Identified the hydrochemical and the sulfur cycle process in subsidence area of Pingyu mining area using multi-isotopes combined with hydrochemistry methods

Groundwater serves as an important water source for residents in and around mining areas.To achieve scientific planning and efficient utilization of water resources in mining areas,it is essential to figure out the chemical formation process and the ground water sulfur cycle that transpire after the coal mining activities.Based on studies of hydrochemistry and D,^(18)O-H_(2)O,^(34)S-SO_(4)isotopes,this study applied principal component analysis,ion ratio and other methods in its attempts to reveal the hydrogeochemical action and sulfur cycle in the subsidence area of Pingyu mining area.The study discovered that,in the studied area,precipitation provides the major supply of groundwater and the main water chemistry effects are dominated by oxidation dissolution of sulfide minerals as well as the dissolution of carbonate and silicate rocks.The sulfate in groundwater primarily originates from oxidation and dissolution of sulfide minerals in coal-bearing strata and human activities.The mixed sulfate formed by the oxidation of sulfide minerals and by human activities continuously recharges the groundwater,promoting the dissolution of carbonate rock and silicate rock in the process.

Five-phase Synchronous Reluctance Machines Equipped with a Novel Type of Fractional Slot Winding

Multi-phase machines are so attractive for electrical machine designers because of their valuable advantages such as high reliability and fault tolerant ability.Meanwhile,fractional slot concentrated windings(FSCW)are well known because of short end winding length,simple structure,field weakening sufficiency,fault tolerant capability and higher slot fill factor.The five-phase machines equipped with FSCW,are very good candidates for the purpose of designing motors for high reliable applications,like electric cars,major transporting buses,high speed trains and massive trucks.But,in comparison to the general distributed windings,the FSCWs contain high magnetomotive force(MMF)space harmonic contents,which cause unwanted effects on the machine ability,such as localized iron saturation and core losses.This manuscript introduces several new five-phase fractional slot winding layouts,by the means of slot shifting concept in order to design the new types of synchronous reluctance motors(SynRels).In order to examine the proposed winding’s performances,three sample machines are designed as case studies,and analytical study and finite element analysis(FEA)is used for validation.

Survey on performance of vertical slot and nature-like fishways at Angu hydropower station, Southwest China

To restore dam-blocked natural fish migratory passages,a growing number of artificial fishways have been built in water conservancy and hydropower projects in China.The Angu hydropower station involved diverse important fish habitats in the lower reaches of the Daduhe River in Southwest China.Therefore,a vertical slot fishway(VSF)and a nature-like fishway(NLF)were built near the backwater area of the reservoir to connect the upstream and downstream habitats.Hydrodynamic and aquatic ecological surveys were conducted after the completion of the project to estimate the fish passing effect of the two fishways.The results indicated that both fishways were in effective operation and could maintain the desired hydrodynamic conditions and be used by several local fish species.During the survey,149 fish from 15 species and 111 fish from 17 species were captured by the traps in the VSF and NLF,respectively,while 1263 fish from 27 species were found in the downstream area.Some species captured in the VSF were not found in the NLF,and vice versa,which implied the different preferences of fish.Meanwhile,3789 signals including 2099 upward ones and 1690 downward ones were monitored with an ultrasonic fish detector at the inlet of the VSF.These findings revealed the characteristics of fish species observed in and near the fishways and provided valuable insights into the different fish passing capabilities of VSFandNLF.

计算机视觉技术赋能大学英语课堂展示中的学习投入研究

学习投入是预测学习者学习效果的重要指标,学术界对其与课堂展示间的相关性研究鲜有涉猎。文本以某综合性大学303名非英语专业本科生为研究对象,采用人工智能与计算机视觉技术模型YOLOv7对大学英语课堂中的课堂展示实录进行学习投入多模态数据分析,并辅以问卷调查,形成双向印证。研究发现,学生课堂展示中的行为投入、认知投入和情感投入值均等于或高于3.78,投入结果均值达4.01,说明学生在课堂展示中的学习投入情况良好。此外,不同时段课堂展示对学生行为投入的影响显著,学生专注度及参与度在课堂前10分钟的课堂展示中效果最佳。文本为课堂展示的有效性提供了智能化、多模态、多维度的实证支持,为课堂教学的数智技术应用提供了新视角。

