Petrography and origin of the Lower Ordovician microbial carbonates in the Songzi Area of Hubei Province,middle Yangtze region,China

This study is the first systematic assessment of the Lower Ordovician microbial carbonates in Songzi,Hubei Province,China.This paper divides the microbial carbonates into two types according to growth patterns,namely nongranular and granular.The nongranular types include stromatolites,thrombolites,dendrolites,leiolites and laminites;the granular types are mainly oncolites and may include a small amount of microbiogenic oolite.According to their geometric features,the stromatolites can be divided into four types:stratiform,wavy,columnar and domal.Additionally,dipyramidal columnar stromatolites are identified for the first time and represent a new type of columnar stromatolite.The thrombolites are divided into three types:speckled,reticulated and banded.The grazing gastropod Ecculiomphalus and traces of bioturbation are observed in the speckled and reticulated thrombolites.This paper considers these two kinds of thrombolites to represent bioturbated thrombolites.These findings not only fill gaps in the field of domestic Ordovician bioturbated thrombolites but also provide new information for the study of thrombolites.Based on the analysis of the sedimentary characteristics of microbialites,the depositional environments of the various types of microbialites are described,and the distribution patterns of their depositional environments are summarized.The relationship between the development of microbialites and the evolution and radiation of metazoans during the Early to Middle Ordovician is discussed.Consistent with the correspondence between the stepwise and rapid radiation of metazoans and the abrupt reduction in the number of microbialites between the late Early Ordovician and the early Middle Ordovician,fossils of benthonic grazing gastropods(Ecculiomphalus)were found in the stromatolites and thrombolite of the study area.It is believed that the gradual reduction in microbialites was related to the rapid increase in the abundance of metazoans.Grazers not only grazed on the microorganisms that formed stromatolites,resulting in a continuous reduction in the number of stromatolites,but also disrupted the growth state of the stromatolites,resulting in the formation of unique bioturbated thrombolites in the study area.Hydrocarbon potential analysis shows that the microbialites in the Nanjinguan Formation represent better source rocks than those in the other formations.

Three-dimensional velocity structure around the focal area of the 2021 MS6.4 Yangbi earthquake

On May 21,2021,an MS6.4 earthquake occurred in Yangbi,Yunnan province,China,which exhibited typical foreshock-mainshock-aftershock characteristics.To better understand the velocity structure of the focal area and adjacent fault zones,Pg/Sg travel times at 12 seismic stations for the local earthquakes with ML≥1.5 from 2009-2019 and the Yangbi sequence in May of 2021 were used to invert the three-dimensional(3D)structures for both vP and v_(P)/v_(S).The obtained structure extends deeply to 15 km for area(25°N-26.5°N,99.5°E-101°E)at a horizontal resolution of 10×10 km,and the accuracy of the v_(P) velocity was verified using airgun signals excited by the Binchuan Airgun Transmitting Seismic Station(BATSS).The resulting v_(P) and v^(P)/v_(S) images correlate with existing fault zones and the Yangbi sequence,including:(1)The shallow velocity structure at 0 km agrees with local topography,where the Binchuan basin exhibits low-v_(P) and high-v_(P)/v_(S) values.From 3-15 km,v_(P) and v_(P)/v_(S) show variations,and the boundaries are consistent with the main faults(e.g.,the Weixi-Qiaohou-Weishan,Honghe,and Chenghai faults).(2)The largest foreshock(M_(S)5.6),main-shock(MS6.4),and largest aftershock(M_(S)5.2)occurred near the boundaries where both vP and v_(P)/v_(S) have clear contrasts.(3)Small earthquakes are also concentrated in the transition zone between high-and low-vP and v_(P)/v_(S) anomalies,and are biased toward low-v_(P)/v_(S) zones.(4)Boundaries in v_(P) and v_(P)/v_(S) are observed at 20 km west of the Weixi-Qiaohou-Weishan fault,indicating that there may exist one hidden fault.

