Grubbs催化剂催化油酸甲酯与乙烯复分解反应

以生物质油酸甲酯(MO)作原料,与乙烯进行交叉复分解反应,可同时制备1-癸烯和9-癸烯酸甲酯。首先评估了3种常用的烯烃复分解催化剂对体系的影响,筛选出了Grubbs I代催化剂为最佳催化剂,以MO的转化率和1-癸烯、9-癸烯酸甲酯的产率以及选择性为评价指标对Grubbs I代催化剂的工艺条件进行探索,结果显示:溶剂为甲苯,MO浓度0.1 mol/L,温度40℃、乙烯压力0.2 MPa,反应时间2 h,催化剂用量为MO的1%(摩尔分数)时,得到MO转化率为97.4%,1-癸烯的产率和选择性分别为97.4%和100%,9-癸烯酸甲酯的产率和选择性分别为76.4%和78.4%。Grubbs II作催化剂的较佳工艺条件为溶剂为甲苯,MO浓度0.1 mol/L,乙烯压力0.5 MPa,温度40℃,反应时间1 h,催化剂用量为MO的0.5%,该条件下1-癸烯产率达到76.4%,9-癸烯酸甲酯产率达80.1%,MO转化率为92.7%。

基于Grubbs准则的改进的2D CA-CFAR

在不同程度的噪声存在下,现代雷达通过恒虚警率(constant false alarm rate, CFAR)检测算法最大化提升目标的检测概率。针对车载毫米波雷达目标检测过程中传统2维单元均值类恒虚警率(two-dimensional cell averaging CFAR,2D CA-CFAR)检测算法在相邻多目标条件下出现的目标遮蔽问题,提出了一种基于格拉布斯(Grubbs)准则的2D CA-CFAR的改进算法。该方法利用Grubbs准则剔除参考窗中的奇异值和干扰目标,从而获得更加准确的检测阈值。仿真结果表明:改进的算法极大地降低了多目标环境中传统2D CA-CFAR检测器的“遮盖效应”,验证了所提算法的有效性。

Grubbs三代催化剂的合成及其催化双环戊二烯可控成型

用Grubbs二代催化剂(G2)与吡啶类配体反应制备了一系列Grubbs三代催化剂(G3),采用^(1)HNMR对其进行了结构表征。利用制备的G3催化双环戊二烯(DCPD)本体聚合,在添加三苯基膦阻聚剂实现DCPD聚合过程可控的基础上,采用模具浇注法制备了聚双环戊二烯(p-DCPD)板材,探讨了阻聚剂、不同催化剂及催化剂用量对p-DCPD板材性能的影响,采用FTIR、TGA和DSC对制备的p-DCPD板材进行了表征,通过同步热分析仪、差示扫描量热仪、微机控制电子万能实验机、悬臂梁冲击试验机对p-DCPD板材的力学性能进行了测试。结果表明,三苯基膦对G3的调控效果优于G2,合成的G3在催化DCPD本体聚合时,表现出较高的催化活性,且其催化制备的p-DCPD板材的力学性能明显优于G2催化制备的样品。尤其是,由苯亚甲基-[1,3-双(三甲基苯基)-2-咪唑啉亚基]-二氯-二(3-甲基吡啶)合钌(G3-5)制得的p-DCPD板材表现出优异的热稳定性,具有紧致的交联结构。

基于EMD距离和Grubbs准则的煤矿电网选线

针对煤矿电网发生单相接地故障时难以正确选线的问题,提出一种基于EMD距离(Earth Mover′s Distance)和Grubbs准则的煤矿电网选线。故障发生后两两计算各馈线零序电流波形间的EMD距离,从而得到综合EMD距离矩阵。基于Grubbs准则筛选出综合EMD距离矩阵中的异常值,其对应线路即为故障线路。仿真分析证明,所提算法准确性不受故障线路、故障位置、故障合闸角及接地电阻等因素的影响,具有较高的准确性和较强的适用性。

