The Development Trend of and Suggestions for China’s Hydrogen Energy Industry

1.Introduction Driven by the current round of technological revolution and industrial transformation,and based on a consensus among countries around the world,the world’s energy landscape is undergoing profound adjustments to promote a transition to clean,low-carbon energy in order to cope with global climate change.As a clean and carbon-free secondary energy source,hydrogen energy is an important component of the energy strategy in various countries.Fuel cell technology is also of great importance in directing the current global energy technology revolution.

Enhancing suspension vibration reduction by diagonal inerter

The diagonal inerter is integrated into a suspension vibration reduction system(SVRS).The dynamic model of the SVRS with diagonal inerter and damping is established.The dynamic model is of strong geometric nonlinearity.The retaining nonlinearity up to cubic terms is validated under impact excitation.The conditions omitting the static deformation are determined.The effects of the diagonal inerter on the vibration reduction performance of the SVRS are explored under impact and random excitations.The vibration reduction performance of the proposed SVRS with both diagonal inerter and damping is better than that of either the SVRS without them or the SVRS with the diagonal damping only.

Morphological effect on electrochemical performance of nanostructural CrN

Size and morphology are critical factors in determining the electrochemical performance of the supercapacitor materials,due to the manifestation of the nanosize effect.Herein,different nanostructures of the CrN material are prepared by the combination of a thermal-nitridation process and a template technique.High-temperature nitridation could not only transform the hexagonal Cr_(2)O_(3)into cubic CrN,but also keep the template morphology barely unchanged.The obtained CrN nanostructures,including(i)hierarchical microspheres assembled by nanoparticles,(ii)microlayers,and(iii)nanoparticles,are studied for the electrochemical supercapacitor.The CrN microspheres show the best specific capacitance(213.2 F/g),cyclic stability(capacitance retention rate of 96%after 5000 cycles in 1-mol/L KOH solution),high energy density(28.9 Wh/kg),and power density(443.4 W/kg),comparing with the other two nanostructures.Based on the impedance spectroscopy and nitrogen adsorption analysis,it is revealed that the enhancement arised mainly from a high-conductance and specific surface area of CrN microspheres.This work presents a general strategy of fabricating controllable CrN nanostructures to achieve the enhanced supercapacitor performance.

A Digital Controller Design Method to Improve Performance of PFC Converter

With the rapid development of digital signal processing chip in recent years, DSP began to be used in more switching power supply. The advantages of digital control of their own, making the digital control PFC become a hotspot research. However, compared with the simulation system, the digital control technology still has many problems. In this paper, the problem of digital PI compensator as a voltage compensator is discussed, and the Single-pole voltage loop compensator is used in digital control PFC circuit. Because current loop bandwidth is narrow, a method to expand current loop bandwidth is put forward. Output power 300 W of prototype is made, and experimental results verify the correctness of the theory.

Promotion effect of FOXCUT as a microRNA sponge for miR-24-3p on progression in triple-negative breast cancer through the p38 MAPK signaling pathway

Background:Triple-negative breast cancer(TNBC)is a type of highly invasive breast cancer with a poor prognosis.According to new research,long noncoding RNAs(lncRNAs)play a significant role in the progression of cancer.Although the role of lncRNAs in breast cancer has been well reported,few studies have focused on TNBC.This study aimed to explore the biological function and clinical significance of forkhead box C1 promoter upstream transcript(FOXCUT)in triple-negative breast cancer.Methods:Based on a bioinformatic analysis of the cancer genome atlas(TCGA)database,we detected that the lncRNA FOXCUT was overexpressed in TNBC tissues,which was further validated in an external cohort of tissues from the General Surgery Department of the First Affiliated Hospital of Nanjing Medical University.The functions of FOXCUT in proliferation,migration,and invasion were detected in vitro or in vivo.Luciferase assays and RNA immunoprecipitation(RIP)were performed to reveal that FOXCUT acted as a competitive endogenous RNA(ceRNA)for the microRNA miR-24-3p and consequently inhibited the degradation of p38.Results:lncRNA FOXCUT was markedly highly expressed in breast cancer,which was associated with poor prognosis in some cases.Knockdown of FOXCUT significantly inhibited cancer growth and metastasis in vitro or in vivo.Mechanistically,FOXCUT competitively bounded to miR-24-3p to prevent the degradation of p38,which might act as an oncogene in breast cancer.Conclusion:Collectively,this research revealed a novel FOXCUT/miR-24-3p/p38 axis that affected breast cancer progression and suggested that the lncRNA FOXCUT could be a diagnostic marker and therapeutic target for breast cancer.

