Search

We report a high-resolution photoelectron imaging and photodetachment spectroscopy study of cryogenically cooled IO–. The high-resolution photoelectron spectra yield a more accurate electron affinity (EA) of 2.3805(5) eV for IO as well as a more accurate spin–orbit splitting energy between the 2Π3/2and 2Π1/2states of IO as 2093(5) cm–1. Photodetachment spectroscopy confirmed several excited states for the IO–anion predicted by theoretical calculations, including two valence-type excited states, the repulsive 3Π state, and a shallow bound 1Π state. More interestingly, we have observed two vibrational resonances which are proposed to be due to a dipole-induced resonant state, about 230 cm–1above the detachment threshold of IO–.

A large thick Fe based amorphous composite coating was deposited on the carbon steel substrate by laser cladding method. The phase composition and microstructure are characterized using X-ray diffraction and scanning electron microscope, respectively. The results demonstrate that the large thick laser cladding coating has a typical layered structure mainly consisting of amorphous and nanocrystal phases. The wear resistance and microhardness property are tested by the Vickers hardness tester and MLS-225 type wet sand rubber wheel abrasion tester. The results show that the large thick laser cladding coating has excellent wear resistance and hardness.

A 1mm thick Al-based composite coating was fabricated on the TC4 Ti-based substrate by using the amorphous powder and the pulse laser cladding technology. The microstructure, phase composition, hardness and friction of the coating were characterized by SEM, DSC, XRD and frictional wear tester, respectively. The results showed that the coating was composed of the micron-sized crystal phases and small amounts of amorphous matrix; the coating has the dense structure and metallurgically bonds with the substrate. The microhardness of the coating was up to 500-600 HV0.2, which was about two times of that of the TC4 Ti-based substrate. The friction coefficient of the coating was lower than that of the TC4 alloy, which improved the friction and wear properties of the TC4 substrate obviously.

Twenty-seven novel pyrazole carboxamide with diarylamine-modified scaffold were designed, synthesized and characterized in detail via1H NMR, 13C NMR, IR and ESI-HRMS. Preliminary bioassays showed that some of the target compounds exhibited good antifungal activity against Rhizoctonia solani, Rhizoctonia cerealisand Sclerotinia sclerotiorum.

The Fe-based amorphous composite coatings were prepared by pulse laser cladding method. The amorphous powder with the size ranging from 100 to 200 meshes was cladded on the low carbon steel plate,and the nominal composition of the powder was (wt.%) Cr:14.95, Mo:25.7, B:1.24, C:3.45, Y:3.40, Fe:51.29. The microstructure, phase composition and hardness were characterized by XRD, SEM, DSC and semi-automatic Vickers hardness tester in this study, respectively. The results show that the coating which is composed of amorphous and nanocrystal phases has the dense structure and metallurgical bonding with the substrate. The hardness of coatings was about 5 times higher than that of the substrate. With the increase of cladding layer, the average hardness of coating showed an increasing trend, and the intrinsic mechanism was discussed.

A Fe-based amorphous composite coating doped by molybdenum was fabricated by the pulse laser cladding technology. The substrate was a low carbon steel plate. The nominal composition of the powder in the range from 100 to 200 meshes was (wt.%) Cr:14.95, Mo:25.7, B:1.24, C:3.45, Y:3.40, Fe:51.29, which was selected for the laser cladding process. The microstructure, phase composition, hardness and corrosion resistance of the coatings were characterized by means of SEM, EDS, XRD , DSC and potentiodynamic polarization test. The results show that the coating which was composed of amorphous and nanocrystal phases had the dense structure and metallurgical bonding with the substrate, meanwhile with low porosity and cracks. The addition of molybdenum played an important role in improving the corrosion resistance of the coatings. With the increasing content of molybdenum, the hardness had no significant change, while the corrosion resistance of the coatings significantly increased. From the results of polarization curves, the corrosion current density of the coating added 0 wt.% Mo is higher than that of the coatings added 2 wt.% Mo and 10 wt.% Mo. The molybdenum has a superior effect on the corrosion resistance in Fe-based amorphous composite coating.

