3D deformation effect and optimal excavated design of surface mine

The three-dimensional (3D) deformation effect of the slope engineering underthe step-by-step excavation for the Antaibao surface mine was analyzed using the FLAG^3Dtechnique. An optimal excavated scheme with a relatively steeper slope angle of 47^(。) instead of 30^(。) was successfully implemented at the west wall in the geological section73200 of the mine area, where the 3D effect of the nonlinear large deformation of theslope was taken into account. Based on the above research conclusion, put forward thecountermeasures of shortening mining length, excavating by different regions, timely footbackfilling to protect the excavated slope, and monitoring and feedback adjustment bystudying the nonlinear effect. The results show that these countermeasures are effective incontrolling maximum deformation and increasing the stability of the slope.

Identifying Combinatorial Growth Inhibitory Effects of Various Plant Extracts on Leukemia Cells through Systematic Experimental Design

Plant extracts are widely studied for their anti-cancer and cancer preventive effects. In this study, we compared the leukemia growth inhibition effects of seven different plant extracts, theaflavin, epigallocatechin gallate (EGCG), epicathechin (EC), apigenin, quercetin, chrysin and tannic acid, in vitro using the K562 erythroleukemia cell line and application of the design of experiments (DoE) methodology. Our systematic approach enabled us to isolate the main factor contribution, two-factor interactions and produced interaction relationships and/or models to describe growth inhibitory effects of different plant extracts when they are used in combination. The results identified tannic acid as the most significant inhibitor in this group and had synergistic effects with EGCG at specific concentrations. The fitted model of their combined effects showed that the most potent combination is at low concentrations of tannic acid (10 - 20 μM) and high concentrations of EGCG (80 - 100 μM). We further showed that tannic acid induced both growth inhibition and apoptosis in K562 cells in ranges between 10 - 100 μM. The polyphenol caused cell cycle arrest at G2- phase under the higher concentrations. In summary, use of DoE techniques effectively identified the most prominent inducer in this group of plant bioactive compounds and produced combinatorial bioactivity of various polyphenols and flavonoids over the entire range of concentrations under study. This study exemplifies the usefulness of DoE and serves as a guide in its utility for in vitro assessment of bioactivity in plant constituents.

Application of Box-Behnken Design in Optimization of Allelopathic Effects of Potamogeton Pectinatus Against Microcystis Aeruginosa

Allelopathic effects of submerged macrophytes against algae are affected by many environmental factors which can only be measured one by one by traditional methods. Box-Behnken design of response surface methodology was used to optimize three environmental factors(temperature, light intensity and total dissolved solids) of allelopathic effects of Potamogeton pectinatus against Microcystis aeruginosa at the same time. By solving the regression equation and analyzing the response surface contour plots, the optimal conditions of the relatively inhibitory rate of Microcystis aeruginosa were that the temperature was 23℃, the light intensity was 2,700,lx and the total dissolved solids were 4,415,mg/L. Under these conditions, the optimal value of relatively inhibitory rate of Microcystis aeruginosa was 81.9%. According to validation experiments, the results of analysis indicated that the experimental values fitted well with the predicted ones.

Effects of site conditions on earthquake ground motion and their applications in seismic design in loess region

The Loess Plateau is an earthquake prone region of China, where the effects of loess deposit on ground motion were discovered during the 2008 Wenchuan earthquake(Ms8.0) and the 2013 Minxian-Zhangxian earthquake(Ms6.6). The field investigations, observations, and analyses indicated that large number of casualties and tremendous economic losses were caused not only by collapse and damage of houses with poor seismic performance, landslides, but also amplification effects of site conditions, topography and thickness of loess deposit, on ground motion. In this paper, we chose Dazhai Village and Majiagou Village as the typical loess site affected by the two earthquakes for intensity evaluation, borehole exploration, temporary strong motion array, micro tremor survey, and numerical analysis. The aim is to explore the relations between amplification factors and site conditions in terms of topography and thickness of loess deposit. We also developed site amplification factors of ground motion for engineering design consideration at loess sites. The results showed that the amplification effects are more predominant with increase in thickness of loess deposit and slope height. The amplification mayincrease seismic intensity by 1 degree, PGA and predominant period by 2 times, respectively.

