Submersible electrical motor direct-drive progressing cavity pump (PCP) rodless lifting was studied to solve the traditional rod-drive pump problems, such as rod-tubing wearing, low efficiency and short running time. ...Submersible electrical motor direct-drive progressing cavity pump (PCP) rodless lifting was studied to solve the traditional rod-drive pump problems, such as rod-tubing wearing, low efficiency and short running time. The theoretical researches and laboratory experiments of key tools such as submersible motor and the construction technology of lifting system were introduced. The field application and economic benefit were analyzed and compared with the traditional rod pumping unit. A new low speed and large torque permanent magnet synchronous motor was developed. This motor was used to drive PCP without gear reducer, which improved the reliability and feasibility. It can run at the speed from 50 to 500 r/min with stepless speed regulation, and it can perform high efficiency and large torque. Besides, other key supporting tools, such as motor protector and flex shaft, were developed. The submersible electrical motor direct- drive PCP technology can be used in a 139.7 mm (5.5 in) casing well, with daily output ranging from 5 to 50 m3. Until now, the technology has been deployed more than 100 wells. The field application results show that it eliminates the rod-tubing wearing and saves electric energy by more than 30% compared with the traditional rod pumping unit. And it also makes the oil produced in a safe and environmental friendly way.展开更多
Offshore wind energy is an important part of clean energy,and the adoption of wind energy to generate electricity will contribute to the implementation of the carbon peaking and carbon neutrality goals.The combination...Offshore wind energy is an important part of clean energy,and the adoption of wind energy to generate electricity will contribute to the implementation of the carbon peaking and carbon neutrality goals.The combination of the fractional frequency transmission system(FFTS) and the direct-drive wind turbine generator will be beneficial to the development of the offshore wind power industry.The use of fractional frequency in FFTS is beneficial to the transmission of electrical energy,but it will also lead to an increase in the volume and weight of the generator,which is unfavorable for wind power generation.Improving the torque density of the generator can effectively reduce the volume of the generators.The vernier permanent magnet machine(VPM) operates on the magnetic flux modulation principle and has the merits of high torque density.In the field of electric machines,the vernier machine based on the principle of magnetic flux modulation has been proved its feasibility to reduce the volume and weight.However,in the field of low-speed direct-drive machines for high-power fractional frequency power generation,there are still few related researches.Therefore,this paper studies the application of magnetic flux modulation in fractional frequency and high-power direct-drive wind turbine generators,mainly analyzes the influence of different pole ratios and different pole pairs on the generator,and draws some conclusions to provide reference for the design of wind turbine generators.展开更多
Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform.In order to validate the performance of ShenGuang(SG) l...Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform.In order to validate the performance of ShenGuang(SG) laser facility and test nuclear diagnostics, all 48-beam lasers with an on-target energy of 48 kJ were firstly used to drive room-temperature, DT gas-filled glass targets.The optimization has been carried out and optimal drive uniformity was obtained by the combination of beam repointing and target.The final irradiation uniformity of less than 5% on polar direct-drive capsules of 540 μm in diameter was achieved, and the highest thermonuclear yield of the polar direct-drive DT fuel implosion at the SG was 1.04 × 10^(13).The experiment results show neutron yields severely depend on the irradiation uniformity and laser timing,and decrease with the increase of the diameter and fuel pressure of the target.The thin CH ablator does not impact the implosion performance, but the laser drive uniformity is important.The simulated results validate that the cos γ distribution laser design is reasonable and can achieve a symmetric pressure distribution.Further optimization will focus on measuring the symmetry of the hot spot by self-emission imaging, increasing the diameter, and decreasing the fuel pressure.展开更多
Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits.They can be used in banking,commercial and financial tr...Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits.They can be used in banking,commercial and financial transactions,scientific measurements,etc.This article presents the Very Large Scale Integration(VLSI)design of Binary Coded Decimal(BCD)-4221 area-optimized adder architecture using unconventional BCD-4221 representation.Unconventional BCD number representations such as BCD4221 also possess the additional advantage of more effectively representing the 10's complement representation which can be used to accelerate the decimal arithmetic operations.The design uses a binary Carry Lookahead Adder(CLA)along with some other logic blocks which are required to perform internal calculations with BCD-4221 numbers.The design is verified by using Xilinx Vivado 2016.1.Synthesis results have been obtained by Cadence Genus16.1 synthesis tool using 90 nm technology.The performance parameters such as area,power,delay,and area-delay Product(ADP)are compared with earlier reported circuits.Our proposed circuit shows significant area and ADP improvement over existing designs.展开更多
Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique wa...Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.展开更多
BACKGROUND Juvenile systemic lupus erythematosus(SLE)is a severe,life-threatening disease.However,the role of rituximab in managing juvenile SLE remains undefined,although early biological intervention may improve dis...BACKGROUND Juvenile systemic lupus erythematosus(SLE)is a severe,life-threatening disease.However,the role of rituximab in managing juvenile SLE remains undefined,although early biological intervention may improve disease outcomes.AIM To assess the differences in the outcomes of different types of rituximab administration(early and late).METHODS In this retrospective cohort study,the information of 36 children with SLE with administration(LRA)was analyzed.We compared initial disease characteristics at onset,at baseline(start of rituximab),and at the end of the study(EOS)at 12 months,as well as outcomes and treatment characteristics.RESULTS The main differences at baseline were a higher daily median dose of corticosteroids,increased MAS frequency,and a higher Systemic Lupus Erythematosus Disease Activity Index(SLEDAI)in the ERA group.No differences in the main SLE outcomes between groups at the EOS were observed.The part of lupus nephritis patients who achieved remission changed from 44%to 31%in ERA and 32%to 11%in the LRA group.Patients with ERA had a shorter time to achieve low daily corticosteroid dose(≤0.2 mg/kg)at 1.2(0.9;1.4)years compared to 2.8(2.3;4.0)years(P=0.000001)and higher probability to achieve this low dose[hazard ratio(HR)=57.8(95%confidence interval(CI):7.2-463.2),P=0.00001 and remission(SLEDAI=0);HR=37.6(95%CI:4.45-333.3),P=0.00001].No differences in adverse events,including severe adverse events,were observed.CONCLUSION ERA demonstrated a better steroid-sparing effect and a possibility of earlier remission or low disease activity,except for lupus nephritis.Further investigations are required.展开更多
基金Supported by the PetroChina Science and Technology Project(2016B-4104)
文摘Submersible electrical motor direct-drive progressing cavity pump (PCP) rodless lifting was studied to solve the traditional rod-drive pump problems, such as rod-tubing wearing, low efficiency and short running time. The theoretical researches and laboratory experiments of key tools such as submersible motor and the construction technology of lifting system were introduced. The field application and economic benefit were analyzed and compared with the traditional rod pumping unit. A new low speed and large torque permanent magnet synchronous motor was developed. This motor was used to drive PCP without gear reducer, which improved the reliability and feasibility. It can run at the speed from 50 to 500 r/min with stepless speed regulation, and it can perform high efficiency and large torque. Besides, other key supporting tools, such as motor protector and flex shaft, were developed. The submersible electrical motor direct- drive PCP technology can be used in a 139.7 mm (5.5 in) casing well, with daily output ranging from 5 to 50 m3. Until now, the technology has been deployed more than 100 wells. The field application results show that it eliminates the rod-tubing wearing and saves electric energy by more than 30% compared with the traditional rod pumping unit. And it also makes the oil produced in a safe and environmental friendly way.
文摘针对超密集网络(ultra dense network,UDN)中基站密集部署导致的严重层间干扰问题,构建了考虑频谱复用和共信道干扰条件下最大化系统总吞吐量问题模型,提出了一种基于块坐标下降(block coordinate descent,BCD)法的联合频谱资源优化(joint resource optimization based on BCD,JROBB)方法。该方法将原问题分解为分簇、子信道分配和功率分配三个子问题,通过BCD法迭代优化子信道分配和功率分配,逼近原问题的最优解。仿真分析表明,在复杂度提升有限的情况下,系统总吞吐量比现有典型算法平均至少提升22%,可以有效提升频谱利用率。
基金supported by the Science and Technology Foundation of SGCC (5500-202099509A-0-0-00)“Research on Fractional Frequency Transmission Technology for Largely Enhancing Transmission Capacity and Development of Its Key Devices”。
文摘Offshore wind energy is an important part of clean energy,and the adoption of wind energy to generate electricity will contribute to the implementation of the carbon peaking and carbon neutrality goals.The combination of the fractional frequency transmission system(FFTS) and the direct-drive wind turbine generator will be beneficial to the development of the offshore wind power industry.The use of fractional frequency in FFTS is beneficial to the transmission of electrical energy,but it will also lead to an increase in the volume and weight of the generator,which is unfavorable for wind power generation.Improving the torque density of the generator can effectively reduce the volume of the generators.The vernier permanent magnet machine(VPM) operates on the magnetic flux modulation principle and has the merits of high torque density.In the field of electric machines,the vernier machine based on the principle of magnetic flux modulation has been proved its feasibility to reduce the volume and weight.However,in the field of low-speed direct-drive machines for high-power fractional frequency power generation,there are still few related researches.Therefore,this paper studies the application of magnetic flux modulation in fractional frequency and high-power direct-drive wind turbine generators,mainly analyzes the influence of different pole ratios and different pole pairs on the generator,and draws some conclusions to provide reference for the design of wind turbine generators.
