A new doubly achromatic two-magnet beam bending system is described.Itconsists of two nonuniform dipoles separated by a small drift space.Some doublyachromatic relations are derived.The system showed excellent achroma...A new doubly achromatic two-magnet beam bending system is described.Itconsists of two nonuniform dipoles separated by a small drift space.Some doublyachromatic relations are derived.The system showed excellent achromatic and focusingproperties and good quality of electron beam with small diameter.Very small diver-gence and axial symmetry were produced at the output of the system.The system isspecially suitable for low energy electron linac beam with large energy spread.展开更多
Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized ...Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized with rapid prototypes of 3D CAD of products. Rapid prototyping has been an effective tool of R&D of new products. A novel rapid prototyping and manufacturing (RP&M) technique is brought forward. The principle of the process is to form layered sections and to make the prototype or part layer by layer by deflection projection of electric charged powder granules passing through electric or magnetic field and by controllable line and field scan of the powder granule beam. The feasibility issue of the process is theoretically and experimentally investigated.It shows that deflection projection of electric charged powder granules beam passing through electric field can be significant and feasible to the rapid prototyping technique.展开更多
Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating materia...Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating material to improve the flexural strength of fiber-modified concrete beams.The scope included preparing rectangular prism concrete beams with a concrete mixture including fly ash and fiber and coating them with four different liquid polymers at a uniform thickness following the curing process while one set of samples was maintained under the same conditions as a control group without coating.In addition,cylindrical samples were prepared to determine the compressive strength of the concrete mixture.Following the curing process in an unconfined open-air laboratory environment for another 28 days,concrete samples were tested to determine the flexural strength and deflection characteristics under center point loading equipment.The results revealed that all four coating types enhanced both the flexural strength and the average maximum deflection of the beams compared to the control group.While the enhancement in the flexural strength changed approximately between 5%and 36%depending on the coating type,the improvements in average maximum deflections varied between 3.7%and 28.4%.展开更多
With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the...With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the deflection angle of laser galvanometer in the narrow space of scanner with high precision remains to be studied. In this paper, an angle measurement method based on magnetic field is proposed, and the effect of the shapes of permanent magnets(PMs) on the measurement is studied by theoretical and experimental study under the condition that the maximum available space for the PMs is a 10 mm side cube. An angle measuring experimental device is set up, and the contrast experiment is carried out with different PMs which are the same as simulation. The experimental results show that cylindrical PM is more suitable than other PMs, which is consistent with the simulation results, and the maximum nonlinearity error is 0.562%. This method has the advantages of small volume,non-contact measurement, small moment of inertia, good dynamic response and no external excitation for the PMs, so it has a broad application prospect in micro laser galvanometer scanner.展开更多
美国材料实验协会(American Society of Testing Materials,ASTM)F2052-21标准(对应中文标准YY/T 0987.2)规定了磁共振环境中医疗器械磁致位移力的标准测试方法,在国际上被广泛接受和应用。该方法是用细线将被测植入物悬挂于磁场中,测...美国材料实验协会(American Society of Testing Materials,ASTM)F2052-21标准(对应中文标准YY/T 0987.2)规定了磁共振环境中医疗器械磁致位移力的标准测试方法,在国际上被广泛接受和应用。该方法是用细线将被测植入物悬挂于磁场中,测量悬线相对竖直方向的偏转角,从而计算磁致位移力相对重力的大小。然而,当该方法应用于极轻型植入物测试时,很难满足悬线质量小于植入物质量的1%的要求。该文提出了一种基于配重修正的极轻型植入物磁致位移力测试方法:使用质量超出待测植入物质量的1%的悬线和夹持物,按照标准方法测量偏转角度,再使用待测植入物质量在被测物总质量中的占比对偏转角度进行修正,从而获得准确的测量结果。该文对配重修正法进行了理论计算和实验验证,结果表明,所提出的配重修正法能够有效测量极轻型植入物的磁致位移力偏转角。展开更多
Polarized atomic beam has found many applications in studying atomic scattering processes, producing polarized nuclei, measuring surface parameters, verifying the parity violation principle and enriching isotopes. Pre...Polarized atomic beam has found many applications in studying atomic scattering processes, producing polarized nuclei, measuring surface parameters, verifying the parity violation principle and enriching isotopes. Previous researches, however, were all concentrated on alkali atoms, no work on the production and application of the polarized beam of the multivalence-electron atoms has been reported. As an effort to extend our method of isotope enrichment by magnetic deflection of a polarized atomic beam from alkali atoms to more complicated multivalence-electron atoms, recently we produced a partially polarized europium atomic beam by a single laser optical pumping and observed obvious isotope enrichment effect through the method.展开更多
To investigate the deflection effect of gas plasma plume controlled by magnetic field,a novel experimental scheme was presented.The Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain...To investigate the deflection effect of gas plasma plume controlled by magnetic field,a novel experimental scheme was presented.The Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain gas plasma on a high temperature magneto hydrodynamic(MHD)experiment rig.The plasma jet was deflected under the action of an external magnetic field,resulting in a thrust-vector effect.Particle image velocimetry(PIV)collected two-dimensional images of jet flow field.Through image processing and velocity vector analysis,the jet deflection angle can be obtained quantitatively.At 1800-2500 K,the jet deflection was verified experimentally under the condition of 0.45 T magnetic field strength.The results indicate that the jet deflection angle increases gradually with the increase of gas temperature,and above 2200 K,the jet deflection angle increase obviously.In the process of gas plasma jet,it is feasible to realize the jet deflection controlled by MHD by adding an external magnetic field.展开更多
文摘A new doubly achromatic two-magnet beam bending system is described.Itconsists of two nonuniform dipoles separated by a small drift space.Some doublyachromatic relations are derived.The system showed excellent achromatic and focusingproperties and good quality of electron beam with small diameter.Very small diver-gence and axial symmetry were produced at the output of the system.The system isspecially suitable for low energy electron linac beam with large energy spread.