Profiled Cylindrical Roller Design in Consideration of Grinding Undercut Effect

In this paper, the effect of the grinding undercut of the raceways on the longitudinal pressure distribution of the profiled rollers, which are the most popular axial profile employed by the bearing manufacturers, was discussed. Based on the profiled roller geometrical equations and numerical calculation of three dimensional elastic contact problems of finite length, a new numerical method for calculating the crown drop evaluation considering the effect of grinding undercut was used. The analyses of two structure case, that roller length is greater or less than raceway width, were carried out and compared with each other. The Results show that the width of grinding undercut must be considered in determining the crown drop of rollers.

Thermal resistance matrix representation of thermal effects and thermal design of microwave power HBTs with two-dimensional array layout

Based on the thermal network of the two-dimensional heterojunction bipolar transistors(HBTs) array, the thermal resistance matrix is presented, including the self-heating thermal resistance and thermal coupling resistance to describe the self-heating and thermal coupling effects, respectively.For HBT cells along the emitter length direction, the thermal coupling resistance is far smaller than the self-heating thermal resistance, and the peak junction temperature is mainly determined by the self-heating thermal resistance.However, the thermal coupling resistance is in the same order with the self-heating thermal resistance for HBT cells along the emitter width direction.Furthermore, the dependence of the thermal resistance matrix on cell spacing along the emitter length direction and cell spacing along the emitter width direction is also investigated, respectively.It is shown that the moderate increase of cell spacings along the emitter length direction and the emitter width direction could effectively lower the self-heating thermal resistance and thermal coupling resistance,and hence the peak junction temperature is decreased, which sheds light on adopting a two-dimensional non-uniform cell spacing layout to improve the uneven temperature distribution.By taking a 2 × 6 HBTs array for example, a twodimensional non-uniform cell spacing layout is designed, which can effectively lower the peak junction temperature and reduce the non-uniformity of the dissipated power.For the HBTs array with optimized layout, the high power-handling capability and thermal dissipation capability are kept when the bias voltage increases.

专业设计、用户设计还是AI设计?设计源效应的心理机制

设计源效应是指企业产品设计来源信息对消费者产品偏好和企业态度的影响。目前,专业设计师、用户和AI是三种常见的产品设计源。这三种产品设计源通过不同的作用机制对消费者心理和行为产生积极或消极的影响。其中,能力是专业设计源效应产生的作用机制,能力、权力和心理距离是用户设计源效应产生的作用机制,而价值和信息是AI设计源效应产生的作用机制。同时,设计源效应是有作用条件的,会受到消费者、产品、企业因素的约束。未来研究可以深入探讨消费者对混合设计源的反应、进一步探讨设计源效应的作用机制和作用条件。

小学数学作业设计有效性实践研究

在“双减”背景下,基于学生综合能力的培养,学生的基础知识与技能需要得到不断的夯实,数学的活动经验需要持续的积累,数学的基本思想需要得到感悟。基于此,以发展学生核心素养为目标,以相关理论知识为指导,结合学生的认识规律,尝试从调查性实践作业、操作性实践作业、探究性实践作业、应用性实践作业四个层面开展实践探索。在此基础上,提炼出普遍的、可操作性的、广泛被学生认可的实践经验,探索构建小学数学作业设计的“4436”模式,为小学数学教师提供可借鉴的实践作业设计样例和设计策略。

课程思政融入妇产科教学的实践与探索

培养德才兼备的医疗卫生人才是医学高等教育的目标,“课程思政”是高等医学院校教育的内在要求和根本任务,也是“立德树人”的有力手段。文章根据目前课程思政现状,阐述在妇产科理论及临床实践教学中融入课程思政的设计策略、实施情况及阶段性成效,总结“课程思政”融入妇产科教学存在的问题以及构建课程思政教育体系的建议,探讨当代医学生思想政治教育新模式,以期为临床课程有效开展课程思政提供理论依据及思路参考。

霍尔效应实验教学设计及内容拓展探索

从霍尔效应的发现及历史发展出发,介绍了磁感应强度、载流子浓度及迁移率的测量原理,进而拓展引入了前沿科学研究内容——光场调控霍尔效应及动力学演化过程。教学内容由浅入深、由古及今,引发学生的思考,拓宽学生的视野,使学生对霍尔效应有一个全面的认识,为培养追求卓越、引领未来的领军人才奠定基础。