The relentless pressure for designs with new optical functions, small volume, and light weight has greatly increased the importance of aspheric surfaces. In this paper, we propose an annularly stitched aspheric surface (ASAS) description method to increase the freedom and flexibility of imaging system design. The rotationally symmetric ASAS consists of a circular central zone and one or more annular zones. Two neighboring zones are constrained to have the same derivatives on their joint curve, and this means the ASAS is C^1 continuous. This finding is proved and verified by the mathematical deduction of the surface formulas. Two optimization strategies and two design methods with the C^1 continuous constraints are also discussed. This surface can greatly facilitate the design and even achieve some previously impossible designs without increasing the fabrication difficulty. Two different systems with the proposed ASAS are optimized and the results are presented. The design results verified the practicability of the ASAS.

In order to make the food safety testing instrument more flexible and convenient and process a lot of data, combining the advantages of the VB interface design and MATLAB secondary development, the serial communication software is developed based food safety testing instrument. The test data is uploaded to computer through RS232 serial port. The research staff needs only to input the parameters simply, and all the parameters were automatically matching with the testing instrument, the test data reception, processing, preservation, search and delete functions was completed through VB calling MATLAB. The software has the abilities of friendly interface, easy to use, high stability, and can shield and correct the misuse of users. It has high value in engineering and can be widely used in similar embedded test instrument.

A Fe-based amorphous composite coating was deposited on a carbon steel substrate by arc spraying, and remelted with different laser energies by the Nd: YAG laser cladding system, in order to improve the mechanical properties of the coatings. The microstructure and microhardness of the composite coatings were investigated. The variation of harndness was measured as a function of the modified layer depth, which indicates that the laser remelting improves the bonding strength and hardness. Increasing the laser power, the quality of coating gets better, but the amorphous volume fraction decreases. It is obtained that the optimal laser electric current for the coating of 280 μm thickness is about 300 A, in which the remelted coating with medium energy densities has the highest average Vickers hardness of 741. Through the volume fraction change of the nanocrytals, the hardness of the composite coating is regulated by the laser power input, which amplified the application fields of the amorphous coatings.

The microstructure and corrosion resistance of Fe-based amorphous coatings prepared by laser remelting after arc spraying were studied. The laser remelting process was carried out under different energy inputs, and the processing parameters varied with the different currents, pulse widths and scanning speeds. The corrosion behavior of the coatings in 1 mol/L NaCl solution was studied through potentiodynamic and potentiostatic polarization test. The morphology and microstructure of the coatings were characterized by using X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical analyzer. A Vickers hardness tester was also used to measure the microhardness of the coatings. The analysis of the microstructure shows that the amorphous coatings are composed of amorphous matrix and nanocrystalline phases. The diffusion of elements indicates a metallurgical bonding between the coating and substrate. The electrochemical corrosion results obtained from the Tafel polarization curves verify that the amorphous composite coatings prepared by different methods show no significant differences in their corrosion resistance, while the microhardness of laser remelting coatings increase obviously with the increase of laser currents. The corrosion resistance of laser remelting coatings is improved extensively due to the amorphous matrix and embedded nanocrystals, which popularizes the applications of amorphous coatings to a large extent.

In this study, Mg2Si in in-situ Mg2Si/Al composites were subjected to modification treatment using rare earth element Holmium (Ho). The phase composition and microstructure before and after modification of Mg2Si were also analyzed using X-ray diffraction (XRD) and optical microscope (OM); in addition, its mechanical properties were detected as well. The results showed that moderate addition of rare earth element Ho in in-situ Mg2Si/Al composites presents good modification effects on Mg2Si, the morphology of primary Mg2Si was changed from cross shape before modification to dispersed irregular mass; optimal modification effect was obtained when 0.4% rare earth element Ho was added. Under this condition, the average size of primary Mg2Si was decreased from 74 μm before modification to 16 μm; its mechanical properties were promoted significantly; and its tensile strength increased from 134 MPa before modification to 174.6 MPa, its brinell hardness elevated from 76 HB to 90 HB.