Flow characteristics of radial inflow in impeller rear cavity with baffle plate

The research purpose of this paper is to explore the influence of the baffle plate on the airflow in the rear cavity of the centrifugal impeller and optimize the performance of the secondary air system’s air bleed section.In this paper,a comprehensive experimental study was carried out on the flow characteristics in the impeller rear cavity with baffle plate.The windage torque,flow structure and pressure drop between inlet and outlet were measured respectively.The experiment was carried out with the condition that the range of rotational Reynolds number was from 8.33×10^(5)to 22.2×10^(5)and the range of mass flow rate coefficient was from 0.92×10^(4)to 2.92×10^(4).The results show that the static cavity and the narrow stator-rotor cavity formed by the baffle plate effectively suppress the overall swirl coefficient in the cavity.Thus,the static pressure and total pressure drop in the rotor-stator cavity were reduced.The influence of the baffle plate on the windage torque of the rotary disk is related to the turbulence parameters.Under large turbulence parameters,the windage torque would be reduced with baffle plate,while under small turbulence parameters,the baffle plate would increase with baffle plate.In general,the baffle plate can improve the flow capacity and optimize the bleed air performance with proper structure and operation conditions.

Promoting spintronic terahertz radiation via Tamm plasmon coupling

Spectral fingerprint and terahertz(THz)field-induced carrier dynamics demands the exploration of broadband and intense THz signal sources.Spintronic THz emitters(STEs),with high stability,a low cost,and an ultrabroad bandwidth,have been a hot topic in the field of THz sources.One of the main barriers to their practical application is lack of an STE with strong radiation intensity.Here,through the combination of optical physics and ultrafast photonics,the Tamm plasmon coupling(TPC)facilitating THz radiation is realized between spin THz thin films and photonic crystal structures.Simulation results show that the spectral absorptance can be increased from 36.8%to 94.3%for spin THz thin films with TPC.This coupling with narrowband resonance not only improves the optical-to-spin conversion efficiency,but also guarantees THz transmission with a negligible loss(~4%)for the photonic crystal structure.According to the simulation,we prepared this structure successfully and experimentally realized a 264%THz radiation enhancement.Furthermore,the spin THz thin films with TPC exhibited invariant absorptivity under different polarization modes of the pump beam and weakening confinement on an obliquely incident pump laser.This approach is easy to implement and offers possibilities to overcome compatibility issues between the optical structure design and low energy consumption for ultrafast THz optospintronics and other similar devices.

Resonance cavity-enhanced all-optical switching in a GdCo alloy absorber

In spintronic applications,there is a constant demand for lower power consumption,high densities,and fast writing speed of data storage.All-optical switching(AOS)is a technique that uses laser pulses to switch the magnetic state of a recording medium without any external devices,offering unsurpassed recording rates and a simple structure.Despite extensive research on the mechanism of AOS,low energy consumption and fast magnetization reversing remain challenging engineering questions.In this paper,we propose a newly designed cavity-enhanced AOS in Gd Co alloy,which promotes optical absorption by twofold,leading to a 50%reduction in energy consumption.Additionally,the time-resolved measurement shows that the time of reversing magnetization reduces at the same time.This new approach makes AOS an ideal solution for energy-effective and fast magnetic recording,paving the way for future developments in high-speed,low-power-consumption data recording devices.

Discoloration mechanism,structures and recent applications of thermochromic materials via different methods:A review

Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anticounterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed.

Transportation characteristics of gas-solid two-phase flow in a long-distance pipeline

In this study, experiments on fly ash conveying were carried out with a home-made long-distance positive-pressure pneumatic conveying system equipped with a high performance electrical capacitance tomography system to observe the transient characteristics of gas-solid two-phase flow. The experimen- tal results indicated that solids throughput increased with increasing solids-gas ratio when the conveying pipeline was not plugged. Moreover, the optimum operating state was determined for the 1000 m long conveying pipeline with a throttle plate of 26 orifices. At this state the solids throughput was about 12.97 t/h. Additionally, the transportation pattern of fly ash gradually changed from sparse-dense flow to partial and plug flows with increasing conveying distance because of the conveying pressure loss, These experimental results provide important reference data for the development of pneumatic conveying technology.

