Stanford A型主动脉夹层的个体化血流数值模拟

目的研究Stanford A型主动脉夹层的血流动力学变化。方法收集4名Stanford A型主动脉夹层患者和2名健康志愿者的主动脉计算机断层扫描血管造影(computed tomography angiography,CTA)图像,建立主动脉三维模型并进行网格划分,使用流体仿真软件对模型进行数值模拟。结果健康志愿者主动脉内血流近似层流。夹层真腔的血流近似层流,位于破口附近的真腔和被假腔压迫的真腔会在局部形成湍流。真腔的壁面压力高于假腔。心脏收缩期,假腔的壁面压力峰值位于夹层第一个破口处,被假腔压迫的真腔和假腔破口处出现较高的壁面剪切力且破口处出现了应力集中。相比于单一破口的夹层,有2个破口的夹层其破口周围的壁面剪切力更低。结论个体化计算流体力学分析可以为主动脉夹层的个性化诊疗提供参考。

Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2X)environments.In the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2X wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2X wireless channels.The statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and discussed.Simulation results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and analysis.The proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2X communication systems.

Wavelength calibration and spectral analysis of vacuum ultraviolet spectroscopy in EAST

A vacuum ultraviolet(VUV)spectroscopy with a focal length of 1 m has been engineered specifically for observing edge impurity emissions in Experimental Advanced Superconducting Tokamak(EAST).In this study,wavelength calibration for the VUV spectroscopy is achieved utilizing a zinc lamp.The grating angle and charge-coupled device(CCD)position are carefully calibrated for different wavelength positions.The wavelength calibration of the VUV spectroscopy is crucial for improving the accuracy of impurity spectral data,and is required to identify more impurity spectral lines for impurity transport research.Impurity spectra of EAST plasmas have also been obtained in the wavelength range of 50–300 nm with relatively high spectral resolution.It is found that the impurity emissions in the edge region are still dominated by low-Z impurities,such as carbon,oxygen,and nitrogen,albeit with the application of fulltungsten divertors on the EAST tokamak.

Vector Approximate Message Passing with Sparse Bayesian Learning for Gaussian Mixture Prior

Compressed sensing(CS)aims for seeking appropriate algorithms to recover a sparse vector from noisy linear observations.Currently,various Bayesian-based algorithms such as sparse Bayesian learning(SBL)and approximate message passing(AMP)based algorithms have been proposed.For SBL,it has accurate performance with robustness while its computational complexity is high due to matrix inversion.For AMP,its performance is guaranteed by the severe restriction of the measurement matrix,which limits its application in solving CS problem.To overcome the drawbacks of the above algorithms,in this paper,we present a low complexity algorithm for the single linear model that incorporates the vector AMP(VAMP)into the SBL structure with expectation maximization(EM).Specifically,we apply the variance auto-tuning into the VAMP to implement the E step in SBL,which decrease the iterations that require to converge compared with VAMP-EM algorithm when using a Gaussian mixture(GM)prior.Simulation results show that the proposed algorithm has better performance with high robustness under various cases of difficult measurement matrices.

Inversion techniques to obtain local rotation velocity and ion temperature profiles for the x-ray crystal spectrometer on EAST

Inversion techniques are conducted based on the tangential x-ray crystal spectroscopy(TXCS)geometry on EAST to obtain the local profiles of ion temperature(Ti)and toroidal rotation velocity(vt).Firstly,local emissivity profiles of the impurity argon are obtained using the asymmetrical Abel inversion.Then,the local vt and Ti profiles are calculated by considering the local emissivity profiles and the TXCS detailed geometry.In addition,how the changes in the vt profiles affect the accuracy in the Ti profiles is discussed in detail.It is also found that the lineintegrated Ti profiles are becoming less accurate with the increase in the radial gradient in the local vt profiles.Nonetheless,accurate Ti radial profiles are reconstructed after considering the effects of the emissivity and velocity,which are verified by comparing the inverted vt and Ti profiles with those local profile measurements from the Charge eXchange Recombination Spectroscopy(CXRS)on EAST.

