Similarity criterion of flood discharge atomization

By combining the results of prototype observation of flood discharge atomization at the Wujiangdu Hydropower Station, and by adopting the serial model test method, the model scale effect was examined, the influences of the Reynolds and Weber numbers of water flow on the rain intensity of flood discharge atomization were analyzed and a rain intensity conversion relation was established. It is demonstrated that the level of atomization follows the geometric similarity relations and it is possible to ignore the influence of the surface tension of the flow when the Weber number is greater than 500. Despite limitations such as incomplete data sets, it is undoubtedly helpful to study the scale effect of atomization flow, and it is beneficial to identify the rules of the model test results in order to extrapolate to prototype prediction.

Stress test and analysis based on SMS fiber structure with high sensitivity

Single mode-multimode-single mode （SMS） sensor is widely used for parameters measurement, such as bending, dis-placement, temperature, strain, refractive index, etc. Generally, SMS sensor has advantages of simple structure, low cost and easy layout, therefore it has become a research hotspot in recent years. In this paper, the multimode fiber with large core is used for manufacturing SMS structure with high sensitivity. Firstly, the multimode fiber with core/cladding diameters of 105/ 125 jitm has access to the system by means of single mode optical fiber. Secondly, SMS device structure is manufactured by welding the eccentric shaft of multimode optical fiber. Afterwards, mode interference effect and spectral response characteristics of the structure of single mode-multimode-single mode optical fiber are analyzed theoretically. Finally, with the help of a wide spectrum light source and a spectrum analyzer, the transmission spectra characteristics of SMS optical fiber with strain is tested. By observing the curve that the wave changes with stress, the sensitivity is calculated and it is consistent with theoretical value .

Multistix^(TM)10SG试纸条与Combur10Test^RM试纸条临床应用结果比较

目的 :比较MultistixTM10SG与Combur 10TestRM两种试纸条临床测定结果 ,评价其应用价值。方法 :按C1initek - 5 0 0型及Miditron -M尿干化学分析仪及试纸条使用说明书上进行。结果 :浓度接近两种试纸条同一量级比较 ,完全符合率 :>96 %有G1u、BIL、Ket、UBG、Nit5项 ,达到 91%有Pro 1项 ,达到 70 %以上有BLO、Leu 2项 ,最低SG为 4 4 .8% ,pH为 4 2 .6 %。结论 :两种试纸条各具特点 ,质量稳定 ,均适合临床应用。MultistixTM10SG试纸条各测试块检测化学成分浓度阳性程度的量级分配更加合理 ,为尿干化学法首选试纸条。

Suppression of Coriolis error in weak equivalence principle test using ^85Rb-^87Rb dual-species atom interferometer

Coriolis effect is an important error source in the weak equivalence principle(WEP)test using atom interferometer.In this paper,the problem of Coriolis error in WEP test is studied theoretically and experimentally.In theoretical simulation,the Coriolis effect is analyzed by establishing an error model.The measurement errors of Eotvos coefficient(η)in WEP test related to experimental parameters,such as horizontal-velocity difference and horizontal-position difference of atomic clouds,horizontal-position difference of detectors,and rotation compensation of Raman laser’s mirror are calculated.In experimental investigation,the position difference between^85Rb and^87Rb atomic clouds is reduced to 0.1 mm by optimizing the experimental parameters,an alternating detection method is used to suppress the error caused by detection position difference,thus the Coriolis error related to the atomic clouds and detectors is reduced to 1.1 × 10^-9.This Coriolis error is further corrected by com pensating the rotation of Raman laser's mirror,and the total uncertainty o f rj measurement related to the Coriolis effect is reduced as δη=4.4 × 10^-11.

SOA服务互操作性测试工具WS-I Test Tools应用分析

依据Web服务互操作性组织发布的WS-I基本概要1.1(WS-I Basic Profile 1.1),利用WS-I Test Tools测试工具,搭建Soap应用测试环境,对概要文件进行了测试应用分析。

Quantitative Testing of Defect for Gun Barrels

The magnetic flux leakage (MFL) method is commonly used in the nondestructive evaluation (NDE) of gun barrels. The key point of MFL testing is to estimate the crack geometry parameters based on the measured signal. The analysis of magnetic leakage fields can be obtained by solving Maxwell’s equations using finite element method (FEM). The radial component of magnetic flux density is measured in MFL testing. The peak-peak value, the separation distance between positive and negative peaks of signal and the lift-off value of Hall-sensor are used as the main features of every sample. This paper establishes the multi-regression equations related to the width (the depth) of crack and the main characteristic values. The regression model is tested by use of the magnetic leakage data. The experimental results indicate that the regression equations can accurately predict the 2-D defect geometry parameters and the MFL quantitative testing can be achieved.