林区桥梁墩柱加固虚拟仿真实验教学探索与实践

以林区桥梁墩柱加固为例,基于现代教学理念以及虚拟仿真技术设计桥梁墩柱加固虚拟仿真资源,并实现在线共享。实验解决了土木类大型实验经费高、周期长、存在一定安全隐患的难题。结合虚拟教研室的建设,采取浸入式、自主式、交互式、探究式、反馈式教学方法相结合,探索开展虚拟综合性实验设计、实施以及教学评估,构建了混合教学模式下虚拟仿真实验教学体系。教学实践证明,通过虚拟仿真实验教学有利于混合式教学模式下学生的自主探究以及创新实践,全方面地提升了学生综合素质。

递进式N×N型采样方式次谐波海洋湍流相位屏模拟方法

以N×N型采样方式次谐波法为基础,引入了递进式采样,提出了一种递进式N×N型采样方式次谐波法,用于数值模拟海洋湍流相位屏。该方法利用Nikishov提出的海水折射率波动谱模拟海洋湍流相位,通过相位结构函数和补偿效果验证该方法生成相位屏的准确性。通过改变递进区域个数、补偿阶数和谐波次数,比较分析相位屏参数对改变对相位屏准确性的影响。此外,将所提方法与N×N型采样方式次谐波法、改进的次谐波补偿法和改进的次谐波法进行比较。结果表明:递进式N×N型采样方式次谐波法只需谐波次数为11时,补偿效果即可达到0.9995,并且在准确度相同的情况下具有更快的模拟速度。

An accessible seismological dataset of 2021 Yangbi M_(S)6.4 earthquake

A M_(S)6.4 earthquake occurred on 21 May 2021 in Yangbi county,Dali prefecture,Yunnan,China,at 21:48 Beijing Time(13:48 UTC).Earthquakes with an M3.0 or higher occurred before and after the main shock.Seismic data analysis is essential for the in-depth investigation of the 2021 Yangbi M_(S)6.4 earthquake sequence and the seismotectonics of northwestern Yunnan.Institute of Geophysics,China Earthquake Administration(CEA),has compiled a dataset of seismological observations from 157 broadband stations located within 500 km of the epicenter,and has made this dataset available to the earthquake science research community.The dataset(total file size:329 GB)consists of event waveforms with a sampling frequency of 100 sps collected from 18 to 28 May 2021,20-Hz and 100-Hz continuous waveforms collected from 12 to 31 May 2021,and seismic instrument response files.To promote data sharing,the dataset also includes the seismic event waveforms from 20 to 22 May 2021 recorded at 50 stations of the ongoing Binchuan Active Source Geophysical Observation Project,for which the data protection period has not expired.Sample waveforms of the main shock are included in the appendix of this article and can be downloaded from the Earthquake Science website.The event and continuous waveforms are available from the Earthquake Science Data Center website(www.esdc.ac.cn)on application.

Estimation of the Probability of Long-Distance Dispersal: Stratified Diffusion of <i>Spartina alterniflora</i>in the Yangtze River Estuary

