Mathematical Statistics Method of Evaluating Application Effects of a New Type of Gas Anchor

Based on the basic formula of the confidence interval and the sampling error of mathematical statistics, the mathematical statistics method of evaluating application effects of a new type of gas anchor was given in this paper. By the method mentioned above, the confidence interval and the sampling errors of the relevant mean value differences of Daqing Oilfield S block’s 150 wells, according to the mean value differences of the liquid producing capacity per day, the oil production per day, the submergence depth of the 10 sampling test wells, in which before and after a new type of gas anchor were laid down, were calculated. The calculation results show that a new type of gas anchor has a better effect of increasing oil production of oil well and enhancing pump efficiency. Through the real value differences analysis of the liquid producing capacity per day, the oil production per day, the submergence depth of 150 wells mentioned above, in which before and after a new type of gas anchor were laid down, it was verified. By using the confidence interval and the sampling errors of the liquid producing capacity per day, the oil production per day, the submergence depth mentioned above, in which before and after a new type of gas anchor were laid down, the application effects of a new type of gas anchor could be evaluated. And a mathematical statistics method of evaluation application effects of a new type of gas anchor is presented.

Anchoring effect and energy-absorbing support mechanism of large deformation bolt

To research the anchoring effect of large deformation bolt,tensile and drawing models are established.Then,the evolution laws of drawing force,bolt axial force and interfacial shear stress are analyzed.Additionally,the influence of structure element position on the anchoring effect of large deformation bolt is discussed.At last,the energy-absorbing support mechanism is discussed.Results show that during the drawing process of normal bolt,drawing force,bolt axial force and interfacial shear stress all gradually increase as increasing the drawing displacement,but when the large deformation bolt enters the structural deformation stage,these three values will keep stable;when the structure element of large deformation bolt approaches the drawing end,the fluctuation range of drawing force decreases,the distributions of bolt axial force and interfacial shear stress of anchorage section are steady and the increasing rate of interfacial shear stress decreases,which are advantageous for keeping the stress stability of the anchorage body.During the working process of large deformation bolt,the strain of bolt body is small,the working resistance is stable and the distributions of bolt axial force and interfacial shear stress are steady.When a rock burst event occurs,the bolt and bonding interface cannot easily break,which weakens the dynamic disaster degree.

The influence of surface effects on Frederiks transition in nematic liquid crystal doped with ferroelectric nanoparticles

Motivated by our recent work,in this work,we present the numerical study of the anchoring effect on the Frederiks threshold field in a nematic liquid crystal doped with ferroelectric colloidal nanoparticles.Assuming weak anchoring conditions,we employ the relaxation method and Maxwell construction to numerically solve the Euler–Lagrangian differential equation for the total free energy together the Rapini–Papoular surface energy to take into account anchoring of nematic liquid crystal molecules at the substrates.In this study,we focus our attention on obtaining the phase diagrams of Frederiks transition for different values of anchoring strength which have been not computed in our previous work.In this way,the effect of nanoparticle radius,nanoparticle volume fraction,nanoparticle polarization,and cell thickness on the Frederiks transition for different values of anchoring conditions are summarized in the phase diagrams.The numerical results show that by increasing the nanoparticles size and nanoparticle volume fraction in the ferronematic system,the Frederiks threshold field is strongly reduced.

Influences of surface and flexoelectric polarization on the effective anchoring energy in nematic liquid crystal

The physical effects on surface and flexoelectric polarization in a weak anchoring nematic liquid crystal cell are investigated systematically. We derive the analytic expressions of two effective anchoring energies for lower and upper substrates respectively as well as their effective anchoring strengths and corresponding tilt angles of effective easy direction.All of these quantities are relevant to the magnitudes of both two polarizations and the applied voltage U. Based on these expressions, the variations of effective anchoring strength and the tilt angle with the applied voltage are calculated for the fixed values of two polarizations. For an original weak anchoring hybrid aligned nematic cell, it may be equivalent to a planar cell for a small value of U and has a threshold voltage. The variation of reduced threshold voltage with reduced surface polarization strength is also calculated. The role of surface polarization is important without the adsorptive ions considered.