基金Project supported by the National Natural Science Foundation of China(Grant No.11605178)the Science Challenging Project,China(Grant Nos.JCKY2016212A505 and TZ2016001)
文摘Low density and low convergence implosion occurs in the exploding-pusher target experiment, and generates neutrons isotropically to develop a high yield platform.In order to validate the performance of ShenGuang(SG) laser facility and test nuclear diagnostics, all 48-beam lasers with an on-target energy of 48 kJ were firstly used to drive room-temperature, DT gas-filled glass targets.The optimization has been carried out and optimal drive uniformity was obtained by the combination of beam repointing and target.The final irradiation uniformity of less than 5% on polar direct-drive capsules of 540 μm in diameter was achieved, and the highest thermonuclear yield of the polar direct-drive DT fuel implosion at the SG was 1.04 × 10^(13).The experiment results show neutron yields severely depend on the irradiation uniformity and laser timing,and decrease with the increase of the diameter and fuel pressure of the target.The thin CH ablator does not impact the implosion performance, but the laser drive uniformity is important.The simulated results validate that the cos γ distribution laser design is reasonable and can achieve a symmetric pressure distribution.Further optimization will focus on measuring the symmetry of the hot spot by self-emission imaging, increasing the diameter, and decreasing the fuel pressure.
文摘Decimal arithmetic circuits are promising to provide a solution for accurate decimal arithmetic operations which are not possible with binary arithmetic circuits.They can be used in banking,commercial and financial transactions,scientific measurements,etc.This article presents the Very Large Scale Integration(VLSI)design of Binary Coded Decimal(BCD)-4221 area-optimized adder architecture using unconventional BCD-4221 representation.Unconventional BCD number representations such as BCD4221 also possess the additional advantage of more effectively representing the 10's complement representation which can be used to accelerate the decimal arithmetic operations.The design uses a binary Carry Lookahead Adder(CLA)along with some other logic blocks which are required to perform internal calculations with BCD-4221 numbers.The design is verified by using Xilinx Vivado 2016.1.Synthesis results have been obtained by Cadence Genus16.1 synthesis tool using 90 nm technology.The performance parameters such as area,power,delay,and area-delay Product(ADP)are compared with earlier reported circuits.Our proposed circuit shows significant area and ADP improvement over existing designs.
文摘Code converters are essential in digital nano communication;therefore,a low-complexity optimal QCA layout for a BCD to Excess-3 code converter has been proposed in this paper.A QCA clockphase-based design technique was adopted to investigate integration with other complicated circuits.Using a unique XOR gate,the recommended circuit’s cell complexity has been decreased.The findings produced using the QCADesigner-2.0.3,a reliable simulation tool,prove the effectiveness of the current structure over earlier designs by considering the number of cells deployed,the area occupied,and the latency as design metrics.In addition,the popular tool QCAPro was used to estimate the energy dissipation of the proposed design.The proposed technique reduces the occupied space by∼40%,improves cell complexity by∼20%,and reduces energy dissipation by∼1.8 times(atγ=1.5EK)compared to the current scalable designs.This paper also studied the suggested structure’s energy dissipation and compared it to existing works for a better performance evaluation.
基金Supported by Ministry of Science and Higher Education of the Russian Federation,No.075-15-2022-301the Russian Science Foundation Grant,No.22-45-08004.
文摘BACKGROUND Juvenile systemic lupus erythematosus(SLE)is a severe,life-threatening disease.However,the role of rituximab in managing juvenile SLE remains undefined,although early biological intervention may improve disease outcomes.AIM To assess the differences in the outcomes of different types of rituximab administration(early and late).METHODS In this retrospective cohort study,the information of 36 children with SLE with administration(LRA)was analyzed.We compared initial disease characteristics at onset,at baseline(start of rituximab),and at the end of the study(EOS)at 12 months,as well as outcomes and treatment characteristics.RESULTS The main differences at baseline were a higher daily median dose of corticosteroids,increased MAS frequency,and a higher Systemic Lupus Erythematosus Disease Activity Index(SLEDAI)in the ERA group.No differences in the main SLE outcomes between groups at the EOS were observed.The part of lupus nephritis patients who achieved remission changed from 44%to 31%in ERA and 32%to 11%in the LRA group.Patients with ERA had a shorter time to achieve low daily corticosteroid dose(≤0.2 mg/kg)at 1.2(0.9;1.4)years compared to 2.8(2.3;4.0)years(P=0.000001)and higher probability to achieve this low dose[hazard ratio(HR)=57.8(95%confidence interval(CI):7.2-463.2),P=0.00001 and remission(SLEDAI=0);HR=37.6(95%CI:4.45-333.3),P=0.00001].No differences in adverse events,including severe adverse events,were observed.CONCLUSION ERA demonstrated a better steroid-sparing effect and a possibility of earlier remission or low disease activity,except for lupus nephritis.Further investigations are required.