全病程MDT营养管理对老年食管癌患者放疗进程的影响

目的:探究全病程多学科诊疗模式(multidisciplinary team,MDT)营养管理对老年食管癌患者放疗进程的影响。方法:收集山西医科大学第一医院2018年1月至2019年9月经病理证实为食管鳞癌的老年患者60例,随机分为对照组(30例)与实验组(30例),均行放疗,对照组给予常规营养干预,实验组给予全病程MDT营养干预,统计患者BMI、营养状况、不良反应发生率、治疗时间等。结果:对照组患者PG-SGA评分、中-重度营养不良发生率较实验组(86.3%vs.70%)明显升高;放疗后患者主观综合营养评估法(patient-generated subjective global assessment,PG-SGA)评分较放疗前升高,且对照组升高更明显(P<0.05);对照组总蛋白(total protein,TP)、白蛋白(albumin,ALB)、前白蛋白(prealbumin,PA)先下降后上升,而实验组较平稳或逐渐上升;对照组放疗后血液学指标白细胞(white blood cell,WBC)、血红蛋白(hemoglobin,HB)下降较实验组明显,且WBC的下降差异有统计学意义(P<0.05);与对照组相比,实验组ALB、PA、TP、BMI放疗后升高(P<0.05),2级以上急性黏膜反应(13.3%)、骨髓抑制(26.3%)发生率低(P<0.05),生活质量好(P<0.05),且总治疗时间[(41.97±2.59)d]短(P<0.05)。结论:全病程MDT营养管理明显改善患者营养不良状况,减少不良反应发生率及总治疗时间,提升生存质量。

Integrated transcriptomic and metabolomic analyses of a wax deficient citrus mutant exhibiting jasmonic acid-mediated defense against fungal pathogens

Naturally,resistant crop germplasms are important resources for managing the issues of agricultural product safety and environment deterioration.We found a spontaneous mutant of‘Newhall’navel orange(Citrus sinensis Osbeck)(MT)with broad-spectrum protections against fungal pathogens in the orchard,postharvest-storage,and artificial inoculation conditions.To understand the defense mechanism of MT fruit,we constructed a genome-scale metabolic network that integrated metabolome and transcriptome datasets.The coordinated transcriptomic and metabolic data were enriched in two sub-networks,showing the decrease in very long chain fatty acid(by 41.53%)and cuticular wax synthesis(by 81.34%),and increase in the synthesis of jasmonic acid(JA)(by 95.23%)and JA-induced metabolites such as 5-dimethylnobietin(by 28.37%)in MT.Furthermore,cytological and biochemical analyses confirmed that the response to fungal infection in MT was independent of wax deficiency and was correlated with the levels of jasmonates,and the expression of plant defensin gene PDF1.2.Results of exogenous application of MeJA and JA inhibitors such as propyl gallate proved that JA-mediated defense contributes to the strong tolerance against pathogens in MT.Our results indicated that jasmonate biosynthesis and signaling are stimulated by the fatty acid redirection of MT,and participate in the tolerance of pathogenic fungi.

The electrochemical characteristics of AB_(4)-type rare earth-Mg-Ni-based superlattice structure hydrogen storage alloys for nickel metal hydride battery

Rare earth-Mg-Ni-based alloys with superlattice structures are new generation negative electrode materials for the nickel metal hydride batteries.Among them,the novel AB_(4)-type superlattice structure alloy is supposed to have superior cycling stability and rate capability.Yet its preparation is hindered by the crucial requirement of temperature and the special composition which is close to the other superlattice structure.Here,we prepare rare earth-Mg-Ni-based alloy and study the phase transformation of alloys to make clear the formation of AB_(4)-type phase.It is found Pr_(5)Co_(19)-type phase is converted from Ce_(5)Co_(19)-type phase and shows good stability at higher temperature compared to the Ce_(5)Co_(19)-type phase in the range of 930-970℃.Afterwards,with further 5℃increasing,AB_(4)-type superlattice structure forms at a temperature of 975℃by consuming Pr_(5)Co_(19)-type phase.In contrast with A_(5)B_(19)-type alloy,AB_(4)-type alloy has superior rate capability owing to the dominant advantages of charge transfer and hydrogen diffusion.Besides,AB_(4)-type alloy shows long lifespan whose capacity retention rates are 89.2%at the 100;cycle and 82.8%at the 200;cycle,respectively.AB_(4)-type alloy delivers 1.53 wt.%hydrogen storage capacity at room temperature and exhibits higher plateau pressure than Pr_(5)Co_(19)-type alloy.The work provides novel AB_(4)-type alloy with preferable electrochemical performance as negative electrode material to inspire the development of nickel metal hydride batteries.

