Conversion factor analysis of self-balanced loading test of cast-in-situ piles based on analogue test method

Based on the characteristics of pile-soil interaction and the Mohr-Coulomb strength theory,a new method of determining the side friction at a pile-soil interaction is proposed.Combined with the actual engineering cases,the effectiveness of the analogue test method is verified by comparing it with the traditional anchor pile method and self-balanced method.Taking the self-balanced test of the bridge pile foundation in the Songhua River as an example,the conversion factor of sandy soil and weathered mudstone are confirmed by the analogue test method.The results show that the conversion factor of sandy soil and weathered mudstone in the Songhua River area should consider the geological conditions and the construction technology,etc.The standard values are relatively conservative.It is suggested that the engineering application should be properly revised.The recommended range of the conversion factor of sandy soil in this area is 0.65 to 0.85,and that of weathered mudstone is 1.0.

Experimental investigation on hard rock fragmentation of inserted tooth cutter using a newly designed indentation testing apparatus

This investigation aims to explore the effects of stress conditions and rock cutting rates on hard rock fragmentation through indentation tests on a newly designed triaxial testing apparatus.This apparatus was designed to realize a triaxial loading and indentation test of cylindrical specimens using inserted tooth cutter.The boreability and crushing efficiency of granite rock was investigated by analyzing the change rules of the thrusting force,penetration depth,characteristics of chippings and failure patterns.Several quantitative indexes were used to evaluate rock boreability in this investigation.The granite rock samples all had a chiselled pit and a crushed rock core.Under initial stress conditions,only flat-shape chippings were stripped from the rock surface when the thrusting force reached 20 kN.The rock cutting special energy had a close correlation with the initial stress conditions and inserted tooth shape.Moreover,a thrusting force prediction model was proposed in this paper.The contribution of this study is that for the first time the influence mechanism of the initial triaxial stress conditions on rock fragmentation is investigated using an inserted tooth and the newly designed testing apparatus.This study has a crucial importance for practical underground hard rock crushing in geoengineering.

Effect of burial depth of a new tunnel on the seismic response of an existing tunnel

Burial depth is a crucial factor affecting the forces and deformation of tunnels during earthquakes.One key issue is a lack of understanding of the effect of a change in the buried depth of a single-side tunnel on the seismic response of a double-tunnel system.In this study,shaking table tests were designed and performed based on a tunnel under construction in Dalian,China.Numerical models were established using the equivalent linear method combined with ABAQUS finite element software to analyze the seismic response of the interacting system.The results showed that the amplification coefficient of the soil acceleration did not change evidently with the burial depth of the new tunnel but decreased as the seismic amplitude increased.In addition,the existing tunnel acceleration,earth pressure,and internal force were hardly affected by the change in the burial depth;for the new tunnel,the acceleration and internal force decreased as the burial depth increased,while the earth pressure increased.This shows that the earth pressure distribution in a double-tunnel system is relatively complex and mainly concentrated on the arch spandrel and arch springing of the relative area.Overall,when the horizontal clearance between the center of the two tunnels was more than twice the sum of the radius of the outer edges of the two tunnels,the change in the burial depth of the new tunnel had little effect on the existing one,and the tunnel structure was deemed safe.These results provide a preliminary understanding and reference for the seismic performance of a double-tunnel system.

New cheaper human papilloma virus mass screening strategy reduces cervical cancer incidence in Changsha city:A clinical trial

BACKGROUND Cervical cancer is the second leading cause of death in women worldwide,second only to breast cancer.Around 80%of women have been infected with human papillomavirus(HPV)in their lifetime.Early screening and treatment are effective means of preventing cervical cancer,but due to economic reasons,many parts of the world do not have free screening programs to protect women’s health.AIM To increase HPV cervical cancer screening in Changsha and reduce the incidence of cervical cancer.METHODS Cervical cancer screening included gynecological examination,vaginal secretion examination and HPV high-risk typing testing.Cervical cytology examination(ThinPrep cytology test)was performed for individuals who test positive for HPV types other than 16 and 18.Vaginal colposcopy examination was performed for HPV16 and 18 positive individuals,as well as for those who were positive for ThinPrep cytology test.If the results of vaginal colposcopy examination were abnormal,histopathological examination was performed.We conducted a cost-benefit analysis after 4 years.RESULTS From 2019 to 2022,523437 women aged 35-64 years in Changsha city were screened and 73313 were positive,with a 14%positive rate.The detection rate of precancerous lesions of cervical cancer was 0.6%and the detection rate of cervical cancer was 0.037%.Among 311212 patients who underwent two cancers examinations,the incidence rate was reduced by more than half in the second examination.The average screening cost per woman was 120 RMB.The average cost of detecting early cases was 10619 RMB,with an early detection cost coefficient of 0.083.CONCLUSION Our screening strategy was effective and cost-effective,making it valuable for early diagnosis and treatment of cervical cancer.It is worth promoting in economically limited areas.