In the comparative analysis of image characteristics of shadow-free and shaded area, an algorithm for shaded area, avoiding the area whose illumination is weak and tending to the area with strong light via looking for the strongest and weakest light area, is established, which can thereby improve the efficiency of power generation. The result demonstrates that the method can find the region with the strongest sunlight fast and accurately.

The comprehensive MPPT algorithm, which is combined with three approaches including the constant voltage tracking method (CVT), the perturbation and observation method (P&O), and the incremental node-voltage conductance method (INC), aims to study how to improve the solar energy utilization of the solar battery energy-saving control system of field monitoring equipment. To obtain the parameters needed for numerical simulation, solar power meter is used to measure light intensity curve within 30 seconds in spring. Then we establish the photovoltaic array simulation model and get the power tracking curve. Comparing with the curves based on the comprehensive MPPT algorithm with the mainstream MPPT algorithms, its proven that the time consumption of tracking MPP is shorter and that the efficiency of photovoltaic power generation is higher.

T Vehicle scheduling for personnel evacuation plays a significant role in disaster rescue. However, current vehicle scheduling methods do not meet the needs of emergency response in disaster rescue. This paper proposes a rapid vehicle scheduling method to evacuate the crowd and reduce losses in an emergent situation. We construct a specific model for vehicle scheduling problem in disaster rescue firstly, and then put forward a heuristic algorithm to solve this problem. An empirical example is used to evaluate the effectiveness of the method. Scheduling and evacuation data are computed in real-time and considerations about dangerous zones of different dangerous levels are also included in this method. The characteristics of the method make it more suitable in actual emergency rescue.

Due to the rising tendency of chemical accidents, it is urgent to develop a real-time gas diffusion simulation system on computer during the emergent chemical accidents, and high computation efficiency of gas diffusion model is indispensable in the simulation system. This paper develops an efficient diffusion model based on Gaussian Puff Model and proposes a special numerical simulation method for the model. With the proposed model and the proposed method, the spatial density distribution of the gas spread can be computed rapidly and displayed visually in GIS. To validate the correctness, efficiency, reliability and flexibility of the model, two groups of simulations in different aspects (space and time) are performed respectively. The result of simulation is as well as expected, and the system based on the model will provide a reliable guarantee for rescue during emergent chemical accidents.

With development of modern science and technology, pile type and pile foundation type, construction technology and construction equipment, pile foundation theory and design method have large evolution. Pile foundation has been to the ordinary foundation type used in the field with week soil texture for constructing all kinds of buildings, especially for high-rise building, heavy duty factory and the structure with special requirement.

The effect of Al-10Sr master alloy modifier with different content on the microstructure and properties of as-cast Al-12.6Si-0.35 Mg alloy was investigated. The results show that, eutectic silicon varies from original needle and flake to fibrous shape; The shape, size, and quantity of α -Al all changed; When Sr content is 0.023%, the modification effect is most ideal, α -Al shows the highest quantity and smallest size. Meanwhile, the tensile strength and elongation of the alloy reach to the optimum values of 248.2 MPa and 7.2% respectively. These two values are 1.34 and 2.77 times higher than the 185 MPa and 2.6% before modification respectively.

Fc-bascd alloy layer reinforced by Ti(C, N) particles was produced on the surface of cast steel. X-ray diffraction (XRD) was used for phase identification in the composite coating. The microstructure of laser cladding layer was analyzed by means of optical microscope (OM), electron probe microscope analyzer (EPMA), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that Ti(C0.3N0.7) particle is introduced by an in-situ metallurgical reaction of TiN particle and graphite powder in the process of laser cladding. The shape of lots of Ti(C0.3N0.7) particle is irregular. The sizes of Ti(C0.3N0.7) particles range from 0.1 to 6.0 μm, and they arc dispersed evenly in the matrix, which is fine dendritic or cellular crystal. A new kind of phase named Ti(C0.3N0.7) particles arc tightly bonded with α-Fe microstructure, and there is a clean and smooth phase interface between ceramic reinforcement phase and the matrix.