A generalized nonlinear three-dimensional Hoek‒Brown failure criterion

To understand the strengths of rocks under complex stress states,a generalized nonlinear threedimensional(3D)Hoek‒Brown failure(NGHB)criterion was proposed in this study.This criterion shares the same parameters with the generalized HB(GHB)criterion and inherits the parameter advantages of GHB.Two new parameters,b,and n,were introduced into the NGHB criterion that primarily controls the deviatoric plane shape of the NGHB criterion under triaxial tension and compression,respectively.The NGHB criterion can consider the influence of intermediate principal stress(IPS),where the deviatoric plane shape satisfies the smoothness requirements,while the HB criterion not.This criterion can degenerate into the two modified 3D HB criteria,the Priest criterion under triaxial compression condition and the HB criterion under triaxial compression and tension condition.This criterion was verified using true triaxial test data for different parameters,six types of rocks,and two kinds of in situ rock masses.For comparison,three existing 3D HB criteria were selected for performance comparison research.The result showed that the NGHB criterion gave better prediction performance than other criteria.The prediction errors of the strength of six types of rocks and two kinds of in situ rock masses were in the range of 2.0724%-3.5091%and 1.0144%-3.2321%,respectively.The proposed criterion lays a preliminary theoretical foundation for prediction of engineering rock mass strength under complex in situ stress conditions.

Estimating shear strength of high-level pillars supported with cemented backfilling using the HoekeBrown strength criterion

Deep metal mines are often mined using the high-level pillars with subsequent cementation backfilling(HLSCB)mining method.At the design stage,it is therefore important to have a reasonable method for determining the shear strength of the high-level pillars(i.e.cohesion and internal friction angle)when they are supported by cemented backfilling.In this study,a formula was derived for the upper limit of the confining pressure σ3max on a high-level pillar supported by cemented backfilling in a deep metal mine.A new method of estimating the shear strength of such pillars was then proposed based on the Hoek eBrown failure criterion.Our analysis indicates that the horizontal stress σhh acting on the cemented backfill pillar can be simplified by expressing it as a constant value.A reasonable and effective value for σ3max can then be determined.The value of s3max predicted using the proposed method is generally less than 3 MPa.Within this range,the shear strength of the high-level pillar is accurately calculated using the equivalent MohreCoulomb theory.The proposed method can effectively avoid the calculation of inaccurate shear strength values for the high-level pillars when the original HoekeBrown criterion is used in the presence of large confining pressures,i.e.the situation in which the cohesion value is too large and the friction angle is too small can effectively be avoided.The proposed method is applied to a deep metal mine in China that is being excavated using the HLSCB method.The shear strength parameters of the high-level pillars obtained using the proposed method were input in the numerical simulations.The numerical results show that the recommended level heights and sizes of the high-level pillars and rooms in the mine are rational.

Nonlinear empirical failure criterion for rocks under triaxial compression

Based on existing triaxial compression experimental data,a new empirical failure criterion with wide applicability was proposed considering hydrostatic pressure,second stress invariance,and maximum shear stress.Four fitting evaluation indicators were used to verify the consistency of the new failure criterion,and the differences with the other 6 failure criteria were discussed.The characteristics of the new failure criteria in the principal stress space were finally analyzed.The results indicate that(1)the new failure criterion exhibits strong predictive ability for triaxial experiments and has good applicability for both intact and jointed rocks;(2)the influence of hydrostatic pressure on the failure surface exhibits a non-linear trend,and different hydrostatic pressure also exhibits different distribution patterns on the deviatoric stress plane,with a distribution characteristic pattern of hexagonal snowflake-regular hexagon.The maximum shear stress has a torsional effect on the new criterion,in the three-dimensional failure surface.The parameters a and b of the rock have an impact on the failure surface morphology of the new criterion function on the offset surface.

Rockburst criterion and evaluation method for potential rockburst pit depth considering excavation damage effect

Excavation-induced disturbances in deep tunnels will lead to deterioration of rock properties and formation of excavation damaged zone(EDZ).This excavation damage effect may affect the potential rockburst pit depth.Taking two diversion tunnels of Jinping II hydropower station for example,the relationship between rockburst pit depth and excavation damage effect is first surveyed.The results indicate that the rockburst pit depth in tunnels with severe damage to rock masses is relatively large.Subsequently,the excavation-induced damage effect is characterized by disturbance factor D based on the Hoek-Brown criterion and wave velocity method.It is found that the EDZ could be further divided into a high-damage zone(HDZ)with D=1 and weak-damage zone(WDZ),and D decays from one to zero linearly.For this,a quantitative evaluation method for potential rockburst pit depth is established by presenting a three-element rockburst criterion considering rock strength,geostress and disturbance factor.The evaluation results obtained by this method match well with actual observations.In addition,the weakening of rock mass strength promotes the formation and expansion of potential rockburst pits.The potential rockburst pit depth is positively correlated with HDZ and WDZ depths,and the HDZ depth has a significant contribution to the potential rockburst pit depth.

