小尺度山区地质灾害隐患的无人机精细化识别方法与实践

本文针对小空间尺度范围内以滑坡、崩塌为主的山区地质灾害,提出了一套基于小型无人机摄影测量的精细化隐患识别方法。首先,针对工作区开展至少两期无人机摄影测量作业,经处理后得到实景三维模型、数字正射影像(DOM)、数字表面模型(DSM)等精细化成果;其次,以两期DOM与DSM变化检测为主实现灾害体识别;然后,基于灾害体共性特征建立典型识别标志,并依此采用三维实景目视解译为主方法实现孕灾体识别;最后,通过地面核查确认或排除隐患。将该套方法应用到三峡库首秭归泄滩河左岸顺向斜坡区域,共识别出10处不同类型隐患,证明了方法的可行性。

裂隙优势流入渗诱发堆积层滑坡浅层破坏机理研究

土体裂隙为雨水提供了入渗通道,沿此通道形成的优势流主导着降雨入渗过程,导致滑坡稳定性逐步恶化,促使变形持续发展。以徐洼滑坡为例,结合地质勘察、现场宏观巡查以及监测数据等,在分析徐洼滑坡变形特征的基础上,阐明裂隙对滑坡浅层破坏的影响,利用数值模拟,分析不同深度裂隙引起的优势流入渗过程,在此基础上,通过无限边坡模型,计算优势流作用下浅层滑坡的稳定性演化特征,最终厘清优势流入渗诱发浅层破坏机理。研究表明:(1)裂隙提高了坡体的透水性,坡体变形与裂隙发育相互促进,而引起浅层破坏的往往是滑坡变形产生地表拉张裂隙的持续演化;(2)裂隙改变了雨水的入渗过程,一部分沿坡体表面向下垂直入渗,一部分沿裂隙入渗至裂隙末端向四周扩散,随着裂隙发育,降雨入渗由优势流主导;(3)滑坡变形与裂隙发育的关系密切,无裂隙时,坡体仅表层处于不稳定状态,表现为表层侵蚀破坏,随着裂隙演化,裂隙影响深度内坡体处于不稳定状态,表现为滑动破坏,裂隙末端的暂饱和区为最危险滑面。

基于特征优选和机器学习的第四系空间信息提取研究

【目的】第四系土体是土质滑坡的主要物源,其分布及厚度是开展土质滑坡隐患识别的重要基础。随着机器学习技术的兴起,图像分类技术与人工智能算法结合已成为遥感识别的主流。【方法】以三峡库首秭归向斜盆地为研究区,以Landsat-8影像为基础数据源,以区内现有土质滑坡数据构建样本,采用机器学习软件EnMAP-Box,建立第四系厚度及空间分布信息的随机森林分类模型,筛选出用于识别第四系土体厚度的最优特征子集,得出第四系相对厚度空间分布。【结果】结果表明:Landsat-8遥感影像的光谱特征、主成分、植被指数、湿度、坡度、绿度、均值等与第四系厚度具有强相关性,可作为识别第四系土体厚度的重要特征因子;随机森林模型能有效识别第四系土体厚度信息,且对岩质区提取精度较高;经实地调查验证,模型性能均衡,预测结果合理,可用于多植被中低山区环境的第四系识别。【结论】研究成果可为土质滑坡隐患识别和风险防控提供重要数据支撑。

林下不同栽培模式下三叶青叶片光合特性的比较

目的:探究林下不同栽培模式的三叶青生长和光合特性的差异规律。方法:设置一年生三叶青林下地栽和袋栽2种模式,测定不同栽培模式下三叶青藤叶生长性状和光合特性的相关指标。结果:林下袋栽三叶青的主要农艺性状要优于林下地栽。袋栽模式下三叶青主茎长是地栽的3.04倍,林下袋栽的节数是地栽的2.09倍;林下袋栽模式下叶片的SPAD值和含氮量均显著高于地栽模式;2种模式下的光合指标之间变化趋势不尽相同,袋栽模式下叶片净光合速率、瞬时水分利用率、光合有效辐和叶面温度等指标均显著高于地栽模式;各个指标相关性分析表明三叶青的净光合速率与叶面温度呈显著正相关;光合有效辐射与SPAD值、叶片氮含量呈极显著正相关,与叶面温度呈显著正相关,而与主茎长和节数呈显著负相关。结论:林下袋栽模式下三叶青的生长和光合性能显著优于林下地栽,可为三叶青人工种植模式提供参考。