Analysis and application of the scale effect of flood discharge atomization model

The phenomenon of discharge atomization occurs as hydraulic structures discharging,which influences the safety of power station,electrical equipment and produces environmental pollution.A series of physical model tests and feedback analysis are adapted to preliminarily study the scale effect of discharge atomization model by use of the field observation data of discharge atomization.The effect of Re and We numbers of flow on the atomization intensity is analyzed.A conversion relationship of atomization intensity between prototype and model results and the similarity criteria of the atomization range are developed. The conclusion is that the surface tension of discharge atomization model could be ignored when the Weber number is larger than 500.Some case studies are given by use of the similitude criteria of the atomization model.

Progress on mechanical and tribological characterization of 2D materials by AFM force spectroscopy

Two-dimensional(2D)materials are potential candidates for electronic devices due to their unique structures and exceptional physical properties,making them a focal point in nanotechnology research.Accurate assessment of the mechanical and tribological properties of 2D materials is imperative to fully exploit their potential across diverse applications.However,their nanoscale thickness and planar nature pose significant challenges in testing and characterizing their mechanical properties.Among the in situ characterization techniques,atomic force microscopy(AFM)has gained widespread applications in exploring the mechanical behaviour of nanomaterials,because of the easy measurement capability of nano force and displacement from the AFM tips.Specifically,AFM-based force spectroscopy is a common approach for studying the mechanical and tribological properties of 2D materials.This review comprehensively details the methods based on normal force spectroscopy,which are utilized to test and characterize the elastic and fracture properties,adhesion,and fatigue of 2D materials.Additionally,the methods using lateral force spectroscopy can characterize the interfacial properties of 2D materials,including surface friction of 2D materials,shear behaviour of interlayers as well as nanoflake-substrate interfaces.The influence of various factors,such as testing methods,external environments,and the properties of test samples,on the measured mechanical properties is also addressed.In the end,the current challenges and issues in AFM-based measurements of mechanical and tribological properties of 2D materials are discussed,which identifies the trend in the combination of multiple methods concerning the future development of the in situ testing techniques.

14台POCT血气分析仪与中心实验室检测结果的一致性分析

目的分析14台床旁检测(POCT)血气分析仪和中心实验室血气分析仪检测结果的一致性。方法采用中心实验室血气分析仪及14台POCT血气分析仪分别检测3个浓度水平质控品,每天检测2次,连续检测4 d,共24次,根据检测结果计算pH、动脉血二氧化碳分压(PCO_(2))、动脉血氧分压(PO_(2))、K^(+)、Na^(+)、Cl^(-)、Ca^(2+)的均值、标准差和变异系数等;计算14台POCT血气分析仪检测结果与中心实验室检测结果的偏倚及偏倚率;应用ANOVA检验、Passing-Bablok回归分析对14台POCT血气分析仪与中心实验室检测结果一致性进行分析评价。结果14台POCT血气分析仪各比对项目检测结果的变异系数均小于生产商声明的性能范围。14台POCT血气分析各比对项目的检测结果与中心实验室的偏倚均小于国家卫生健康委员会临床检验中心室间质量评价标准。14台POCT台血气分析各比对项目的检测结果比较,差异均无统计学意义(P>0.05)。14台POCT血气分析仪检测结果与中心实验室pH值、PCO_(2)、PO_(2)、K^(+)、Na^(+)、Cl^(-)、Ca^(2+)检测结果模拟回归方程的截距和斜率均在95%置信区间,且P>0.05,与中心实验室检测结果具有高度的一致性。结论14台POCT血气分析仪具有良好的精密度,且14台POCT血气分析仪之间及与中心实验室间均具有较好的一致性。