The relative contribution of long-distance dispersal and local diffusion in the spread of invasive species has been a subject of much debate. Invasion of the intertidal mudflats by Spartina alterniflora is an ideal example of stratified diffusion, involving both long-distance dispersal of seeds and local diffusion due to clonal growth. In conjunction with experimental data on range radius-versus-time curve, a traveling wave equation-based model is used to investigate the sensitivity of the spread rate of exotic S. alterniflora to parameters of long distance dispersal (c, maximum colonial establishment rate) and local colony diffusion (r, intrinsic growth rate) at two tidal marshes, the Eastern Chongming and the Jiuduansha Islands, at the Yangtze River estuary. Both Eastern Chong ming and Jiuduansha Islands are now national natural reserves in China, which were established in 2005. However, the mudflats and salt marshes in the two reserves are now heavily infested with introduced S. alterniflora, which may threaten the estuarine ecosystems and their biodiversity. S. alterniflora was first found in 1995 on Chongming. For rapid sediment accretion in mudflats in the estuary, S. alterniflora was also intentionally introduced to Jiuduansha in 1997 and Chongming in 2001, which has led to a rapid range expansion in the estuary. Our results show that range expansion of species with stratified diffusion is affected by both long-distance dispersal and local colony diffusion, and that there is a critical c*, below which the spread rate is more influenced by long-distance dispersal than by local diffusion. After applying this model to the invasion of S. alterniflora in the Yangtze River estuary, we derive that c = 1.7 × 10-3, c* = 0.126 and c = 4.8 × 10-3 km-2·yr-1, c* = 0.140 km-2·yr-1 at Chongming and Jiuduansha (Shanghai), respectively. Our results suggest that the range spread of S. alterniflora in the Yangtze River estuary is more influenced by long-distance dispersal than local colony diffusion, and that S. alterniflora generates about 1.7 × 10-3 to 4.8 × 10-3 colonies per square kilometers per year. This study provides important information about dispersal dynamics of S. alterniflora that may be useful for finding optimal control strategies. ·

“三融合,四突出”教学路径探索——物理化学C课程教学创新

针对传统课堂的教学“痛点”问题,团队教师以课程思政为主导,以现代信息技术为媒介,优化教学目标,重构教学内容,重塑教学过程,强化互动辩论,完善考评机制,持续改进,探索出“三融合,四突出”的教学创新路径。全面解决课程“痛点”问题,全力打造“两性一度”金课,促进学生创新能力和综合素质的提升。

农产品检测用脱氧雪腐镰刀菌烯醇纯度标准物质的研制

[目的]本文旨在研制脱氧雪腐镰刀菌烯醇(deoxynivalenol,DON)国家级纯度标准物质,为农产品中DON的检测等工作提供物质基础。[方法]利用质量平衡法和定量核磁共振法对DON纯度标准物质进行纯度定值。质量平衡法包括采用液相色谱面积归一化法测定DON主成分含量,采用卡尔费休库仑法测定纯度标准物质中水分含量,采用顶空气相色谱-质谱法测定挥发性杂质含量,以及采用电感耦合等离子质谱法测定无机离子杂质含量。定量核磁共振法采用苯甲酸为内标,选择合适的共振峰,内标法定量标准物质的纯度,并对标准物质进行均匀性、稳定性检测和不确定度评估。[结果]质量平衡法的纯度定值结果为99.47%,定量核磁共振法定值结果为99.45%,最终所研制的DON纯度标准物质的纯度为99.5%,扩展不确定度为0.4%,均匀性良好,且满足12个月以上的稳定性要求。[结论]本试验所研制的DON纯度标准物质符合国家标准物质技术规范,目前已被批准为国家一级标准物质,并已被用于小麦、玉米等农产品实际检测过程中。

近晶相液晶超结构的多元外场调控

利用液晶的自组装和刺激响应特性,实现近晶相液晶多层级超结构的灵活构筑、动态操控和多功能应用对于激发更多前沿的创新性功能器件并推动液晶超结构的实用化进程具有重要意义。本文从近晶相液晶超结构的生长制备、多元外界刺激对缺陷结构的调制方法和动态调控规律等方面进行系统研究。首先,探究了图案化取向场和旋涂条件对近晶相液晶拓扑超结构的形态与大小的操控;然后,验证了焦锥畴超结构的微透镜成像功能,并通过材料复合优化和引入聚合物稳定策略,实现了正方焦锥畴阵列在35℃下(向列相)的电刺激动态调控性能;最后,研究了手性、光场和热场对双相态液晶超结构带来的多维度调控。本研究充分利用光取向场、聚合物网络、电场、手性、光场等多元外场刺激,实现了对近晶相液晶多层级超结构的多维度调控。