数字大平板SLOT技术在脊柱侧弯上的临床应用

目的探讨数字大平板SLOT技术在脊柱侧弯上的临床应用价值。方法选择52例脊柱侧弯患者,应用数字大平板SLOT技术对脊柱从上至下进行连续曝光,再经过SLOT Radiography软件对采集图像进行处理,得到全脊柱图像,并对图像进行评价。结果 52例脊柱侧弯患者,S形侧弯14例(27%),左侧弯23例(44%),右侧弯15例(29%);其中胸椎侧弯17例,腰椎侧弯21例,合并椎体畸形7例,合并骨盆倾斜改变1例。所有病例都能在一张X线胶片上清晰显示颈、胸、腰、骶尾椎,整个图像无拼接伪影,椎体的清晰度符合标准的脊柱影像要求,并能准确的测量Cobb角。结论数字大平板的SLOT全景技术能有效地去除拼接伪影,使全脊柱能同时在1张X线胶片上完整无缝呈现,全景图像清晰,密度均匀一致,影像质量完全达到了临床对侧弯长度和Cobb角测量的要求,为脊柱侧弯矫形术治疗方案的旋转,术前设计及术后评估提供了可靠的影像学依据。

Slot双下肢全长摄影在全膝关节置换术中的应用价值

目的探讨动态平板透视的狭缝全景摄影技术(Slot)双下肢全长摄影在膝关节置换术的临床应用价值。方法回顾性分析2013年11月-2017年3月89例膝关节置换患者,共99个膝关节进行全膝关节置换术,每位患者在手术前后分别使用动态平板透视摄影系统的狭缝全景技术进行负重位的双下肢全长摄影,采用0~2分的评分方式对图像质量进行评估,0分图像质量差,1分图像质量中等,2分者为图像质量优良,并在图像质量优良的图片上通过后处理软件对患者的手术膝进行术前和术后下肢力线及胫股角进行测量,对术前进行全面评估,同时通过对比分析评价手术效果。结果 (1)89例患者Slot双下肢全长摄像一次成功率100%,成像时间短,操作简便、快捷,每位患者图像质量评分均为2分,质量优良,完全满足诊断及临床的要求;(2)89例患者术前均得到全面准确的评估,80例为骨性关节炎,9例为创伤性骨关节炎,其中,合并膝内翻畸形17例,膝外翻畸形患者8例,无合并内外翻畸形者64例;(3)术后所有患者假体对位、对线良好,假体周围无骨折,所有患者下肢力线和胫股角均为正常范围,17例膝关节内翻畸形患者,胫股角手术前后比较差异有统计学意义(t=-6.590,P=0.000);8例膝外翻畸形患者,胫股角手术前后比较差异有统计学意义(t=5.597,P=0.001),膝内外翻畸形较术前均得到良好的校正;无合并内外翻畸形64例患者术后下肢力线与重力垂线夹角和胫股角与手术前后比较,差异无统计学意义(t_(前者)=0.725,P=0.487,t_(后者)=-2.090,P=0.070)。结论使用狭缝全景摄影技术对双下肢全长进行成像,其成功率高、检查时间短、辐射剂量低,且图像拼接操作简便,质量优良,满足临床诊断需求,对临床术前手术方案制定及术后评估具有重要应用价值。

导、隔板倾斜对竖缝式鱼道水力特性的影响

为了明晰鱼道在建造以及组装时产生的误差对其内部水力特性的影响,针对导、隔板倾斜类误差展开研究.当前国内外竖缝式鱼道应用广泛,但在前期的鱼道工程现场勘测中,施工误差普遍存在于鱼道中,针对导、隔板倾斜类型的误差并依据现场对该误差情况的统计,采用三维数值模拟的方法,并通过物理模型试验对数学模型计算参数进行修正,在倾斜角度±15°的范围内每隔5°共测试了7种计算工况.结果表明:导、隔板倾斜(倾斜角度±15°内)后,鱼道池室内水流结构的二维特性所受影响有限且不足以造成不同规律;主流轨迹线范围增大,主流流速的衰减效果更加明显;目标导、隔板竖缝处的紊动能整体高于鱼类偏好紊动能上限,高总水力应变的分布范围明显增大,且有随着导、隔板倾斜幅度增大而增大的趋势;目标导、隔板下游竖缝平均流速有所升高.

slot波导包覆层对功率密度的影响

理论模拟研究了硅基绝缘(SOI)的slot波导中槽内限制功率与slot波导的结构参数以及包覆层折射率的关系。结果表明,如果包覆层的折射率偏离衬底SiO2的折射率,相同参数下的slot波导的传输损耗大于包覆层为SiO2的结构的传输损耗。分析表明,如果包层与衬底折射率不同,限制的光功率会从slot缝隙中渗透到折射率较高的衬底或者包层中,从而引起能量的损耗。理论模拟得到了在缝隙宽度为0.12μm的情况下,slot波导槽内最大的光功率限制为28.54%,这个值包含了纳米线波导与slot波导直接耦合产生的耦合损耗以及slot波导自身的传输损耗。

Full Wave Analysis of a Broad Wall Waveguide Slot Coupler

A rigorous analysis of a broad wall slot coupler composed of two crossed rectangular waveguides by using FDTD method is presented. Two types of slots, a longitudinal/transverse slot and a centered-inclined slot, are analyzed. Coupling slot characteristics are obtained, including scattering parameters and the resonant length for different waveguide dimensions and frequencies. The numerical results are all in good agreement with those by the method of moments. A coupler system with a short circuit port is also analyzed to help designing the slot array.