谭家河滑坡监测与精细化预警模型研究

为研究谭家河滑坡的变形阈值,通过综合分析降雨、库水位和GNSS自动监测等数据,针对谭家河滑坡实际情况,建立了谭家河滑坡的5级递进式分级预警模型。研究结果显示:①滑坡高水位位移变化小,低水位位移变化大;②谭家河滑坡位移速率与库水位速率相关,库水位下降、位移增加,库水位上升、位移减小;③在库水位160 m以下、库水位速率阈值为0.6 m/d、位移速率阈值为0.5 mm/d条件下,滑坡形成“阶跃”;④在库水位下降期间以及低库水位运行期,累计降雨量大于175 mm会对滑坡的变形产生影响,也可形成“阶跃”。

“阶跃型”滑坡位移监测动态预警系统

“阶跃型”演化规律是滑坡在等速变形阶段受外界因素影响表现出的一种波动特性,具有变形周期长、机制复杂、临灾预警难度大的特点。基于“阶跃型”滑坡变形-时间曲线的特征和规律,通过引入“一个降雨过程”定义滑坡监测序列的多期降雨区间,将预警过程划分为前期+当期降雨和当期降雨两种模式,以诱因-时间-空间作为滑坡预警的重要指标,建立了滑坡综合预警判据模型,据此提出设计麻池村1号滑坡综合动态分级预警系统的方法。并结合麻池村1号滑坡的地质条件、监测数据等信息,深入分析了滑坡的变形演化规律及预警阈值。结果表明:①滑坡变形破坏模式为牵引式,属于典型的降雨诱发的“阶跃型”堆积层滑坡;②前期降雨有效持时为10 d,前期+当期降雨模式下的降雨阈值分别为24、32 mm,当期降雨模式下滑坡的的降雨阈值为37 mm,滑坡的位移速率阈值为12 mm;③以降雨量、位移速率到达阈值时为Ⅲ级黄色预警中心面(线),构建滑坡的综合动态分级预警系统,将滑坡预警从传统的“阈值预警”升级为“过程预警”,使得预警更具针对性。

考虑破坏模式的危岩崩塌易发性评价--以兴山县古洞口水库首段为例

本文以古洞口—平水段为研究对象,通过分析研究区特有的地质特征与边坡发育情况,将崩塌按受力状态与起始运动方式划分为:滑移式、倾倒式、错断式3类,利用ArcGIS软件的空间分析功能,具体分析了区内危岩破坏模式与各控制因素的相关关系,并结合3类崩塌的发育特征确定相应评价因子,最后采用模糊层次分析法(FAHP)建立指标体系,通过指标体系得出古洞口—平水段崩塌灾害易发性评价结果.结果显示:3类崩塌灾害易发性与此类灾害点的分布密度较吻合,易发性评价结果符合实际.结果表明:距公路越近,崩塌发生的可能性越大,滑移式崩塌主要分布在顺向坡地区,倾倒式崩塌主要分布在逆向坡地区,错断式崩塌主要分布在横向坡地区,评价模型的正确率AUC值均接近于1,说明易发性评价的精度较好,评价结果对研究区崩塌灾害风险管控具有一定的指导意义.

Fractal model of spontaneous imbibition in low-permeability reservoirs coupled with heterogeneity of pore seepage channels and threshold pressure

Spontaneous imbibition(SI)is an important mechanism for enhancing oil recovery in low-permeability reservoirs.Due to the strong heterogeneity,and the non-Darcy flow,the construction of SI model for lowpermeability reservoirs is extremely challenging.Commonly,traditional SI models based on single or averaged capillary tortuosity ignore the influence of heterogeneity of pore seepage channels and the threshold pressure(TP)on imbibition.Therefore,in this work,based on capillary model and fractal theory,a mathematical model of characterizing SI considering heterogeneity of pore seepage channels is established.On this basis,the threshold pressure was introduced to determine the pore radius at which the wetted phase can displace oil.The proposed new SI model was verified by imbibition experimental data.The study shows that for weakly heterogeneous cores with permeability of 0-1 m D,the traditional SI model can characterize the imbibition process relatively accurately,and the new imbibition model can increase the coefficient of determination by 1.05 times.However,traditional model has serious deviations in predicting the imbibition recovery for cores with permeability of 10-50 m D.The new SI model coupling with heterogeneity of pore seepage channels and threshold pressure effectively solves this problem,and the determination coefficient is increased from 0.344 to 0.922,which is increased by2.68 times.For low-permeability reservoirs,the production of the oil in transitional pores(0.01-0.1μm)and mesopores(0.1-1μm)significantly affects the imbibition recovery,as the research shows that when the heterogeneity of pore seepage channels is ignored,the oil recovery in transitional pores and mesopores decreases by 7.54%and 4.26%,respectively.Sensitivity analysis shows that increasing interfacial tension,decreasing contact angle,oil-water viscosity ratio and threshold pressure will increase imbibition recovery.In addition,there are critical values for the influence of these factors on the imbibition recovery,which provides theoretical support for surfactant optimization.