Self-starting passively mode-locked all fiber laser based on carbon nanotubes with radially polarized emission

We demonstrate an all fiber passively mode-locked laser emitting a radially polarized beam by using a few-mode fiber Bragg grating to achieve mode selection and spectrum filtering. An offset splicing of single-mode fiber with four-mode fiber is utilized as a mode coupler in the laser cavity. Carbon nanotubes are introduced into the laser cavity as the saturable absorber to achieve self-start mode locking. The laser operates at 1547.5 nm with a narrow spectrum width of 0.3 nm at 30 d B. The emitted mode-locked pulses have a duration of 22.73 ps and repetition of10.61 MHz. A radially polarized beam has been obtained with high mode purity by adjusting the polarization in the laser cavity.

Spintronic terahertz emitter with integrated electromagnetic control

Spintronic thin films are considered as one of the promising terahertz(THz)source candidates,owing to their high performance and low cost.Much effort has been made to achieve spintronic THz sources with broadband and high conversion efficiency.However,the development of spintronic THz emitters with good compatibility,low cost,and miniaturized technology still faces many challenges.Therefore,it is urgent to extend commercial and portable spintronic THz emitters to satisfy many practical applications.Herein,we design a new generation of spintronic THz emitters composed of an alter-nating electromagnet and a miniaturized electronic controller.Not only can this new type of spintronic THz emitter largely simplify the ancillary equipment for spintronic sources,it also has a twice larger THz signal compared to the traditional THz time-domain spectroscopy systems with a mechanical chopper.Experimental results and theoretical calculations for electromagnetic coils show that our design can stably generate THz signals that are independent of the frequency and magnetic field of alternating signals.As the spin thin film is optimized,a magnetic field as low as 75 G satisfies the require-ment for high performance THz emission.Hence,not only is the efficiency of the pump power enhanced,but also the driving current in the electromagnet is decreased.We believe that it has a wide range of applications and profound implications in THz technology based on spintronic emitters in the future.

低张气充盈法多层螺旋CT增强扫描在胃部病变内镜治疗术前的评估价值

目的探讨低张气充盈法多层螺旋CT增强扫描(EMSCT-LTGF)在胃部病变内镜治疗术前评估的价值。方法回顾性分析2018年1月至2019年4月临汾市中心医院收治具有完整资料的胃部病变60例,均经手术获得病理结果,包括神经内分泌瘤、息肉、腺瘤、平滑肌瘤、胃肠道间质瘤、脂肪瘤、异位胰腺、外压、胃壁脓肿、胃溃疡等,术前行EMSCT-LTGF评估,并与病理结果对照。结果与病理结果进行对照后发现,EMSCT-LTGF与胃镜在检出病变溃疡方面的比较差异无统计学意义。EMSCT-LTGF判断病变深度与病理结果比较差异无统计学意义。结论EMSCT-LTGF在评估胃部病变溃疡、深度、形态、直径、密度、血供、淋巴结及远处脏器转移、邻近结构有无侵犯等方面有较高价值,能够为胃部病变内镜治疗术前提供准确的依据。

Effective Impulse for Fully Clamped Rectangular Plates Under Internal Blast Loading

Under internal blast loading,the response of a beam or plate is highly correlated with the phenomenon of saturated impulse,which governs the deflection of the structure.This paper aims to investigate the phenomenon of saturated impulse for fully clamped rectangular plates subjected to internal blast loading.Based on the rigid,perfectly plastic assumption,the relationship between saturation duration and saturation deflection is derived.Influences of the peak shock wave,the duration of shock wave and the peak quasi-static pressure loading on saturation duration and saturation deflection are discussed.It is found that there is a critical duration for the internal blast impulse to reach saturation,and beyond this duration,the deflection of plate will no longer increase as the loading increases further.The saturation deflection and saturation duration both exhibit regular variation patterns with the changes of the dimensionless peak shock wave,the duration of shock wave and the peak quasi-static pressure loading.

Multi-layer magnetic recording driven by a tunable laser

All-optical magnetization switching with features of low-power consumption and high writing speed is a promising road map to satisfy the demand for volume data storage. To promote denser and faster magnetic recording technologies, herein, all-optical helicity-dependent switching(AO-HDS) in multi-layer magnetic recording is proposed based on the chromatic aberration of an optical lens(Thorlabs’ s N-BK7 plano-convex uncoated lens).The power of the incident beams and the thickness of the multi-layer magnetic recording film are designed carefully. Besides, the uniformity of this multi-layer magnetic recording is optimized. At last, a prototype system of information multiplexing based on this multi-layer magnetic recording technology is constructed as well. Flexible and controllable magnetization reversals in different layers are also demonstrated by tuning the wavelength and helicity of working beams. We believe that such a prototype system can pave the way for increasing the storage density in an effective and low-cost mode.