自动粪便分析仪与人工复核法检测粪便结果的比较分析

目的比较自动粪便分析仪与人工复核法两种粪便检测方法的检验效果。方法收集2022年9月—2023年8月三明市第二医院就诊患者的9402份新鲜粪便标本,分别使用FA160自动粪便分析仪和人工复核法检测粪便有形成分(白细胞、红细胞、脂肪球、真菌)和隐血,记录两种方法的检测结果并进行统计学分析。结果自动粪便分析仪检测白细胞、红细胞、脂肪球、真菌和隐血的阳性检出率分别为4.90%、2.67%、6.31%、4.54%、25.34%,人工复核法阳性检出率分别为4.17%、2.22%、5.55%、5.29%、25.23%,自动粪便分析仪对粪便有形成分的阳性检出率除真菌略低于人工复核外,其他各项指标均高于人工复核,且差异均有统计学意义(均P<0.05),而粪便隐血试验的阳性检出率比较差异无统计学意义(P>0.05)。以人工复核法为标准,自动粪便分析仪检测白细胞、红细胞、脂肪球、真菌、隐血的阳性符合率分别为91.07%、96.17%、94.83%、78.07%、98.19%;阴性符合率分别为98.85%、99.46%、98.90%、99.56%、99.25%;阳性预测值分别为77.44%、80.08%、83.47%、90.87%、97.77%;阴性预测值分别为99.61%、99.91%、99.69%、98.79%、99.39%。结论自动粪便分析仪与人工复核法的检测结果虽然符合率较高,但还存在漏检和误检。因此对自动分析结果必须进行人工复核,提高检测结果的准确性,为临床提供可靠的参考依据。

三种石英晶体谐振器频率测试方法对比分析研究

测试石英晶体谐振器频率的传统方法有间接计算法、信号源起振法和网络分析仪法,三种方法各有大的缺陷。根据石英晶体谐振器频率的特点,提出三种新的测试方法:示波器测试法、频率计测试法和频谱仪测试法。这三种方法在基本测试原理、设备配置要求、测试精度和适用环境等方面存在差异。对三种方法的优缺点进行了详细比较,并针对不同应用条件提出了选用建议:如果只单纯测量石英晶体谐振器频率,选用频谱仪测试法;如果需要测量频率的同时还需要知道频率的特性等内容,宜选用频率计测试法;示波器测试法则可用在对石英晶体谐振器频率定性的粗测。此外,还根据各自的优势探讨了仪器协作测试的可能性。

泌尿系统疾病诊断中应用尿液沉渣隐血检验及尿液分析仪的价值

目的探讨尿液沉渣隐血检验及尿液分析仪在泌尿系统疾病诊断中的应用价值,以期为临床早期明确诊断、制订治疗方案提供参考依据。方法选取我院2020年6月至2022年6月就诊的260例泌尿系统疾病患者作为研究对象,入院后均行尿液沉渣隐血检验及尿液分析仪检测,以干化学试带法检验结果为“金标准”,比较尿液沉渣隐血检验、尿液分析仪检测单独、联合检查对红细胞、白细胞阳性诊断结果、诊断效能,并比较其对于不同类型泌尿系统疾病的检出率。结果与尿液沉渣隐血检验、尿液分析仪单独诊断比较,联合诊断对于红细胞阳性诊断灵敏度96.20%、准确度95.38%较高,漏诊率3.80%较低(P<0.05);与尿液沉渣隐血检验、尿液分析仪单独诊断比较,联合诊断对于白细胞阳性诊断灵敏度95.06%、准确度95.38%较高,漏诊率4.94%较低(P<0.05);且联合诊断对肾小球病、肾结石、急性肾炎综合征、肾肿瘤检出率高于尿液沉渣隐血检验、尿液分析仪单独诊断(P<0.05)。结论尿液沉渣隐血检验、尿液分析仪联合应用可有效提高泌尿系统疾病诊断效能,为临床早期诊断、鉴别疾病类型提供参考,以针对性制订治疗方案,改善预后。

阳极溶出伏安法便携式重金属分析仪性能测试方法研究

阳极溶出伏安法便携式重金属分析仪被广泛应用于水体、土壤、食品、固态物质的重金属含量检测。除镉、铅、铜外,使用该分析仪检测砷、汞、锌、铬、锰、镍、锡、铊、铁、钴、硒、银、碲、金、铋等重金属时,需选择合适的计量性能测试项目及测试方法。同时,JJF 2037-2023《便携式溶出伏安法重金属检测仪校准规范》对测量镉、铅、铜元素的便携式溶出伏安法重金属检测仪的计量特性及校准方法做出了要求。

