特发性低促性腺激素性性腺功能减退症FGFR1与CEP290基因变异研究

特发性低促性腺激素性性腺功能减退症(idiopathic hypogonadotropic hypogonadism,IHH)是由于促性腺激素释放激素(gonadotropin-releasing hormone,GnRH)缺乏或作用缺陷引起以性腺发育不良为特征的内分泌罕见病。依据是否并发嗅觉障碍可以分为嗅觉正常特发性低促性腺激素性性腺功能减退症(normosmic isolated hypogonadotropic hypogonadism,nIHH)和嗅觉障碍的卡尔曼综合征(Kallmann syndrome,KS)。本研究收集并分析了1例nIHH散发病例的临床资料。全外显子测序证实患儿同时携带FGFR1基因变异(c.2008G>A,p.E670K)和遗传于其母亲的CEP290基因变异(c.964G>A,p.D322N)。生物信息学分析发现FGFR1基因突变(c.2008G>A)改变FGFR1蛋白TK2结构域,影响FGFR1受体的功能及下游细胞信号转导通路的激活。CEP290基因(c.964G>A)可能影响GnRH神经元的正确迁徙途径导致IHH,CEP290蛋白与FGFR1蛋白之间存在相互作用。本研究结果扩展了IHH致病基因表达谱,为探究IHH的致病机制提供了新的方向,并为该类疾病的临床精准诊疗提供了借鉴和参考。

A Superaerophobic Bimetallic Selenides Heterostructure for Efficient Industrial-Level Oxygen Evolution at Ultra-High Current Densities

Cost-effective and stable electrocatalysts with ultra-high current densities for electrochemical oxygen evolution reaction(OER)are critical to the energy crisis and environmental pollution.Herein,we report a superaerophobic three dimensional(3D)heterostructured nanowrinkles of bimetallic selenides consisting of crystalline NiSe2 and NiFe2Se4 grown on NiFe alloy(NiSe2/NiFe2Se4@NiFe)prepared by a thermal selenization procedure.In this unique 3D heterostructure,numerous nanowrinkles of NiSe2/NiFe2Se4 hybrid with a thickness of ~100 nm are grown on NiFe alloy in a uniform manner.Profiting by the large active surface area and high electronic conductivity,the superaerophobic NiSe2/NiFe2Se4@NiFe heterostructure exhibits excellent electrocatalytic activity and durability towards OER in alkaline media,outputting the low potentials of 1.53 and 1.54 V to achieve ultra-high current densities of 500 and 1000 mA cm^−2,respectively,which is among the most active Ni/Fe-based selenides,and even superior to the benchmark Ir/C catalyst.The in-situ derived FeOOH and NiOOH species from NiSe2/NiFe2Se4@NiFe are deemed to be efficient active sites for OER.

Bimetallic Oxyhydroxide as a High-Performance Water Oxidation Electrocatalyst under Industry-Relevant Conditions

Developing high-performing oxygen evolution reaction(OER)electrocatalysts under high-current operation conditions is critical for future commercial applications of alkaline water electrolysis for clean energy generation.Herein,we prepared a three-dimensional(3D)bimetallic oxyhydroxide hybrid grown on a Ni foam(NiFeOOH/NF)prepared by immersing Ni foam(NF)into Fe(NO_(3))_(3) solution.In this unique 3D structure,the NiFeOOH/NF hybrid was composed of crystalline Ni(OH)_(2) and amorphous FeOOH evenly grown on the NF surface.As a bimetallic oxyhydroxide electrocatalyst,the NiFeOOH/NF hybrid exhibited excellent catalytic activity,surpassing not only the other reported Ni–Fe based electrocatalysts,but also the commercial Ir/C catalyst.In situ electrochemical Raman spectroscopy demonstrated the active FeOOH and NiOOH phases involved in the OER process.Profiting from the synergy of Fe and Ni catalytic sites,the NiFeOOH/NF hybrid delivered an outstanding OER performance under challenging industrial conditions in a 10.0 mol·L^(-1) KOH electrolyte at 80℃,requiring potentials as small as 1.47 and 1.51 V to achieve the super-high catalytic current densities of 100 and 500mA∙cm^(-2),respectively.