Synergistic effect of a new wedge-bond-type anchor for CFRP tendons

In order to improve the anchoring force of anchors for carbon fiber reinforced polymer(CFRP) tendons further, a new wedge-bond-type anchor for CFRP tendons was developed. The increment in anchoring force induced by the clamping segment of anchor was studied. Taking the deformation of all parts in clamping segment in the transverse direction into consideration, the calculation formula for the increment of anchoring force was proposed based on the linear elastic hypotheses. The proposed model is verified by experiments and conclusions are drawn that the anchoring force is influenced mainly by the inclination angle of clamping pieces, the length of clamping part and the thickness of bonding medium. Especially, the thickness of bonding medium should be lowered in design to improve the synergistic effect of anchors.

ANCHORING EFFECT ANALYSIS OF TENSIONED BOLTS

The paper analyses quantitatively the anchoring effect of tensioned bolts on surrounding rock strength, and defines two concepts: one is the surrounding rock strength increased amount Δτ13 and the other is the strength influence factor k. The anchoring effect of tensioned bolts is considered to increase a strength increased amount Δτ13 where Δτ13 is the product k and ten-sioned load p, i. e. Δτ13 = kp, where k is a function of two variables x and y. The distribu-tive properties both Δτ13 and k are also discussed in the paper, obtaining some useful results for designing bolting support parameters.

Molecule‑Level Multiscale Design of Nonflammable Gel Polymer Electrolyte to Build Stable SEI/CEI for Lithium Metal Battery

The risk of flammability is an unavoidable issue for gel polymer electrolytes(GPEs).Usually,flameretardant solvents are necessary to be used,but most of them would react with anode/cathode easily and cause serious interfacial instability,which is a big challenge for design and application of nonflammable GPEs.Here,a nonflammable GPE(SGPE)is developed by in situ polymerizing trifluoroethyl methacrylate(TFMA)monomers with flame-retardant triethyl phosphate(TEP)solvents and LiTFSI–LiDFOB dual lithium salts.TEP is strongly anchored to PTFMA matrix via polarity interaction between-P=O and-CH_(2)CF_(3).It reduces free TEP molecules,which obviously mitigates interfacial reactions,and enhances flame-retardant performance of TEP surprisingly.Anchored TEP molecules are also inhibited in solvation of Li^(+),leading to anion-dominated solvation sheath,which creates inorganic-rich solid electrolyte interface/cathode electrolyte interface layers.Such coordination structure changes Li^(+)transport from sluggish vehicular to fast structural transport,raising ionic conductivity to 1.03 mS cm^(-1) and transfer number to 0.41 at 30℃.The Li|SGPE|Li cell presents highly reversible Li stripping/plating performance for over 1000 h at 0.1 mA cm^(−2),and 4.2 V LiCoO_(2)|SGPE|Li battery delivers high average specific capacity>120 mAh g^(−1) over 200 cycles.This study paves a new way to make nonflammable GPE that is compatible with Li metal anode.

Free-Fall Penetration Behaviors of A New Dynamically Installed Plate Anchor in Marine Clay

A new dynamically installed plate anchor, the Flying Wing Anchor~?, has been developed as a sustainable anchor concept for deep-water offshore wind turbines. The anchor is firstly installed by free-fall penetration and then followed by drag embedment. If the anchor is subjected to environmental loads, it dives deeper to mobilize a higher capacity. This study presents a series of free-fall penetration tests with model anchors in different weights to assess the anchor behavior during the free-fall penetration performance in one-layer soil with a constant shear strength profile. Anchor velocities and embedment depths were measured by a magnetometer. An energy-based model and a force-based model were calibrated against the test results of model anchors with different weights. Based on the calibrated force-based model, a series of design charts were developed to estimate the embedment depth of anchors in different sizes and with different impact velocities in various marine clays. The framework to plot design charts presented herein can be potentially applied to other dynamically installed anchors to predict embedment depth in engineering practice.

Stability Analysis of Cross-Channel Excavation for Existing Anchor Removal Project in Subway Construction

The cutter head will be stuck when the shield machine pass through the area existing anchor left by foundation construction of surrounding high-rise building.Subsurface excavation method is an efficient way to remove the existed anchor.In this paper,a three-dimensional finite element model is developed to study stability of cross-channel excavation.The time-spatial effects of arch crown settlement,intrados uplift and side wall horizontal convergence are analyzed according to different excavation size,lining thickness and lining order.The results show that the excavation size is the main factor to control the deformation of the surrounding soil,especially in arch crown settlement;The influence of lining thickness on the spatial effect of surrounding soil deformation is obvious when the excavation size is large,but little on the time effect;The influence of the lining order on the deformation of the surrounding soil is obvious,in particular,the larger the excavation size,the more obvious advantages of the lining order.Finally,based on the time-spatial effects comparison of nine excavation schemes of the cross-channel,an optimum excavation scheme is adopted in the actual project.

