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.

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。

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.

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。

可自动校准距离的智能手机视力测试APP(WHOeyes)的真实世界应用

目的:开发一款可自动校准测试距离的智能手机视力检测APP(WHOeye的iOS版本),并评估其实用性。方法:WHOeyes在经过验证的视力检测APP“V@home”的基础上新增自动距离校准(automatic distance calibration,ADC)功能。研究招募了3组不同年龄(≤20岁、20~40岁、>40岁)的中国受试者,分别使用糖尿病视网膜病变早期治疗研究(Early Treatment Diabetic Retinopathy Study,ETDRS)视力表和WHOeyes进行远距离和近距离的视力检测。ADC功能用于确定WHOeyes的测试距离。红外测距仪用于确定ETDRS的测试距离以及WHOeyes的实际测试距离。通过问卷调查评估用户满意度。结果:WHOeyes ADC确定的实际测试距离在3个年龄组中均与预期测试距离总体上表现出良好的一致性(P>0.50)。在远距离和近距离视力检测方面,WHOeyes的准确性与ETDRS相当。WHOeyes与ETDRS之间的平均视力差异范围为–0.084~0.012 logMAR,各组的二次加权卡帕系数(quadratic weighted kappa,QWK)均大于0.75。WHOeyes在近距离和远距离视力检测中的重测信度高,平均差异范围为–0.040~0.004 logMAR,QWK均大于0.85。问卷调查显示WHOeyes具有较好的用户体验和接受度。结论:与金标准ETDRS视力表方法相比,WHOeyes测试距离较为准确,可以提供准确的远距离和近距离视力测量结果。

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。

Fermi Surface Nesting with Heavy Quasiparticles in the Locally Noncentrosymmetric Superconductor CeRh_(2)As_(2)

The locally noncentrosymmetric heavy fermion superconductor CeRh_(2)As_(2) has attracted considerable interests due to its rich superconducting phases,accompanied by possible quadrupole density wave and pronounced antiferromagnetic excitations.To understand the underlying physics,here we report measurements from highresolution angle-resolved photoemission.Our results reveal fine splittings of the conduction bands related to the locally noncentrosymmetric structure,as well as a quasi-two-dimensional Fermi surface(FS)with strong 4f contributions.The FS shows signs of nesting with an in-plane vector q_(1)=(π/α,π/α),which is facilitated by the heavy bands nearˉ𝑋arising from the characteristic conduction-X hybridization.The FS nesting provides a natural explanation for the observed antiferromagnetic spin fluctuations at(π/α,π/α),which might be the driving force for its unconventional superconductivity.Our experimental results can be reasonably explained by density functional theory plus dynamical mean field theory calculations,which can capture the strong correlation effects.Our study not only provides spectroscopic signature of the key factors underlying the field-induced superconducting transition,but also uncovers the critical role of FS nesting and lattice Kondo effect in the underlying magnetic fluctuations.

孕灾机理与综合遥感结合的三峡库首顺层岩质滑坡隐患识别

隐患识别是实现地质灾害从注重灾后救助向注重灾前预防转变的重要技术工作。本文以三峡库首秭归沙镇溪镇周边岸坡段顺层岩质滑坡隐患识别为基础,提出基于孕灾机理与综合遥感相结合的地质灾害隐患识别方法。首先,借助资料整理分析、遥感调查和现场调查等查明孕灾环境,并建立孕灾指标体系;其次,针对典型灾害体开展地质结构与致灾机理分析,以揭示典型孕灾模式,并建立综合遥感判识标志;再次,采用易发性分区评价,结合高分光学卫星遥感与InSAR等天基遥感变化检测技术,圈定隐患识别的易发重点靶区;然后,针对高易发靶区,利用无人机摄影测量、LiDAR等空基遥感技术识别疑似隐患体;最后,通过地面核查与专家判识,确认并圈定地质灾害隐患。利用该套技术方法,在工作区内共识别出8处地质灾害隐患,其中5处为具备孕灾模式但尚未出现明显变形的顺层岩质滑坡隐患体。结果表明,该套技术方法以查明孕灾环境及建立孕灾模式为核心与前提、以综合遥感探测为重要技术支撑,可以弥补目前主要依赖遥感变化探测开展隐患识别易造成精度较低甚至失效的缺陷,尤其适合于山高坡陡、植被覆盖茂密地区的隐蔽性、突发性地质灾害的隐患识别。

