无结缝线桥固定术与有结缝线桥固定术对肩袖损伤患者关节活动度、ASES评分和术后并发症的影响

目的探讨无结缝线桥固定术与有结缝线桥固定术对肩袖损伤患者关节活动度、美国肩肘外科协会评分(ASES)和术后并发症的影响。方法回顾性分析2020年6月至2022年6月于南阳市中心医院就诊的104例肩袖损伤患者的临床资料,按治疗方式的不同将患者分为对照组50例和研究组54例。对照组患者接受有结缝线桥固定术,研究组患者接受无结缝线桥固定术。术后随访12个月,比较两组患者术前及术后12个月的前屈活动度、外旋活动度、疼痛视觉模拟评分(VAS)、ASES评分、肩关节Constant评分、加州大学洛杉矶分校肩关节功能评分(UCLA)、肩袖再撕裂发生情况以及术后并发症发生情况。结果术前两组患者的前屈活动度、外旋活动度以及VAS评分比较差异均无统计学意义(P>0.05);术后12个月,两组患者的前屈活动度、外旋活动度明显高于术前,VAS评分明显低于术前,差异均有统计学意义(P<0.05),但两组患者术后12个月的前屈活动度、外旋活动度和VAS评分比较差异均无统计学意义(P>0.05);术前两组患者的ASES、肩关节Constant、UCLA、VAS评分比较差异均无统计学意义(P>0.05);术后12个月,两组患者的ASES、肩关节Constant、UCLA、VAS评分明显高于术前,差异均有统计学意义(P<0.05),但两组患者术后12个月的ASES评分、肩关节Constant评分和UCLA评分比较差异均无统计学意义(P>0.05);研究组患者的肩袖再撕裂率为1.85%,明显低于对照组的12.00%,差异有统计学意义(P<0.05);研究组患者的术后并发症率为5.56%,略低于对照组的8.00%,但差异无统计学意义(P>0.05)。结论无结缝线桥固定术与有结缝线桥固定术临床治疗效果接近,但无结缝线桥固定术可显著降低肩袖再撕裂率。

有结针织设备上钩针运动机构设计

有结针织设备中上钩针的运动包括摆动和转动,是两个运动的复合运动。根据有结渔网机编织工艺对上钩针的运动要求,分别选择了实现上钩针摆动和上钩针转动的机构结构类型,具体为平面连杆-凸轮组合机构、圆柱凸轮-连杆-齿轮齿条组合机构。机构尺度综合时先对上钩针的运动要求进行了处理,使运动要求曲线的加速度连续。进一步,采用解析法研究了机构尺度综合方法。通过实例说明了具体设计过程,得到了两种机构中凸轮的轮廓曲线数据。

新型有结织网机孔板运动机构的运动分析与仿真

提出一种适用于伺服系统驱动的有结织网机孔板运动机构,以配合上、下针钩及梭盘快速完成打结动作。相比传统并联机构,该机构由两个驱动副轴线垂直的平面机构耦合组成,属于一种自由度少、耦合度弱的2RSS-RC并联机构。根据螺旋理论与修正Kutzbach-Grübler公式得出该机构的自由度为3,运动性质为2个移动和1个转动;通过两耦合投影面建立封闭矢量环方程并对机构进行逆运动学分析;基于蒙特卡洛法和位置逆解,使用MATLAB软件编程求出该并联机构的工作空间;通过分段5次多项式插值对机构进行路径规划,利用Adams仿真软件验证运动学模型的正确性。结果表明,此孔板运动机构满足有结织网机所需的打结工艺的性能要求,研究可为有结织网机孔板运动机构实现伺服驱动化奠定理论基础。

有结织物打结工艺及机件运动解析

分析织网机编织有结结节的打结工艺过程,主要由上钩针、下钩针、梳钩、孔板、线盘和梭子等机件按照不同的运动规律及相互配合运动完成,打结工艺分为7个阶段,包括脱圈、经线换位、经线垫入上钩针并成圈、经线垫入下钩针、下钩针回拉经线、下钩针上经线套纬线、脱圈和紧结。在分析打结工艺的基础上,确定每种机件的运动要求,研究不同阶段的运动要求与打结动作之间的对应关系,并以梭距为7.5 mm的渔网机为例,确定出各个机件运动要求中的具体参数,为优化设计相应编织设备奠定基础。

