Novel ternary metals-based telluride electrocatalyst with synergistic effects of high valence non-3d metal and oxophilic Te for pH-universal hydrogen evolution reaction

Electrocatalyst designs based on oxophilic foreign atoms are considered a promising approach for developing efficient pH-universal hydrogen evolution reaction(HER)electrocatalysts by overcoming the sluggish alkaline HER kinetics.Here,we design ternary transition metals-based nickel telluride(Mo WNi Te)catalysts consisting of high valence non-3d Mo and W metals and oxophilic Te as a first demonstration of non-precious heterogeneous electrocatalysts following the bifunctional mechanism.The Mo WNi Te showed excellent HER catalytic performance with overpotentials of 72,125,and 182 mV to reach the current densities of 10,100,and 1000 mA cm^(-2),respectively,and the corresponding Tafel slope of 47,52,and 58 mV dec-1in alkaline media,which is much superior to commercial Pt/C.Additionally,the HER performance of Mo WNi Te is well maintained up to 3000 h at the current density of 100 mA cm^(-2).It is further demonstrated that the Mo WNi Te exhibits remarkable HER activities with an overpotential of 45 mV(31 mV)and Tafel slope of 60 mV dec-1(34 mV dec-1)at 10 mA cm^(-2)in neutral(acid)media.The superior HER performance of Mo WNi Te is attributed to the electronic structure modulation,inducing highly active low valence states by the incorporation of high valence non-3d transition metals.It is also attributed to the oxophilic effect of Te,accelerating water dissociation kinetics through a bifunctional catalytic mechanism in alkaline media.Density functional theory calculations further reveal that such synergistic effects lead to reduced free energy for an efficient water dissociation process,resulting in remarkable HER catalytic performances within universal pH environments.

An online fast multi-track locating algorithm for high-resolution single-event effect test platform

To improve the efficiency and accuracy of single-event effect(SEE)research at the Heavy Ion Research Facility at Lanzhou,Hi’Beam-SEE must precisely localize the position at which each heavy ion hitting the integrated circuit(IC)causes SEE.In this study,we propose a fast multi-track location(FML)method based on deep learning to locate the position of each particle track with high speed and accuracy.FML can process a vast amount of data supplied by Hi’Beam-SEE online,revealing sensitive areas in real time.FML is a slot-based object-centric encoder-decoder structure in which each slot can learn the location information of each track in the image.To make the method more accurate for real data,we designed an algorithm to generate a simulated dataset with a distribution similar to that of the real data,which was then used to train the model.Extensive comparison experiments demonstrated that the FML method,which has the best performance on simulated datasets,has high accuracy on real datasets as well.In particular,FML can reach 238 fps and a standard error of 1.6237μm.This study discusses the design and performance of FML.

Real world effectiveness of PCSK-9 inhibitors combined with statins versus statins-based therapy among patients with very high risk of atherosclerotic cardiovascular disease in China(RWE-PCSK study)

BACKGROUND The efficacy and safety of proprotein convertase subtilisin/kexin type 9(PCSK-9) inhibitors were confirmed by several clinical trials, but its effectiveness in routine clinical practice in China has not been evaluated. This study aims to describe the real world effectiveness of PCSK-9 inhibitors combined with statins compared with statins-based therapy among patients with very high risk of atherosclerotic cardiovascular disease(ASCVD).METHODS This is a multi-center observational study, enrolled patients from 32 hospitals who underwent percutaneous coronary intervention(PCI) from January to June in 2019. There are 453 patients treated with PCSK-9 inhibitors combined with statins in PCSK-9 inhibitor group and 2,610 patients treated with statins-based lipid lowering therapies in statins-based group. The lipid control rate and incidence of major adverse cardiovascular events(MACE) over six months were compared between two groups.A propensity score-matched(PSM) analysis was used to balance two groups on confounding factors. Survival analysis using Kaplan-Meier methods was applied for MACE.RESULTS In a total of 3,063 patients, 89.91% of patients had received moderate or high-intensity statins-based therapy before PCI, but only 9.47% of patients had low-density lipoprotein cholesterol(LDL-C) levels below 1.4 mmol/L at baseline. In the PSM selected patients, LDL-C level was reduced by 42.57% in PCSK-9 inhibitor group and 30.81%(P < 0.001) in statins-based group after six months. The proportion of LDL-C ≤ 1.0 mmol/L increased from 5.29% to 29.26% in PCSK-9 inhibitor group and 0.23% to 6.11% in statins-based group, and the proportion of LDL-C ≤ 1.4 mmol/L increased from 10.36% to 47.69% in PCSK-9 inhibitor group and 2.99% to 18.43% in statins-based group(P < 0.001 for both). There was no significant difference between PCSK-9 inhibitor and statins-based treatment in reducing the risk of MACE(hazard ratio = 2.52, 95% CI: 0.49-12.97, P = 0.250).CONCLUSIONS In the real world, PCSK-9 inhibitors combined with statins could significantly reduce LDL-C levels among patients with very high risk of ASCVD in China. The long-term clinical benefits for patients received PCSK-9 inhibitor to reduce the risk of MACE is still unclear and requires further study.