不同原料添加提升曲药酱香风味的研究

为探究不同原料添加对提升曲药酱香风味的影响,该研究采用顶空固相微萃取结合气相色谱-质谱联用技术(HS-SPME-GC-MS)探究了不同添加量(5%、10%、15%)原料(烘焙或浸泡的黄豆、豆粕和绿豆)在不同温度条件下的地衣芽孢杆菌培养曲药的挥发性风味物质。结果表明,添加烘焙原料的曲药挥发性风味物质含量高于添加浸泡原料的曲药,并且在50℃条件下更利于吡嗪类物质的产生。对高产吡嗪类物质的曲药通过正交偏最小二乘判别分析(OPLS-DA)发现,黄豆曲药和豆粕曲药成分相似,但与纯麸皮曲药和绿豆曲药表现出差异性。筛选出12种差异性的挥发性风味物质,其中,添加15%烘焙豆粕在50℃条件下培养更利于生成2,5-二甲基吡嗪、2,3,5-三甲基吡嗪、2,3,5,6-四甲基吡嗪和异戊酸等促进酱香风味形成的物质。研究结果表明,添加15%烘焙豆粕可以提高曲药酱香风味,可为酱香白酒的酱香风味品质的提高提供参考。

《伤寒论》紧脉如“转索无常”探讨

《伤寒论·辨脉法第一》中“脉紧者,如转索无常也”是后世诸多医家对紧脉脉象的基本认识和定义,但因转索无常之象难以理解,且辨脉法篇真实作者存疑,紧脉的“转索无常”也一直饱受争议。本文通过对比《金匮要略》相关原文,探讨紧脉此种定义所存的不恰当之处,转索无常应为宿食之脉,属于紧脉中的一种特殊情况,其作为紧脉的定义并不合适,再结合中医经典与后世医家论述,紧脉脉象单纯地为紧字所表达的本意更佳,即具有拘紧、紧绷感的脉象,较客观细致的说法是脉管横向的拘紧感。

水煤浆煤气化细渣水流分级提炭分质

针对传统浮选存在药剂消耗量大,分质效率低等问题,采用无须添加药剂,通过叶轮搅拌和上升水流作用分选的新型水流分级装置,考察了直接水流分级、先筛分再逐级分级以及宽粒级水流分级对水煤浆煤气化细渣的提炭分质特性。结果显示,水流分级的浮渣产率随叶轮转速、水流速增加而增加,浮渣烧失量则呈先增加后降低趋势。相较于直接水流分级,对气化渣先筛分再水流分级可避免灰渣细颗粒(<0.074mm)中炭灰难以有效分离的问题,从而显著提升其提炭效率。采用宽粒级(>0.074mm)筛分,再对水流分级条件优化,可实现提取浮渣烧失量达84.44%,可燃体回收率达65.85%,综合效率达43.39%。本研究表明通过预筛分再水流分级,可实现煤气化渣的高效提炭分质。

城市温室气体排放推演及其评估方法

气候变化已成为人类可持续发展面临的重大挑战。为应对这一紧迫问题,世界各国相继制定了温室气体减排计划和碳中和时间表。随着全球气候变化对城市温室气体排放管理需求的不断增加,城市温室气体排放推演及其评估方法日益受到重视。这些方法通过模拟未来城市的温室气体排放趋势,使政府、企业和各部门能够更好地了解城市如何通过低碳转型应对气候变化并推动可持续发展,从而在实现气候目标方面发挥关键作用。然而,尽管这些方法在气候行动规划中愈加重要,国际上依然缺乏统一的标准和方法论,这使得各城市在评估其气候行动计划和能源转型策略的有效性时面临挑战。为此,本文提出并探讨了一套标准化的城市温室气体排放推演与评估方法,旨在为全球城市提供统一的技术指南。该方法涵盖数据收集、模型选择、情景定义与评估指标等关键环节。通过对两个典型城市的案例研究,本文验证了该标准方法的适用性和有效性,展示了其在支持全球城市低碳转型和气候行动中的重要作用。这一标准化方法的推广将为全球城市的气候治理和可持续发展提供坚实的技术基础,为标准研制提供有力支撑。

