Thermal conductivity of GeTe crystals based on machine learning potentials

GeTe has attracted extensive research interest for thermoelectric applications.In this paper,we first train a neuroevolution potential(NEP)based on a dataset constructed by ab initio molecular dynamics,with the Gaussian approximation potential(GAP)as a reference.The phonon density of states is then calculated by two machine learning potentials and compared with density functional theory results,with the GAP potential having higher accuracy.Next,the thermal conductivity of a GeTe crystal at 300 K is calculated by the equilibrium molecular dynamics method using both machine learning potentials,and both of them are in good agreement with the experimental results;however,the calculation speed when using the NEP potential is about 500 times faster than when using the GAP potential.Finally,the lattice thermal conductivity in the range of 300 K-600 K is calculated using the NEP potential.The lattice thermal conductivity decreases as the temperature increases due to the phonon anharmonic effect.This study provides a theoretical tool for the study of the thermal conductivity of GeTe.

Tetrathiafulvalene esters with high redox potentials and improved solubilities for non-aqueous redox flow battery applications

The exploitation of high performance redox-active substances is critically important for the development of non-aqueous redoxflow batteries.Herein,three tetrathiofulvalene(TTF)derivatives with different substitution groups,namely TTF diethyl ester(TTFDE),TTF tetramethyl ester(TTFTM),and TTF tetraethyl ester(TTFTE),are prepared and their energy storage properties are evaluated.It has been found that the redox potential and solubility of these TTF derivatives in conventional carbonate electrolytes increases with the number of ester groups.The battery with a catholyte of 0.2 mol L^(-1) of TTFTE delivers a specific capacity of more than 10 Ah L^(-1) at the current density of 0.5 C with two discharge voltage platforms locating at as high as 3.85 and 3.60 V vs.Li/Liþ.Its capacity retention can be improved from 2.34 Ah L^(-1) to 3.60 Ah L^(-1) after 100 cycles by the use of an anion exchange membrane to block the crossover of TTF species.The excellent cycling stability of the TIF esters is supported by their well-delocalized electrons,as revealed by the density function theory calculations.Therefore,the introduction of more and larger electron-withdrawing groups is a promising strategy to simultaneously increase the redox-potential and solubility of redox-active ma-terials for non-aqueous redoxflow batteries.

Masseter Vestibular evoked myogenic potentials: A new tool to assess the vestibulomasseteric reflex pathway

Purpose: This review article provides the readers with an in-depth insight in understanding and interpreting various research literatures on the masseter vestibular evoked myogenic potentials(mVEMP). The article also reviews the contemporary researches involving the clinical applications of the mVEMP. Conclusions: Masseter VEMP is an evolving yet clinically promising neuro-otology test tool that has recently gained more research interest and is considered an additional tool to diagnose various vestibular disorders. Masseter VEMP assesses the functional integrity of the acoustic-masseteric and vestibulo-masseteric reflex pathways. The mVEMP could be used as a complementary test to evaluate the same peripheral generator as the cervical VEMP but a different central pathway i.e., vestibulo-trigeminal pathway. Various research studies that have experimented on parameters such as the effect of different electrode montages(zygomatic vs mandibular configurations), stimulation rates, filter settings and stimuli used to evoke mVEMP have been discussed in this article that could assist in the optimization of a comprehensive clinical protocol. The latency and the amplitude of mVEMP waveforms serve as significant parameters in differentiating normals from those of the clinical populations. Along with the cVEMPs and oVEMPs, mVEMP might help diagnose brainstem lesions in REM Sleep behaviour disorders, Multiple Sclerosis and Parkinson's disease. However, further studies are required to probe in this area of research.

Median Nerve Somatosensory Evoked Potentials in Patients with Chiari Malformation