Investigations of the mechanical response of dummy HTPB propellant grain under ultrahigh acceleration overload conditions using onboard flight-test measurements

In this paper,to study the mechanical responses of a solid propellant subjected to ultrahigh acceleration overload during the gun-launch process,specifically designed projectile flight tests with an onboard measurement system were performed.Two projectiles containing dummy HTPB propellant grains were successfully recovered after the flight tests with an ultrahigh acceleration overload value of 8100 g.The onboard-measured time-resolved axial displacement,contact stress and overload values were successfully obtained and analysed.Uniaxial compression tests of the dummy HTPB propellant used in the gunlaunched tests were carried out at low and intermediate strain rates to characterize the propellant's dynamic properties.A linear viscoelastic constitutive model was employed and applied in finite-element simulations of the projectile-launching process.During the launch process,the dummy propellant grain exhibited large deformation due to the high acceleration overload,possibly leading to friction between the motor case and propellant grain.The calculated contact stress showed good agreement with the experimental results,though discrepancies in the overall displacement of the dummy propellant grain were observed.The dynamic mechanical response process of the dummy propellant grain was analysed in detail.The results can be used to estimate the structural integrity of the analysed dummy propellant grain during the gun-launch process.

Quality of life after pancreatic surgery

BACKGROUND Pancreatic surgery is challenging owing to the anatomical characteristics of the pancreas.Increasing attention has been paid to changes in quality of life(QOL)after pancreatic surgery.AIM To summarize and analyze current research results on QOL after pancreatic surgery.METHODS A systematic search of the literature available on PubMed and EMBASE was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Relevant studies were identified by screening the references of retrieved articles.Studies on patients’QOL after pancreatic surgery published after January 1,2012,were included.These included prospective and retrospective studies on patients'QOL after several types of pancreatic surgeries.The results of these primary studies were summarized inductively.RESULTS A total of 45 articles were included in the study,of which 13 were related to pancreaticoduodenectomy(PD),seven to duodenum-preserving pancreatic head resection(DPPHR),nine to distal pancreatectomy(DP),two to central pancre-atectomy(CP),and 14 to total pancreatectomy(TP).Some studies showed that 3-6 months were needed for QOL recovery after PD,whereas others showed that 6-12 months was more accurate.Although TP and PD had similar influences on QOL,patients needed longer to recover to preoperative or baseline levels after TP.The QOL was better after DPPHR than PD.However,the superiority of the QOL between patients who underwent CP and PD remains controversial.The decrease in exocrine and endocrine functions postoperatively was the main factor affecting the QOL.Minimally invasive surgery could improve patients’QOL in the early Core Tip:This review summarizes and analyzes current research results on quality of life(QOL)after pancreatic surgery.The article covers the discussion and analysis of the QOL of various pancreatic surgeries.Which kind of surgical procedure has better QOL is controversial.The long-term benefits on QOL of minimally invasive surgery over open surgery are contro-INTRODUCTION The pancreas,located in the retroperitoneum,is a glandular organ with endocrine and exocrine functions.It can be divided into four main parts:Head,neck,body,and tail.Pancreatic surgery can be divided into pancreaticoduoden-ectomy(PD),duodenum-preserving pancreatic head resection(DPPHR),distal pancreatectomy(DP),central pancre-atectomy(CP),and total pancreatectomy(TP).Pancreatic surgery is challenging due to the organ’s complex anatomical structure,peripheral vascularity,and intractable postoperative complications.Following the standardization of surgical steps and improvements in relevant medical techniques and surgical instruments,the safety of pancreatic surgery has significantly improved.Perioperative morbidity,mortality,and other related indicators have become more acceptable.However,owing to the organ’s essential role in digestion,absorption,and blood glucose regulation,changes in the quality of life(QOL)of patients after pancreatic surgery have attracted the attention of surgeons.More patients with non-malignant pancreatic diseases are willing to undergo surgical treatment because of the acceptable safety.In this case,from the perspective of the patient postoperatively,the significance of rehabilitation reflects the traditional perioperative outcome and QOL[1].The QOL is a new concept that extends beyond health.Although there is no consensus on its conception[2],we can consider it a multi-dimensional architecture that incorporates objective and individual subjective views of aspects of one’s physical,psychological,and social well-being[3-5].It includes evaluating physical health,and many subscales,such as emotion,job,culture,family,sociability,economy,cognition,happiness,sex,and some symptoms[6].Since people have realized the importance of QOL,many QOL scales have emerged,including the European Organization for Research and Treatment of Cancer QLQ-C30,European Quality of Life 5-dimension,36-item Short,etc.However,it is challenging to follow up on patients’QOL once they are discharged from the hospital.Consequently,most relevant studies had small sample sizes or lacked long-term follow-up results.Moreover,a summary of studies on QOL after pancreatic surgery is lacking.This study assessed the QOL in patients who underwent PD,DPPHR,DP,CP and TP.We conducted this study to describe the existing findings on the QOL after pancreatic surgery to make it easier for surgeons and patients to decide on a surgical approach.In addition,we attempted to identify controversial results to encourage further targeted research.

