Life-Cycle Bearing Capacity for Pre-Stressed T-beams Based on Full-Scale Destructive Test

To investigate the evolution of load-bearing characteristics of pre-stressed beams throughout their service life and to provide a basis for accurately assessing the actual working state of damaged pre-stressed concrete T-beams,destructive tests were conducted on full-scale pre-stressed concrete beams.Based on the measurement and ana-lysis of beam deflection,strain,and crack development under various loading levels during the research tests,combined with the verification coefficient indicators specified in the codes,the verification coefficients of bridges at different stages of damage can be examined.The results indicate that the T-beams experience complete,incom-plete linear,and non-linear stages during the destructive test process.In the complete linear elastic stage,both the deflection and bottom strain verification coefficients comply with the specifications,indicating a good structural load-bearing capacity no longer adheres to the code’s requirements.In the non-linear stage,both coefficients exhi-bit a sharp increase,resulting in a further decrease in the structure’s load-bearing capacity.According to the pro-visions of the current code,the beam can be in the incomplete linear stage when both values fall within the code’s specified range.The strain verification coefficient sourced from the compression zone at the bottom of theflange is not recommended for assessing the bridge’s load-bearing capacity.

甘薯杂粮粉品质特征与主要理化性质的Mantel test分析

以不同品种甘薯全粉为原料,复配黄豆粉、芝麻粉制备甘薯杂粮粉,并测定其β-胡萝卜素、玉米黄质、槲皮素含量,利用曼特尔检验(Mantel test)方法探讨这3种天然成分含量与其理化指标之间的相关性,研究甘薯品种对甘薯杂粮粉品质的影响。结果表明:甘薯杂粮粉的抗氧化能力与β-胡萝卜素含量呈强正相关(r=0.80),与玉米黄质含量(r=0.26)和槲皮素含量(r=-0.14)呈现弱相关性。甘薯杂粮粉的干物质含量与β-胡萝卜素含量呈负相关(r=-0.72),与玉米黄质含量(r=0.91)和槲皮素含量(r=1.00)呈强正相关。总体表明β-胡萝卜素是甘薯杂粮粉中有效的抗氧化成分。

Design and process test of a novel MOEMS accelerometer based on Raman-Nath diffraction

A novel micro-opto-electro-mechanical system （MOEMS） accelerometer based on Raman-Nath diffraction is presented. It mainly consists of an FPW delay line oscillator and optical strip waveguides. The fun- damental theories and principles of the device are introduced briefly. A flexural plate-wave delay-line oscillator is designed to work as an acousto-optic （AO） shifter, which has a Klein-Cook parameter of 0.38. Single-mode optical strip waveguides of 2 μm in width and thicknesses of 0.6 μm are designed by using the effective index method for light transmission. The E^y00 mode waveguide polarizers are designed to ensure the consistency of the light polarization in the waveguides. The fabrication process, based on （100） oriented, 450-#m-thick silicon wafers is proposed in detail, and some difficulties in the process are discussed carefully. At last, a series of process tests are undertaken to solve the proposed problems. The results indicate that the proposed design and fabrication process of the device is dependable and realizable.

Optimization of Extraction Process of Zihua Qinghuo Capsule by Orthogonal Test

With quercetin content and yield of dry extract as investigation indices, three factors, amount of water added, decoction time and decoction times were investigated by an orthogonal test, so as to select the optimal water extraction process for Zihua Qinghuo Capsule. The determined extraction process was adding 8 times of water in five herbs including Viola philippica and decocting for 2 times, 1.5 h each time. Pilot scale test demonstrated that the selected process is stable and feasible, and could provide reliable reference for practical production.

Lognormal Process Software Reliability Modeling with Testing-Effort

We propose a software reliability growth model with testing-effort based on a continuous-state space stochastic process, such as a lognormal process, and conduct its goodness-of-fit evaluation. We also discuss a parameter estimation method of our model. Then, we derive several software reliability assessment measures by the probability distribution of its solution process, and compare our model with existing continuous-state space software reliability growth models in terms of the mean square error and the Akaike’s information criterion by using actual fault count data.