Development of vacuum ultraviolet spectroscopy for measuring edge impurity emission in the EAST tokamak

The dominant wavelength range of edge impurity emissions moves from the visible range to the vacuum ultraviolet(VUV)range,as heating power increasing in the Experimental Advanced Superconducting Tokamak(EAST).The measurement provided by the existing visible spectroscopies in EAST is not sufficient for impurity transport studies for high-parameters plasmas.Therefore,in this study,a VUV spectroscopy is newly developed to measure edge impurity emissions in EAST.One Seya-Namioka VUV spectrometer(McPherson 234/302)is used in the system,equipped with a concave-corrected holographic grating with groove density of 600 grooves mm-1.Impurity line emissions can be observed in the wavelength range ofλ=50-700 nm,covering VUV,near ultraviolet and visible ranges.The observed vertical range is Z=-350-350 mm.The minimum sampling time can be set to 5 ms under full vertical binning(FVB)mode.VUV spectroscopy has been used to measure the edge impurity emission for the 2019 EAST experimental campaign.Impurity spectra are identified for several impurity species,i.e.,lithium(Li),carbon(C),oxygen(O),and iron(Fe).Several candidates for tungsten(W)lines are also measured but their clear identification is very difficult due to a strong overlap with Fe lines.Time evolutions of impurity carbon emissions of CⅡat 134.5 nm and CⅢat 97.7 nm are analyzed to prove the system capability of time-resolved measurement.The measurements of the VUV spectroscopy are very helpful for edge impurity transport study in the high-parameters plasma in EAST.

Measurement of molybdenum ion density for L-mode and H-mode plasma discharges in the EAST tokamak

We report the measurement of total molybdenum ion density for L-mode and H-mode plasmas on EAST using spectral lines observation and calculation based on an impurity transport code.A flat-filed extreme ultraviolet spectrometer with some spatial resolution is used to obtain the radial profiles of molybdenum spectral line emissions.The absolute calibration for the extreme ultraviolet spectrometer is finished by comparing the calculated bremsstrahlung intensity with the readings of CCD detector.Molybdenum ion transport study is performed using the radial ion density profiles and one-dimensional impurity transport code STRAHL.The total molybdenum density profiles are determined from the transport analysis.The molybdenum density during L-mode and H-mode phases are obtained,which are about 3 and 4 orders of magnitude smaller than the electron density,respectively.An inward pinch is found during the H-mode phase that leads to the peaked profile of molybdenum density.

Collaborative Multiple Access And Energy-Efficient Resource Allocation in Distributed Maritime Wireless Networks

With the rapid increasing of maritime activities, maritime wireless networks(MWNs) with high reliability, high energy efficiency, and low delay are required. However, the centralized networking with fixed resource scheduling is not suitable for MWNs due to the special environment. In this paper,we introduce the collaborative relay communication in distributed MWNs to improve the link reliability, and propose an orthogonal time-frequency resource block reservation based multiple access(RRMA) scheme for both one-hop direct link and two-hop collaborative relay link to reduce the interference. To further improve the network performance, we formulate an energy efficiency(EE) maximization resource allocation problem and solve it by an iterative algorithm based on the Dinkelbach method. Finally, numerical results are provided to investigate the proposed RRMA scheme and resource allocation algorithm, showing that the low outage probability and transmission delay can be attained by the proposed RRMA scheme. Moreover,the proposed resource allocation algorithm is capable of achieving high EE in distributed MWNs.