Study on dynamic response of high speed train window glass under tunnel aerodynamic effects

Purpose-This paper aims to analyze the bearing characteristics of the high speed train window glass under aerodynamic load effects.Design/methodology/approach-In order to obtain the dynamic strain response of passenger compartment window glass during high-speed train crossing the tunnel,taking the passenger compartment window glass of the CRH3 high speed train onWuhan-Guangzhou High Speed Railway as the research object,this study tests the strain dynamic response and maximum principal stress of the high speed train passing through the tunnel entrance and exit,the tunnel and tunnel groups as well as trains meeting in the tunnel at an average speed of 300 km$h-1.Findings-The results show that while crossing the tunnel,the passenger compartment window glass of high speed train is subjected to the alternating action of positive and negative air pressures,which shows the typical mechanic characteristics of the alternating fatigue stress of positive-negative transient strain.The maximum principal stress of passenger compartment window glass for high speed train caused by tunnel aerodynamic effects does not exceed 5 MPa,and the maximum value occurs at the corresponding time of crossing the tunnel groups.The high speed train window glass bears medium and low strain rates under the action of tunnel aerodynamic effects,while the maximum strain rate occurs at the meeting moment when the window glass meets the train head approaching from the opposite side in the tunnel.The shear modulus of laminated glass PVB film that makes up high speed train window glass is sensitive to the temperature and action time.The dynamically equivalent thickness and stiffness of the laminated glass and the dynamic bearing capacity of the window glass decrease with the increase of the action time under tunnel aerodynamic pressure.Thus,the influence of the loading action time and fatigue under tunnel aerodynamic effects on the glass strength should be considered in the design for the bearing performance of high speed train window glass.Originality/value-The research results provide data support for the analysis of mechanical characteristics,damage mechanism,strength design and structural optimization of high speed train glass.

Mechanism of Action of Rare Earths in High Effective Fe Powder Welding Rods

The optimum coating composition of alkali Fe powder welding rods was designed by orthogonal experiment with mix rates. A new kind of effective RE-Fe powder welding rod was prepared which could be used at the condition of direct and indirect current. The arc characteristics and stabilities of effective Fe powder welding rods containing RE were analyzed by HANNOVER analyzer. The efficiency of Fe powder welding rods was tested by weighting method. It was found that the stability of Fe powder welding rods was improved when it was added with rare earths. The results of impact experiment at low temperatures and SEM analysis on impact break showed that the grain was refined, the welding joint was cleaned, and the mechanical properties of joint was enhanced with proper RE content. It was provided with good processing property for this effective RE-Fe powder welding rod, and its efficiency could arrive at 180%.

Effective Observation of 518 Cases with Arthralgia－Syndrome treated by High Voltage－Low Frequency Electrotherapy on Acupoints

ＥｆｆｅｃｔｉｖｅＯｂｓｅｒｖａｔｉｏｎｏｆ５１８ＣａｓｅｓｗｉｔｈＡｒｔｈｒａｌｇｉａ－ＳｙｎｄｒｏｍｅｔｒｅａｔｅｄｂｙＨｉｇｈＶｏｌｔａｇｅ－ＬｏｗＦｒｅｑｕｅｎｃｙＥｌｅｃｔｒｏｔｈｅｒａｐｙｏｎＡｃｕｐｏｉｎｔｓ￥ＬｉｕＡｏｓｈｕａｎｇ；Ｈ...

Size effect of sandstone after high temperature under uniaxial compression

Uniaxial compression tests on sandstone samples with five different sizes after high temperature processes were performed in order to investigate the size effect and its evolution. The test results show that the density, longitudinal wave velocity, peak strength, average modulus and secant modulus of sandstone decrease with the increase of temperature, however, peak strain increases gradually. With the increase of ratio of height to diameter, peak strength of sandstone decreases, which has an obvious size effect. A new theoretical model of size effect of sandstone material considering the influence of temperature is put forward, and with the increase of temperature, the size effect is more apparent. The threshold decreases gradually with the increase of temperature, and the deviations of the experimental values and the theoretical values are between 0.44% and 6.06%, which shows quite a credibility of the theoretical model.