Big Data Testing Techniques:Taxonomy,Challenges and Future Trends

Big Data is reforming many industrial domains by providing decision support through analyzing large data volumes.Big Data testing aims to ensure that Big Data systems run smoothly and error-free while maintaining the performance and quality of data.However,because of the diversity and complexity of data,testing Big Data is challenging.Though numerous research efforts deal with Big Data testing,a comprehensive review to address testing techniques and challenges of BigData is not available as yet.Therefore,we have systematically reviewed the Big Data testing techniques’evidence occurring in the period 2010–2021.This paper discusses testing data processing by highlighting the techniques used in every processing phase.Furthermore,we discuss the challenges and future directions.Our findings show that diverse functional,non-functional and combined(functional and non-functional)testing techniques have been used to solve specific problems related to Big Data.At the same time,most of the testing challenges have been faced during the MapReduce validation phase.In addition,the combinatorial testing technique is one of the most applied techniques in combination with other techniques(i.e.,random testing,mutation testing,input space partitioning and equivalence testing)to find various functional faults through Big Data testing.

Uniaxial compression CT and acoustic emission test on the coal crack propagation destruction process

Acoustic emission test and CT scanning are important techniques in the study of coal crack propagation. A uniaxial compression test was performed on coal samples by integrating CT and acoustic emission. The test comparison analyzes the acoustic emission load and CT images for an effective observation on the entire process, from crack propagation to the samples＇ destruction. The box dimension of the coal samples＇ acoustic emission series and the CT images were obtained through calculations by using the authors＇ own program. The results show that the fractal dimension of both the acoustic emission energy and CT image increase rapidly, indicating coal and rock mass has entered a dangerous condition. Hence, measures should be taken to unload the pressure of the coal and rock mass. The test results provide intuitive observation data for the coal meso-damage model. The test contributes to in-depth studies of coal or rock crack propagation mechanisms and provides a theoretical basis for rock burst mechanism.

Optimization of Extraction Process of Prunellae Spica Compound by Orthogonal Test

[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.

Δ<i>I_DDQ</i>Testing of a CMOS Digital-to-Analog Converter Considering Process Variation Effects

In this paper, we present the implementation of a built-in current sensor (BICS) which takes into account the increased background current of defect-free circuits and the effects of process variation on ΔIDDQ testing of CMOS data converters. A 12-bit digital-to-analog converter (DAC) is designed as the circuit under test (CUT). The BICS uses frequency as the output for fault detection in CUT. A fault is detected if it causes the output frequency to deviate more than ±10% from the reference frequency. The output frequencies of the BICS for various (MOSIS) model parameters are simulated to check for the effect of process variation on the frequency deviation. A set of eight faults simulating manufacturing defects in CMOS data converters are injected using fault-injection transistors and tested successfully.

洒点喷涂在压路机零部件上的应用

为了降低路面机械涂装的制造成本,通过对洒点漆的组成、洒点喷涂工艺、喷涂设备及其施工参数进行了研究并进行施工验证试验,同时对比分析了洒点喷涂工艺与刮腻子工艺在工程机械行业的应用成本。结果表明洒点漆喷涂漆施工工艺及喷涂质量满足工程机械的部分零部件涂装要求,可用于工程机械外观等级要求不高的零部件上。相比刮腻子工艺,洒点漆喷涂工艺可节省涂装成本,降低制造费用,可在工程机械行业推广应用。

Kolmogorov-Smirnov APF Test for Inhomogeneous Poisson Processes with Shift Parameter

In this article, we study the Kolmogorov-Smirnov type goodness-of-fit test for the inhomogeneous Poisson process with the unknown translation parameter as multidimensional parameter. The basic hypothesis and the alternative are composite and carry to the intensity measure of inhomogeneous Poisson process and the intensity function is regular. For this model of shift parameter, we propose test which is asymptotically partially distribution free and consistent. We show that under null hypothesis the limit distribution of this statistic does not depend on unknown parameter.

