Quantum-mechanical understanding on structure dependence of image potentials of single-walled boron nitride nanotubes

The recent discovery of field emission devices based on one-dimensional nanostructures has attracted much interest in emerging applications on next-generation flat panel displays,molecule-based sensors,and so forth.To achieve a comprehensive understanding of surface potentials at the nano-emitters during the tunneling process,in this study we systematically investigated the image potentials of single-walled boron nitride nanotubes with different edges,diameters and lengths in the frame of a composite first-principles calculation.The image potentials of zigzag single-walled boron nitride nanotubes are found to be dependent on the non-equivalent sides.Only the image potentials of isolated armchair single-walled boron nitride nanotube can be well fitted with the image potential of an ideal metal sphere of a size comparable to the tube diameter.On the contrary,the image potentials of zigzag and grounded armchair single-walled boron nitride nanotubes exhibit a strong length-dependence characteristic and are significantly different from that of an ideal metal sphere,which originates from the significant axial symmetry breaking of induced charge at the tip for the long tube.The correlation between the testing electron and electronic structure of single-walled boron nitride nanotube has also been discussed.

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.

A robust method for evaluating the potentials of 15-minute cities:Implications for sustainable urban futures

The‘15-minute city’(15minC)concept,which aspires to bring essential services within reach via a 15-minute walk for all residents,represents a pivotal paradigm shift in sustainable urban development.However,the achievability of this concept for different cities varies considerably across diverse population distributions,urban contexts,and development priorities.In this study,we propose a robust method for evaluating a city’s 15minC potential-a city’s capability to achieve widespread 15-minute accessibility while maintaining an optimal balance between resource efficiency and resident accessibility.We employ the Location Set Covering Problem optimization model to analyze the resources required to achieve full coverage of 15-minute accessibility and the knee point detection algorithm to assess a city’s 15minC potential.Across 23 major Chinese cities,our method exhibits a sharp sensitivity to delineate distinct 15minC potentials.It reveals that cities’current 15minC development level doesn’t align with their inherent potential uniformly.Key determinants include how well current facility locations match population centers and the population density in remote areas.Further,reducing facility constructions by twothirds has only a marginal impact on accessibility,emphasizing the need for tailored,data-driven planning in effective and sustainable urban development based on the distinct potentials of cities.Our approach prioritizes resource efficiency,minimizing the inefficient use of facilities that serve only a small portion of residents while maximizing the benefits of the 15minC and therefore has significant implications for a sustainable urban future.

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.

Clinical characteristics and analysis of vestibular-evoked myogenic potentials in patients with sudden sensorineural hearing loss in different ages

BACKGROUND Numerous studies have found that patients experiencing sudden sensorineural hearing loss(SSHL),with or without accompanying vertigo,often show impaired vestibular function.However,there is a dearth of studies analyzing vestibularevoked myogenic potentials(VEMPs)in SSHL patients across various age groups.AIM To investigate vestibular condition in SSHL patients across various age demographics.METHODS Clinical data of 84 SSHL patients were investigated retrospectively.Audiometry,cervical vestibular evoked myogenic potentials(c-VEMPs),and ocular vestibular evoked myogenic potentials(o-VEMPs)were conducted on these patients.Parameters assessed included the latencies of P1 and N1 waves,as well as the amplitudes of P1–N1 waves.Moreover,the study evaluated the influence of factors such as sex,affected side,configuration of hearing loss,and presence of accompanying vertigo.RESULTS Among the 84 SSHL patients,no significant differences were observed among the three groups in terms of gender,affected side,and the presence or absence of vertigo.Group II(aged 41–60 years)had the highest number of SSHL cases.The rates of absent o-VEMPs in the affected ears were 20.83%,31.58%,and 22.72%for the three age groups,respectively,with no statistically significant difference among them.The rates of absent c-VEMPs in the affected ears were 8.3%,34.21%,and 18.18%for the three age groups,respectively,with significant differences.In the unaffected ears,there were differences observed in the extraction rates of o-VEMPs in the unaffected ears among the age groups.In the three age groups,no significant differences were noted in the three age groups in the latencies of P1 and N1 waves or in the amplitude of N1–P1 waves for c-VEMPs and o-VEMPs,either on the affected side or on the unaffected side,across the three age groups.CONCLUSION The extraction rate of VEMPs is more valuable than parameters.Regardless of the presence of vertigo,vestibular organs are involved in SSHL.Notably,SSHL patients aged 41–60 appear more susceptible to damage to the inferior vestibular nerve and saccule.