Fe-based alloy layer reinforced by Ti(C, N) particles was produced on the surface of cast steel. X-ray diffraction (XRD) was used for phase identification in the composite coating. The microstructure of laser cladding layer was analyzed by means of optical microscope (OM), electron probe microscope analyzer (EPMA), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that Ti(C0.3N0.7) particle is introduced by an in-situ metallurgical reaction of TiN particle and graphite powder in the process of laser cladding. The shape of lots of Ti(C0.3N0.7) particle is irregular. The sizes of Ti(C0.3N0.7) particles range from 0.1 to 6.0 μm, and they are dispersed evenly in the matrix, which is fine dendritic or cellular crystal. A new kind of phase named Ti(C0.3N0.7) particles are tightly bonded with α-Fe microstructure, and there is a clean and smooth phase interface between ceramic reinforcement phase and the matrix.

n this study, we conducted heat treatments on W6Mo5Cr4V2Si steel using different annealing, quenching, and tempering processes. Meanwhile, the microstructure and hardness performance of this steel are analyzed. The results showed that, in the annealing temperature range of 790°C-870°C, the higher the annealing temperature was, the better the annealing effect that W6Mo5Cr4V2Si steel presented; W6Mo5Cr4V2Si steel exhibited the lowest annealing hardness of 22.6 HRC after annealing at 870°Cfor 2 h; In the condition of annealing at 830°C for 3 h, quenching at 1200 °C around, and tempering temperature range of 400 °C-700 °C, W6Mo5Cr4V2Si steel showed the highest hardness at tempering of 560 °C around, which is about 66.7 HRC. The tempering structure of this steel was mainly composed by needle or strip-typed martensite, a small amount of residual austenite, and carbide particles.

The influence of laser remelting on the mechanical property and fracture behavior of the superplastic diffusion bonding between TiAl intermetallics and TC4 alloy was investigated. The joint bonded by the pre-remelted samples displayed well diffusion, but the mechanical properties of the joint should be further enhanced. The mechanical properties of the joint pre-remelted under the diffusion bonding conditions of 915/80MPa/1h are lower than that of the joint without remelting. After the heat treatment on pre-remelted joint sample at 860, the mechanical properties have been enhanced greatly.

Carbon dioxide (CO2) laser was applied to fabricate TiC reinforced composite coatings. Different microstructures of ceramic phases were observed by SEM. The main phases of coatings were detected by XRD, while the individual one was examined by electron probe X-ray microanalysis .The effect of composition of binder phases on morphology was explained by the ratio of the temperature gradient in front of the liquid/ solid interface to the growth rate.

Accurate and reliable forecasts of key hydrological variables such as stream flow are of importance due to their profound impacts on real world water resources applications. Data-driven methods have proven their applicability to modeling complex and non-linear hydrological processes. This paper presents a novel visual modeling system that has been developed to overcome the problems involved in implementation of data-driven models for hydrological forecasts using conventional programming languages: problems such as the effort and skill needed to program the models, the lack of reusability of existing models, and the lack of shared tools to perform tedious tasks such as preprocessing data. The system provides an integrated visual modeling environment within which users are able to graphically design and verify specific forecasting models for particular problems without writing code. A set of popular data-driven models are offered by the system. Plug-in models created by wrapping existing code are also allowed to run within the system due to the system's open architecture. The system's feasibility and capability is demonstrated through a case study of forecasting 1-day ahead flow in a river basin located in China. The encouraging simulation results show that the system can simplify the process of implementing hydrological forecast. [ABSTRACT FROM AUTHOR]

Motion tracking has shown promise as a powerful technique to improve interaction function in Virtual Reality (VR).Users can interact naturally with virtual environment by using body motion as the interface. This paper presents a design of a telescope-style interaction system combined with an inertial/magnetic motion tracking unit for users’ interacting with the virtual environment and a near-to-eye display system supplying visual virtual environment to users. Since the movement acceleration will cause the error of accelerometer measurement, users will feel uncomfortable and cannot interact well with the virtual environment because of pictures’ jitter. To enhance the user's immersion in the virtual environment, a Kalman filter is designed to ensure the accuracy of users’ motion information. Performance of the estimation’s precision is shown in the experiments and results.