废旧磷酸铁锂电池钠盐焙烧提锂工艺

废旧锂离子电池的无害化处理和资源化回收是保护环境、节约资源、促进循环经济发展的必然选择。提出了一种钠盐焙烧—常温水浸工艺,用于从废旧磷酸铁锂电池中回收锂。系统研究了硫酸钠添加量、焙烧温度、焙烧时间等对锂选择性浸出的影响,并对焙烧产物进行了XRD和SEM表征。结果表明,在硫酸钠与磷酸铁锂正极粉质量比为1.6、焙烧温度650℃、焙烧时间2.0 h、水浸时间15 min的条件下,锂的浸出率达到96.81%,回收得到的硫酸锂产品纯度达到97.36%。与传统方法相比,该工艺具有不使用强酸、高效锂铁分离、回收过程简便等优势,具备广泛的工业应用前景。

Enhanced thermal stability and mechanical properties of high-temperature resistant Al-Cu alloy with Zr and Mn micro-alloying

The high temperature(HT)thermal stability and mechanical properties of Al-5%Cu(AC)and Al-5%Cu-0.2%Mn-0.2 Zr%(ACMZ)alloys from 573 to 673 K were systematically studied.The results displayed that micro-alloying additions of Zr and Mn elements have presented a significant role in stabilizing the main strengthening metastableθ′precipitates at a temperature as high as 573 K.Simultaneously,the HT tensile test demonstrated that ACMZ alloy retained their strength of(88.6±8.8)MPa,which was much higher than that of AC alloy((32.5±0.8)MPa)after the thermal exposure at 573 K for 200 h.Finally,the underlying mechanisms of strength and ductility enhancement mechanism of the ACMZ alloy at HT were discussed in detail.

降雨型堆积层滑坡降雨阈值及预警模型研究--以王家坡滑坡为例

堆积层滑坡在降雨作用下,累积位移曲线呈现不规则的“阶跃”状.针对此类型滑坡,将滑坡所处的地质条件与滑坡的变形特征相结合,进而建立合理的预警模型,是提高滑坡预警精度的必要手段.本文以王家坡滑坡为典型研究案例,在分析降雨、滑坡位移以及位移速率等监测资料的基础上,确定王家坡滑坡的位移回落时间、降雨阈值.考虑滑坡变形对降雨的响应机制,将实际降雨工况分为当期降雨和前期降雨+当期降雨两种类型,通过数值模拟分析降雨条件下王家坡滑坡的稳定性,对传统的经验性降雨阈值进行改进,针对当期降雨,建立降雨诱发滑坡失稳滑动的I-D阈值曲线,针对前期降雨+当期降雨,建立滑坡破坏的A-I-D阈值曲面.最后,基于改进的I-D阈值曲线和A-I-D阈值曲面建立了王家坡滑坡4级预警模型.