The Aharonov-Bohm Effect: An Exploration of Quantum Interference and Electromagnetic Potentials

The AB(Aharonov-Bohm)effect is a pivotal quantum mechanical phenomenon that illustrates the fundamental role of the electromagnetic vector potential A in determining the phase of a charged particle’s wave function,even in regions where the magnetic field B is zero.This effect demonstrates that quantum particles are influenced not only by the fields directly present but also by the potentials associated with those fields.In the AB effect,an electron beam is split into two paths,with one path encircling a solenoid and the other bypassing it.Despite the absence of a magnetic field in the regions traversed by the beams,the vector potential A associated with the magnetic flux Φ through the solenoid induces a phase shift in the electron’s wave function.This phase shift,quantified by △φ=qΦ/hc,manifests as a change in the interference pattern observed in the detection screen.The phenomenon underscores the principle of gauge invariance in QED(quantum electrodynamics),where physical observables remain invariant under local gauge transformations of the vector and scalar potentials.This reinforces the notion that the vector potential A has a profound impact on quantum systems,beyond its classical role.This article outlines the AB effect,including its theoretical framework,experimental observations,and implications.The focus on the role of the vector potential in quantum mechanics provides a comprehensive understanding of this important phenomenon.

Mass Increase with Strong and Gravitational Potentials, and Mass Defect with Electromagnetic Potential

The proposal is “mass increases due to strong and gravitational potentials, while it decreases due to Electromagnetic potential”. This proposal explains the big difference in mass between hadrons (protons, neutrons, & mesons) and their components (quarks), mass difference between nucleus and its individual components (protons and neutrons), massless of gamma photons, abnormal masses of mesons and bosons, and the excess in galaxy masses (dark matter). Also, this proposal shows the exact relation between mass and energy: Strong Potential=−3.04mc2| Electric Potential |=−5.57×10−3mc2Gravitational Potential=−1.22×10−7mc2where m represents the excess in mass due to strong potential, or gravitational potential and represents the decrease in mass due to electromagnetic potential. Released energy here equals potential energy and doesn’t equal decrease in mass using the formula E = mc2. Released energy is transferred to heat, photons, kinetic energy… Finally, proposal will try to describe the relation between photon energy and mass of its components using the general equation of kinetic energy: Photon Energy=1/2mc2m is the sum of the individual masses of its components, while the total mass of photon is zero.

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.

洛河洛阳段沉积物重金属空间分布及潜在生态风险

为明晰洛河洛阳段沉积物重金属分布、风险及来源,以洛河洛阳段为研究对象,采集入城区段、主城区段和出城区段13个点位的表层沉积物,分析重金属(Pb、Cd、Cr、Mo、Cu和Zn)的空间分特征,并利用地累积指数(I geo)法、潜在生态风险指数(RI)法和主成分分析等方法评价重金属污染程度、潜在生态风险及来源解析,结果显示:洛河洛阳段沉积物重金属平均质量分数Pb(42.90 mg·kg^(-1))、Cd(2.41 mg·kg^(-1))、Cr(76.86 mg·kg^(-1))、Mo(9.31 mg·kg^(-1))、Cu(35.15 mg·kg^(-1))及Zn(145.60 mg·kg^(-1))分别为黄河流域河南段重金属元素土壤背景值的1.7、14.2、1.1、13.7、1.5和2.2倍.Pb、Cr和Cu质量分数均表现为入城区段显著高于出城区段,Cd、Mo和Zn表现为主城区段显著高于出城区段,这6种重金属质量分数在入城区段与主城区段间无显著差异.入城区段和主城区段多数点位的Cd为偏重污染程度及以上,Mo为中度污染或偏重污染程度,其余为轻度或低污染程度.源解析显示,Pb、Cd、Mo、Cu和Zn主要为人为源,Cr以自然源为主.潜在生态风险指数法结果显示,入城区点位达到强生态危害水平(Ⅲ级)及以上,主城区段所有点位均达到很强生态危害水平(Ⅳ级),出城区段所有点位均达到强生态危害水平(Ⅲ级),其中,Cd对RI的贡献最大,占比64.10%,其次是Mo(32.67%).洛阳市应重点关注由钼产业可能引起的环境风险,并进一步降低Cd污染水平,方能降低洛河沉积物重金属的污染及潜在生态风险.