This paper has studied the formation mechanism of frame-shaped segregation in 40Cr wire rod rolled from bloom by means of the composition measurement, the electron microscopic observation and the energy spectrum analysis method. The results show that the frame-shaped segregation in wire rod originated from the positive segregation in columnar-to-equiaxed grain transition zone of bloom. The main influence factors are the solidification behavior of liquid steel in columnar-to-equiaxed grain transition zone, the temperature gradient of different solidification regions in bloom, the diffusion rate of the solute and inclusions in transition zone and so on. It may reduce the frame-shaped segregation by improving the purity of liquid steel, adopting the electromagnetic stirring in secondary cooling zone and enhancing the cooling intensity of the secondary cooling zone.

The uneven illumination distribution would affect the accuracy and stability of an optical multi-touch system. In this paper, different self-adaptive methods based on the type of interference source are integrated. When the ambient lighting changes, the luminance of the captured image will changes accordingly. This method tests the type of interference source by the speed and the region of ambient lighting change, and uses different function to update the background image rapidly. Experimental results show that with the help of the presented solutions, the ghost points are efficiently reduced and the system can adapt to the changes of ambient lighting in only 1 second.

A Fe-based amorphous composite coating with different thickness on the Al thin plate is prepared by the electrothermal explosion spraying. Compared with other thermal spraying techniques, the electrothermal explosion spraying method can obtain a very high spraying velocity up to 4000m/s. The coating consists of the amorphous matrix and nanocrystal phases (α-Fe)，no laminar phenomenon is observed. The diffusion occurs between the substrate and the coating, showing a diffusion-metallurgical bond. The average hardness of coatings is 8 times larger than that of the Al substrate. The unique hierarchical microstructure at multiple length scales leads to the superior micro-hardness and wear resistance of the coating. The Fe-based composite coatings on Al thin plate have great potential as the promising lightweight wear-resistance structural materials used in the aero technical industry.

Fe-based amorphous composite coatings were deposited on the surface of ASTM-1020 steel plate by different technologies: arc spraying, laser remelting, TIG remelting (with and without water cooling). The microstructure, phase structure and micro-hardness were characterized by using a combination of SEM, XRD and Vickers hardness tester. It shows that the coating prepared by arc spraying presents typical lamellar structure and poor adherence to the substrate. After the remelting treatment, the coating quality is significantly improved by decreasing structure defects such as cracks and pores; the interface shows the metallurgical bonding. The dendritic crystals could be obtained within all the remelted coatings with different appearances. The microstructures of TIG remelted coatings show much more regular and have obvious orientation, which cannot be seen in laser remelted coating. However, the average grain size of the laser remelted coating is much smaller than that of TIG remelted coatings. The micro-hardness values of all of the deposited coatings are much higher than that of the substrate, and the coating prepared by laser remelting shows the highest hardness.

Molybdenum (Mo) thin films were deposited on soda-lime glass substrate by using RF magnetron sputtering. As is well known, base pressure in sputtering is a processing parameter for preparing high quality Mo films, in addition to RF power and working pressure. The structure, surface roughness and electrical resistivity of Mo thin films were investigated at three base pressures of 1.8×10-7, 5.8×10-7and 2.7×10-6 torr. Experimental results indicate that the Mo films deposited at a low base pressure of 1.8×10-7 torr exhibit a low electrical resistivity of 8.910-6 –cm, a low root mean square value of roughness of 4.92nm and a stronger peak intensity of (110) plane than that of the other two pressures. This finding suggests that Mo films sputtered at a low base pressure have higher crystallinity, larger grain size, smoother surface morphology and lower electrical resistivity than those sputtered at a high base pressure.

A thick Fe-based amorphous and nanocrystalline composite coating was prepared by in-situ tungsten inert gas (TIG) cladding method. The results show that the cladding coating mainly consists of amorphous phase and nanocrystalline grains. The microstructure study shows that the Fe-based composite coatings have unique microstructure including nano-sized grains surrounded by nano-scale amorphous shell layer (encapsulated structure) and the homogeneously distributed dendrites/cellular crystals. The unique microstructure gives rise to the superior micro-hardness and wear resistance of the coating. The Fe-based coatings have great potential as promising wear-resistance structural materials used in electric power and cement industry.