库水位变动条件下谭家河滑坡变形阈值分析

水库型滑坡主要受水库蓄水、水位升降以及降雨等综合因素影响,稳定性差、变形机理复杂,同时其规模一般较大、危害性强;以三峡库首区域典型代表性水库滑坡-秭归谭家河滑坡为例,对丰富的专业监测数据进行了深入细致的分析,研究结果表明:滑坡主要受到库水位变动的影响,当库水位达到172 m时,滑坡开始产生较大的变形;由于长期库水位变动的影响,滑坡在高库水位和库水位下降时,位移速率较大,监测曲线形成阶跃,滑坡同时受到浮托减重效应和动水压力效应的影响.在库水位下降期,7d累积降雨量大于70 mm,以及在145 m低水位运行期,7 d累积降雨量超过170 mm,会对滑坡的变形产生明显的影响.

Parameter Optimization for Amplify-and-Forward Relaying Systems with Pilot Symbol Assisted Modulation Scheme

Cooperative diversity is a promising technology for future wireless networks. In this paper, we consider a cooperative communication system operating in an amplify-and-forward (AF) mode with a pilot symbol as-sisted modulation (PSAM) scheme. It is assumed that a linear minimum mean square estimator (LMMSE) is used for the channel estimation at the receiver. A simple and easy-to-evaluate asymptotical upper bound (AUB) of the symbol-error-rate (SER) is derived for uncoded AF cooperative communication systems with quadrature amplitude modulation (QAM) constellations. Based on the AUB, we propose a criterion for the parameter optimization in the PSAM scheme. We discuss how the pilot spacing and the length of the Wiener ?lter should be chosen under the constraint of a tradeoff between pilot overhead, estimation accuracy, and receiver complexity. We also formulate an power allocation problem for the considered system. It is shown that the power allocation problem can optimally be solved by means of a gradient search method. Numerical simulations are presented to verify the correctness of the theoretical results and to demonstrate the benefits of the parameter optimization.

基于前期雨型影响的汉江支流堵河左岸麻池村1号滑坡监测预警降雨阈值研究

【目的】降雨是诱发滑坡变形破坏的重要因素,不同降雨模式引起的降雨入渗类型对滑坡稳定性影响各不相同,由此形成的滑坡灾害经常造成严重的经济损失和人员伤亡,合理的考虑前期降雨是实现准确预警预报的前提。【方法】以麻池村1号滑坡为例,首先精细分析了降雨作用下滑坡的地表-深部位移变形特征,定性评价滑坡变形过程与降雨因素的响应关系,以此研究4种不同降雨型式下滑坡渗透稳定性系数的动态演变规律,探讨不同降雨模式对滑坡的影响,并通过滑坡阶跃区段位移与前期降雨指标的相关性分析,确定了对滑坡稳定性最不利的前期降雨型式下的降雨阈值。【结果】结果显示:GNSS监测系统自2019年6月首测以来,地表累积位移为881.22~1067.88 mm,最大日位移速率达264 mm/d(G6),2021年汛期强降雨频次增高,滑坡各变形区域出现“整体阶跃”现象。【结论】结果表明:(1)滑坡受降雨因素影响,变形呈现阶跃型演化特征,深部位移曲线反映了不同岩土成分结构的水敏性;(2)递增型前期降雨对滑坡的稳定性尤为不利,递增型降雨更有利于地表雨水的入渗;(3)滑坡的前期有效降雨持时为10 d,其对应的7次“阶跃”变形与前期降雨型式密切相关,递增型的前期降雨更易诱发滑坡加速变形。基于“一个降雨过程”理论,获取“前期(10 d)+当期降雨(1 d)”模式下递增型前期降雨的滑坡降雨阈值为86 mm。验证表明该降雨阈值预测效果较好,具有重要的灾害预警意义和参考价值。

