraints algorithm is proposed on basis of point-vector model, which can calculate the locating constraints to the triangle model of part in real time. The proposed method has been integrated in the virtual assembly system to solve practical assembly problems.

Spin defects in silicon carbide (SiC) with mature wafer-scale fabrication and micro/nano-processing technologies have recently drawn considerable attention. Although room-temperature single-spin manipulation of colour centres in SiC has been demonstrated, the typically detected contrast is less than 2$\%$, and the photon count rate is also low. Here, we present the coherent manipulation of single divacancy spins in 4H-SiC with a high readout contrast ($-30\%$) and a high photon count rate (150 kilo counts per second) under ambient conditions, which are competitive with the nitrogen-vacancy centres in diamond. Coupling between a single defect spin and a nearby nuclear spin is also observed. We further provide a theoretical explanation for the high readout contrast by analysing the defect levels and decay paths. Since the high readout contrast is of utmost importance in many applications of quantum technologies, this work might open a new territory for SiC-based quantum devices with many advanced properties of the host material.The coherent manipulation of single defect spins in Silicon Carbide with a high readout contrast and a high photon count rate is demonstrated at room temperature, which is of utmost importance in many practical applications of quantum technologies.

Abstract. The key of Open University construction is the teachers’ team building, and the teachers’ professional development is the most important part. Open University teachers’ professional development has not fit for our teaching requirements any more. The rapid development of information society put forward some severe challenges to Open University teachers’ professional development. Under the view of philosophy of technology, fit for the request of the new situation, It must have some progress on Open University teachers’ professional development: first, to improve the professional academic level; second, to improve the teaching skills; third, to improve the information technology. Those three parts constitute connotation of professional distance education teachers. In the deep analysis the difference between Open University teachers’ professional development and the reality, base on this reason, they offered a good plan, which we hopefully can enhance, the Open University teachers’ professional level, and also can improve the distance education quality.

Density-functional theory has been used to calculate the energetically global-minimum geometries and electronic states of AgnH2S (n=2, 4, 6) clusters. The lowest-energy structures of Ag2, Ag4, Ag6, Ag2H2S, Ag4H2S and Ag6H2S clusters were obtained, respectively. The calculation results show that the lowest-energy structures of Ag2, Ag4 and Ag6 clusters are planar geometries. The binding energies of Agn(n=2, 4, 6) clusters are gradually increasing in our calculations. Compare the infrared spectrum peaks of Ag4 cluster with that of Ag6 cluster, which show that the peaks shift to shortwave. After adsorption, we found that the peaks shift to shortwave by comparison.

With the development of electronic resist technology, the wireless definite direction technology becomes more and more important. By comparing the same external signal amplitudes which are received from two channel or more than two channels, ratio amplitude method realize the direction function. This paper analyzes and studies the influence of various system errors, and analyzes the multi-beam direction finding technology at the same time. The orientation of radar emitter which falls into different beam can also be measured.

All electronic structures and infrared adsorption spectra of AgnH2S (n=3, 5) clusters have been performed by using density functional theory. We obtain the lowest-energy structures of Ag3, Ag5, Ag3H2S and Ag5H2S clusters. The calculation results show that the lowest-energy structures of Ag3 and Ag5 clusters are planar geometries. The lowest-energy structures of Ag3H2S and Ag5H2S can be obtained by adsorbs immediately H2S on Ag3 and Ag5 clusters. The peak of infrared spectrum is 120cm-1 for Ag3 cluster, which is smaller than that of Ag5 cluster (180 cm-1). The peak of infrared spectrum is 350cm-1 for Ag3H2S cluster, which is larger than that of Ag5H2S cluster (290 cm-1). The comparison illustrates that adsorption H2S molecule make the peak of infrared spectrum shifting to shortwave.

Using Streptomyces erythreus isolated from pharmaceutical residues as a biosorbent, the characteristics and mechanism of its absorbing Pb2+ was studied. The results showed that absorptive ability of bacterial mycelia modified by sodium hydroxide was improved greatly. The reaction mechanism of modified bacterial mycelia uptake Pb2+ was analyzed by back scattered electron microscope(BSEM) and infrared spectroscopy (IR). The results of experiments indicated that some chemical groups such as -COO-、C-H and O-H among cell walls of bacterial mycelia might play the key functions adsorbing Pb2+. It was presumed that the process of modified bacterial mycelia lead uptake might be a chemical and physical process collaboratively which occurred on the cell surface of bacterial mycelia chiefly based on exchangeable reaction.

This paper analyzes the classification of intelligent recording and broadcasting system, mainly introduced how to construct an recording and broadcasting system, and put forward how to use streaming media courseware intelligently copy , broadcast and make teaching video to express the high efficiency, under the background of current network environment has increasingly become mature .

Use the simple geometric features of a one-dimensional model to calculate the rotor critical speed, the shaft use the beam element to simulate, considering the shear deformation, continuous mass, the rotation inertia and gyro effect, bearing simplified as linear stiffness and damping element, disc use the lumped mass element to simulate, considering the mass and the effect of inertia, finite element method is applied, established the rotor-bearing system dynamics model, through the example to validate, the results show that the model is the advantage of calculation on a smaller scale, solution speed and high precision, easy to adjust the parameters for the model, suitable for large needs to adjust the parameters in the early stage of design and analysis of the rotor-bearing system, it has great reference value for the design and analysis of rotor dynamics.