The Combined Effects of High Temperature and Carbon Monoxide on Heat Stress Response

ＴｈｅＣｏｍｂｉｎｅｄＥｆｆｅｃｔｓｏｆＨｉｇｈＴｅｍｐｅｒａｔｕｒｅａｎｄＣａｒｂｏｎ ＭｏｎｏｘｉｄｅｏｎＨｅａｔＳｔｒｅｓｓＲｅｓｐｏｎｓｅＷＵＴａｎｇ－ｃｈｕｎ（邬堂春）；ＨＥＨａｎ－ｚｈｅｎ（贺涵贞）；Ｔａｎｇｕａｙ；ＲｏｂｅｒｔＭ．；ＷＵ...

Tracking Survey of Immune Effects of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome (HP-PRRS) in Changping District, Beijing City

The epidemiology of highly pathogenic porcine reproductive and respiratory syndrome( HP-PRRS) in Changping District,Beijing City was investigated from 2010 to 2015. Through statistics of vaccine,immune procedure and antibody levels,the epidemic prevention effect of HP-PRRS in Changping District was scientifically assessed.

High temperature effects in moving shock reflection with protruding Mach stem

The influence of high temperature effects on the protrusion of Mach stem in strong shock reflection over a wedge was numerically investigated.A two-dimensional inviscid solver applies finite volume method and unstructured quadrilateral grids were employed to simulate the flow.Theoretical analysis was also conducted to understand the phenomenon.Both numerical and theoretical results indicate a wall-jet penetrating forward is responsible for the occurrence of Mach stem protrusion.The protrusion degree seems to depend on the thermal energy buffer capacity of the testing gas.Approaches to increase the energy buffer capacity,such as vibrational relaxation,molecular dissociation,and increase of frozen heat capacity,all tend to escalate the protrusion effect.

Martensite Aging Effect and Thermal Cyclic Characteristics in Ti-Pd and Ti-Pd-Ni High Temperature Shape Memory Alloys

The effect of thermal cycling and aging in martensitic state in Ti-Pd-Ni alloys were investigated by DSC and TEM observations. It is shown that the thermal cycling causes the decreases in M8 and Af temperatures in Ti50Pd50-xNix, (x=10, 20, 30) alloys, but no obvious thermal cycling effect was observed in Ti50Pd50Pd40Ni10 alloys and the aging effect shows a curious feature, i.e., the Af temperature does not saturate even after relatively long time aging, which is considered to be due to the occurrence of recovery recrystallization during aging.

The Confinement Effect of Inert Materials on the Detonation of Insensitive High Explosives

The paper aims to theoretically and numerically investigate the confinement effect of inert materials on the detonation of insensitive high explosives. An improved shock polar theory based on the Zeldovich-von Neumann-D&ouml;ring model of explosive detonation is established and can fully categorize the confinement interactions between insensitive high explosive and inert materials into six types for the inert materials with smaller sonic velocities than the Chapman-Jouguet velocity of explosive detonation. To confirm the theoretical categorization and obtain the flow details, a second-order, cell-centered Lagrangian hydrodynamic method based on the characteristic theory of the two-dimensional first-order hyperbolic partial differential equations with Ignition-Growth chemistry reaction law is proposed and can exactly numerically simulate the confinement interactions. The numerical result confirms the theoretical categorization and can further merge six types of interaction styles into five types for the inert materials with smaller sonic velocity, moreover, the numerical method can give a new type of interaction style existing a precursor wave in the confining inert material with a larger sonic velocity than the Chapman-Jouguet velocity of explosive detonation, in which a shock polar theory is invalid. The numerical method can also give the effect of inert materials on the edge angles of detonation wave front.

High valence metals engineering strategies of Fe/Co/Ni-based catalysts for boosted OER electrocatalysis

Electrocatalysis for the oxygen evolution reactions(OER)has attracted much attention due to its important role in water splitting and rechargeable metal-air batteries.Therefore,designing highly efficient and low-cost catalysts for OER process is essential as the conventional catalysts still rely on precious metals.Transition metal-based compounds have been widely investigated as active OER catalysts,and renewed interest in the high valence metals engineered compounds has been achieved for superior catalytic activity and stability.However,an in-depth understanding of the construction strategies and induced effects for the high valence metals engineered catalysts is still lacking and desired.In this review,we have summarized the construction strategies of high valence metals as dopants or formed heterostructures with the iron/cobalt/nickel(Fe/Co/Ni)-based catalysts.Then the induced effects on Fe/Co/Ni-based catalysts by incorporating high valence metals,e.g.,accelerating the surface reconstruction,forming amorphous structure,generating vacancies/defects,and acting as stabilizers,are highlighted.The impacts of high valence metals on OER performance are elucidated based on different elements,including molybdenum(Mo),tungsten(W),cerium(Ce),vanadium(V),chromium(Cr),manganese(Mn),niobium(Nb),zirconium(Zr).The correlations of construction strategies,induced effects,catalytic activity and OER reaction pathways are elaborated.Finally,the remaining challenges for further enhancements of OER performance induced by high valence metals are presented.