紫荆皮与紫金皮的本草考证及现代应用

紫荆皮,现又名紫金皮,作为传统民族中药,因各地方使用来源不同,造成同名异物和异物同名,用药长期混乱。目前收载及争议最多的为豆科紫荆的Cercis chinensis Bunge树皮和木兰科南五味子的Kadsuralongipedunculata Finet et Gagnep.根皮两种来源,针对现状亟待对其古籍文献记载进行追本溯源明确两者的药用历史及联系。现通过对紫荆皮和紫金皮两个易混名称进行历代本草和医籍文献的检索、归纳和分析,对两者的名称、基原、性味归经及功效主治进行考证辨析,并结合现代记载及应用,作出阐述。通过考证发现,紫荆皮和紫金皮两者名称不可互用,功效区别甚远,临床应区分使用。在名称上,若以紫荆皮为正名,应以红内消作别名;若以紫金皮为正名,应以红木香作别名。紫荆皮和紫金皮从宋开始出现并出现混淆,到元明逐渐应用广泛并开始加以区分,在历代古籍中多交替或同时出现,混用现象直至现代。在基原上,紫荆皮应为豆科紫荆Cercis chinensis Bunge的树皮;紫金皮应为木兰科南五味子Kadsura longipedunculata Finet et Gagnep.的根皮。在功效主治上,紫荆皮的主要功效为破宿血、下五淋,用于消无名肿毒及解蛇虫毒等证;紫金皮的主要功效为活血通络止痛、治膝风、理脾胃,用于打扑损伤、筋断刺痛等证。木兰科南五味子根皮不仅为古代临床长期的药用品种,也是现代应用最广的主流品种。现通过对紫荆皮和紫金皮两者的古籍梳理,厘清了紫荆皮和紫金皮的名称、基原、性味归经及功效主治等方面的历史沿革,对今后两者的区分、现代应用、标准修订及开发提供了一定的参考依据。

基于“阶跃”变形特征的降雨型滑坡预警判据探讨

由于滑坡灾害的发生具有随机性和复杂性,经常给人们生活造成严重的经济损失,甚至威胁生命安全,故建立滑坡预警判据及模型是减小损失的重要手段。文章首先确定了有效降雨量-变形速率-改进切线角为降雨型阶跃滑坡的预警关键判据。然后运用斜率单变点法确定滑坡“阶跃”变形曲线上的“破坏拐点”和“稳定拐点”并提取变形加速区间的详细信息,以此求解有效降雨量-变形速率-改进切线角综合预警判据阈值。最后,结合麻池村1号滑坡各发展阶段宏观变形特征,将时空演化规律有机结合,建立了4级递进式综合判据分级预警模型。结果表明:麻池村1号滑坡的运移形式为牵引式,在降雨因素的激发下,累计位移曲线呈典型的“阶跃”变形特征;麻池村1号滑坡变形受前期降雨影响,前期降雨与当期降雨组成一个降雨过程的时间间隔阈值为10 d,“前期+当期降雨”模式下对应的降雨阈值分别为24 mm、32 mm;基于监测数据精细化分析以及改进切线角法获取的麻池村1号滑坡的位移速率阈值为12 mm/d。研究可为此类型滑坡灾害的预警提供理论基础和技术指导。

基于数值模拟的危岩崩塌特征及防治研究

针对兴山县赵家娅危岩崩塌的高位危岩崩塌破坏,运用数值模拟手段,对区域危岩体稳定性、演化规律及崩塌破坏运动特征进行模拟分析,获得崩塌落石的运动轨迹、弹跳高度、冲击能量等。结果表明,赵家娅危岩在天然状况下稳定性较好,在连续降雨或暴雨条件下,裂隙水逐渐渗透,存在主控结构面失稳发生崩塌破坏的可能;危岩发生崩塌破坏后,大部分落石将停留在坡面上,少部分落石碰撞回弹后停止在坡脚公路;结合现场实际情况及RocFall模拟提出“清危+坡面平整+被动防护网”的治理措施。研究成果可为类似高位危岩崩塌灾害治理工程提供参考。

掌心里的天机——从旋光、特异性识别到手性污染

生活中许多重要的化学物质均具有手性,但大众对其认识不足。本文详细介绍了三个科普实验:手性万花筒、简易旋光仪和手性指示剂。手性万花筒可简单鉴别手性物质与非手性物质;简易旋光仪可直观地区分手性物质是左旋还是右旋,并检测手性物质的旋光度;手性指示剂无需仪器,通过颜色变化就可分辨特定结构的对映体,适合向更专业的人群展示手性物质的特异性识别。这三个实验深入浅出,操作简单,现象生动有趣,向大众科普了手性化学物质的物理性质和化学性质,有良好的科普实践展示效果,多方位展示了手性之美、化学之美。