具有多重码的预约Slotted ALOHA协议性能分析

本文对具有多重码的预约Ｓｌｏｔｔｅｄ ＡＬＯＨＡ协议进行了性能分析。它是基于帧的协议且在一个时隙内有多重码可用来传输分组信息。文中利用离散时间、离散状态的Ｍａｒｋｏｖ链来分析一个小区上行链路的话音分组吞吐量和数据分组延时性能，并提出了两种改进碰撞解决的方法，得到了较好的系统特性。

日调节水电站双出口鱼道水力特性与鱼道运行方式研究

受日调节水电站水库水位变动的影响,鱼道进口和出口的水位均会发生改变,进而对鱼道池室内部水力特性产生明显影响。本文基于三维数值模拟,重点分析了日调节水电站双出口鱼道出口水位上升和下降时对鱼道水力特性的影响。结果表明:鱼道出口水位下降,当高位和低位出口同时开启时,鱼道内最大流速均小于1.20 m/s,未形成流速屏障,且分岔段水面壅高幅度较小;鱼道低位出口段的流场连通性较好,高位出口段内也存在明显的流速,此时低位出口起主要过鱼作用,高位出口宜同时保持开启,有助于已上溯至高位出口段的鱼类完成上溯。鱼道出口水位上升,鱼道中最大流速出现在鱼道进口段的下游竖缝处;水位低于2.2 m时,高位出口和低位出口可同时开启,鱼道内不会出现流速屏障;水位高于2.2 m时,鱼道进口段的下游竖缝处最大流速为1.3~1.5 m/s,阻碍鱼类上溯,且在分岔段易出现明显壅水现象。因此,在水位上升过程中,应先保持高位、低位出口同时开启,再根据鱼道进口处流速和分岔段水深,确定低位出口延时关闭时机,供已上溯至低位出口段的鱼类完成上溯。本研究可为日调节水电站双出口鱼道的出口切换运行方式提供参考。

Modified Reynolds Equation for Squeeze-Film Air Damping of Slotted Plates in MEMS Devices

A differential equation for calculating squeeze-film air damping in slotted plates is developed by modifying the Reynolds equation. A term is added to account for the effect of airflow through the slots on the air damping of the plate. The end effect of the airflow in the slots is also treated by substituting an effective channel length for the geometric channel length （i. e. the thickness of the plate）..The damping pressure distribution, damping force, and damping force coefficient of the slotted plates can be found by solving the equation under appropriate boundary conditions. With restrictions on the thickness and the lateral dimensions of the slotted plate removed,the equation provides a useful tool for analysing the squeeze-film air damping effect of slotted plates with finite thickness and finite lateral dimensions. For a typical slotted plate structure, the damping force coefficient obtained by this equation agrees well with that generated by ANSYS.

HFC上行信道多重码预约Slotted ALOHA随机多址接入的性能分析

1 引言 光纤同轴电缆混合(hybrid fiber/coax,HFC)网络具有光纤的高带宽和同轴电缆的共享性,是较为经济可行的宽带用户接入方案之一.HFC能提供话音、数据、视频等业务的综合接入,为宽带信号进入家庭铺平了'最后一公里'.

基于slot波导的硅基长波红外偏振无关定向耦合器分析

硅基长波红外集成光电子器件是集成光学发展的一个新兴领域.阐述了利用等比例放大原理设计该波段下的slot波导的思路,分析了波导的限制因子、偏振特性等性质,并提出了工作波长为10.6μm的偏振无关slot波导定向耦合器.

不同极槽配合车用永磁电机多物理场仿真分析

针对车用永磁同步电机设计面临的诸多挑战,以8极48槽和8极36槽内置式永磁同步电机为研究对象,研究了不同极槽配合对车用永磁同步电机电磁性能以及振动噪声的影响。首先,比较分析不同极槽配合永磁同步电机的转矩波动、空载反电势,探究不同极槽配合对电机电磁性能的影响;其次,基于麦克斯韦应力张量法推导电磁力波的解析模型,并通过解析模型和有限元模型分别分析不同极槽配合的电机电磁力波的空间阶次和频率特征;最后,建立电机多物理场耦合模型,探究不同极槽配合对永磁同步电机振动噪声的影响。结果表明,8极36槽电机在转矩波动、空载反电势等电磁性能方面要显著优于8极48槽电机,然而,由于其存在较低的空间非零电磁力波,更易引发共振,产生振动噪声。分析结果揭示了不同极槽配合对永磁同步电机电磁性能及电机振动噪声的影响,为电机设计选取极槽配合以及后续优化提供了理论参考。