Abnormal SEP reflects dysfunction of the medial lemniscus and posterior cervical cord. These structures are likely to be affected in Chiari malformation. Therefore, SEP abnormalities may provide valuable information in patients with CM. However, the consistency of SEP abnormality or normality with the damage is a matter of research. Knowing whether median nerve somatosensory evoked potential (SEP) is useful in revealing subclinical damage in patients with Chiari malformation is important in the treatment and follow-up plan of the disease. The aim of this study was to investigate the relationship between median nerve SEP values and the severity of cerebellar ectopia in patients with Chiari type 1 malformation. Median nerve SEP values were obtained from 30 healthy individuals and 146 individuals with Chiari malformation. The cerebellar ectopia degree and McRae line length were measured. SEP values were not significantly different between groups. The McRae line was found to be significantly shorter in the control group than in the Chiari malformation group (p = 0.031). There was no correlation between the degree of cerebellar ectopia and the length of the McRae line (r = 0.002, p = 0.979). Neither cerebellar ectopy degree nor McRae line length had a relationship with SEP values (r = -0.153, p = 0.066;r = -0.056, p = 0.500, respectively). There was no difference in cerebellar ectopy degree or SEP values between the groups with cerebellar ectopy with and without a syrinx (p = 0.899;p = 0.080, respectively). Likewise, McRae line length was not found to be related to the presence of a syrinx (p = 0.139). Median nerve SEP examination was not beneficial for diagnosing asymptomatic-oligosymptomatic Chiari malformation as a subclinical injury, whether accompanied by syringomyelia or not.

Entrepreneurship training:its influences on innovation potentials among nursing students

Objective:To evaluate the influences of entrepreneurship training on the innovation potential among nursing students.Methods:A quasi-experimental design was utilized to conduct this study.The study was conducted in the classroom at the faculty of nursing,and the“i Hub”center at Ain Shams University(ASU)in Cairo,Egypt.A purposive sample of 42 nursing students who participated in the“Ain Shams University-innovate”competition from the Faculty of Nursing of ASU were included in this study.Data collection tools included(1)Nursing students'innovation skills assessment questionnaire and(2)Innovative projects evaluation tool.Results:There was a statistically significant difference between the mean scores of nursing students'total innovation skills pre-and post-implementation of entrepreneurship training,where P-value<0.05.Conclusions:The results of the current study support the research hypothesis because the implementation of entrepreneurship training positively affects nursing students'innovation potential.Developing entrepreneurship education in nursing and integrating it into nursing programs will stimulate creativity,innovation,and entrepreneurship among nursing students and health care services.

Theoretical uncertainties of(d,^(3)He)and(^(3)He,d)reactions owing to the uncertainties of optical model potentials

The theoretical uncertainties of single proton transfer cross sections of the(^(3)He,d)and(d,^(3)He)reactions,owing to the uncertainties of the entrance-and exit-channel optical model potentials,are examined with the^(30)Si(^(3)He,d)^(31)P,^(13)B(d,^(3)He)^(12)Be,and^(34)S(^(3)He,d)^(35)Cl reactions at incident energies of 25,46,and 25 MeV,respectively,within the framework of the distorted wave Born approximation.The differential cross sections at the first peaks in the angular distributions of these reactions are found to have uncertainties of approximately 5%,owing to the uncertainties in the optical model potentials from 20,000 calculations of randomly sampled parameters.This amount of uncertainty is found to be nearly independent of the angular momentum transfer and the target masses within the studied range of incident energies.Uncertainties in the single proton spectroscopic factors obtained by matching the theoretical and experimental cross sections at different scattering angles are also discussed.

Identification of injury type using somatosensory and motor evoked potentials in a rat spinal cord injury model

The spinal cord is at risk of injury during spinal surgery.If intraoperative spinal co rd injury is identified early,irreve rsible impairment or loss of neurological function can be prevented.Different types of spinal cord injury result in damage to diffe rent spinal cord regions,which may cause diffe rent somatosensory and motor evoked potential signal res ponses.In this study,we examined electrophysiological and histopathological changes between contusion,distra ction,and dislocation spinal cord injuries in a rat model.We found that contusion led to the most severe dorsal white matter injury and caused considerable attenuation of both somatosensory and motor evoked potentials.Dislocation resulted in loss of myelinated axons in the lateral region of the injured spinal cord along the rostrocaudal axis.The amplitude of attenuation in motor evoked potential responses caused by dislocation was greater than that caused by contusion.After distraction injury,extracellular spaces were slightly but not significantly enlarged;somatosensory evoked potential res ponses slightly decreased and motor evoked potential responses were lost.Correlation analysis showed that histological and electrophysiological findings we re significantly correlated and related to injury type.Intraope rative monitoring of both somatosensory and motor evoked potentials has the potential to identify iatrogenic spinal cord injury type during surgery.