乌玛高速沙漠段风沙环境特征及格状沙丘移动规律

[目的]沙丘移动与风沙环境特征和沙丘形态具有直接关系,探究多种因素作用下的格状沙丘移动规律,能为沙区公路风沙防治提供科学依据。[方法]以乌玛高速沙漠段格状沙丘为研究对象,基于当地气象数据、Google Earth卫星影像,研究了2019-2021年乌玛高速沙漠段K167+300,K172+300,K177+300里程处风沙环境及格状沙丘的形态演变和移动规律。[结果](1)研究区年平均起沙风速介于6.07~6.84 m/s,春夏为主要输沙季节,主风向为西北风,次风向为东南风;年输沙势介于31.77~38.89 VU,方向变率指数(RDP/DP)介于0.73~0.78,属于低风能环境、中变率风况。(2)研究区自东北向西南方向,格状沙丘主梁向东偏移,副梁向南偏移,主副梁走向几乎保持垂直,沙丘形态整体上变化较小;格状沙丘的主副梁长度、主副梁间距、沙丘高度均呈现出增加的趋势,主副梁长度增长率、主副梁偏移率呈减小趋势。(3)沙丘移动方向介于140.43°~152.64°,与年RDD变化基本一致,即向东南偏移;沙丘平均高度介于5.24~8.31 m,沙丘移动速率介于2.31~2.86 m/a,两者表现为负相关关系。(4)输沙势、年均温度与沙丘移动速率为正相关关系,相较而言,年均温度对沙丘移动速率的影响更为显著;年均降水量、植被覆盖度与沙丘移动速率为负相关关系,其中年均降水量对移动速率的影响尤为重要。[结论]格状沙丘的移动与当地风况、降水量、温度、植被覆盖度及沙丘自身形态息息相关,其中输沙势及温度增加会加速沙丘前移,不利于对风沙的防治,而提高降水量及植被覆盖度,对防治沙丘移动引起的公路风沙灾害具有积极作用。

中国土壤硼地球化学异常特征与找矿远景区预测

硼是一种新兴战略矿产,在现代高新技术产业中应用广泛。近年来,硼的需求持续上升,硼矿资源勘查也日益受到重视。本文依托中国地球化学基准值计划所采集的3380件汇水域深层土壤数据,提供了全国B元素地球化学分布和异常特征。全国汇水域土壤深层样品B平均含量为46.4μg/g,B整体上具有南高北低、连片分布的特点,可划分为5个地球化学分区,分别为东北与内蒙古东部地区(Ⅰ)、西北部地区(Ⅱ)、华北地区(Ⅲ)、青藏地区(Ⅳ)和南方地区(Ⅴ)。以B含量70.9和52.4μg/g(累频85%)分别作为南北方异常下限,共圈定出37个B地球化学异常,在全国圈定10个地球化学省和9个小规模异常。根据B异常空间分布,结合地质背景和硼矿床分布,进一步划分出9个成矿远景区,建议加大盐湖型硼矿的找矿勘查力度,并将硬岩(海相沉积)型硼矿作为下一步勘查目标。