基于顺序等效采样的DAC测试方法设计

当前数模转换器(DAC)测试面临不能兼顾采样精度与采样速率的问题,测试时通常只能二者选其一,随着DAC器件的发展,常规测试系统不能满足当前测试领域需求。针对采样速率提升导致系统噪声提高,最终使采样系统有效分辨率恶化的问题,在分析对比了当前采样技术和系统噪声影响的基础上,提出了基于顺序等效采样的DAC测试方法。该方法将高频的原始信号在时间域上展开,其核心是制造采样周期与输入信号的周期的固定频差以进行分周期采样。对采样时钟抖动对系统有效位数的影响进行分析,确定了系统的最大时钟抖动,根据被测信号周期特征设计了测试系统的采样结构与周期。并对一款16bit、500MHz输出的DAC进行了测试,其结果与传统外挂频谱仪的测试结果进行对比。对比结果表明两次实验获得的频谱特征一致,采用本文设计的测试系统获得的测试结果得到了约4dBc无杂散范围提升,约3dBc双音交调参数提升,证明基于顺序等效采样DAC测试方法的有效性。

异侧竖缝式鱼道的数值模拟及试验研究

竖缝式鱼道具有隔板型式简单、水流条件好、主流位置明确等特点,适宜喜爱不同水层鱼类洄游,是目前应用最为广泛的过鱼工程。参考规范要求,以实际工程为例,初步设计3种鱼道池室隔板型式,利用数值模拟的方法,以第1种鱼道池室结构搭建数学模型计算出的竖缝位置流速和池室表层水流流态,与物理模型试验结果进行对比,验证数学模型隔板型式尺寸优化的合理性。根据池室内的水力特性优化隔板型式,对确定的优化隔板型式以比尺为1∶5的局部物理模型试验对不同竖缝处不同水深进行流速测量,以尺为1∶20的整体物理模型试验对竖缝处流速以及沿程水深进行测量。试验结果表明,当鱼道出口水深不小于进口水深时,即运行工况1和运行工况4,各隔板竖缝附近流速均小于设计流速1.2 m/s,当鱼道出口水深小于进口水深时,即运行工况2和运行工况3,鱼道进口处隔板竖缝附近流速较大,运行工况2时,最大流速为1.319 m/s;运行工况3时,最大流速为1.561 m/s,均超过设计流速1.2 m/s。建议鱼道在工况1和工况4条件下运行。同时对始水状态下鱼道的水力特性进行分析,建议采用流速为4 m/s的冲击流速值加强对鱼道首部数级水池隔板与导板的结构设计。

某独居石精矿污染物的去除技术研究

针对某独居石精矿在综合回收过程中出现碱转矿浆变红、酸溶矿浆黏稠起泡沫导致产品变色、生产能力下降问题,采用扫描电子显微镜、红外光谱分析等手段对矿石污染物成分进行分析,并通过条件试验和半工业试验研究了煅烧法对独居石精矿污染物的去除效果。结果表明:碱转变色主要是由覆盖在独居石表面的含羧基、苯环或环烷烃的有机质造成;在煅烧温度400℃、煅烧时间40min条件下,碱转矿浆COD去除率大于94%,有机质去除效果较好,能解决生产处理能力下降30%的问题,还能降低电耗、能耗,解除生产中冒槽引发的职业健康等安全环保风险,同时保证铀、稀土回收率。该法完善了独居石加工流程,具有一定推广价值。

催化热解-冷原子吸收分光光度法测定硅酸盐中痕量汞

硅酸盐中痕量汞测定对确定岩石中汞含量以及理论地球化学、勘查地球化学、生态和环境地球化学研究具有重要意义.但汞在硅酸盐中分布是痕量级,对分析方法检出限指标要求很高,且硅酸盐中二氧化硅质量分数变化大、岩性分类多、干扰基体成分复杂和元素挥发损失等特性使得硅酸盐中痕量汞的准确测试面临挑战.直接进样测汞仪无需化学试剂消解(防止汞元素挥发损失),采用催化管(消除复杂基体干扰)和配置汞捕集装置(元素富集降低检出限)可提供符合绿色化学技术发展趋势的解决方案.本文通过试验探究,优化直接进样测汞仪的参数,其方法检出限(0.5×10^(-9))、测定下限(2.0×10^(-9))、准确度(Δlog C<0.05)、精密度(RSD<10%,n=12)等指标满足DZ/T 0130-2006中《多目标地球化学调查规范》要求,达到或优于硅酸盐化学分析方法GB/T 14506.33-2019(汞量测定:氢化物发生-原子荧光光谱法)的检出限(2×10^(-9))和定量下限(5×10^(-9)),可为硅酸盐样品中痕量汞的原子荧光测试和绿色化学技术更新提供参考.