关节镜下双排缝合桥有结与无结修复治疗老年肩袖损伤的效果比较

目的比较关节镜下双排缝合桥有结与无结修复治疗老年肩袖损伤的效果。方法选择2019年10月至2022年10月就诊于平煤神马医疗集团总医院的100例老年肩袖损伤患者为研究对象,按照随机数字表法分为对照组与研究组,每组50例。所有患者均采用关节镜下双排缝合桥技术,对照组予以有结修复,研究组予以无结修复。比较两组手术时间、视觉模拟评分法(VAS)评分、UCLA评分、Constant-Murley评分及AESE评分、术后关节僵硬和肩袖再撕裂发生率。结果研究组手术时间短于对照组,差异有统计学意义(P<0.05)。两组术后1周及术后3个月VAS评分均明显低于术前,且研究组低于对照组,术后两组UCLA评分、Constant-Murley评分及AESE评分均明显高于术前,且研究组重-巨大撕裂患者UCLA评分、Constant-Murley评分及AESE评分均高于对照组重-巨大撕裂患者,差异有统计学意义(P<0.05)。研究组术后肩袖再撕裂发生率低于对照组,差异有统计学意义(P<0.05)。结论关节镜下双排缝合桥无结修复在老年肩袖损伤治疗中疗效显著,有助于缩短手术时间,减轻术后疼痛,提高关节功能,减少肩袖再撕裂的风险。

无结图及其若干性质

给出了结、无结图、有结图等概念,然后提出了图G_0为无结图的充要条件,并论述了无结图的若干性质.

Synthesis and structures of cdq‑topological quaternary and(4,4,8)‑c topological quinary Zn‑MOFs with both oxalic acid and triazole ligands

Different solvothermal reactions of ZnC2O_(4)with oxalic acid(H_(2)ox)and 1,2,4-triazole(Htrz)successfully gave a new quaternary(NJTU-Bai83,NJTU-Bai=Nanjing Tech University Bai's group)and a new quinary(NJTU-Bai84)anionic metal-organic frameworks(MOFs),where NJTU-Bai83=(Me_(2)NH_(2))2[Zn_(3)(trz)_(2)(ox)_(3)]·2H_(2)O and NJTU-Bai84=(Me_(2)NH_(2))[Zn_(3)(trz)_(3)(ox)_(2)]·H_(2)O,respectively.With the[Zn_(2)(ox)4(trz)_(2)]secondary building unit(SBU)in NJTU-Bai83 replaced by the[Zn_(3)(ox)_(2)(trz)_(6)]and planar[Zn(ox)_(2)(trz)_(2)]ones in NJTU-Bai84,2D supramolecular building layers(SBLs)are changed from the A-layer and B-layer to another A-layer,while pillars are transformed from the tetrahedral[Zn(ox)_(2)(trz)_(2)]SBU to the irregular tetrahedral[Zn(ox)_(2)(trz)_(2)]and planar[Zn(ox)_(2)(trz)_(2)]SBUs.Thus,cdq-topological quaternary NJTU-Bai83 is tuned to(4,4,8)-c new topological quinary NJTU-Bai84.Two MOFs were well characterized by powder X-ray diffraction,thermogravimetric analysis,elemental analysis,etc.CCDC:2351819,NJTU-Bai83;2351820,NJTU-Bai84.

无节结网箱材料

上海网具制造厂在生产有结网箱网的基础上，根据用户要求，最近试制一批网目为1厘米的无结聚乙烯鱼种网，该种网的优点是：

Investigating the charge transfer mechanism of ZnSe QD/COF S-scheme photocatalyst for H_(2)O_(2) production by using femtosecond transient absorption spectroscopy

Hydrogen peroxide(H_(2)O_(2))has gained widespread attention as a versatile oxidant and a mild disin-fectant.Here,an electrostatic self-assembly method is applied to couple ZnSe quantum dots(QDs)with a flower-like covalent organic framework(COF)to form a step-scheme(S-scheme)photocata-lyst for H_(2)O_(2)production.The as-prepared S-scheme photocatalyst exhibits a broad light absorption range with an edge at 810 nm owing to the synergistic effect between the ZnSe QDs and COF.The S-scheme charge-carrier transfer mechanism is validated by performing Fermi level calculations and in-situ X-ray photoelectron and femtosecond transient absorption spectroscopies.Photolumi-nescence,time-resolved photoluminescence,photocurrent response,electrochemical impedance spectroscopy,and electron paramagnetic resonance results show that the S-scheme heterojunction not only promotes charge carrier separation but also boosts the redox ability,resulting in enhanced photocatalytic performance.Remarkably,a 10%-ZnSe QD/COF has excellent photocatalytic H_(2)O_(2)-production activity,and the optimal S-scheme composite with ethanol as the hole scavenger yields a H_(2)O_(2)-production rate of 1895 mol g^(-1)h^(-1).This study presents an example of a high-performance organic/inorganic S-scheme photocatalyst for H_(2)O_(2)production.