中国镍钴矿产资源禀赋条件与找矿潜力

镍、钴属于新能源金属,在高端制造业、合金材料、新能源电池等领域具有不可替代性,需求量逐年陡增。但国内镍钴矿产资源原料极度短缺,对外依存度已高达93%和99%,潜在资源安全威胁凸显,加强国内镍钴矿产资源勘查已迫在眉睫。本文系统分析了我国镍钴矿产资源成矿特征,无论是成矿类型,还是构造背景特征,与全球均存在显著不同。全球60%的镍资源主要赋存于红土型镍钴矿床中,40%的镍资源则储存在岩浆镍钴硫化物矿床内,而我国镍资源的93%赋存在岩浆镍钴硫化物矿床中。世界上60%的钴资源来自沉积型铜钴矿床、23%的岩浆型镍钴矿床、15%的红土型镍钴矿床及2%的热液型含钴矿床,而我国钴资源45%赋存于岩浆镍钴硫化物矿床内、40%的钴资源赋存在与热液相关矿床中,受赋存状态及开发利用条件限制,这部分赋存在热液矿床中的钴资源尚不能有效利用。可见,我国镍钴资源关键来源是岩浆型镍钴矿床。对比我国岩浆镍钴硫化物矿床成矿特征及地质分布特点,本文提出我国岩浆镍钴硫化物矿床独特的资源禀赋条件,重要结合带旁侧滞后发育的铁质系列镁铁-超镁铁质侵入岩是镍钴资源赋存的关键空间,明确勘查工作的重点方向。另外,分析认为,加强钴矿赋存状态研究,创新破解开发利用条件限制,是实现钴资源增储上产的关键路径。这为指导镍钴资源勘查、助力找矿新突破提供了重要依据。

高龄慢病患者潜在不适当用药风险预测模型的构建与验证

目的构建高龄慢病患者潜在不适当用药(PIM)的风险列线图预测模型,为临床决策提供参考。方法回顾性分析2023年1-12月在滁州市第一人民医院就诊的358例高龄慢病患者的临床资料,按7∶3的比例随机分为训练集和验证集。根据是否存在PIM,分为PIM组和非PIM组。在训练集中采用单因素和多因素回归分析,筛选高龄慢病患者PIM的风险因素,利用AIC准则决定最优Nomogram模型,并绘制列线图。通过曲线下面积(AUC)、校准曲线和决策曲线分析(DCA)评价模型的性能。结果训练集、验证集受试者操作特征曲线AUC分别为0.786、0.768;训练集、验证集校准图显示,Brier得分分别为0.164、0.165;Hosmer-Lemeshow拟合优度检验结果分别为χ^(2)=4.405(P=0.883)、χ^(2)=6.645(P=0.674),说明两组的实际曲线和理想曲线重合度较好;训练集、验证集决策曲线分析显示,当高龄慢病患者PIM发生的阈值概率处于20%~94%、30%~94%时,具有临床实用价值。结论构建的列线图模型具有较好的区分度、校准度及临床适用性,可有效、便捷地预测高龄慢病PIM患者,为临床早期识别并给予针对性干预提供参考。

中国银矿床类型、时空分布与找矿远景

我国银矿床分布广泛,矿床成因类型多。近些年来,一些大型-超大型银矿床的相继发现,改写了我国银资源的分布格局。因此亟需对我国银矿床主要成因类型及时空分布规律进行系统总结与研究。本文经过系统整理,梳理出我国77座中型以上(>200t)的银多金属矿床的基本信息与要素,将我国银矿床划分为浅成低温热液型、斑岩型、矽卡岩型、VMS型、SEDEX型、MVT型、沉积型和风化型(红土型)等八种类型,其中以浅成低温热液型最为主要。中国银矿床主要形成于中生代,尤其是晚侏罗世-早白垩世,空间上划分出兴蒙、华北、秦岭-东昆仑、华南、西藏-三江等五个银成矿省。银成矿省成因与陆壳类型(古老和新生地壳)、伸展构造背景和大规模中酸性岩浆活动密切相关。综合上述因素,兴蒙复合造山带仍然是具有巨大找矿潜力的成矿区。那更康切尔沟银多金属矿床的发现表明东昆仑(原特提斯-新特提斯)叠合造山带地区具有很好的找矿潜力。三江复合造山带在银锡矿床的勘查方面亦潜力巨大。