Real Gas Effects on Charging and Discharging Processes of High Pressure Pneumatics

The high pressure pneumatic system has been applied to special industries.It may cause errors when we analyze high pressure pneumatics under ideal gas assumption.However,the real gas effect on the performances of high pressure pneumatics is seldom investigated.In this paper,the real gas effects on air enthalpy and internal energy are estimated firstly to study the real gas effect on the energy conversion.Under ideal gas assumption,enthalpy and internal energy are solely related to air temperature.The estimation result indicates that the pressure enthalpy and pressure internal energy of real pneumatic air obviously decrease the values of enthalpy and internal energy for high pressure pneumatics,and the values of pressure enthalpy and pressure internal energy are close.Based on the relationship among pressure,enthalpy and internal energy,the real gas effects on charging and discharging processes of high pressure pneumatics are estimated,which indicates that the real gas effect accelerates the temperature and pressure decreasing rates during discharging process,and decelerates their increasing rates during charging process.According to the above analysis,and for the inconvenience in building the simulation model for real gas and the difficulty of measuring the detail thermal capacities of pneumatics,a method to compensate the real gas effect under ideal gas assumption is proposed by modulating the thermal capacity of the pneumatic container in simulation.The experiments of switching expansion reduction(SER) for high pressure pneumatics are used to verify this compensating method.SER includes the discharging process of supply tanks and the charging process of expansion tank.The simulated and experimental results of SER are highly consistent.The proposed compensation method provides a convenient way to obtain more realistic simulation results for high pressure pneumatics.

Measuring system of high polymers' pyromagnetic effect

The measurement system is the main equipment of the project.Based on the characteristic of experiment system,a sensor array is designed,and used to continually acquire the global magnetic field.A scientific scheme is developed to get the signal processing and temperature compensation for nondirective weak magnetic field.The software of sampling control system is given,which is complied using C language in Labwindows/CVI.Taking computer as main engine,the system can acquire the nondirective weak magnetic field automatically and continuously use the sensor array,the change of magnetic field can be shown in real-time and intuitively.

Damage effects and mechanism of the silicon NPN monolithic composite transistor induced by high-power microwaves

A two-dimensional model of the silicon NPN monolithic composite transistor is established for the first time by utilizing the semiconductor device simulator, Sentaurus-TCAD. By analyzing the internal distributions of electric field,current density, and temperature of the device, a detailed investigation on the damage process and mechanism induced by high-power microwaves(HPM) is performed. The results indicate that the temperature elevation occurs in the negative half-period and the temperature drop process is in the positive half-period under the HPM injection from the output port.The damage point is located near the edge of the base–emitter junction of T2, while with the input injection it exists between the base and the emitter of T2. Comparing these two kinds of injection, the input injection is more likely to damage the device than the output injection. The dependences of the damage energy threshold and the damage power threshold causing the device failure on the pulse-width are obtained, and the formulas obtained have the same form as the experimental equations, which demonstrates that more power is required to destroy the device if the pulse-width is shorter. Furthermore,the simulation result in this paper has a good coincidence with the experimental result.

Motion stability of high-speed maglev systems in consideration of aerodynamic effects: a study of a single magnetic suspension system

In this study, the intrinsic mechanism of aerodynamic effects on the motion stability of a high-speed maglev system was investigated. The concept of a critical speed for maglev vehicles considering the aerodynamic effect is proposed. The study was carried out based on a single magnetic suspension system, which is convenient for proposing relevant concepts and obtaining explicit expressions. This study shows that the motion stability of the suspension system is closely related to the vehicle speed when aerodynamic effects are considered. With increases of the vehicle speed, the stability behavior of the system changes. At a certain vehicle speed,the stability of the system reaches a critical state, followed by instability. The speed corresponding to the critical state is the critical speed. Analysis reveals that when the system reaches the critical state, it takes two forms, with two critical speeds, and thus two expressions for the critical speed are obtained. The conditions of the existence of the critical speed were determined, and the effects of the control parameters and the lift coefficient on the critical speed were analyzed by numerical analysis. The results show that the first critical speed appears when the aerodynamic force is upward,and the second critical speed appears when the aerodynamic force is downward. Moreover, both critical speeds decrease with the increase of the lift coefficient.