黑木耳超微颗粒混悬液制备工艺研究

采用高压均质法制备黑木耳超微颗粒混悬液,并对制备工艺进行优化。结果表明,采用高压均质法可制备黑木耳超微颗粒混悬液,优化后的工艺参数为均质压力10 Mpa,均质固液比1∶5,均质次数4次,制备后的混悬液平均粒度为5.31μm。

俄罗斯液体潜射弹道导弹长期贮存材料工艺技术

对液体潜射弹道导弹长期加注贮存技术的发展进程、最新进展及研究现状进行概述。重点介绍俄罗斯液体潜射弹道导弹的结构设计、材料选取和制造工艺以及出厂加注封装和密封性检测方法,最后指出实现长期加注贮存的技术路径。

2018—2022年京津冀血液筛查实验室检测前质量不合格标本情况分析

目的 探讨2018—2022年京津冀15家血液筛查实验室(血站实验室)检测前质量不合格标本的情况及存在问题,为提升京津冀血站实验室质量同质化建设提供数据支持。方法 选取北京、天津和河北3个地区的血液中心和中心血站的15家血站实验室,其中包括3家血液中心实验室和12家地市级中心血站实验室,分别用代码A~O表示。收集15家血站实验室2018—2022年检测前接收标本总数、质量不合格标本总数以及常见不合格原因(溶血、乳糜、容量不足量、血细胞比容异常、采集后未按要求及时离心和其他原因等)对应标本数,分析检测前标本的不合格情况。结果2018—2022年15家血站实验室检测前质量不合格标本率为1.98‱,呈下降趋势,由2.54‱下降至1.57‱。标本质量不合格原因5年来保持稳定,占比依次是乳糜(74.72%)、溶血(7.41%)、容量不足量(5.42%)、其他原因(4.42%)、血细胞比容异常(4.35%)、采集后未按要求及时离心(3.68%)。15家血站实验室之间检测前质量不合格标本率的比较,差异有统计学意义(P<0.05)。与检测前总体质量不合格标本率相比,11家实验室低于总体水平,其中4家持续保持稳定状态。结论 15家血站实验室的检测前过程控制总体良好,但由于各血站在检测前标本管理过程的流程设计和工作模式的不同导致统计数据存在差异,部分实验室仍有改进空间。

茶叶生产装备自动化与智能化技术研究进展与展望

茶产业是我国传统特色优势产业,大数据、物联网、云计算等新一代信息技术与农业的融合促进了茶产业向智能化转型与升级,在茶叶全产业链赋能增效中发挥重要作用。本文在概述了茶产业智能化技术体系的基础上,围绕种植、加工、检测和销售等4方面总结了国内外信息技术在茶产业智能化中应用的研究成果,分析了茶产业实现智能化的关键技术。最后对茶产业智能化未来发展方向进行展望,建议增强茶产业信息技术基础设施建设、加强人机协作智能茶机设备研发、重视茶叶种植加工大模型开发、提升大数据分析助力茶叶销售能力,为更好利用信息技术进行茶产业升级奠定基础。