水轮发电机受失磁保护限制的最大进相深度的预测模型研究及软件开发

发电机进相运行存在多种限制因素,进相深度的限制判据是由多种因素组成的综合判据,运行人员难以掌握,只能退出失磁保护压板。而发电机进相运行作为一种正常工况,将机组的保护直接退出显然是不合理的。本文从坐标变换原理出发,介绍一种基于PC端程序的发电机进相实验与失磁保护配合校验方法,可自动计算给定条件下的最大进相深度,并分析低励限制与失磁保护的配合正确性,防止发电机进相运行因进相深度过大而非正常停运,无需退出失磁保护。

Development and characterization of the PolyU-1 lunar regolith simulant based on Chang’e-5 returned samples

Leading national space exploration agencies and private enterprises are actively engaged in lunar exploration initiatives to accomplish manned lunar landings and establish permanent lunar bases in the forthcoming years.With limited access to lunar surface materials on Earth,lunar regolith simulants are crucial for lunar exploration research.The Chang’e-5(CE-5)samples have been characterized by state-of-the-art laboratory equipment,providing a unique opportunity to develop a high-quality lunar regolith simulant.We have prepared a high-fidelity PolyU-1 simulant by pulverizing,desiccating,sieving,and blending natural mineral materials on Earth based on key physical,mineral,and chemical characteristics of CE-5 samples.The results showed that the simulant has a high degree of consistency with the CE-5 samples in terms of the particle morphology,mineral and chemical composition.Direct shear tests were conducted on the simulant,and the measured internal friction angle and cohesion values can serve as references for determining the mechanical properties of CE-5 lunar regolith.The PolyU-1 simulant can contribute to experimental studies involving lunar regolith,including the assessment of interaction between rovers and lunar regolith,as well as the development of in-situ resource utilization(ISRU)technologies.

基于近晶相液晶环面焦锥超结构的矢量光阵列

本文从近晶相液晶超结构的生长制备优化、矢量结构光阵列产生和微透镜成像等方面进行系统研究。在实验中基于光控取向技术,精确控制液晶分子在微观尺度上的排列,设计并优化了液晶盒内近晶相环面焦锥畴阵列的制备流程,成功产生并检测到偏振阶数P=2的偏振矢量光阵列并且探讨了环面焦锥畴阵列作为微透镜阵列的多功能应用潜力。本研究将液晶微结构的拓扑属性与结构光场的拓扑特性交叉融合,充分发挥液晶材料在自组装制备方面的独特优势,不仅为特殊结构光场的产生、调控、探测提供了可能,而且还预示着在精确控制应用领域,如光学陷阱、微流控制和高分辨率成像等方面,可能引发一系列创新性的应用。

Improved Flexible Triboelectric Nanogenerator Based on Tile-Nanostructure for Wireless Human Health Monitor

Triboelectric nanogenerators(TENGs)have emerged as promising candidates for integrating with flexible electronics as self-powered systems owing to their intrinsic flexibility,biocompatibility,and miniaturization.In this study,an improved flexible TENG with a tile-nanostructured MXene/polymethyl methacrylate(PMMA)composite electrode(MP-TENG)is proposed for use in wireless human health monitor.The multifunctional tile-nanostructured MXene/PMMA film,which is self-assembled through vacuum filtration,exhibits good conductivity,excellent charge capacity,and high flexibility.Thus,the MXene/PMMA composite electrode can simultaneously function as a charge-generating,charge-trapping,and charge-collecting layer.Furthermore,the charge-trapping capacity of a tile nanostructure can be optimized on the basis of the PMMA concentration.At a mass fraction of 4%PMMA,the MP-TENG achieves the optimal output performance,with an output voltage of 37.8 V,an output current of 1.8μA,and transferred charge of 14.1 nC.The output power is enhanced over twofold compared with the pure MXene-based TENG.Moreover,the MP-TENG has sufficient power capacity and durability to power small electronic devices.Finally,a wireless human motion monitor based on the MP-TENG is utilized to detect physiological signals in various kinematic motions.Consequently,the proposed performance-enhanced MP-TENG proves a considerable potential for use in health monitoring,telemedicine,and self-powered systems.