New Parameters of Cardiopulmonary Exercise Testing in Patients with Chronic Heart Failure: Practical Applications

Cardiopulmonary exercise testing (CPX) has become the cornerstone of risk stratification for heart failure patients. Peak oxygen consumption (VO2) was the first CPX variable to demonstrate prognostic value and is still the most frequently analyzed variable in clinical practice. More recently, several investigations have shown that ventilatory efficiency, typically expressed as the minute ventilation/carbon dioxide production (VE/VCO2) slope, is a strong prognostic marker in patient with HF. The majority of studies report the VE/VCO2 slope to be prognostically superior to peak VO2 which underscore the clinical importance of assessing ventilatory efficiency in HF patients. Other expressions of ventilatory inefficiency like exercise oscillatory breathing (EOB), oxygen uptake efficiency slope (OUES), end-tidal carbon dioxide pressure (PET CO2) at rest, and haemodynamic responses such as heart rate recovery (HRR) are strong predictors of outcomes in patients with heart failure (HF). So there is a need for simplified approaches that integrate the additive prognostic information from cardiopulmonary exercise testing.

Solutions to Teaching Reform Challenges of Elective Courses under the Background of New Liberal Arts:Taking International Trade in Services Course as an Example

Variations in the allocation of university resources,teachers’course selection preferences and teaching commitment levels,as well as students’course preferences and assessment requirements,create subjective differences.These differences,compounded by the demands of the new liberal arts reform,place significant challenges and pressure on elective course instructors.To meet these demands,elective course teachers should enhance their teaching methods and explore new instructional models.The International Trade in Services course,for instance,has implemented six areas of curriculum reform,enriching the practice of elective course improvement.

Comparative Test for New Watermelon Cultivars

Comparative test was conducted on 11 （including the cultivar as control） new watermelon cultivars to identify the yielding ability, stability, adaptability, stress resistance and other important characteristics of the new watermelon oultivars, to thereby obtain new watermelon cultivars with good comprehensive characters suit- able for different regions and different cultivation manners. The results showed that Dali Qilin, Jingangerhao Hemeiren, Hongli Dahonghu, Hongli Baowang, Longjing Heibao and XJ-I had outstanding performance in yield, resistance and quality, and thus were worthy of further experiment demonstration and certification.

Modified Helicobacter test using a new test meal and a 13C-urea breath test in Helicobacter pylori positive and negative dyspepsia patients on proton pump inhibitors

AIM To determine the sensitivity and specificity of the ^(13)C-urea breath test(UBT) in patients taking proton pump inhibitors(PPIs), using a new test meal Refex. METHODS One hundred and fourteen consecutive patients with dyspepsia, 53 Helicobacter pylori(H. pylori) positive, 49 H. pylori negative, were included in the study. The patients were then given esomeprazole 40 mg for 29 consecutive days, and the ^(13)C-UBT with the new test meal was performed the next morning. RESULTS The sensitivity of the ^(13)C-UBT with a cut off 2.5‰ was92.45%(95%CI: 81.79%-97.91%) by per-protocol(PP) analysis and 78.13 %(95%CI: 66.03%-87.49%) by intention-to-treat(ITT) analysis. The specificity of the ^(13)C-UBT test was 96.00 % in the ITT population(95%CI: 86.29%-99.51%) and 97.96% in the PP population(95%CI: 89.15%-99.95%).CONCLUSION The new test meal based ^(13)C-UBT is highly accurate in patients on PPIs and can be used in those unable to stop their PPI treatment.

Performance Testing of Tractor Hydraulic Fluids to Simulate In-Use Conditions

Tractor hydraulic fluids are tested to maximize their performance levels and to ensure manufacturer′s standards are met.Common tractor hydraulic fluid tests include: Gear Wear Protection,Brake Chatter Reduction,Wet-Clutch Capacity,and Pump Performance tests.These tests are run by Southwest Research Institute,in the U.S.A.,for tractors built by John Deere and Case-New Holland.This paper details current methods for evaluating tractor hydraulic fluids.The tests that are described utilize full size equipment and were developed by the tractor′s original equipment manufacturers(OEMs).

