黄斑分支静脉阻塞患者中心凹无血管区面积改变

目的分析视网膜黄斑分支静脉阻塞患者的黄斑区中心凹无血管区(FAZ)平均面积的变化特点。方法收集黄斑分支静脉阻塞患者23例,视网膜分支静脉阻塞患者26例的眼底荧光血管造影图片,分别测定两组患者患眼和健眼的FAZ平均面积,应用差数t检验、成组t检验和卡方检验进行统计比较,并与其视力进行相关性分析。结果黄斑分支静脉阻塞患者患眼FAZ平均面积为083±048mm2,健眼为036±006mm2,经统计学比较表明患眼FAZ平均面积大于健眼(t=453,P<001)。视网膜分支静脉阻塞患者患眼FAZ平均面积为052±014mm2,健眼为039±007mm2,经统计学比较表明患眼FAZ平均面积大于健眼(t=467,P<001)。两组患者患眼的FAZ平均面积有显著性差异(t=315,P<001),表明黄斑分支静脉阻塞患者患眼FAZ平均面积大于视网膜分支静脉阻塞患者的患眼FAZ平均面积;两组患者健眼的FAZ平均面积比较无显著性差异(t=053,P>005)。黄斑分支静脉阻塞患者的患眼视力与FAZ面积呈负相关(r=-0683),而视网膜分支静脉阻塞患者的患眼视力与FAZ面积无相关。结论视网膜黄斑分支静脉阻塞患者的FAZ平均面积较健眼扩大,也大于视网膜分支静脉阻塞患者的患眼FAZ平均面积。     

A New Model Supporting Stability Quality of Materials and Industrial Products

Stabilizing the quality of industrial product materials remains a challenge. This applies mainly to new or significantly modified materials. It also refers to special processes. The tests of product quality can stabilize the quality of industrial product materials. The popular method for this is using the non-destructive testing (NDT). The NDT identifies incompatibility but does not determine the cause of its occurrence. Hence, it was necessary to support the process of identifying causes of incompatibilities in products. The purpose of the article was to develop a model based on a new approach to determine the ranking of actions that are possible as part of the process of stabilizing the quality of industrial products. The model was developed to improve quality through sequential and systematic methods of identification (and reduce) and incompatibility. The quality management techniques and decision method were applied and combined in this model, i.e., SMART(-ER) the method, method of selecting a team of experts, brainstorming (BM), Ishikawa diagram with the 5M rule, Likert scale validation technique, arithmetic average, and Grey Relational Analysis (GRA). The test of this model was carried out to find cracks in the outer hull of 418 alloy four-point bearing (CPW-S 5616), which was identified by NDT (magnetic-powder method). As a result, a ranking of activities was obtained to stabilize the quality of the product and the main cause of incompatibility was indicated, i.e., the cause which can influence to the most degree influence on occurrence the incompatibility. The originality of the proposed model is an application in the right order of specially selected and combined qualitative methods and supporting decision methods. The finding of causes of incompatibility of products is the basis of product improvement in the area of stabilizing the quality of materials, mainly by the occurrence of special processes. The universality of the model refers to the possibility of its application for any material, processes of its formation, and processes of products, and any incompatibilities where the model can be integrated with quality control.     

Effect of H2S Corrosion on the Fracture Toughness of the X80 Pipeline Steel Welded Joint

To analyze the causes and mechanisms affecting the fracture toughness of X80 pipeline steel welded joints against H₂S, the fracture toughness of different zones of X80 pipeline steel welded joints in both air and saturated H₂S solution was investigated. The fracture toughness of welded joints degraded significantly in the saturated H₂S solution, where the crack tip opening displacement (CTOD) characteristic value in the coarse grain heat-affected zone (CGHAZ) and weld metal (WM) was only 8% and 12% of that in air, respectively. However, the sub-critical grain heat-affected zone (SCHAZ) showed better resistance to H₂S corrosion, with the CTOD characteristic value reaching 42% of that in air. The resistance of the welded joint to H₂S corrosion was sensitive to microstructures. The grain boundary ferrite (GBF) presented in WM, and the angle of grain boundary orientation in CGHAZ was not conducive to hindering crack propagation. Moreover, the formation of the resultant hydrogen cracks owing to the H₂S corrosion also reduced the fracture toughness of the welded joint.     