大株红景天对糖尿病视网膜病变大鼠眼血流影响的实验研究

目的:探讨大株红景天对糖尿病视网膜病变(DR)大鼠眼血流的影响。方法:将90只SD大鼠随机分为对照组、模型组和干预组各30只。模型组和干预组大鼠高糖高脂饲料喂养+链脲佐菌素(40mg/kg)腹腔注射,以构建DR模型大鼠,同时对照组大鼠基础饲料喂养+等量生理盐水腹腔注射。造模成功后,干预组大鼠注射大株红景天注射液(10mL/次,1次/d),对照组和模型组大鼠注射等量生理盐水。连续干预治疗4wk。采用Laser Doppler Flowmetry激光血流仪检测大鼠眼部血流,采用TUNEL法检测大鼠视网膜细胞凋亡,采用RT-PCR法和Western blot法检测大鼠视网膜组织血管内皮生长因子(VEGF)、胶质纤维酸性蛋白(GFAP)和谷氨酸/天冬氨酸转运体(GLAST)表达。结果:模型组和干预组大鼠全血粘度、全血粘度高切、全血粘度低切和血沉高于对照组(P<0.01),而干预组大鼠各指标较模型组降低(P<0.01)。模型组和干预组大鼠PSV和EDC低于对照组(P<0.01),RI高于对照组(P<0.01);而干预组大鼠PSV和EDC较模型组增加(P<0.01),RI较模型组降低(P<0.01)。模型组和干预组大鼠视网膜细胞凋亡率大于对照组(P<0.01),而干预组凋亡率较模型组降低(P<0.01)。模型组和干预组大鼠视网膜组织VEGF和GFAP表达高于对照组(P<0.01),GLAST表达低于对照组(P<0.01);而干预组大鼠VEGF和GFAP表达较模型组降低(P<0.01),GLAST表达较模型组增加(P<0.01)。结论:大株红景天注射液能显著改善糖尿病视网膜病变模型大鼠眼部血液流变学和血流动力学,减少模型大鼠视网膜细胞凋亡,下调视网膜组织VEGF和GFAP表达,上调GLAST表达。

应用型地质工程人才协同培养模式探索和实践——以三峡大学地质工程专业为例

本文结合三峡大学地质工程应用型人才培养的实践,采用校企协同编制培养方案和开展课堂教学,校校协同和校地协同建设地质实习基地,提出了应用型地质工程人才协同培养的"协同、构建、实现、运行"的四步模式(CEIO模式),从而达到"专业基础扎实、实践能力强"的应用型人才培养目标。

Deflection Measurement for Bridges Based on Secant Inclination

Deflection is a significant indicator of bridge’s strength and its whole stiffness, so the research on deflection measurement is an important aspect of bridge health monitoring. There have existed many measurement methods of bridge deflection so far, while inclination method is gradually catching more and more attention for its fair obviously comprehensive advantages. However, the inclination method at present focuses on measuring the rotation of bridge’s section at testing point, that is, the tangent angle of deflection curve. With the tangent angle, the deflection curve can be determined by the methods of curve fitting or (and) integration or conjugate beam. The methods mentioned above, are not only complicated in calculation, but also bad in accuracy. The deflection measurement method proposed by this paper is based on measuring the inclination of two points initiatively in horizontal line, that is, the secant angle of the deflection curve, and on the simple triangle function operation. The proposed method is simple in theory, but good in accuracy for either static or dynamic load. The numerical simulation suggests that the error of the proposed method is less than 1%.

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.