Rational design of porous carbon allotropes as anchoring materials for lithium sulfur batteries

The shuttle effect seriously impedes the development and practical application of lithium sulfur(Li-S)batteries.It is still a long-term challenge to find effective anchoring materials to hinder the shuttle effect of Li-S batteries.Using carbon allotrope as anchoring materials is an effective strategy to alleviate the shuttling effect.However,the influence factors of carbon allotrope on the adsorption performance of LIPSS at the atomic level are not clear,which limits the application of carbon allotrope in Li-S batteries.Herein,using first-principles simulations,a systematical calculation of carbon allotropes with various ring size(6 ≤S≤16) and shape is conducted to understand the adsorption mechanism.The results show that the T-G monolayers with suitable ring structure and high charge transfer can significantly enhance the interaction between the monolayer and LiPSs,allowing them to have high capacity and high coulombic efficiency.Further diffusion studies show that LiPSs on the T-G monolayer have the low diffusion barriers,which ensures the charging and discharging rate of batteries.Our studies could provide material design principles of carbon allotrope monolayers used as anchoring materials of the high performance Li-S batteries.

Effect of Surface Texture on Tensile Shear Strength of 1060Al-PET Welding Joints

Joining metal to plastic can lighten weight of products to reduce energy consumption.However,it is difficult to achieve high-strength welding between metal and plastic.To address this problem,the methods of surface texture pretreatment and laser irradiation welding was proposed to achieve the high-strength connection of metal and plastic.In this study,with different parameters of laser power and texture morphology,1060 Al with surface texture treatment was joined to polyethylene terephthalate(PET)by laser irradiation welding from metal side.Study showed that as the laser power increased,the tensile shear strength of joints increased first,and decreased thereafter.Tensile shear tests demonstrated that the mechanical force of joint was strengthened contributed to mechanical anchorage formed by surface texture.The depth-width ratio of the texture grooves affected the tensile shear process of the joint.According to the result of temperature simulation,the existence of texture grooves reduced the heat transfer efficiency,and the heat dissipation at interface was also impeded in course of laser welding.Finally,the maximum tensile strength of 1060Al-PET joint reached 48.4 MPa,which was close to the strength of PET matrix.The bonding mechanism of the 1060Al-PET joints was composed of mechanical bonding and chemical bonding.This study proposes an effective method to join metal to plastic which achieved high-strength connection between metal and plastic.

TiS_(2)-graphene heterostructures enabling polysulfide anchoring and fast electrocatalyst for lithium-sulfur batteries:A first-principles calculation

Lithium-sulfur batteries have attracted attention because of their high energy density.However,the "shuttle effect" caused by the dissolving of polysulfide in the electrolyte has greatly hindered the widespread commercial use of lithiumsulfur batteries.In this paper,a novel two-dimensional TiS2/graphene heterostructure is theoretically designed as the anchoring material for lithium-sulfur batteries to suppress the shuttle effect.This heterostructure formed by the stacking of graphene and TiS2 monolayer is the van der Waals type,which retains the intrinsic metallic electronic structure of graphene and TiS2 monolayer.Graphene improves the electronic conductivity of the sulfur cathode,and the transferred electrons from graphene enhance the polarity of the TiS2 monolayer.Simulations of the polysulfide adsorption show that the TiS2/graphene hetero structure can maintain good metallic properties and the appropriate adsorption energies of 0.98-3.72 eV,which can effectively anchor polysulfides.Charge transfer analysis suggests that further enhancement of polarity is beneficial to reduce the high proportion of van der Waals(vdW) force in the adsorption energy,thereby further enhancing the anchoring ability.Low Li2 S decomposition barrier and Li-ion migration barrier imply that the heterostructure has the ability to catalyze fast electrochemical kinetic processes.Therefore,TiS2/graphene heterostructure could be an important candidate for ideal anchoring materials of lithium-sulfur batteries.