大鼠椎骨生物力学与骨组织形态计量学的灰色关联分析

目的:运用灰色关联分析,探讨大鼠椎骨生物力学与骨组织形态计量学之间的相关关系.方法:10.5月龄未交配的雌性SD大鼠48只,随机分为6组:① 10.5月龄基础对照组(Basal);② 13月龄假手术组(Sham-1);③ 13月龄去卵巢10周组(OVX-1);④ 16月龄假手术组(Sham-2);⑤ 16月龄去卵巢22...     

Multi-Response Optimisation of Automotive Door Using Grey Relational Analysis with Entropy Weights

Tail-welded blanks (TWBs) are widely used in automotive bodies to improve the structural performance and reduce weight. The stiffness and modal lightweight design optimisation of TWBs for automotive doors was performed in this study. The finite element model was validated through physical experiments. An L27 (3¹²) Taguchi orthogonal array was used to collect the sample points. The multi-objective optimisation problem was transformed into a single-objective optimisation problem based on the grey relational degree. The optimal combination of structural design parameters was obtained for a tail-welded door using the proposed method, and the weight of the door structure was reduced by 2.83 kg. The proposed optimisation method has fewer iterations and a lower computational cost, enabling the design of lightweight TWBs.     

减小后光学区直径角膜塑形镜矫治近视的临床观察

目的:探讨与常规后光学区直径(6mm-BOZD)相比,减小后光学区直径(5mm-BOZD)角膜塑形镜在青少年近视矫治过程中的有效性及安全性。方法:采用前瞻性随机对照试验。选取2016-04/2019-01就诊的青少年近视患者100例100眼(均取右眼数据),球镜度为-1.00～-5.00D,随机分为两组：试验组患者配戴5mm-BOZD角膜塑形镜,对照组患者配戴6mm-BOZD角膜塑形镜。比较两组患者治疗1a期间的眼轴长度(AL)、等效球镜度(SE)、相对周边屈光度(RPR)、最佳矫正视力(BCVA)、裸眼近视力(NVA)、应用Efron分级记录眼前节情况、角膜滞后量(CH)、角膜阻力因子(CRF)、角膜补偿眼压(IOPcc)、平均非侵入性泪膜破裂时间(NIKBUTav)及高阶像差(RMS_h)。结果:治疗1a后,试验组患者的AL增加0.05±0.05mm,对照组增加0.15±0.05mm(t=-8.949,P<0.001);试验组患者SE增加-0.18±0.27D,对照组增加-0.42±0.35D(t=3.609,P=0.001);两组患者在N30°、N20°...     

毛细管区带电泳法分离测定铁强化酱油中乙二胺四乙酸铁钠

目的建立利用毛细管区带电泳(CZE)技术分离测定铁强化酱油中的铁营养强化剂乙二胺四乙酸铁钠(NaFeEDTA)的方法。方法在25kV电压下阳极端检测,采用含有30mmolL柠檬酸、20mmolL三羟甲基氨基甲烷(Tris)、0.15mmolL十二烷基溴化铵(CTAB)和0.05mmolL十二烷基硫酸钠(SDS)的缓冲溶液作为分离介质,254nm紫外检测器检测,样品经稀释后进样分析。结果方法的线性范围广,精密度和准确度高,重复测定(n=6)的相对标准偏差RSD为2.15%,样品平均加标回收率为94.3%～101.2%。NaFeEDTA在铁强化酱油的最低检出限为4μgml(SN=3)。结论使用不同品牌的酱油作为载体对NaFeEDTA的测定没有影响,本方法具有直接、准确、快速、简便等优点。     