CO_(2)快速吞吐提高页岩油采收率现场试验

页岩油注CO_(2)吞吐提高采收率技术处于探索阶段,目前面临着CO_(2)与页岩储层及流体相互作用机制不明确、数值模拟技术不成熟、缺乏规模注采及低成本回收工艺等技术难题。为探索页岩油注CO_(2)提高采收率主控机理,以苏北盆地溱潼凹陷古近系阜宁组二段页岩油为对象开展了超临界CO_(2)水岩反应实验,分析了高温高压条件下页岩矿物溶蚀作用及其对孔隙度和渗透率的影响,并通过注CO_(2)恒质膨胀实验、最小混相压力测试评价了地层超压条件下注CO_(2)后原油高压物性变化特征,并在此基础上开展考虑多因素数值模拟研究优化了设计注入参数,最终通过矿场试验验证了技术可行性。研究结果表明:(1) CO_(2)水岩反应以碳酸质矿物溶蚀占主导,长英质矿物部分溶解,生成中大孔隙;(2)在地层原油中注入适量的CO_(2),显著萃取了原油中间烃组分,原油黏度从5.151 mPa·s下降到1.250 mPa·s,且CO_(2)首先萃取轻烃组分,随生产时间增加萃取组分逐渐变为重烃;(3)基于人工压裂与天然缝网混合介质组分数模模型,优化设计单井吞吐注气量1.7×10~4 t,注气速度500~600 t/d,焖井时间50 d;(4)低压侧加热的页岩油CO_(2)吞吐地面工艺,可依据CO_(2)注入地面工艺多参数数据模型,实现精准控温,避免注入管线冻堵及井下油管和套管材料低温脆断问题;(5)产出气CO_(2)浓度高于80%时,采用气相回收直注工艺,实现产出气回收成本降至104元/t。结论认为,CO_(2)快速吞吐有效提高了页岩油采收率,形成的机理认识和技术系列可为页岩油注CO_(2)吞吐开发提供参考和借鉴。

过程性评价对工科物理教学质量的影响研究

本研究以课堂测验的形式探索过程性评价对学习效果的影响。学生层面上,通过使用学习投入问卷对工科学生的大学物理学习投入进行测量,发现过程性评价除了检查课堂学习效果,还是提升学生情感投入的一个有效途径。教师层面,通过使用Rasch模型对大学物理课堂测试数据进行分析,发现过程性评价有助于出题教师优化测试题库,任课教师根据测试反馈也可以不断建构和修正教学内容,提高教学质量。

五味痛风丸提取及制备工艺研究

目的:将五味痛风汤开发为五味痛风丸。方法:以加水倍数、煎煮时间、煎煮次数为考察因素,以秦皮乙素转移率和干浸膏率为评价指标,采用正交设计优化五味痛风丸的提取工艺,并进行丸剂成型工艺研究。结果:最佳提取工艺为加12倍水、煎煮1.5小时、煎煮3次;最佳成型工艺为提取液减压浓缩至相对密度为1.30~1.40,吴茱萸和红曲粉碎过100目筛,混匀后制丸,70℃干燥24小时。结论:该提取、制备工艺稳定可行。

模具和工艺参数对铝合金成形件回弹仿真研究

为研究成形参数对铝合金冲压成形件回弹的影响,以6016铝合金材料进行拉伸试验获取材料数据为基础,获取材料参数;以有限元DYNAFORM软件为载体,通过数值模拟对S形件进行拉延成形及后处理回弹分析;分别以模具参数、工艺参数为变化量,分析单因素参数对S形件回弹量的影响规律,同时考虑各参数的相互耦合作用,运用正交试验对对多参数进行优化组合,分析凸凹模间隙值、凹模圆角半径、摩擦系数、压边力、冲压速度与回弹量之间的关系;研究表明影响S形件回弹量的成形工艺参数主次顺序依次为凸凹模间隙值(A)、凹模圆角半径(E)、摩擦系数(D)、压边力(C)、冲压速度(B),为冲压生产从业人员和同类型冲压成形件提供有益的参考。

复杂内孔结构磨粒流加工的检测评价与优化

为提高军工零件的内孔加工的可靠性和加工质量,通过正交试验法,分析磨粒流加工中,磨料粒度、磨料质量分数、磨粒流工作压力和循环加工次数对阶梯内孔倒圆角半径、材料去除率、内孔表面粗糙度的影响规律,磨粒流工作压力是内孔倒圆角半径的首要影响因素,较为显著,材料去除率的首要影响因素是磨料质量分数,而内孔表面粗糙度的首要影响因素是循环加工次数,通过非线性回归分析建立了复杂内孔磨粒流加工效果评价的模型。以改进的带精英策略的快速非支配排序遗传算法(NSGA-II)进行多目标工艺参数寻优,得到了综合平衡权重下的最佳工艺方案(磨料粒度1 000#,磨料质量分数为50%,工作压力为7.5 MPa,循环加工次数为30次),验证试验表明优化结果和实际加工效果具有较好的一致性。