一种IGrubbs-LWLR的区域高程异常拟合方法

针对测量数据中粗差干扰及高程异常拟合方法选择较为困难的问题,结合格拉布斯(Grubbs)法判别粗差的原理,提出一种改进格拉布斯(Improved Grubbs,IGrubbs)结合局部加权线性回归(Local Weighted Linear Regression,LWLR)的拟合模型构建法。在原Grubbs法则的基础上,引入自适应迭代,在训练数据中,对粗差进行识别,并设定粗差剔除完成的指标参数,从而降低原方法中发生误判或漏判的概率,并利用局部加权线性回归法通过预处理后的训练样本数据来建立区域高程异常拟合模型。实验结果表明,相较于传统Grubbs法则,改进后的Grubbs法对于高程异常数据中的粗差剔除更为快速有效,且利用局部加权线性回归法所构建的区域高程异常拟合模型的预测精度及稳定性也得到一定程度的提高,对今后工程中的测高工作具备一定的参考意义。

Enhanced Hoek-Brown(H-B)criterion for rocks exposed to chemical corrosion

Underground constructions often encounter water environments,where water–rock interaction can increase porosity,thereby weakening engineering rocks.Correspondingly,the failure criterion for chemically corroded rocks becomes essential in the stability analysis and design of such structures.This study enhances the applicability of the Hoek-Brown(H-B)criterion for engineering structures operating in chemically corrosive conditions by introducing a kinetic porosity-dependent instantaneous mi(KPIM).A multiscale experimental investigation,including nuclear magnetic resonance(NMR),X-ray diffraction(XRD),scanning electron microscopy(SEM),pH and ion chromatography analysis,and triaxial compression tests,is employed to quantify pore structural changes and their linkage with the strength responses of limestone under coupled chemical-mechanical(C-M)conditions.By employing ion chromatography and NMR analysis,along with incorporating the principles of free-face dissolution theory accounting for both congruent and incongruent dissolution,a kinetic chemical corrosion model is developed.This model aims to calculate the kinetic porosity alterations within rocks exposed to varying H+concentrations and durations.Subsequently,utilizing the generalized mixture rule(GMR),the kinetic porositydependent mi is formulated.Evaluation of the KPIM-enhanced H-B criterion using compression test data from 5 types of rocks demonstrated a high level of consistency between the criterion and the experimental results,with a coefficient of determination greater than 0.96,a mean absolute percentage error less than 4.84%,and a root-mean-square deviation less than 5.95 MPa.Finally,the physical significance of the porosity-dependent instantaneous mi is clarified:it serves as an indicator of a rock’s capacity to leverage the confining pressure effect.

Strength criterion for crystalline rocks considering grain size effect and tensile-compressive strength ratio

The macroscopic mechanical properties of rocks are significantly influenced by their microstructure.As a material bonded by mineral grains,the grain morphology of crystalline rock is the primary factor influencing the strength.However,most strength criteria neglect the strength variations caused by different grain characteristics in rocks.Furthermore,the traditional linear criteria tend to overestimate tensile strength and exhibit apex singularity.To address these shortcomings,a piecewise strength criterion that considers the grain size effect has been proposed.A part of an ellipse was employed to construct the envelope of the tensive-shear region on the meridian plane,to accurately reproduce the low tensile-compressive strength ratio.Based on the analysis of experimental data,both linear and exponential modification functions that account for grain size effects were integrated into the proposed criterion.The corresponding finite element algorithm has been implemented.The accuracy and applicability of the proposed criterion were validated by comparing with the experimental data.