中小学人工智能机器人课程教学模式研究

AI机器人课程在培养创新人才方面具有优势,在AI机器人课程中,学生通过动手实践来培养问题意识、开拓创新思维、开展机器人教育具有重要意义。然而,目前国内中小学机器人教育依然以竞赛、获奖为主要目的,机器人课程的教学缺少一套完整统一的课程体系,在机器人课程的教学方法中重模仿、轻应用。所以,我国中小学机器人课程需要改革。文章借鉴体验学习理论,将“体验情境—反思观察—总结内化—创新分享”的教学模式应用于中小学课程中进行实践探究,结果表明,该教学模式可以有效提升学生对课程的兴趣、培养学生的创新思维,对教师开展机器人课程具有借鉴意义。

A Novel Soft Start Method of Super Large Capacity High Voltage Motor

The large current generated by starting directly of super large capacity and high voltage induction motor would have a huge impact on the grid as well as the motor itself.The variation of the power factor and electromagnetic torque during direct start of motors with different capacity and voltage levels are obtained.Aiming at the problem that the secondary impact of auto-transformer starter is too large and the cost of magnetic control starter is too high,the auto-transformer and magnetic control soft start method of super large capacity and high voltage motor is proposed and the basic working principle is analyzed.The calculation formula of cost for magnetic control soft starter and auto-transformer and magnetic control soft starter is deduced,and specific examples are analyzed and compared.It is concluded that the choice of auto-transformer with appropriate tapping ratio can greatly reduce the cost of auto-transformer and magnetic control soft starter compared with the other one.Finally,the simulation and experiment results show that the start method can effectively avoid secondary current impact and constrain the motor starting current to less than 2.5 times the rated current.

自吸射流搅拌桨液-液非均相混合特性分析

自吸射流搅拌槽作为新型搅拌装置在非均相强化混合过程中具有潜在的工程应用前景。以水为连续相,油为分散相,运用数值模拟和实验研究了自吸射流搅拌槽内液-液非均相混合过程及强化非均相混合过程的影响因素。结果表明,搅拌转速及分散相相含率对液-液非均相自吸射流轴线上无量纲速度影响较小。自吸射流管倾角β对搅拌槽内流场和分散相分布的影响显著,β<0°时,不利于油水非均相在搅拌槽内径向混合;β=0°时,搅拌槽内无自吸和射流现象,不利于轴向混合;β>0°时,搅拌桨上部产生自吸流,下部产生射流,高油相相含率流体被自吸射流管吸入,向下以射流方式进入低油相相含率流体,有效提高了搅拌槽底部湍流动能,强化了油水非均相混合过程。

Multi-Function Uninterrupted Phase-Separation Passing System and its Control Method

At present, sudden load changes and terminal voltage fluctuations are two primary problems in the uninterrupted phase-separation passing (UPP) system. To further enhance the reliability of the UPP system and compensate for the voltage sag at the end of the traction power supply network caused by the suddenly connection of locomotive to the power grid, a multi-function uninterrupted phase-separation passing system (MUPPS) and its control strategy are proposed. It has the advantages of linear load change and improving power supply reliability. First, the topology and working principles of a MUPPS are studied;secondly, the current variation characteristics of the bridge arm when the power is continuously supplied by MUPPS during the phase-separation passing are analyzed. Then, the characteristics of a MUPPS to provide reactive power and stabilize the terminal voltage of the traction arm are analyzed. Then, the power transmission characteristics of a MUPPS under emergency working conditions are analyzed. The control strategy for the two conditions is proposed. Finally, simulation analysis and small capacity experiments are conducted. The theoretical analysis and test confirm the correctness and effectiveness of the MUPPS.

Parallel diode-clamped linear converter for withstand test and partial discharge measurement of electric equipment

High-voltage withstand tests are essential for electric equipment like power transformers,electric cable lines,gas insulated switchgears etc.The partial discharge(PD)measurement for such equipment under applied high voltage is also required at the same time.Pulse Width Modulation(PWM)-based variable frequency power supply(VFPS)finds wide applications in the series resonance high-voltage testing circuits.However,the steep rising and falling voltage edges in the PWM process will produce large amount of partial discharge interference in a wide spectrum range,which will confuse the real partial discharge signal of the device and lead to the wrong estimation of the insulation status.This paper proposes a new VFPS based on the highefficiency linear power amplifier without PD interference.The topology and principle of the VFPS are given and discussed.A prototype rated at 232 V/35 A was designed and constructed to verify the feasibility of the proposed VFPS.Physical experiments were carried out on the prototype.

Optimal electromagnetic hybrid negative current compensation method for high-speed railway power supply system

To achieve economical compensation for the huge-capacity negative sequence currents generated by high-speed railway load, an electromagnetic hybrid compensation system(EHCS) and control strategy is proposed.The EHCS is made up of a small-capacity railway static power conditioner(RPC) and a large-capacity magnetic static var compensator(MSVC). Compared with traditional compensation methods, the EHCS makes full use of the SVC’s advantages of economy and reliability and of RPC’s advantages of technical capability and flexibility. Based on the idea of injecting a negative sequence, the compensation principle of the EHCS is analyzed in detail. Then the minimum installation capacity of an EHCS is theoretically deduced. Furthermore, a constraint optimization compensation strategy that meets national standards, which reduces compensation capacity further, is proposed. An experimental platform based on a digital signal processor(DSP) and a programmable logic controller(PLC) is built to verify the analysis. Simulated and experimental results are given to demonstrate the effectiveness and feasibility of the proposed method.