ANALYSIS ON INCREMENTAL COHESION OF SURROUNDING ROCK DUE TO PRESTRESSED CABLE ANCHOR

A new method for determining the incremental cohesion △Cm of surrounding rock due to prestressed cable anchor is presented, and the formulas for △Cm are deduced and △Cm distributions also are discussed, based on the two anchorage effects, one is the effect with the prestressed vaIue △σ3 of cable anchor improving the stress state of surrounding rock and increasing the surrounding rock strength, the other is the fully encapsulated effect. The determined incremental cohesion △Cm is subiected to the model test and field measurement in the references, and coincides well with those tested results. The formulas for △Cm can be used in designing supoport parameters and related numerical analyses of prestressed cable anchor.

Study on the Influence of Radial Pressurization on Anchoring Performance of Bolts

Supporting soft rock roadways in coal mines has long posed a formidable challenge. Addressing issues such as the formation of soft rock strata, poor fracture development, limited tolerance, and the frequent and severe damage sustained by conventional bolts due to their low elongation and bearing capacity, this study employs bottom expansion and filling technology. It combines theoretical analysis with booster bolt pull-out tests to scrutinize the radial stress distribution of bolts under extrusion forces. Moreover, it conducts a comparative analysis of bolt bearing characteristics under varying radial pressurization conditions, delving into the impact of radial directional increases in compressive stress on bolt anchoring performance.

地缘政治风险与人民币货币锚效应——基于“一带一路”合作国家和地区的实证分析

防范化解地缘政治风险,保持人民币币值的相对稳定,对稳慎推进人民币国际化具有重大意义。通过分析2015年8月至2022年7月“一带一路”合作国家和地区56种货币的汇率月频数据,探究了不同区域的货币锚定人民币的程度,并进一步基于Frankel经典货币锚模型测度了地缘政治风险对人民币货币锚效应的影响。实证结果表明:第一,美元虽仍是大部分地区的锚定货币,但人民币已逐步成长为东欧、东南欧、东南亚和东亚地区钉住的货币锚。第二,地缘政治风险能够显著影响人民币在部分地区的货币锚效应,但是在不同区域和不同贸易开放度的情况下具有显著的异质性。当地缘政治风险上升时,东欧和东南欧地区会更多地锚定人民币以规避汇率风险,而东南亚和东亚地区却会选择降低锚定人民币的权重以寻求汇率稳定;高贸易开放度的国家会更多地锚定人民币,低贸易开放度的国家更可能会减少锚定人民币。研究结果为稳慎推进人民币国际化和精准实施人民币国际化的国别策略提供了参考依据。

托顶煤巷道锚固“梁-拱”结构分类及顶板冲击失稳机制

我国煤矿托顶煤巷道冲击地压频发,且冲击动载下顶板灾害尤为严重。为探究托顶煤巷道顶板锚固结构类型和冲击失稳机制,以陕西某矿301工作面回风巷道大面积冲击垮顶为工程背景,运用相似实验、理论分析及数据统计等方法,分析了托顶煤巷道围岩应力、位移和巷表加速度的动载响应特征,研究了顶煤厚度与支护构件影响下顶板锚固结构的分类特征,探究了弹性波下托顶煤巷道的应力响应机制,提出顶板锚固“梁-拱”结构的冲击失稳机制,评估了301工作面回风巷道的抗冲能力,并提出了相应的抗冲支护优化方案。结果表明:①冲击动载下托顶煤围岩应力和位移等监测数据验证了顶板存在内、外层的梁或拱形锚固结构,因顶煤厚度增加,顶板内层锚固结构存在由“梁”向“拱”的转换;②基于顶煤厚度与支护构件相对关系,将顶板锚固结构划分为薄顶煤的“叠加梁-拱”、厚顶煤的“组合梁-拱”和特厚顶煤的“组合拱”,建立了厚煤梁由“梁”向“拱”转化的临界厚度指标;③顶板锚固梁结构和锚固拱结构的冲击失稳机制为动静载荷下分别达到其拉伸、剪切强度极限后破坏,锚固“梁-拱”结构对冲击载荷的放大效应受其尺寸影响明显;④特厚顶煤的“组合拱”结构中内层拱承载强度较低,可增加锚杆长度提升内层拱厚,对应的“组合拱”结构的承载能力上升明显,与抗冲能力评估结果相符。