Damage effect and mechanism of the GaAs high electron mobility transistor induced by high power microwave

In this paper, we present the damage effect and mechanism of high power microwave(HPM) on Al GaAs/GaAs pseudomorphic high-electron-mobility transistor(p HEMT) of low-noise amplifier(LNA). A detailed investigation is carried out by simulation and experiment study. A two-dimensional electro-thermal model of the typical GaAs p HEMT induced by HPM is established in this paper. The simulation result reveals that avalanche breakdown, intrinsic excitation, and thermal breakdown all contribute to damage process. Heat accumulation occurs during the positive half cycle and the cylinder under the gate near the source side is most susceptible to burn-out. Experiment is carried out by injecting high power microwave into GaAs p HEMT LNA samples. It is found that the damage to LNA is because of the burn-out at first stage p HEMT. The interiors of the damaged samples are observed by scanning electron microscopy(SEM) and energy dispersive spectrometer(EDS). Experimental results accord well with the simulation of our model.

Modulating Effects of Chlorogenic Acid on Lipids and Glucose Metabolism and Expression of Hepatic Peroxisome Proliferator-activated Receptor-α in Golden Hamsters Fed on High Fat Diet

Objective To examine the effects of chlorogenic acid (CGA) on lipid and glucose metabolism under a high dietary fat burden and to explore the possible role of peroxisome proliferator-activated receptor-α (PPAR-α) in these effects. Methods Twenty male golden hamsters were randomly divided into CGA treatment group (n=10, given peritoneal injection of CGA solution prepared with PBS, 80 mg CGA/kg body weight daily), and control group (n=10, given PBS i.p. at the average volume of the treatment group). Animals in both groups were given 15% high fat diet. Eight weeks after treatment with CGA, the level of biochemical parameters in fasting serum and tissues and the expression of hepatic mRNA and protein PPAR-α were determined. Results Eight weeks after treatment with CGA, the levels of fasting serum triglyceride (TG), free fatty acid (FFA), total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol (HDL-C), glucose (FSG), and insulin (FSI) were significantly lower in the GGA treatment group than in the control group. CGA also led to higher activity of hepatic lipase (HL), lower contents of TG and FFA in liver, and lower activity of lipoprotein lipase (LPL) in skeletal muscle. Furthermore, CGA significantly elevated significantly elevated the expression level of mRNA and protein expression in hepatic PPAR-α. Conclusion CGA can modify lipids and glucose metabolism, which may be attributed to PPAR-α facilitated lipid clearance in liver and improved insulin sensitivity.

The effect of high-temperature annealing on LaFe_(11.5)Si_(1.5) and the magneto-caloric properties of La_(1-x)Ce_xFe_(11.5)Si_(1.5) compounds

The powder X-ray diffraction patterns of LaFe11.5Si1.5 compounds annealed at different high temperatures from 1323 K (5 h) to 1623 K (2 h) show that a large amount of 1:13 phase begins to form in LaFe11.5Si1.5 compound annealed at 1423 K (5 h). In the temperature range from 1423 to 1523 K, α-Fe and LaFeSi phases rapidly decrease to form 1:13 phase. LaFeSi phase is rarely observed, and the most amount of 1:13 phase is obtained in the compound annealed at 1523 K (5 h). With the annealing temperature increasing to 1573 and 1623 K, LaFeSi is detected again in the LaFe11.5Si1.5 compound. According to the results of annealing at different high-temperatures, the La1-xCexFe11.5Si1.5 compounds are annealed at high temperatures of 1373 K (2 h) + 1523 K (5 h). The main phase is NaZn13-type phase, and the impurity is a small amount of α-Fe in La1-xCexFe11.5Si1.5 compounds with 0 ≤ x ≤ 0.35, and there is a large amount of Ce2Fe17 phase in La0.5Ce0.5Fe11.5Si1.5. It indicates that the substitution of cerium atoms for La in LaFe11.5Si1.5 compounds has limit. At the same time, the substitution of Ce for La has large effect on magnetocaloric properties. With increasing Ce content from x = 0 to x = 0.35, the Curie temperature decreases linearly from 196 to 168 K, the magnetic entropy change increases from 16.5 to 57.3 J·kg-1·K-1 in a low magnetic field change of 0-2 T, and the thermal hysteresis also increases from 3 K to 8 K.