Similarity of Binding Potentials Between Plant DUF538 and Animal Lipocalin: Cholesterol Binding Ability of DUF538

Objective DUF538(domain of unknown function 538) domain containing proteins are known as putative hypothetical proteins in plants. Until yet, there is no much information regarding their structure and function. Methods In the present research work, the homologous structures and binding potentials were identified between plant/mammalian lipocalins and plant DUF538 protein by using bioinformatics and experimental tools including molecular dynamics simulation, molecular docking and recombinant technology-based techniques. Results Molecular docking analysis of their interactions with lipidic ligands including cholesterol and palmitic acid revealed the similar and comparable binding potentials between DUF538 and lipocalin proteins. Both the test proteins were found to have more affinity to cholesterol molecule in compare to palmitic acid. By using recombinant technology-based experiments, the heterologously expressed and purified fused product of DUF538 protein exhibited about 61% cholesterol binding ability. Conclusion As a conclusion, plants DUF538 protein family was predicted to be the structural and may be the functional homologues of plants/animals lipocalin superfamily.

THE ANALYTIC SMOOTHING EFFECT OF LINEAR LANDAU EQUATION WITH SOFT POTENTIALS

In this work,we study the linearized Landau equation with soft potentials and show that the smooth solution to the Cauchy problem with initial datum in L^(2)(ℝ^(3))enjoys an analytic regularization effect,and that the evolution of the analytic radius is the same as the heat equations.

A Study of Compound Action Potentials in Current-Coupled Tracts: the General Case

In this paper, the authors investigate compound action potentials formed when the underlying tract's axons have current-mediated coupling amongst themselves, and no field-mediated coupling. The key finding of the paper is that, for the case of biophysically inhomogeneous axon tracts, the compound action potential is governed by a Hodgkin-Huxley like equation itself in certain cases. The paper extends an earlier result for the identical axon case.

A Class of Potentials for Hyperbolic Transcendental Entire Maps

We identify a class of transcendental entire maps of finite order, of disjoint-type, satisfying the rapid derivative growth condition. Within this class, we show that there exist hyperbolic transcendental entire maps that generate a large class of potentials which intersect the so-called tame potentials and form a distinct class of potentials. The methods and techniques derived from the thermodynamic formalism are applied to these potentials for transcendental entire maps acting on some subset of the Julia set which is conjugated to the shift map over a code space with a countable alphabet endowed with the euclidean induced metric on the complex plane.

新能源汽车碳减排潜力分析

在“碳达峰、碳中和”双碳目标驱动下,新能源汽车凭借其碳减排优势受到了广泛关注.旨在促进新能源汽车碳减排潜力评估的相关研究,从新能源汽车碳排放计量与分析、车网协同优化低碳运行、车辆碳排放总量态势预测等三个方面进行分析与综述,归纳了相关领域最新研究成果,总结各类建模方法优缺点,重点阐述了汽车节能减排核算体系与行业碳排放管理体系等相关成果,并提出新能源汽车碳减排潜力分析研究的发展趋势及未来研究方向.

位涡源汇和位涡环流及其天气气候意义

在扼要回顾地表位涡研究进展的基础上,本文介绍了复杂地形下的位涡及位涡制造的计算及近年来关于位涡源汇和位涡环流(PVC)的研究进展,侧重介绍青藏高原表层位涡的特殊性及其对天气气候的重要影响。阐明对于绝热和无摩擦大气运动,由于位涡本身的结构重组(位涡重构)可以引起垂直涡度的发展,在夏季可以激发高原涡形成,冬季使青藏高原东部成为重要的表面涡源。基于导得的包括非绝热加热作用的、与等熵面的位移相联系的垂直运动(ωID)方程,进一步阐明青藏高原制造的正位涡沿西风气流东传会引起下游地区低空气旋性涡度、偏南风、和上升运动发展,导致位涡平流随高度增加,激发极端天气气候事件发生发展。指出青藏高原地表加热和云底的潜热释放的日变化显著地影响着地表层位涡的日变化,导致青藏高原的低涡降水系统多在午后至夜间发生发展。证明与传统的青藏高原感热加热指数相比,青藏高原地表层位涡指数能够更好地刻画关于降水的季节变化,与亚洲夏季风降水相关更密切。本文还简单介绍了PVC的概念。指出由于区域边界面的PVC的辐散辐合的变化直接与区域位涡的变化相关联,为保持北半球位涡总量的相对稳定,跨赤道面上的PVC变化与地表PVC的变化必须相互补充,因此跨赤道面上的位涡环流的变化可以成为监测近地表气候变化的窗口。近赤道的海气相互作用能够直接造成沿赤道垂直面上的纬向风垂直切变的变化,激发跨赤道位涡环流异常,从而通过大气内部PVC的变化和青藏高原的调控影响北半球近地表的气候变化。结果表明位涡环流分析为建立热带和热带外大气环流变化的联系开辟了新的蹊径,有着广阔的应用前景。