矿用锚索捻距与拉伸力学性能及锚固效果关系研究

矿用锚索主要由多根钢绞线缠绕而成,具有可弯曲、抗破断能力强及成本低廉等优点,在煤矿巷道围岩,特别是巷道顶板稳定性控制中广泛采用。捻距是制作锚索的重要参数之一,当选取煤矿锚索时,因了解尚浅而往往忽略这一参数。为探究捻距参数对锚索拉伸力学性能与锚固效果是否存在影响,论文采用理论分析与室内试验相结合的方法,初步厘清了捻距参数对锚索拉伸时的几何变形特征的影响,明晰了其对锚索锚固力的影响机制。基于试验获得的锚索拉伸及锚固拉拔数据构建数值模拟模型,与井下试验结果进行对比,得到了捻距与其极限拉伸载荷、最大锚固力的关系式,获取了能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距。研究结果表明:当锚索受到拉伸时,在一定范围内捻距与延伸率的关系为负相关,与拉伸极限载荷的关系为正相关;锚索-锚固剂界面存在一定的几何匹配关系,当捻距减小至其13倍公称直径时,最大锚固力随着捻距的减小而增大;综合分析锚索极限拉伸载荷与最大锚固力等因素发现,能够充分发挥锚索拉伸力学性能与锚固效果的最佳捻距为13~14倍公称直径。研究成果增加了锚索捻距对拉伸力学性能影响的认识,明晰了对其锚固机制的理解,为锚索制作及选取煤矿锚索提供了参考及理论支撑。

密砂中单盘螺旋锚安装效应对抗拔能力影响的数值分析

目的研究密砂中单盘螺旋锚安装过程中锚周土体变形特性及其对抗拔能力的影响,为螺旋锚基础精细化设计提供技术支撑。方法利用MatDEM软件建立密砂中螺旋锚安装及拉拔过程的数值计算模型,通过与室内模型试验结果对比标定颗粒微观力学参数,进而分析钻入和预埋两种安装方式下不同埋深和盘径的螺旋锚安装效应及上拔承载力。结果当H/d w≤10时,钻入安装的极限上拔力较预埋低,当H/d w>10后,安装方式带来承载力差别不再随埋深增加而增加;随着盘径增大,两种安装方式下螺旋锚的承载能力均表现出增大的趋势,钻入方式下的Q ut比预埋下的Q up降低量从33%增至53%,预埋方式螺旋锚的承载能力高于钻入。结论钻入安装螺旋锚的上拔承载力低于预埋方式的承载力,但当埋深比超过10后,安装扰动对承载力的影响随着深度变化很小;随着盘径增加,安装扰动对极限上拔承载力的影响增大,相较于埋深变化带来的安装扰动差异,盘径变化带来的影响更明显。

侵害品种权法定赔偿数额的司法决策因素检视及因应

品种创新是种业振兴的关键,识别侵害品种权法定赔偿的司法决策因素,以提高品种权司法保护水平,进而激励育种创新,实有必要。以2002-2023年侵害品种权适用法定赔偿的案例为样本,分析其时空特征,建立多元回归模型,探究法定赔偿数额的参考因素与影响因素。结果表明:侵害品种权法定赔偿适用“泛化”且判赔额较低,提高法定赔偿上限的立法举措效果甚微;法定赔偿参考因素缺乏量化标准,维权合理开支定位不清;锚定效应、审判经验等因素对司法决策影响显著。为提高品种权司法保护质效,建议采取如下措施:通过严格适用法定赔偿,消除举证责任障碍,降低证明标准,以克服法定赔偿“泛化”适用;通过确立赔偿数额计算标准和规则,另行计赔维权合理开支,以避免裁判的主观性;通过提高司法决策信息质量,提升法官素养,提供司法决策空间,以减少锚定效应,保证裁判的公平性。

观众效应对直播间消费行为的作用机制研究

运用直播平台数据,分析观众效应对直播间消费行为的作用机制,探讨主播身份和粉丝结构在其中的调节作用。研究表明:①观众效应对于主播奖励收入和销售收入均存在显著的正向作用,在有他人真实临场或虚拟临场的情境下,消费者的在线购买决策容易被激发。②当主播身份为网红明星时,观众效应对于主播奖励收入的正向作用会增强;当主播身份为意见领袖时,观众效应对于主播销售收入的正向作用也会增强。③粉丝群体在直播间承担着重要作用,在粉丝结构中,新粉丝占比较高时,观众效应对于主播销售收入的正向作用会增强。