Open and close-ended CoMoS_(3) nanotubes for hydrogen evolution in acidic and basic conditions

Electrochemical hydrogen evolution reaction(HER) is a promising route to harvest high-purity hydrogen(H_(2)).Efficient and selective energy transformations rely on the development of novel catalytic materials in terms of compositions and structures that survive under harsh conditions.This study focuses on a unique nanostructured CoMoS_(3) catalyst for HER under strong acidic and basic electrolyte.The morphologies of the catalysts are fine-tuned by altering reaction times in a hydrothermal reaction.Limited reaction time generates twisted thin-sheet CoMoS_(3)(12 h),which spins into a nanotube with an extended synthetic time(16 h).As the reaction time increases to 20 h,the CoMoS_(3) composite creates open-ended nanotubes,facilitating reactants to penetrate and react actively in the inner space of the nanotubes.Further,prolonged reaction time(24 h) results in the formation of the close-ended CoMoS_(3) nanotubes.We find out that the open-ended structure plays an important role in achieving fast kinetics as well as creating more active sites in HER reaction.The catalyst delivers a profound performance under both acidic and basic conditions,with overpotentials of 93 mV and 115 mV(at a current density of 10 mA/cm^(2)) in the acidic and basic electrolytes,respectively.Moreover,it shows superior long-term durability in both solutions.This work will provide a great foundation for understanding the morphology effect with the same composited catalyst towards energy conversion reactions,not limited to HER.

Space-resolved vacuum-ultraviolet spectroscopy for measuring impurity emission from divertor region of EAST tokamak

The measurement of impurity distribution in the divertor region of tokamaks is key to studying edge impurity transport.Therefore,a space-resolved vacuum-ultraviolet(VUV)spectrometer is designed to measure impurity emission in the divertor region on EAST.For good spectral resolution,an eagle-type VUV spectrometer with 1 m long focal length with spherical holograph grating is used in the system.For light collection,a collimating mirror is installed between the EAST plasma and the VUV spectrometer to extend the observing range to cover the upper divertor region.Two types of detectors,i.e.a back-illuminated charge-coupled device detector and a photomultiplier-tube detector,are adopted for the spectral measurement and high-frequency intensity measurement for feedback control,respectively.The angle between the entrance and exit optical axis is fixed at 15°.The detector can be moved along the exit axis to maintain a good focusing position when the wavelength is scanned by rotating the grating.The profile of impurity emissions is projected through the space-resolved slit,which is set horizontally.The spectrometer is equipped with two gratings with 2400 grooves/mm and2160 grooves/mm,respectively.The overall aberration of the system is reduced by accurate detector positioning.As a result,the total spectral broadening can be reduced to about 0.013 nm.The simulated performance of the system is found to satisfy the requirement of measurement of impurity emissions from the divertor area of the EAST tokamak.

Constructing nanoporous Ni foam current collectors for stable lithium metal anodes

Lithium metal,as the most ideal anode material for high energy density batteries,has been researched for several decades.However,the dendrite formation and large volume change during repetitive lithium plating/stripping lead to a serious safety issue and impede the practical application of lithium metal anode.Herein,a nanoporous Ni foam current collector with high surface area and surface flaws is constructed via a facile oxidation-reduction method.The inherent macropore structure of Ni foam can partly accommodate the volume variation during Li plating/stripping.The well-distributed nanopores on the skeleton of Ni foam can effectively reduce the local current density,regulate the uniform lithium nucleation and deposition with homogenous distribution of Li^(+) flux.Moreover,the surface flaws induce the formation of ring Li structures at initial nucleation/deposition processes and concave Li metal spontaneously formed based on the ring Li structures during cycling,which can direct the even Li plating/stripping.Therefore,highly stable Coulombic efficiency is achieved at 1 mA cm^(-2) for 200 cycles.The symmetrical cell,based on the nanoporous Ni foam current collector,presents long lifespans of 1200 and 700 h respectively at different current densities of 0.5 and 1 mA cm^(-2) without short circuit.In addition,the LiFePO4 full cell,with the Li metal anode based on the nanoporous Ni foam current collector,shows excellent cycling performance at 1 C for 300 cycles and rate performance.