Maximum Correntropy Criterion-Based UKF for Loosely Coupling INS and UWB in Indoor Localization

Indoor positioning is a key technology in today’s intelligent environments,and it plays a crucial role in many application areas.This paper proposed an unscented Kalman filter(UKF)based on the maximum correntropy criterion(MCC)instead of the minimummean square error criterion(MMSE).This innovative approach is applied to the loose coupling of the Inertial Navigation System(INS)and Ultra-Wideband(UWB).By introducing the maximum correntropy criterion,the MCCUKF algorithm dynamically adjusts the covariance matrices of the system noise and the measurement noise,thus enhancing its adaptability to diverse environmental localization requirements.Particularly in the presence of non-Gaussian noise,especially heavy-tailed noise,the MCCUKF exhibits superior accuracy and robustness compared to the traditional UKF.The method initially generates an estimate of the predicted state and covariance matrix through the unscented transform(UT)and then recharacterizes the measurement information using a nonlinear regression method at the cost of theMCC.Subsequently,the state and covariance matrices of the filter are updated by employing the unscented transformation on the measurement equations.Moreover,to mitigate the influence of non-line-of-sight(NLOS)errors positioning accuracy,this paper proposes a k-medoid clustering algorithm based on bisection k-means(Bikmeans).This algorithm preprocesses the UWB distance measurements to yield a more precise position estimation.Simulation results demonstrate that MCCUKF is robust to the uncertainty of UWB and realizes stable integration of INS and UWB systems.

Three-dimensional limit variation analysis on the ultimate pullout capacity of the anchor cables based on the Hoek-Brown failure criterion

Only simplified two-dimensional model and a single failure mode are adopted to calculate the ultimate pullout capacity(UPC)of anchor cables in most previous research.This study focuses on a more comprehensive combination failure mode that consists of bond failure of an anchorage body and failure of an anchored rock mass.The three-dimensional ultimate pullout capacity of the anchor cables is calculated based on the Hoek-Brown failure criterion and variation analysis method.The numerical solution for the curvilinear function in fracture plane is obtained based on the finite difference theory,which more accurately reflects the failure state of the anchor cable,as opposed to that being assumed in advance.The results reveal that relying solely on a single failure mode for UPC calculations has limitations,as changes in parameter values not only directly impact the UPC value but also can alter the failure model and thus the calculation method.

基于Grubbs规则和MATLAB语言快速剔除异常值方法的建立及其在药物苦度评价中的应用

目的:建立基于Grubbs规则和MATLAB语言的异常值剔除方法,并评价其在药物苦度评价中的的应用效果。方法:以Grubbs规则为参考,建立基于MATLAB语言的异常值自动循环剔除方法。选择20名志愿者分别进行单组口尝试验(通草)和多组口尝试验(通草、明党参、茯苓等10种药材);选择7个传感器进行电子舌测试(川木通)。以上述试验所得的苦度评价数据(口尝试验为苦度值,电子舌测试为传感器响应值)为数据源,选择5名研究者,采用基于Grubbs规则的查表逐一剔除法(方法一)、基于Grubbs规则的Excel软件剔除法(方法二)、基于Grubbs规则和MATLAB语言的异常值自动循环剔除法(方法三)进行异常值的判定及剔除;以异常值剔除时间和错误概率为指标,评价上述3种方法的应用效果。结果:单组口尝试验苦度评价数据中有2个异常值,3种方法的剔除时间分别为(745.400 0±25.904 4)、(288.333 3±31.253 1)、(0.000 3±0.000 0)s,错误概率分别为20.0%、0、0;多组口尝试验苦度评价数据中有6个异常值,3种方法的剔除时间分别为(3 693.107 7±75.023 3)、(1 494.761 4±53.826 9)、(0.005 2±0.000 0)s,错误概率分别为10.0%、4.0%、0;电子舌测试苦度评价数据中有3个异常值,3种方法的剔除时间分别为(2 992.673 3±84.117 6)、(1 276.367 1±55.024 5)、(0.002 3±0.000 0)s,错误概率分别为5.7%、2.9%、0。3种方法的剔除结果一致;方法二的剔除时间显著短于方法一(P<0.01),方法三的剔除时间显著短于方法一和方法二(P<0.01);3种方法错误概率无显著差异(P>0.05)。结论:基于Grubbs规则和MATLAB语言的异常值自动循环剔除法可显著缩短苦度评价数据异常值的剔除时间,提高数据处理效率,可用于药物苦度评价。