渔网编织设备发展现状

分析了构成网状织物的元素之一——结节的2种类型,即有结型和无结型,无结型又分为层叠型和无结经编型,以及对应织物的结构特点、适用场合和编织装置的类型。比较了国内不同生产厂家生产的有结型渔网机的结构和性能特点,重点分析了有结型渔网机在实际使用中存在的问题。结果表明,目前使用的有结型渔网机的基本结构仍然仿制上个世纪七八十年代国外的产品,速度、编织效率低。提出了从优化传动系统,提高光、机、电、气、液等一体化和计算机控制技术,优选主动驱动件的结构形式,考虑机构的动力学设计和提高零部件的制造精度等方面,综合提升整机的技术水平。

微管壳式换热器在能量转换循环中的应用

目前,超临界二氧化碳(S-CO_(2))布雷顿循环普遍采用印刷电路板换热器(PCHE)来保证其相对其他能量转换循环的紧凑性优势。PCHE芯体为整体结构,若内部出现泄漏或结垢等问题,很难进行维护与检修。本文提出了一种微管壳式换热器(MSTE),其结构与传统管壳式换热器类似,但其管径缩小至微通道级。由于MSTE的流道横截面积占总截面积之比较PCHE大,在典型的回热器与冷却器设计工况下,相对PCHE而言,采用MSTE可将体积与质量均减小30%以上。灵敏性分析结果显示,采用本文设计的MSTE结构的回热器与冷却器,回热器冷热流道入口温度升高20℃左右,压缩机入口温度变化均不超过1℃,说明该种结构换热器的换热能力足够支撑能量转换循环的一般工况波动。

Microstructure and mechanical properties of Mg_(94)Zn_2Y_4 extruded alloy with long-period stacking ordered structure

The microstructure and mechanical properties of Mg94Zn2Y4 extruded alloy containing long-period stacking ordered structures were systematically investigated by SEM and TEM analyses. The results show that the 18R-LPSO structure and α-Mg phase are observed in cast Mg94Zn2Y4 alloy. After extrusion, the LPSO structures are delaminated and Mg-slices with width of 50-200 nm are generated. By ageing at 498 K for 36 h, the ageing peak is attained andβ′phase is precipitated. Due to this novel precipitation, the microhardness ofα-Mg matrix increases apparently from HV108.9 to HV129.7. While the microhardness for LPSO structure is stabilized at about HV145. TEM observations and SAED patterns indicate that the β′ phase has unique orientation relationships betweenα-Mg and LPSO structures, the direction in the close-packed planes ofβ′precipitates perpendicular to that ofα-Mg and LPSO structures. The ultimate tensile strength for the peak-aged alloy achieves 410.7 MPa and the significant strength originates from the coexistence ofβ′precipitates and 18R-LPSO structures.

Investigation of Mechanical Stresses for Cylinder Head of High Power Diesel Engine

Aim To ivestigate the influence on the cylinder head's stress distribution and value caused by its structure's changes.Methods Three types of cylinder heads of high power diesel engines were analysed with finite element method using I-DEAS Master series software.The actual condition of the cylinder head was simulated with different kinds of elements.Tempera- ture method was used to exert the predeformation of the bolts to the finite element model,so the pretightening force was discribed accurately Results Stress distribution regularities of the cylinder head under different working conditions were taken On the basis,the analysing results ofthreeof design schemes were compared and the optimum structure was taken Conclusion Transition condition between the head plate and the standing board ,shape of the head plate and the jobbing sheet,etc will affect the cylinder head's bearing condition

Rapid Manufacturing of Metal Parts

As a key technology of rapid prototyping and manufacturing (RP&M), rapid manufacturing of metal parts is a target of RP&M. Introducing selective laser sintering (SLS), an important branch of RP&M, this paper gives a new method oriented on low power SLS system to fabricate metal parts. With this kind of technology, the mixture of metal and polymer powder is sintered first to get green part, then, after debinding and metal infiltration, dense parts are gotten. In the end, influencing factors of this technology are analyzed. At the same time, some applications are given.

FEM modeling of dynamical recrystallization during multi-pass hot rolling of AM50 alloy and experimental verification

The microstructure simulation during the multi-pass hot rolling of AM50 alloy was studied by DEFORM-3D. The excellent agreement with the experiment observations shows that the present modeling and user routine are feasible for the reproduce of the hot rolling process. The multi-pass hot rolling contributes to the achievement of a uniformly recrystallized microstructure with fine grains in the rolled sheet. The sheet temperature before the finish rolling strongly affects the final grain size, but hardly affects the grain size distribution. This modeling and the user routine also have a potential to be applied in the researches of the other multi-pass hot deformation process.