激光粒度分析仪测试条件对粒径分析的影响

合适的激光粒度分析仪测试条件对于粒径分布数据的准确性至关重要。对比不同粒径粉末在欧美克LS-909激光粒度分析仪、SCF-105B湿法进样器中的测试结果并进行分析。结果表明,对于小于1μm的粉末样品,建议超声60 min以上,遮光率选择5%~8%,泵速选择2000~3000 r/min;对于几十μm的粉末样品,可不超声,遮光率选择10%~15%,泵速选择1500~2500 r/min;对于几百μm的样品,建议不超声,遮光率选择10%~20%,泵速选择2500~3500 r/min。在以上条件下测得的数据可靠且重复性高。

铋试金-高分辨率连续光源火焰原子吸收光谱法测定矿石中的痕量金

这是一篇分析测试领域的论文。铋试金作为一种高效分离富集矿石中痕量贵金属的绿色环保火试金方法,有效避免了铅试金有毒污染的问题。本篇采用低毒的Bi_(2)O_(3)作为Au元素的火试金捕集剂,在高温熔融过程中Bi_(2)O_(3)经试金配料中的还原剂面粉还原为Bi后,与样品中的Au形成Au_(2)Bi合金,并采用Ag保护灰吹法使Au与Ag形成约1 mg的Ag合粒;对Ag合粒采用酸溶法将其加热溶解,使Au完全进入溶液。本实验以国家标准物质GBW 07205中Au元素含量为参考,对连续光源火焰原子吸收光谱仪的CCD检测器有效像素点进行了优化选择,综合其灵敏度和稳定性,选择7作为CCD检测器的有效像素点。在质量浓度0~20μg/mL范围内与其对应吸光度运用二次方程最小二乘法拟合校准曲线,校准曲线拟合系数为0.9998;特征浓度为0.06997μg/mL,方法检出限为0.0127μg/mL。按照选定实验方法及优化仪器参数下对国家标准物质中Au进行测定,测定值与标准值吻合良好,相对标准偏差(RSD,n=6)为2.23%~4.54%。将所建立的方法应用于实际矿石样品中Au的测试,加标回收率为92.6%~106%;相对标准偏差(n=6)为2.53%~4.70%,满足国家地质矿产行业标准DZ/T 0130—2006的要求。

2型糖尿病患者眼表变化及影响因素分析

目的探讨2型糖尿病患者眼表功能的变化及影响因素分析。方法回顾性病例对照研究。收集2022年9月至2023年9月在我院确诊的2型糖尿病患者61例(122只眼)为病例组,年龄(61.44±7.14)岁;同年龄段健康人群为对照组61例(122只眼),年龄(64.52±6.93)岁。所有受试者均采用Keratograph 5M眼表综合分析仪检测平均泪膜破裂时间(ATBUT)、泪河高度(TMH)及上下睑板腺缺失评分,泪液分泌检测滤纸条行基础泪液分泌检查(sIt),荧光素钠眼科检测试纸行角膜染色检查(FL),眼表疾病指数量表(OSDI)主观评分。2型糖尿病患者记录糖尿病病程,并行糖化血红蛋白(HbA1c)检查。根据患者年龄及HbA1c进行分组,分析不同分组条件下以上指标有无差异。结果病例组与对照组的ATBUT、TMH、上下睑板腺缺失评分、sIt、FL、OSDI评分组间比较差异有统计学意义(P<0.05);在2型糖尿病患者中,HbA1c≥7.5%患者的ATBUT、sIt、TMH、FL、上下睑板腺缺失评分与HbA1c<7.5%的患者之间存在差异,差异均有统计学意义(P<0.05);以ATBUT为因变量进行回归分析发现HbA1c(P<0.001)、睑板腺缺失评分(P=0.014)对ATBUT具有影响,HbA1c值每增加1%,ATBUT减小1.635 s,而睑板腺缺失评分每增加1分,ATBUT减少0.747 s。结论与同年龄段健康人群相比,2型糖尿病患者易出现ATBUT缩短、泪液分泌量下降、泪河高度降低、睑板腺缺失增加、角膜荧光素染色评分增高,且血糖控制水平与泪膜破裂时间密切相关。