In this paper, the Mo-Si-Ni-Al metal-ceramic composite cladding layer on the surface of the 304 stainless steel was applied by using tungsten inert gas (TIG) method. The phase composition and microstructure of the cladding layer were characterized by XRD, SEM and EDS. With the high temperature erosion experiment in the range of 873-1073 K, the erosion behavior of the Mo-Si-Ni-Al cladding layer was studied. The maximum total mass loss was observed in the specimen, which was tested at 923 K and 45°erosion angle. The high temperature erosion mechanism of the Mo-Si-Ni-Al cladding layer was discussed.

In order to improve the surface properties of the aluminum alloy, an amorphous composite coating was prepared on the surface of the aluminum alloy substrate by electrothermal explosion spraying with fully amorphous Fe-Si-B ribbons. The microstructure, phase structure and micro-hardness of the coating were characterized by SEM, XRD and Vickers hardness tester. The results show that the composite coating is composed of amorphous phase and nanocrystal phase. The coating has dense structure and low porosity. It has not been seen rough laminar microstructure that is frequently obtained by other thermal spray techniques. The amorphous composite coatings with different thickness present higher hardness and show good mechanical properties.

Not Available

Since the early 1980s, great progress has been made in microbubble column flotation technology. As one of the important mineral processing methods, the application and development of this technology in China are summarized in this paper from four respects. Firstly, a patented cyclone- static microbubble separation method was proposed to overcome the notable problems mentioned in the previous flotation columns. Secondly, microbuble column flotation was introduced to separate the high ash as well hard-to-separate coal slime generated from dense medium processes. The characteristics of the microbubble column, and the flotation process for fine coal and the high ash coal separation was analyzed. Thirdly, the application of microbubble column flotation in China was detailed introduced, especially the characteristics of series microbubble column flotation equipment, and efficient column type coal slime separation crafts were discussed. The application of microbubble column flotation particularly in low ash content coal preparation, and discarded coal slime processing technology were presented. Finally, microbubble column flotation has been extended to non-coal mineral processing, such as magnetite concentrate upgrading (concentration iron and removing silicon), sulfide copper mine separation, white tungsten flotation, etc., the related research was briefly introduced in this paper as well.

Aim at high-to-float high-ash fine coal with large content of granules, in order to reduce pollution of carried fine slime to quality of concentrate coal, soluble glass, sodium hexametaphosphate and cornstarch these three kinds of regulators were choosen to carry out flotation reducing ash experiment. Result showed that, cause of poor selectivity of fine coal is mainly small quality, big surface area and the poor dispersion of fine coal. When sodium hexametaphosphate dosage is 1500g/t, the kerosene dosage is 370g/t, the foam beater GF dosage is 150g/t, production rate of concentrate coal is 57.69%，and ash content of concentrate coal is 12.04%. Under the same condition, separation index of sodium hexametaphosphate as regulator is superior to cornstarch and soluble glass.

As for certain high ash and difficult floatable fine coal, the coal quality characteristic is the frangible and easyly-clayed main gangue mineral kaolinite, and the high content of fine-grade and intermediate density grade materials. In order to reduce tiny slimes pollution and to increase quality and recovery rate of concentrate, we used cyclonic-static micro-bubble flotation column and XFD-3 flotation machine to experiment on separation process. It probed into re-concentration after grinding rough refined coal, classified flotation process and selective agglomeration-flotation process these three technical processes. The comparison of flotation machine test result showed that, using the flotation column as separation equipment, process of re-concentration after grinding rough refined coal could obtain the best refined coal accumulation index. When medicaments dosage is kerosene 800 g/t, GF 300 g/t, and sodium hexametaphosphate 1500g/t, refined coal production rate of flotation column is 59.47% and ash content is 10.63%.