Measurement of tungsten impurity spectra with a two-crystal X-ray crystal spectrometer on EAST

Spectral measurement of tungsten(W)impurity is essential to study impurity transport.Therefore,an X-ray crystal spectrometer(XCS)on EAST was used to measure the line spectra from highly ionized W ions.On EAST,both poloidal XCS and tangential XCS have been developed to measure the plasma temperature as well as the rotation velocity.Recently,He-like and H-like argon spectra have also been obtained using a two-crystal setup.W lines are identified in this study.Through a careful analysis,the W lines of 3.9336,3.9321,and 3.664(A)are found to be diffracted by He-like or H-like crystals.The lines are confirmed with the NIST database.We also calculated the ion temperature with Doppler broadening of these lines.The ion temperature from the W lines is entirely consistent with that from Ar line spectra.The measurement of these W line spectra could be used to study W impurity transport in future work.

Capacity Optimization Using Augmented Lagrange Method in Intelligent Reflecting Surface-Based MIMO Communication Systems

In this paper,we present an algorithm for capacity optimization in intelligent reflecting surface(IRS)-based multiple-input multiple-output(MIMO)communication systems.To maximize the capacity of elements in IRS,we use augmented Lagrange method with the equivalent transformations on the covariance matrix and reflection matrix constraints.This results an adjustable phase shift on the incident signal.Furthermore,we reshape the complex-valued covariance matrix and reflection matrix to a vector for the ease of calculating partial derivatives to find the search direction.Then,the quasi-Newton updates and modified Broyden-Fletcher-Goldfarb-Shano(BFGS)method in the complex domain form are used to find the local minimum.Finally,numerical simulation results demonstrate that our proposed IRS-aided system using the algorithm performs better than the state-of-the-art and the conventional communication systems.

Measurement of impurity lines with two-crystal x-ray spectrometers on EAST

To simultaneously measure the He-like and H-like argon spectra, a two-crystal assembly has been deployed to replace the previous single crystal on the tangential x-ray crystal spectrometer.By selecting appropriate crystals with similar Bragg angles, plasma temperature in the range of 0.5 keV≤Te≤10 keV and rotation can be diagnosed based on the He-like and H-like argon spectra. However, due to the added complexity in the two-crystal assembly in which the spectra might be diffracted by two crystals, some additional impurity lines were identified. For example,tungsten（W） lines in different ionization states were diffracted by the He-like and H-like crystal.Additional molybdenum（Mo） lines in the wavelength range of He-like and H-like argon spectra lines were also summarized. The existence of these additional lines caused the fitted temperature to be different from the true values. This paper presents the identified lines through a comparison with available database, which should be included in the fitting procedure.

First experimental results of intrinsic torque on EAST

Direct measurements of the intrinsic torque profile in L-mode plasmas on the EAST tokamak have been performed using the balanced neutral beam injection.Co-and counter-current neutral beams are modulated to balance the intrinsic and externally injected torques, which result in the rotation profile close to zero and flat.The experimental results show that the intrinsic torque derived from momentum balance equations is found to be in the co-current direction, peaked in the plasma edge and negligibly small in the core.

The Impact of BW Emotional Index on China's A - Share Market Returns

Investor sentiment has its characteristics of the inherent complexity and changing. In this paper, through the analysis of the "investor sentiment and cross-sectional data on the impact of stock returns"[1] published by Baker and others in 2006, combining with the specific situation of China's securities market, and basing on the BW model to select Shanghai and Shenzhen 300 index turnover rate and other 5 emotional indices, and using the principal component analysis to build a monthly investor sentiment index of China's securities market. The principal component analysis of residual that calculated by a regression of emotional indicators and macroeconomic data is carried out, to get macroscopical emotional indicators that removes macro factors. Finally, OLS regression analysis is carried out with the Shanghai Composite Index and Shenzhen Component Index to find that the constructed emotional index has a significant effect on the yield of China's stock market, thus verifying the validity of the emotional index.

Performance Comparison among ASK, FSK and DPSK in Visible Light Communication

We consider the detection of Amplitude-Shift Keying (ASK), Frequency-Shift Keying (FSK) and Differential Phase-Shift Keying (DPSK) in Visible Light Communication (VLC). And their performance is compared according to data rate, transmission distance and incident angle respectively.