Comparative Test of New Late Indica Hybrid Rice Combinations with Good Quality

[Objectives]This study was conducted to screen rice varieties suitable for planting in Nanchang City with high quality,high yield,good yield,and strong disease and stress resistance.[Methods]Seven new late indica hybrid rice combinations with good quality bred in Jiangxi Province in recent years and seven new late indica hybrid rice combinations with good quality bred by Nanchang Academy of Agricultural Sciences were introduced,and compared with Tianyouhuazhan as a control.[Results]The rice quality and taste of the tested combinations were better than those of the control.Among the tested combinations,Yuliangyoufuxiangzhan,Xintaiyousizhan,Yuxiangliangyou No.8 and Guangheyou 33 had good stress resistance,high yield and good rice quality.[Conclusions]This study provides a theoretical basis for the selection and breeding of new rice varieties in Nanchang City.

基于新课标的中小学生计算思维量表构建研究

对学生计算思维的培养已成为数字时代的核心议题,科学、精准的评价则是培养学生计算思维能力的基础。然而,针对义务教育阶段学生的计算思维测评,目前国内尚无依托相关课程标准制定的本土化的、权威的量表。为此,研究首次依托《义务教育信息科技课程标准(2022年版)》(以下简称“新课标”)中的计算思维定义及培养要求,共以12920名(N1=1029,N2=1458,N3=10433)小学生和初中生为研究样本,运用收敛混合方法构建一个面向我国教育实际的、经严格论证的中小学生计算思维量表。结果显示:经过两轮的收敛混合分析,修改后的计算思维量表共包含5个因子及15个题项,具有良好的内容效度;经过大样本实证检验分析,量表具有良好的信效度,且具有跨性别、年级和地区测量等值性,可以用来测量中小学生的计算思维水平。

龙燕1号燕麦新品种的选育

为了选育高产、优质、适应东北三省及内蒙古地区种植的燕麦新品种,试验于2015年采用母本边锋和父本牧乐思进行种间杂交,并通过系统衍生法进行选育,对选育得到的燕麦新品种进行品种比较试验、区域试验及生产试验。结果表明:经选育得到龙燕1号燕麦,其2019—2020年两年平均干草产量及种子产量分别为15 100.0 kg/hm^(2)、4 760.3 kg/hm^(2),较对照牧乐思、白燕7号分别增产16.84%、11.71%和14.96%、11.11%,差异显著(P<0.05);两年(2022,2023年)多点(齐齐哈尔市、哈尔滨市、双鸭山市、绥化市)的平均干草产量龙燕1号最高,达9 857.14 kg/hm^(2),分别比对照青海444、青引2号增产18.11%、45.30%,差异极显著(P<0.01);在4个试验区哈尔滨市、兰西县、杜蒙县、肇东市的两年平均干草产量分别达到11 812.73 kg/hm^(2)、9 602.57 kg/hm^(2)、12 263.64 kg/hm^(2)和11 961.97 kg/hm^(2),比对照白燕7号分别增产11.57%、11.92%、12.60%、11.24%。说明饲用燕麦新品种龙燕1号燕麦相较亲本具有更好的生产性能,在东北三省均可种植。

上海市域铁路新建项目工程验收办法及安全评估方案研究

[目的]上海市域铁路已有多个项目开工建设,但目前尚无明确的市域铁路新建项目工程验收办法及安全评估管理办法。为了对市域铁路新建项目工程验收、安全评估等管理办法的制定提供合理化建议,亟需开展市域铁路项目工程验收办法及安全评估方案的研究。[方法]从主要技术标准、建设及运营特点两方面,分析了市域铁路同地铁、国家铁路的差异。阐述了地铁、国家铁路建设项目工程验收及安全评估程序,讨论了二者在项目验收组织、验收程序及验收内容等方面的差异。在此基础上,针对上海市域铁路新建项目工程验收及安全评估的具体工作流程,提出了2个备选方案(方案一、方案二),并对2个方案进行了比选,提出适用于上海市域铁路新建项目验收及安全评估工作流程的建议方案。[结果及结论]上海市域铁路新建项目的工程验收及安全评估建议采用方案二,即上海市域铁路项目工程验收的程序及组织方式基本沿用地铁模式,并参照国家铁路项目的标准设置联调联试流程。

集成电路测试新工科人才产教融合培养模式探索与实践

集成电路测试是集成电路设计制造产业中的重要环节。针对目前国内集成电路测试行业专门技术人才紧缺的现实需求,合肥工业大学联合国内外集成电路产业知名企业,从课程教学内容与教学方法、实验平台建设与实验设计、创新能力培养与学科竞赛等环节入手,在仪器类专业探索现阶段适合于集成电路测试新工科人才培养的校企合作办学模式。近年来,在集成电路测试课程体系完善、实验平台建设、实践环节培养等方面均取得较好的成果,为新工科人才产教融合培养提供实践经验和参考案例。