文摘Rapid prototype manufacturing(RPM) is a new advanced manufacturing technology, which is based on the philosophy of materials increasing of lay by lay forming. Zero adventure rapid design/manufacturing can be realized with rapid prototypes of 3D CAD of products. Rapid prototyping has been an effective tool of R&D of new products. A novel rapid prototyping and manufacturing (RP&M) technique is brought forward. The principle of the process is to form layered sections and to make the prototype or part layer by layer by deflection projection of electric charged powder granules passing through electric or magnetic field and by controllable line and field scan of the powder granule beam. The feasibility issue of the process is theoretically and experimentally investigated.It shows that deflection projection of electric charged powder granules beam passing through electric field can be significant and feasible to the rapid prototyping technique.
文摘Liquid polymers(LP)have become an important structural material used in the construction industry in the last decade.This paper investigates the viability of using commercially available LPs as a coating material to improve the flexural strength of fiber-modified concrete beams.The scope included preparing rectangular prism concrete beams with a concrete mixture including fly ash and fiber and coating them with four different liquid polymers at a uniform thickness following the curing process while one set of samples was maintained under the same conditions as a control group without coating.In addition,cylindrical samples were prepared to determine the compressive strength of the concrete mixture.Following the curing process in an unconfined open-air laboratory environment for another 28 days,concrete samples were tested to determine the flexural strength and deflection characteristics under center point loading equipment.The results revealed that all four coating types enhanced both the flexural strength and the average maximum deflection of the beams compared to the control group.While the enhancement in the flexural strength changed approximately between 5%and 36%depending on the coating type,the improvements in average maximum deflections varied between 3.7%and 28.4%.
基金supported by the Aeronautical Science Foundation of China [grant numbers 20175748009]。
文摘With the wide application of laser in the field of skin plastic surgery, micro laser galvanometer scanner has made great progress in this field with its portability. However, the measurement method used to measure the deflection angle of laser galvanometer in the narrow space of scanner with high precision remains to be studied. In this paper, an angle measurement method based on magnetic field is proposed, and the effect of the shapes of permanent magnets(PMs) on the measurement is studied by theoretical and experimental study under the condition that the maximum available space for the PMs is a 10 mm side cube. An angle measuring experimental device is set up, and the contrast experiment is carried out with different PMs which are the same as simulation. The experimental results show that cylindrical PM is more suitable than other PMs, which is consistent with the simulation results, and the maximum nonlinearity error is 0.562%. This method has the advantages of small volume,non-contact measurement, small moment of inertia, good dynamic response and no external excitation for the PMs, so it has a broad application prospect in micro laser galvanometer scanner.
文摘美国材料实验协会(American Society of Testing Materials,ASTM)F2052-21标准(对应中文标准YY/T 0987.2)规定了磁共振环境中医疗器械磁致位移力的标准测试方法,在国际上被广泛接受和应用。该方法是用细线将被测植入物悬挂于磁场中,测量悬线相对竖直方向的偏转角,从而计算磁致位移力相对重力的大小。然而,当该方法应用于极轻型植入物测试时,很难满足悬线质量小于植入物质量的1%的要求。该文提出了一种基于配重修正的极轻型植入物磁致位移力测试方法:使用质量超出待测植入物质量的1%的悬线和夹持物,按照标准方法测量偏转角度,再使用待测植入物质量在被测物总质量中的占比对偏转角度进行修正,从而获得准确的测量结果。该文对配重修正法进行了理论计算和实验验证,结果表明,所提出的配重修正法能够有效测量极轻型植入物的磁致位移力偏转角。
基金National Natural Science Foundation of ChinaNational Key Laboratory of Magnetic Resonance Atomic Molecular Physics.
文摘Polarized atomic beam has found many applications in studying atomic scattering processes, producing polarized nuclei, measuring surface parameters, verifying the parity violation principle and enriching isotopes. Previous researches, however, were all concentrated on alkali atoms, no work on the production and application of the polarized beam of the multivalence-electron atoms has been reported. As an effort to extend our method of isotope enrichment by magnetic deflection of a polarized atomic beam from alkali atoms to more complicated multivalence-electron atoms, recently we produced a partially polarized europium atomic beam by a single laser optical pumping and observed obvious isotope enrichment effect through the method.
文摘To investigate the deflection effect of gas plasma plume controlled by magnetic field,a novel experimental scheme was presented.The Cs2CO3 catalytic ionization seeds were injected into the combustion chamber to obtain gas plasma on a high temperature magneto hydrodynamic(MHD)experiment rig.The plasma jet was deflected under the action of an external magnetic field,resulting in a thrust-vector effect.Particle image velocimetry(PIV)collected two-dimensional images of jet flow field.Through image processing and velocity vector analysis,the jet deflection angle can be obtained quantitatively.At 1800-2500 K,the jet deflection was verified experimentally under the condition of 0.45 T magnetic field strength.The results indicate that the jet deflection angle increases gradually with the increase of gas temperature,and above 2200 K,the jet deflection angle increase obviously.In the process of gas plasma jet,it is feasible to realize the jet deflection controlled by MHD by adding an external magnetic field.