Enhanced Ion-Selective Diffusion Achieved by Supramolecular Interaction for High Thermovoltage and Thermal Stability

Thermoelectric(TE)generators capable of converting thermal energy into applicable electricity have gained great popularity among emerging energy conversion technologies.Biopolymer-based ionic thermoelectric(i-TE)materials are promising candidates for energy conversion systems because of their wide sources,innocuity,and low manufacturing cost.However,common physically crosslinked biopolymer gels induced by single hydrogen bonding or hydrophobic interaction suffer from low differential thermal voltage and poor thermodynamic stability.Here,we develop a novel i-TE gel with supramolecular structures through multiple noncovalent interactions between ionic liquids(ILs)and gelatin molecular chains.The thermopower and thermoelectric power factor of the ionic gels are as high as 2.83 mV K-1 and 18.33μW m^(-1)K^(-2),respectively.The quasi-solid-state gelatin-[EMIM]DCA i-TE cells achieve ultrahigh 2 h output energy density(E_(2h)=9.9 mJ m^(-2))under an optimal temperature range.Meanwhile,the remarkable stability of the supramolecular structure provides the i-TE hydrogels with a thermal stability of up to 80℃.It breaks the limitation that biopolymer-based i-TE gels can only be applied in the low temperature range and enables biopolymer-based i-TE materials to pursue better performance in a higher temperature range.

双不锈钢管约束海水海砂混凝土柱轴压试验及承载力计算模型

目的 研究双不锈钢管约束海水海砂混凝土柱(DSTSCC)试件的轴压性能、破坏形态和轴压承载力计算模型,为该类构件的轴压承载力计算提供试验和理论研究参考。方法 对24个DSTSCC试件进行轴压试验,分析外管壁厚、芯管壁厚和芯管直径等参数对其破坏形态、应力-应变曲线和承载力的影响规律。结果 双不锈钢管约束试件的破坏形态以腰鼓型破坏为主;由于不锈钢受拉本构无明显的屈服台阶,可以持续地约束核心混凝土,试件应力-应变曲线无明显的下降段,表现出较好的延性特征;随外管壁厚增大,轴压承载力可提高6%~25%;随芯管壁厚增大,轴压承载力可提高3%~20%;随芯管直径增大,轴压承载力呈现为先提高后降低的趋势。结论 基于试验破坏机理分析和理论分析,所建立DSTSCC试件的轴压承载力计算模型相较于既有承载力计算模型,具有更好的适用性。

5种农药对梨小食心虫的室内毒力测定及田间药效评价

【目的】筛选出对梨小食心虫具有较强防效的农药。【方法】采用生测法和喷雾法分别测定5种农药对梨小食心虫的室内毒力和评价田间药效。【结果】5%甲维盐·虱螨脲对梨小食心虫的3龄幼虫的毒力最高,其LC 50值为4.12 mg/L,其次为10%高效氯氟氰菊酯、14%氯虫·高氯氟和10%氯虫苯甲酰胺,LC 50值分别为8.23、15.14和16.07 mg/L;25%甲维·灭幼脲毒力最低,LC 50值为40.65 mg/L;10%氯虫苯甲酰胺1000倍稀释液和5%甲维盐·虱螨脲2000倍稀释液对幼虫毒杀效果最好,处理24 h后,对幼虫校正死亡率均达到85%以上,72 h时达到100%。10%氯虫苯甲酰胺和5%甲维盐·虱螨脲的速效性最好,田间施药1 d后,防效能达到60%以上。施药后5 d,防效分别为87.72%和82.46%,显著高于其他农药。【结论】10%氯虫苯甲酰胺和5%甲维盐·虱螨脲对和田县桃树栽植区梨小食心虫幼虫具有较好的控制效果。