粗差和系统误差显著性检验统计量统一推导新方法

基于均值平移模型的数据探测法和附加系统参数的平差法是目前处理粗差和系统误差的重要方法,其函数模型形式一致,故关于二者的显著性检验统计量理论上可做统一推导。不同于已有文献,文中提出一种统一推导的新方法。新方法的思路更符合数理统计中构造显著性检验统计量的一般思路,具有简洁且易于理解的特点。此外,新方法还具有较强的普适性,除参数平差外,需要时还可用于其他平差方法的粗差与系统误差显著性检验统计量推导。

模拟新建桥梁安全屏障高冲击等级的碰撞测试

针对汽车碰撞桥梁护栏事故频发,人员伤亡较大的情况,进行了新建桥梁安全屏障碰撞的研究。研究模拟新建桥梁的安全屏障在高冲击等级碰撞测试中的效果,分析碰撞中影响车体变形以及碰撞点、碰撞角度、碰撞速度等安全性因素。试验结果表明,在碰撞测试中桥梁护栏的变形程度与吸收的能量呈正比例。新建桥梁需要重视安全屏障的材料、结构设计的合理性,以提高安全屏障吸能水平。

面向新质生产力的检验检测共同体构建途径探索

检测服务在社会健康运行和发展中发挥着越来越重要的作用,随着新质生产力的快速发展,新的检测项目和方法层出不穷,这就迫切需要建政产测学创合作,及时解决问题。本文调研了常州市内检验检测机构与政府、高校、产业联盟和创新创业机构的协同联动机制,总结有益的经验,分析分析当前存在的问题,提出具体的协同联动策略,为实现社会经济的可持续发展提供有力的检测服务。

新型平衡舵阴极保护设计与保护效果评价

目的 针对新型平衡舵结构的电偶腐蚀薄弱区域,设计并优化牺牲阳极保护系统,并对保护效果进行评价。方法 基于边界元法,开展新型平衡舵电偶腐蚀仿真研究,分析电偶腐蚀薄弱区域。针对腐蚀薄弱区域,采用经验法设计牺牲阳极保护系统,开展服役初期和服役3 a后阴极保护效果仿真。从涂层破损率和阳极数量对阴极保护效果的影响出发,优化阴极保护系统。开展物理模型试验,对优化后阴极保护系统的保护效果进行评价。结果 电偶腐蚀主要发生在壳体和底座等支撑材料处,必须采取严格的防腐措施。采用经验法设计的牺牲阳极保护系统在服役初期可以使平衡舵保护电位均负于–800m V,处于良好的阴极保护状态。随着阳极的消耗,服役3 a后,阴极保护系统无法为平衡舵提供有效保护。涂层破损率的增加和阳极数量的减少,都会使平衡舵阴极保护电位正移。通过物理模型试验验证了优化后阴极保护模型的可靠性,对比试验结果,模型的预测误差在5%以内。结论 优化后的阴极保护方案为涂层+8块牺牲阳极,可以在服役3 a涂层破损率达20%的严苛工况下,为平衡舵提供有效阴极保护。优化后的阴极保护系统,铝阳极用量减少30%,有助于节省船舶动力。

高考语文考试内容改革的回顾及展望

伴随着国家教育考试现代化的步伐,高考语文在过去十年间大力推动考试内容改革。在指导思想上,坚持立德树人、为国选才育人;在考查内容上,注重基础知识,突出关键能力;在试题命制上,创新题型设计,降低机械刷题收益;在引导教学上,优化情境设计,加强教考衔接。同时,高考语文也面临一些新的问题和挑战。对此,应进一步加强理论研究,把握好“变”与“不变”的关系,重视高考对教学的反拨作用,打造一支高素质专业化创新型命题教师队伍。

新高考改革十年的三重逻辑

2014年启动的新高考改革是一场全国范围的立体式、系统性重大教育改革,对于基础教育和高等教育均产生了广泛而深刻的影响。在新高考改革十周年之际,系统把握其历史逻辑、理论逻辑和实践逻辑,对于新高考的后续发展与完善及深刻认识中国高考现代化命题具有重要意义。本轮新高考改革是此前系列高考改革探索的迭代升级与高中新课改的逻辑推进。高中学考科目被纳入高校招生评价,具有与高考科目类似的选拔属性,本质上等同于高考科目。十年新高考改革实践再度表明,高中毕业考试与高校招生选拔考试必须分开举行;不宜过度批判考试科目的统一性、过度强调考试科目的选择性。想要将综合素质纳入统一高考招生评价,需以赋予高校一定招生自主权为基本前提。