As certain refractory molybdenum with degree high oxidation and high argillization, on the premise of molybdenum concntrate recovery rate, in order to increase tenor of molybdenum concntrate, we use cyclonic static micro-bubble flotation column as concentration equipment. We used two concentrate courses to replace flotation machine eight concentrate courses. It showed that, in the condition of same recovery rate, tenor of molybdenum concntrate was 26.16%, rising by 8%. Using processes of flotation machine eight concentrate courses - concentrate regrinding - flotation column two concentrate courses, tenor of molybdenum concntrate was 39.33% and the recovery rate was of 8%. The results showed that, by increasing the degree of monomer dissociation of molybdenum ores, cyclonic static micro-bubble flotation column has higher capability in recovering and selecting ores of -400 mm size fraction. The high argillization resulting from the regrinding and unsuppressed gangue minerals are the main factors affecting the tenor of ore concentrate.

Thermal reduction process has been employed for the synthesis of carbon nanotubes (CNTs), during which ether was used as carbon source and metallic sodium play a role of reducing agent. The obtained CNTs have a diameter range of 50 nm and length range of 200-1000 nm. The as-prepared product was characterized by X-ray powder di.raction (XRD), transmission electron microscopy (TEM), and selected area electron diffraction (SAED).

In this paper we describe the synthesis of nanocrystalline boron nitride (BN) with a hollow morphology by the reaction of NH4BF4 and NaNH2 at 500 oC for 24h. Characterized by XRD, FTIR, XPS, TEM, and EDXA spectra, the composition and morphology of the products were confirmed. The possible formation mechanism was also discussed.

Fe-based layer with Ti(CxN1-x) particulates on Adamite roller surface was obtained by a 5 kW traverse-flowing CO2laser cladding technology. The microstructures of the layer were detected by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), and electron probe microscopy analysis (EMPA). The tests of wear resistance was carried out on the test machine. It was seen that a good metallurgical bonding between the coating and the substrate was achieved. The microstructure contains bulky dendritic crystal and small size Ti(CxN1-x) grains that are uniformly distributed in the solid solution matrix. The wear tests showed that the laser coating provided an excellent wear resistance property at room temperature.

To analyze the effects of fabrication and alignment errors on optical systems with complex apertures such as a segmented telescope, a visual basic routine (VBR) is developed using CODE V’s COM interface. One of the eminent features of this VBR is its graphical user interface (GUI). The GUI facilitates the user to model different types of segmentations quickly and precisely. The input parameters describe the basic shapes of the segments (polygon or sector), the chamfers at their corners, and the gaps between them. Fabrication errors (i.e. surface errors and alignment errors such as decenters and tilts for each segment) can also be introduced easily and effectively through the GUI. Geometrical and diffraction-based analyses can then be performed to study and analyze the effects of these errors on the imaging quality of the optical system. Results of tolerance analysis are presented for a test system, which require a very stringent tolerance to be placed on the discrepancy among the radii of curvature for different segments. In short, the VBR is a user friendly and a flexible tool with its application scope in designing complex aperture optical systems.

NURBS surface representation, combined with Differential Evolution (DE), enables us to perform automated non-imaging reflector design. The overall result is a simple automated nonimaging reflector design technique and only a little data such as desired illuminance distribution and searching limits are needed. Merit functions specific to non-imaging reflector design are presented. Using different merit functions, the generated illuminance distribution can be uniform as well as concentrated. DE is performed to obtain the reflector that generates the desired illuminance distribution. The photometric distributions are calculated through Monte-Carlo ray tracing and the illuminance value is used to calculate the merit function value. The validity of the proposed approach is demonstrated by optimization examples. Almost the same uniform illuminance distribution can be obtained using the algorithm proposed in this paper as that obtained by edge-raymethod. A concentrated illuminance distribution can also be generated using the algorithm proposed.

This paper describes a two-dimensional tool-path planning model for minimizing the regularly distributed errors or mid-frequency errors during computer controlled optical surfacing (CCOS) by optimally connecting different tool-path segments. The model was established based on a neuro-fuzzy algorithm, a path neighborhood function which is defined as a victorious output element calculated in a self-organization way, then, the optimum material removal function with a modified weight was derived. The material removal function was studied theoretically and the results of simulation present a Gaussian distribution feature. Discrete removal points and optimized tool-path grid were simulated. Finally, an experiment involving a parabolic mirror was performed for residual error removal and the two-dimensional tool-path planning algorithm was found to be valid.