改进A^(*)算法和人工势场法的路径规划

A^(*)算法存在折线路径多和搜索节点多的问题,人工势场(artificial potential field,APF)法存在局部最优和不可到达的问题,针对两种算法存在的问题进行了研究。利用欧氏距离与投影距离提出一种新的混合式启发函数,依据该函数对A^(*)算法的流程进行改进,减少A^(*)算法的搜索节点,提高搜索效率。利用新A^(*)算法生成的最优节点作为APF算法的局部目标点,辅助机器人摆脱局部最优点;通过加入机器人和目标点的位置关系改进势场函数,修改斥力的增益,优化斥力的生成方向。在改进的基础上将两种算法融合提出一种新的算法,利用APF法的势场函数引导A^(*)算法的搜索。从路径长度、避障效果、迭代次数对改进算法进行对比分析,仿真结果表明,提出的改进算法搜索效率高,实现避障的同时保证计算的路径最优。

云南烟草种质库种子的生活力监测

【目的】开展烟草种质库资源生活力监测,确保库存资源的安全保存。【方法】选择1979至2008年保存于云南省烟草农业科学研究院种质库的烟草种子;于1992、2005和2019年分别开展3次生活力监测,并统计分析发芽率和发芽势。【结果】种子发芽势和发芽率的年降低值与保存年限有关,保存年限越长,生活力年降低值则越高;而不同年份入库种子生活力下降速率并不一致;种子保存前起始生活力越高,生活力降低越慢。【结论】为了确保烟草种子的长期安全保存,应加强烟草种植过程中田间管理,以及在气象条件较好的天气下收获烟草种子,从而提高种子质量;推荐烟草种质入库发芽率≥90%,但如果条件限制,也不能低于70%;应及时监测预警生活力降至70%的种子,并安排繁殖更新;在烟草种子含水量<5.0%的超干燥和室温的保存条件下,第一次监测间隔不能长于10年,以后每次监测间隔应根据烟草种子生活力下降情况相应缩短。

TRPV4在眼病理生理功能中的研究进展

瞬时受体电位香草醛受体4(TRPV4)是一种非选择性阳离子通道,负责感知细胞肿胀、温度、机械牵张、剪切应力和渗透压的变化,通过调节跨膜钙信号进而影响基因表达、细胞形态和细胞骨架等构建。TRPV4在全身广泛表达。在眼内,TRPV4在角膜、晶状体、睫状体、小梁网和视网膜等组织均有功能性表达。本文就TRPV4在眼内各个组织中的表达及生理病理功能方面进行阐述。随着TRPV4在眼部病理生理功能中的深入研究,TRPV4在角膜损伤修复、青光眼及视网膜血管生成方面可能成为潜在的新兴药物靶点,但仍需进一步的深入研究。

黑土地保护视角下黑龙江省畜禽养殖环境效应分析

为合理利用畜禽粪污资源,保护黑龙江省黑土地资源,优化农畜业生产布局,实现农牧业绿色发展,本研究基于2011—2020年统计数据及文献资料,测算了黑龙江省畜禽粪污排放情况,并据此分析黑龙江省畜禽粪污资源化利用潜力及畜禽养殖环境承载力。结果表明:从时间动态来看,2011—2020年,黑龙江省畜禽粪尿、粪尿养分、COD排放量均有小幅下降,降幅分别为3.68%、3.24%和5.82%;畜禽粪污的化肥替代潜力虽整体略有下降,但10年来均保持在35%以上,2020年化肥替代潜力已达到41.89%,具有较高的有机肥替代化肥潜力;黑龙江省畜禽粪污的能源潜力略有增长,但对煤炭的替代潜力呈下降趋势且替代作用并不显著,2020年畜禽粪污的沼气潜力为46.74亿m^(3),折合为标准煤仅占标准煤消费量的2.90%,能源潜力有待进一步开发利用;黑龙江省畜禽粪尿、粪尿氮、粪尿磷的耕地负荷均未超载,无养殖环境风险,畜禽养殖环境容量的空间剩余呈上升趋势,剩余约2/3,以氮为基准计算,余量为13006.13万头猪当量,以磷为基准计算,余量为8463.19万头猪当量,具有较大养殖潜力。从空间分布来看,黑龙江省各地区畜禽粪污排放及资源化利用潜力存在明显差异,哈尔滨市、齐齐哈尔市、绥化市、大庆市以及佳木斯市等畜禽养殖集聚区的畜禽粪尿资源丰富,畜禽粪污的替代化肥潜力、能源潜力及畜禽养殖发展潜力较大。