高职护生述情障碍潜在剖面分析及影响因素

目的:探索高职护生述情障碍潜在类别,并分析其影响因素。方法:采取便利抽样法,于2023年10月—11月纳入安徽省某高职院校2022级及2023级高职护生828人作为研究对象,采用一般资料调查表、中文版多伦多述情障碍量表、中文版人际反应指针问卷进行调查。采用潜在剖面分析探索高职护生述情障碍潜在分型,确定其最佳分型,运用Logistic回归分析探讨述情障碍潜在类别的影响因素。结果:高职护生述情障碍可分为3个类别,其中非述情障碍或低危组62人(7.5%),述情障碍中危组351人(42.4%),述情障碍高危组415人(50.1%)。Logistic回归分析结果显示,家庭居住地、选择护理专业原因、共情能力是高职护生述情障碍潜在类别的影响因素(P<0.05)。结论:高职护生述情障碍存在异质性,护理教育者和教育管理者应及时识别存在述情障碍的高职护生,平衡发展共情能力,降低述情障碍水平。

文旅融合背景下肇庆市夜经济发展潜力及策略研究

夜经济作为经济社会高质量发展的新亮点,是促消费稳增长的重要动力引擎,有效推动了旅游经济的增长。肇庆市重视扩大夜间经济活动的规模及影响力,打造系列深受居民和游客喜爱的夜间文化项目、夜游街区、夜间经济集聚区。文章分析文旅融合背景下肇庆市夜间经济发展的现状及挑战,提出推动肇庆市夜间经济高质量发展的对策建议。研究表明:肇庆市夜经济发展具有较大的文化潜力、旅游潜力、社会发展潜力,但仍面临市场环境、文化特色、旅游效应、政策等方面问题。建议从政府引领、文化内涵和区域业态等方面激发新的增长动力。

四川盆地东部复兴地区侏罗系东岳庙段页岩热演化史及油气地质意义

页岩热演化史与油气生成过程、微观孔隙的形成演化以及油气的富集成藏密切相关,是准确评价页岩油气资源潜力、揭示成藏富集规律的关键参数。为了准确评价四川盆地东部复兴地区侏罗系东岳庙段页岩热演化史、含油气特征及其与海相页岩气的差异,结合研究区典型井地质、测井及地球化学资料,利用BasinMod软件模拟了东岳庙段页岩的埋藏史、热演化史和生烃史,探讨了页岩热演化与油气生成、孔隙演化、成藏富集之间的关系。研究结果表明:(1)研究区东岳庙段页岩在侏罗纪中期进入生烃门限,侏罗纪中晚期达到主生油高峰,并存在两个生烃高峰,分别为侏罗纪末期和白垩纪中期;(2)第一个生烃高峰期以生油为主,持续时间长且生烃速率较快,第二个生烃高峰期以生成凝析油和湿气为主,持续时间较短且生烃强度较低;(3)东岳庙段页岩的平均累计生油强度为9.5×10^(8)t/km^(2),平均累计生气强度为2.5×10^(8)m^(3)/km^(2);(4)东岳庙段页岩孔隙演化过程可分为4个阶段,分别为早期压实减孔阶段、液态烃滞留堵孔阶段、热裂解有机孔形成阶段和热裂解生湿气阶段;(5)压实作用和液态烃滞留堵孔是导致页岩原生孔隙快速减少的主要原因,有机质(主要为固体沥青)与黏土混杂堆积形成的有机黏土复合体是东岳庙段页岩重要的储集空间。结论认为:(1)不同构造部位的埋藏史、热演化史和生烃史影响了页岩油气的生成、排放与滞留,决定了现今页岩油气的含量差异,抬升剥蚀厚度较小且保存条件较好的地区,具有较高的油气滞留量,值得高度关注;(2)成果认识坚定了川东地区陆相页岩油气勘探开发信心,为其他类似地质情况的探区提供了有益借鉴。

农业数字化转型:内在机理、潜在风险与应对机制--基于浙江YN公司的“三位一体”共营制实践

全面推进农业数字化转型不是盲目随机的,而是在“变”与“不变”中呈现出农业现代化发展的内在机理。不变的中国式农业现代化战略目标,变化的资源环境条件、劳动力结构、数字化技术发展以及政府农业政策导向之间的张力和矛盾,驱动了农业数字化转型。从政府、企业和农户多主体角度出发剖析可知,在农业数字化转型中,政府面临“精英俘获”风险,企业面临资产专用性风险,农户面临生产要素缺失风险。以浙江YN公司的案例分析表明,“三位一体”共营制模式能够发挥各主体优势,有效化解农业数字化转型中的风险,推动农业数字化转型的成功实施,形成一个多赢、高效的生态系统。