Pareto optimal allocation of fault current limiter based on immune algorithm considering cost and mitigation effect

This paper presents a multi-objective Pareto optimal method for allocation of fault current limiters based on an immune algorithm, which takes into account two objectives of the cost and fault current mitigation effect. A sensitivity factor calculation method based on the rate of fault current mitigation is proposed to reduce the search space and improve the efficiency of the algorithm.In this approach, the objective functions related to the cost and fault current mitigation effect are established. A modified inversion operator based on equal cost is proposed to converge to global optimal solutions more effectively. The proposed algorithm is tested on the IEEE39-bus system, and obtains the Pareto optimal solutions,from which the user can select the most suitable solutions according to the preferences and relative importance of the objective functions. Simulation results are used to verify the proposed method.

Multi-frequency magnetic resonance elastography of the pancreas:measurement reproducibility and variance among healthy volunteers

Background Patients with chronic pancreatitis often have irreversible pancreatic insufficiency before a clinical diagnosis.Pancreatic cancer is a fatal malignant tumor in the advanced stages.Patients having high risk of pancreatic diseases must be screened early to obtain better outcomes using new imaging modalities.Therefore,this study aimed to investigate the reproducibility of tomoelastography measurements for assessing pancreatic stiffness and fluidity and the variance among healthy volunteers.Methods Forty-seven healthy volunteers were prospectively enrolled and underwent two tomoelastography examinations at a mean interval of 7 days.Two radiologists blindly and independently measured the pancreatic stiffness and fluidity at the first examination to determine the reproducibility between readers.One radiologist measured the adjacent pancreatic slice at the first examination to determine the reproducibility among slices and measured the pancreas at the second examination to determine short-termrepeatability.The stiffness and fluidity of the pancreatic head,body,and tail were compared to determine anatomical differences.The pancreatic stiffness and fluidity were compared based on sex,age,and body mass index(BMI).Results Bland–Altman analyses(all P>0.05)and intraclass correlation coefficients(all>0.9)indicated near perfect reproducibility among readers,slices,and examinations at short intervals.Neither stiffness(P=0.477)nor fluidity(P=0.368)differed among the pancreatic anatomical regions.The mean pancreatic stiffness was 1.45±0.09 m/s;the mean pancreatic fluidity was 0.83±0.06 rad.Stiffness and fluidity did not differ by sex,age,or BMI.Conclusion Tomoelastography is a promising and reproducible tool for assessing pancreatic stiffness and fluidity in healthy volunteers.

Coupled autotransformer and magneticcontrol soft-start method for super-largecapacity high-voltage motors

The large current generated by a direct start of the super-large-capacity high-voltage induction motor would have a huge impact on the power grid as well as the motor itself.Traditional soft starters have the shortcomings of discontinuous adjustment,voltage sags,sudden torque mutation,secondary current impact and high cost.To resolve this issue,the authors propose a novel coupled autotransformer and magnetic-control(CATMC)soft-start method.The structure of the new CATMC soft starter combines the functions of the autotransformer and magnetic control reactor via an innovative electric and magnetic circuit design.In this study,the authors analyse the magnetic circuit structure and working principles of the CATMC soft starter.Then,to validate its principle and performance,the authors conduct a simulation study using ANSYS software and design and test an 18 MW/10 kV CATMC soft starter prototype.The simulation results demonstrate that the CATMC soft starter effectively avoids secondary current impact and constrains the motor starting current to<2.5 times the rated current.The public connection point bus voltage also meets the voltage sag requirement of the IEEE standard and reduces the impact on the power grid.

Saturated-core fault current limiters for AC power systems:Towards reliable,economical and better performance application

With the continuous expansion of power grid capacity,the problem of short-circuit current exceeding the standard is becoming increasingly serious.Fault current limiter is a promising solution and is gradually becoming a research hotspot.In this study,fault current limiters are classified into four categories.And saturated-core fault current limiters are emphatically introduced,including its working principle and comparison with the other three categories.Saturated core fault current limiters are divided into four branches according to the ways leading the core saturated.A comprehensive review of the research activities and emerging technologies of saturated-core fault current limiters for AC power systems is presented in this study.The working principle and typical structure of DC-biased-,permanent-magnet-,superconducting-and hybrid-type saturated-core fault current limiters are introduced.The advantages and disadvantages of four types of saturated core fault current limiters are compared in detail from the aspects of current-limiting performance,iron core size and DC magnetomotive force.Real grid application examples of some types of devices are presented,as well as new progress in the techniques,are covered and discussed in detail.One may find the content of this study helpful as a detailed literature review or as practical technical guidance.