‘YY021’烘烤特性及其杂种优势

为研究烤烟杂交种‘YY021’的烘烤特性及杂种优势,以‘YY021’及其母本‘MSY106’、父本‘LY1306’为研究对象,采用暗箱试验研究上部烟、中部烟和下部烟的变黄、变褐特性;采用电烤箱试验,研究中部烟烘烤过程中烟叶的失水特性、叶绿素降解特性和多酚氧化酶(PPO)活性变化,评价‘YY021’易烤性和耐烤性及其杂种优势。结果表明,上、中、下部位叶片变黄速率均表现为‘YY021’>‘LY1306’>‘MSY106’,下部和中部烟叶变褐速率表现为‘LY1306’>‘MSY106’>‘YY021’,上部烟叶变褐速率表现为‘LY1306’>‘YY021’>‘MSY106’。‘YY021’及其父母本变黄指数和变褐指数均随着叶片部位升高而减小。中部烟叶失水均衡性表现为‘LY1306’显著高于‘MSY106’,‘YY021’介于父母本中间,有中亲优势。‘YY021’中部烟叶绿素降解速率与父母本差异不显著,无杂种优势。中部烟PPO活性均值表现为‘MSY106’>‘YY021’>‘LY1306’,品种间差异显著,‘YY021’有中亲优势。综合上述各指标并参考生产实际表现‘,YY021’中部烟叶易烤性和耐烤性中等,有中亲优势,无超亲优势。

水基炭黑-胶原蛋白纳米流体制备及稳定性实验

纳米流体由于其优异的光热转换性能,已成为新型太阳能集热介质的研究重点;但因其稳定性差、制备工艺复杂,未能在实际应用中得到推广。本文以去离子水为基液,通过两步法制备炭黑-胶原蛋白纳米流体。探究了材料添加顺序、胶原蛋白种类、超声时间、材料配比以及溶液pH等对纳米流体稳定性的影响。结果表明,制备水基炭黑-胶原蛋白纳米流体时,先分散炭黑再加入胶原蛋白可以提高其稳定性;猪皮胶原蛋白更适用于炭黑-胶原蛋白纳米流体的制备;超声45min,炭黑胶原蛋白质量配比为1/20,悬浮液pH在6.5~7.5之间制备得到的纳米流体稳定性较好。本研究有助于今后水基炭黑-胶原蛋白纳米流体产业化应用于太阳能光热转换领域。

不同年龄段健听人颈性前庭诱发肌源性电位参数的研究

目的探讨颈性前庭诱发肌源性电位在不同年龄段健听人群中的正常参考值范围。方法将60例健康志愿者分为儿童组和成人组,利用丹麦WDH集团的Eclipse客观听觉测试平台分别进行颈性前庭诱发肌源性电位测试,对数据进行统计学分析。结果两组中左侧和右侧间P1、Nl潜伏期、P1-N1波间期、振幅、不对称比均无显著差异;两组中男性和女性间P1、Nl潜伏期、P1-N1波间期、振幅、不对称比均无显著差异;儿童组中P1正常值范围为13.97±1.46 ms,N1正常值范围为21.82±1.85 ms,振幅正常范围为100.71±91.17μV,波间期正常范围为7.85±1.12 ms;成人组中P1正常值范围为16.11±2.23 ms,N1正常值范围为24.66±2.35 ms,振幅正常范围为61.26±27.74μV,波间期正常范围为8.58±1.48 ms;两组之间P1、Nl潜伏期、P1-N1波间期、振幅均有显著差异(P<0.05),不对称比无显著差异。结论颈性前庭诱发肌源性电位的波形及参数与侧别、性别无相关性,潜伏期、波间期随年龄增长而延长,振幅随年龄的增长而减小。