This paper proposes a novel wheel-shaped grinding/polishing tool, which is designed to be controlled on both the self-rotation around its axis and the co-rotation around vertical axis Z at the specified speeds respectively. Therefore, the surface material of the workpiece can be removed by virtue of self-rotating motion. On the other hand, the co-rotating motion will also change the manufacturing orbit continually. To analyze the characteristics of the tool, material removal in the manufacturing zone on the workpiece surface is first established through theoretical modeling. Subsequently, a good evaluating method, i.e. power spectral density, for analyzing the frequency spectrum features of material removal function in computer-controlled optical grinding and polishing is introduced in detail. By simulation, the power spectral density of the material removal function was cut into several parts, some frequency with low amplifies of material removal function were removed, and the modified material removal function reflected the actual processing status, which was helpful in removing some residual high frequency errors on the surface of the workpiece. Finally, the high amplitude such as at high frequency of 110mm-1 and 210mm-1 was reserved and some other low amplitude frequencies were removed.

Thermal field analysis for automotive lamps is a complicated thermodynamics problem. According to the features of structure and lighting process of automotive lamps, a simple and convenient model is put forward here for analyzing their thermal field. Under certain assumptions, it simplifies the complicated geometrical structure to the relative simple cavities and only considers the influence of thermal conduction and thermal radiation as main forms of heat transfer for thermal field of the lamps. The consistency of numerical analysis and actual test demonstrates that this modeling method calculates thermal field of the lamps quickly and perfectly, and indicates its practical signification.

In this paper, we are presenting a design method and its results for a space optical system with high resolution and wide field of view. This optical system can be used both in infrared and visible configurations. The designing of this system is based on an on-axis three-mirror anastigmatic (TMA) system. Here the on-axis concept allows wide field of view (FOV) enabling a diversity of designs available for the Multi-Object Spectrometer instruments optimized for low scattered and low emissive light. The available FOVs are upto 1º in both spectrum ranges, whereas the available aperture range is F/15 - F/10. The final optical system is a three-mirror telescope with two on-axis and one off-axis segment and its resolution is 0.3m or even lower. The distinguished feature of this design is that it maintains diffraction-limited image at wide wavelengths. The technological developments in the field of computer generated shaping of large-sized optical surface details with diffraction-limited imagery have opened new avenues towards the designing techniques. Such techniques permit us to expand these technological opportunities to fabricate the aspherical off-axis mirrors for a complex configuration.

Goodyerin is a flavonol glycoside isolated from the whole plants of Goodyera schlechtendalianawhich has been used as a substitute for the crude drug, Anoectochilus formosanus. The pharmacological properties of goodyerin were assayed for effects on spontaneous locomotor activity, on pentobarbital‐induced hypnosis, and on anticonvulsant activity against picrotoxin‐induced seizures in rodents. Goodyerin exhibited a significant and dose‐dependent sedative and anticonvulsant effect. Copyright © 2002 John Wiley & Sons, Ltd.

Researchers from the Chinese Academy of Sciences have developed a versatile plasmid interference system that allows for the rapid characterization of anti-CRISPR proteins (Acrs) and the development of Acr-based technologies. The system was used to discover two novel Acrs, AcrIIA33 and AcrIIA34, which inhibit the activity of SpyCas9 by affecting DNA recognition. Additionally, the researchers created optogenetically engineered variants of the AcrIIA4 protein, called OPERA4, which can control the activity of SpyCas9 by approximately 1000-fold under switching dark-light conditions. The OPERA4 variants were found to achieve potent light-controllable genome editing in human cells as well. This work provides a versatile screening system for characterizing Acrs and developing controllable tools based on Acrs. [Extracted from the article]

A list of the Institute of Management Accountant (IMA) members who became certified management accountants (CMAs) between June 1 and June 30, 2023 is presented including Ryan Abou Zeid, Wei Ai, and Lina Ao.