Shape Optimization With Sensitivity Analysis in Local Domain

For complicated geometries, it is ineflicient to integrate over the entire domain. A new approach for optimization is presented here, based on sensitivity analysis of local do- main and deformation of full domain. Accurate results of design sensitivity analysis are ob- tained with this approach in shape optimization. This method is shown to be efficient when used in optimization programs and results in less distortion of the mesh.

Synthesis of three-dimensional ordered mesoporous MnO_2 and its catalytic performance in formaldehyde oxidation

Three-dimensional（3D）ordered mesoporous MnO2 was prepared using KIT-6 mesoporous molecular sieves as a hard template.The material was used for catalytic oxidation of HCHO.The material has high surface areas and the mesoporous characteristics of the template,with cubic symmetry（ia3d）.It consists of a β-MnO2 crystalline phase corresponding to pyrolusite,with a rutile structure.Transmission electron microscopy and X-ray photoelectron spectroscopy showed that the 3D-MnO2 catalyst has a large number of exposed Mn4＋ ions on the（110）crystal plane surfaces,with a lattice spacing of 0.311 nm; this enhances oxidation of HCHO.Complete conversion of HCHO to CO2 and H2O was achieved at 130 °C on 3D-MnO2; the same conversions on α-MnO2 and β-MnO2 nanorods were obtained at 140 and 180 °C,respectively,under the same conditions.The specific mesoporous structure,high specific surface area,and large number of surface Mn4＋ ions are responsible for the catalytic activity of 3D-MnO2 in HCHO oxidation.

Synthesis of K-doped three-dimensionally ordered macroporous Mn_(0.5)Ce_(0.5)O_δ catalysts and their catalytic performance for soot oxidation

A series of K-doped Mn0.5Ce0.5Oδ （K-MCO） catalysts with three-dimensionally ordered macroporous （3DOM） structure and different K loadings were successfully synthesized using simple methods. These catalysts exhibited well-defined 3DOM nanostructure, which consisted of extensive interconnecting networks of spherical voids. The effects of the calcination temperature and calcination time on the morphological characteristics and crystalline forms of the catalysts were systematically studied. The catalysts showed high catalytic activity for the combustion of soot. 3DOM 20% K-MCO-4h catalyst, in particular, showed the highest catalytic activity of all of the catalysts studied （e.g., Ts0 = 331 ~C and Smco2 = 95.3%）. The occurrence of structural and synergistic effects among the K, Mn, and Ce atoms in the catalysts was favorable for enhancing their catalytic activity towards the combustion of diesel soot. Furthermore, the temperatures required for the complete combustion of the soot （〈400 ℃） were well within the exhaust temperature range （175-400 ℃）, which means that the accumulated soot can be removed under the conditions of the diesel exhaust gas. These catalysts could therefore be used in numerous practical applications because they are easy to synthesize, exhibit high catalytic activity, and can be made from low cost materials.

Finite element analysis of stress at implant-bone interface of dental implants with different structures

The effect of structure,elastic modulus and thickness of lower modulus layer in porous titanium implants on the stress distribution at the implant-bone interface was investigated.Three-dimensional finite element models of different titanium implants were constructed.The structures of the implants included the whole lower modulus style （No.1）,bio-mimetic style （No.2）,the whole lower modulus style in cancellous bone （No.3） and the whole dense style No.4.The stress distributions at bone-implant interface under static loading were analyzed using Ansys Workbench 10.0 software.The results indicated that the distribution of interface stress is strongly depended on the structure of the implants.The maximum stresses in cancellous bone and root region of implant No.2 are lower than those in the other three implants.A decrease in the modulus of the low modulus layer facilitates the interface stress transferring.Increasing the thickness of the low modulus layer can reduce the stress and induce a more uniform stress distribution at the interface.Among the four implants,biomimetic style implant No.2 is superior in transferring implant-bone interface stress to surrounding bones.

ACTIVE STRUCTURAL ACOUSTIC CONTROL IN ENCLOSURE USING RADIATION MODES

The problem of active structural acoustic control in an enclosure using radiation mode is investigated. The response of the coupled enclosure is derived in terms of radiation modes. The potential energy in the enclosure can be decomposed into independent parts and the radiation modes contribute to potential energy independently. The control strategy for minimizing first G radiation modes with large radiation efficiency is proposed, and the optimal model of control forces is presented. Finally, a numerical simulation for minimizing sound transmission into a rectangular enclosure using the proposed method is conducted. Simulation results indicate that one control force can control one radiation mode and controlling the first four-order radiation modes with four control forces can achieve significant potential energy reduction at the low frequency range.