基于Grubbs准则的小波自适应阈值去噪算法

小波阈值去噪法是去除信号中白噪声的有效算法。根据白噪声和信号小波系数的特点,提出一种分解层数自适应确定法和一种基于Grubbs准则的各层阈值选取法,并结合软、硬阈值法的特点,改进了小波系数阈值估计的模型。

Grubbs法在酶联免疫吸附试验乙型肝炎两对半室内质控的应用探讨

目的探讨Grubbs法结合±3s、±2s和7T规则在乙型肝炎两对半酶联免疫吸附试验(ELISA)定量检测中的临时室内质控的可行性。方法查阅同一质控批号的ELISA乙型肝炎两对半定量检测的连续20批室内质控数据,并对Grubbs法结合±3s、±2s和7T规则应用进行统计分析。结果 ELISA乙型肝炎表面抗原(HBsAg)、乙型肝炎表面抗体(HbsAb)、乙型肝炎E抗原(HbeAg)定量测定中20次测定值均处于在控状态;乙型肝炎E抗体(HbeAb)定量测定中Grubbs法显示20次测定值均处于在控状态,但第13次测定结果违反了±2s规则,判定为警告状态,保留数据,且予以注意,积极分析原因,避免后续的检测继续警告甚至失控;乙型肝炎核心抗体(HbcAb)测定20次测定值均处于在控状态。结论 Grubbs法结合±3s、±2s和7T规则能作为ELISA乙型肝炎两对半定量检测的临时室内质控方法。

采用Grubbs催化剂的双环戊二烯开环移位聚合速率调控

以双环戊二烯的反应注塑成型工艺为目的,研究了采用Grubbs催化剂的双环戊二烯开环移位聚合速率调控手段,详细考察了反应气氛、聚合温度、催化剂浓度及调聚剂三苯基膦含量对聚合过程的影响。结果表明,该体系可在少量氧存在的条件下聚合。即使反应温度较低(35℃),凝胶时间仍可小于10 min,且单体转化率接近100%。催化剂浓度对聚合速度影响较大,当催化剂浓度降低至单体的4.17×10^(-6)时,聚合体系凝胶时间可增加到70 min。调聚剂三苯基膦的含量存在一临界点,高于临界点体系不凝胶,单体转化率低;低于临界点反应迅速,单体转化率高。基于上述结果,成功设计并实施了一种两股物料的反应注塑成型工艺路线,各股物料储存时间均大于70min,两者混合后14min凝胶,单体转化率为99.5%。

稳健统计和Grubbs检验法在实验室间能力验证结果分析中的应用——以海洋生物体中总汞测定结果为例

报道了用稳健统计技术(Robust statistical technique)和Grubbs检验法,在实验室间能力验证海洋生物体样品总汞含量检测结果评定分析中的应用。结果分析表明,用稳健统计技术和Grubbs检验法,对多家实验室参加的海洋生物体样品总汞含量检测能力验证数据中的离群值进行评定,其结果具有一致性,相比而言,稳健统计技术的数据处理和计算程序更加科学、直观和简洁方便,可很好地反映多个实验室能力验证的数据统计分析和结果评价。

基于Grubbs准则的小波阈值改进研究

在大坝变形监测中,需利用阈值法对数据信号进行小波去噪,而传统阈值法存在很多缺点。在小波去噪理论的基础上,结合Grubbs准则,提出了一种改进阈值门限的去噪方法,并用MATLAB编程实现了模拟信号以及大坝变形监测数据的去噪处理。实践表明,经小波改进阈值算法去噪后的数据均方根误差相对于改进前有所减低,信噪比也明显提高,改进效果明显。

Grubbs法在酶联免疫法室内质控中探讨

Grubbs法即＂即刻法＂被推荐作为酶联免疫法（ELISA法）项目检验的室内质控方法,简单实用,易于掌握[1].现将我科在实际工作中遇到的问题分析如下. 1 材料与方法 1.1 材料 丙型肝炎病毒抗体（抗-HCV）试剂（北京万泰,批号I20081015）,我科2009年1～3月常规ELISA实验检测所得的质控数据（本科配制）,全自动酶联免疫分析仪BIO-RAD EVOLIS.