某氯丁橡胶厂氯丁二烯无组织排放情况调查

[目的]了解氯丁橡胶厂氯丁二烯无组织排放情况,提出修订卫生防护距离标准的建议。[方法]2010年3月11～12日,在重庆市长寿区某公司对氯丁橡胶生产装置进行调查和监测,采用地面浓度反推法估算该厂氯丁二烯无组织排放量。[结果]该厂年生产氯丁橡胶30 000t,氯丁二烯无组织排放量为8.32kg/h,相当于生产1t氯丁橡胶排放2.43kg,其卫生防护距离理论计算值为1 754m。[结论]生产规模30 000t的氯丁橡胶厂最小风速下卫生防护距离建议为1 800m。     

Application of Iron Tailings-Based Composite Supplementary Cementitious Materials (SCMs) in Green Concrete

How to treat the iron tailings of mining solid waste with high value is an urgent problem on a global scale. In recent years, the application of iron tailings in the building materials industry has attracted the attention of many scholars. The conversion of iron tailings into green building materials helps achieve carbon neutrality and high-value utilization of solid waste, and promotes sustainable development. Although iron tailings have been extensively studied as supplementary cementitious materials, the performance of concrete is not ideal due to its low activity. In this study, the hybrid supplementary cementitious materials system was prepared by iron tailings, phosphorus slag, and steel slag, and the effects of supplementary cementitious materials type, iron tailings content, iron tailings grinding time, and supplementary cementitious materials content on concrete performance were studied. The compressive properties, iron tailings properties, pore structure, interfacial transition zone, and element distribution of hydration products of concrete were tested by compressive strength tests, X-ray Diffractometer (XRD), X-ray Photoelectron Spectroscopy (XPS), Mercury Intrusion Porosimetry (MIP), Backscattering Electron Tests (BSE), and Energy Dispersive Spectrometer (EDS). The results show that further grinding improves the iron tailings activity. There is a synergistic mechanism between steel slag and phosphorus slag in the composite supplementary cementitious materials, which overcomes the low activity defect of iron tailings and produces concrete with a compressive strength exceeding 40 MPa. The composite supplementary cementitious materials can optimize the interfacial transition zone of the concrete interface and reduce the calcium–silicon ratio of the hydration products. However, it will deteriorate the pore structure of the concrete matrix, cause part of the concrete matrix to be damaged and lead to a loss of compressive strength, and the loss is acceptable. This work broadens the methods of comprehensive utilization of iron tailings and also provides a reference for a more detailed understanding of the properties of iron tailings-based concrete.     

准分子激光角膜上皮瓣下磨镶术与多光区准分子激光角膜原位磨镶术治疗高度近视的临床疗效比较

目的比较准分子激光角膜上皮瓣下磨镶术(LASEK)与多光区准分子激光角膜原位磨镶术(M-LASIK)治疗高度近视的临床疗效。方法对62例120只高度近视眼分别行LASEK及多光区LASIK并随访1年,分析其术后裸眼视力、屈光度变化及1年后的最佳矫正视力。结果M-LASIK组在术后初期(1个月时)裸眼视力优于LASEK组(p<0·05),在3、6个月时两者无显著差异(p>0·05),1年时LASEK组平均裸眼视力优于M-LASIK组(p<0·05)。两者在1年时裸眼视力均低于术前最佳矫正视力(p<0·05)。两组屈光状态均呈由远视向近视回退的趋势,其中M-LASIK组要明显于LASEK组。术后1年两组最佳矫正视力无显著差异。结论LASEK与M-LASIK在矫正高度近视薄角膜患者方面均是安全有效的,两者均具有节省角膜组织的优点。LASEK组的远期裸眼视力及屈光回退要优于M-LASIK组。