Shielding Effectiveness of Rural Concealed Communication Cable of Asymmetric/Symmetric Slots with Different Shapes

With the rural concealed communication cable as the study object, the shielding effectiveness of different slot shapes was analyzed by using LBEM （linear boundary element method）. The engineering example results showed that for twocore shielded cable, the coupling capacitance of trapezoid slots （asymmetric and symmetric） changed the most, followed by rectangular slots （asymmetric and symmetric）, and the changes of wedge slots were the smallest, but the change tenden- cies were consistent. In addition, with the increase of slot width of different slots, the coupling capacitance of tow-cored shielded cable showed small change.

用质量控制狭缝式杂交法（Coslot）检测妇女宫颈上皮中人乳头瘤病毒（HPV）DNA

本文报道一种能对ＨＰＶ进行较为准确分型的刚Ａ杂交程序和方法。它具有如下特点：１．由于简化了实验程序，标本消耗减少。因此该方法尤其适用于小组织活检标本（１－２ｍｇ）中ＤＮＡ同源序列检测；２．敏感性高。由于标本消耗减少，使ＨＰＶ检出率大为提高，与斑点杂交技术相比，敏感性提高１．６倍；３．型别特异性强。由于改变了实验条件及在实验过程中实行严格的质量控制，明显减少了不同ＨＰＶ型别的交叉反应，甚至在部分出现交叉反应的标本中，仍可通过强度对比来最后判定ＨＰＶ感染型别。应用该技术对１４３份宫颈炎标本、１７份宫颈不典型增生标本及２５份宫颈癌标本进行了ＨＰＶ１６型检测，阳性率分别为５０．０５％（７３／１４３）、５７％（２７／４７）及７６％（１９／２５），并与Ｄｏｔｂｌｏｔ方法进行了比较。该方法在ＨＰＶ感染与宫颈癌关系的分子流行病学研究中具有重要意义和广阔的应用前景。

二元超宽带高隔离度MIMO二阻带槽天线设计

超宽带(UWB)天线的研究具有重要的意义。本文设计了一种2端口的MIMO二阻带UWB槽天线。该天线由2个单元槽天线组成,通过栅格形隔离枝节连接两单元天线的地板,使天线具有高隔离度;并在天线辐射贴片上刻蚀2个C型槽,使天线产生2个阻带,这2个阻带可以避免无线局域网(WLAN)和X波段的窄带系统信号的干扰。该天线的实测工作带宽为2.8~10.3 GHz,阻带为5.3~6.3 GHz和7.5~8.8 GHz,实测隔离度在工作范围内均大于21 dB;天线的最高增益为6.9 dB。天线的尺寸为30 mm×56 mm×0.8 mm。该天线适用于UWB通信系统。

单缝襟翼缝道对升力线形态的影响研究

某大弯度翼型采用的单缝襟翼缝道对升力特性影响显著,可导致升力线整体形态的变化。基于求解RANS方程方法研究表明,缝道以襟翼相对主翼上翼面后缘点的距离为主要特征,存在升力线形态差异较大的5个区域,按照距离主翼上翼面后缘点的距离由近至远依次命名为D、C、B、A、E区。A区与主翼的间距在(1.01~1.33)%相对弦长之间,具有最高的最大的升力系数和失速迎角,升力线斜率量值较大,为0.088(1/°)。流场特性分析表明此区域内较小迎角时襟翼存在后缘气流分离,随着迎角逐渐增加逐步变化为附体流动。随着襟翼逐渐靠近主翼,依次为B区、C区,此区域内的升力特点是在小迎角时襟翼上就形成了附体流动,中小迎角时产生更大的升力增量,而随着迎角增加襟翼升力有降低趋势,升力线斜率可降低至0.036(1/°),最大升力系数和失速迎角降低。D区距离主翼最小,增升效果降低且升力出现非线性。E区距离主翼最远,与主翼的耦合效果弱,增升作用最差.

曲柄摇臂式开槽机截割稳定性分析

针对现有开槽机的不足,设计了一种曲柄摇臂式开槽机,对其工作过程中的稳定性进行了分析。在截割头卡死主臂以最大转矩输出条件下,开底槽过程中最小倾覆安全系数为1.78、开左帮槽过程中最小倾覆安全系数为2.27、开顶槽过程中最小倾覆安全系数为1.14、开右帮槽过程中最小倾覆安全系数为1.22,验证了极端工况下整机的稳定性和可靠性。