垂直起降无人机气动布局设计研究进展

垂直起降无人机是当前航空领域的研究热点。文章介绍了倾转旋翼、倾转涵道和双系统式三类垂直起降无人机的工作原理和典型机型,分析和讨论了其气动布局特征及其设计研究进展,提出了垂直起降无人机气动布局设计和优化、飞行控制、侧风效应和结构轻量化设计方面的研究建议。

长岭断陷龙凤山气田致密凝析气藏CO_(2)吞吐效果评价

长岭断陷龙凤山气田致密凝析气藏产量递减快,采出程度低,为了减弱近井地带反凝析污染现象和凝析油采出困难的开发难题,通过数值模拟方法和注CO_(2)吞吐实验,分析评价CO_(2)吞吐效果,探讨提高气井产量和气藏采收率的方法。结果表明:与注干气吞吐相比,致密凝析气藏注CO_(2)吞吐更能较为有效地解除反凝析污染;气井反凝析分为反凝析初期(对生产基本无影响)、反凝析加重(对油生产有影响)、反凝析严重(对油气生产影响大)、极端反凝析(几乎不出油)共4个阶段;不同反凝析特征阶段的气井CO_(2)吞吐机理和目的不同,CO_(2)吞吐参数应当相应优化。现场实施表明,注CO_(2)吞吐的5口井在吞吐前处于不同的反凝析阶段,吞吐后取得了快速增加地层能量、解堵近井地带反凝析污染、提高注入能力、增加凝析油和天然气产量等效果。研究成果可为CO_(2)吞吐技术在致密凝析气藏的规模应用提供了经验。

单元教学设计的程序探讨

依据当代教学设计与学习科学研究,可以将单元教学设计程序确定为6+1步骤,这就是明类型、划水平、定任务、写目标、编量规、优结构和配评估。“明类型”明确学生要学到什么,“划水平”规定学生要学到什么程度,“定任务”则指导教师如何开展教学帮助学生学到要学的东西,达到预期的掌握水平。“写目标”要求教师按照内部心理模式和外部行为表现相统一的方式来编写教学目标,“编量规”是依据教学目标来细化具体的评估要求。“优结构”是指通过教师创设学习环境、优化教学结构和运用教学方法来帮助学生达成学习目标。“配评估”则要依据类型、水平、任务、目标、量规和结构的要求,具体确定评估的方式和特征,以评促教,以评促学。单元教学设计程序有利于教学取得减负增效赋能的效果。

基于印花效果的四色经提花面料产品研发

为研发具有印花效果的四色经提花面料新产品,对产品的花稿设计、纱线配置和编织工艺3方面内容进行了研究与实践。通过设计合适的花稿图案,选用5.56tex/36f的加捻涤纶低弹色纱,色彩分别为红、蓝、黄、黑4种颜色的纱线作为经纱,8.33tex/72f的白色或黑色涤纶色纱作为纬纱,运用重经组织结构使这4种不同颜色经纱形成不同的浮长,利用经纱混色配置的方式实现花稿图案的丰富色彩,研发出色彩丰富且立体感强、面密度轻、环保性能好、具有印花效果的轻薄型提花面料。

基于OBE理念的大学生心理健康教育课程设计与实践效果评估

大学生心理健康教育课程在提高大学生心理素质、促进其身心健康和谐发展方面发挥着重要作用。该研究通过梳理大学生心理健康教育课程存在的问题与不足,提出在大学生心理健康教育课程中引入OBE理念的可行性,从而在0BE理念下重新构建大学生心理健康教育课程体系,并对其实施效果进行评估,从而使课程的教与学更加聚焦于学习目标,调动学生的积极性与参与性,更加适应社会对人才需求的变化,为其他高校开展大学生心理健康教育课程改革提供参考。

临床研究生对临床研究设计与实施课程的主观评价及改进建议

目的:调查临床研究生对临床研究设计与实施课程的主观评价,以优化课程内容,提高授课水平。方法:对315名选课研究生进行问卷调查,调查内容包括学生的基本信息、科研经历、对课程效果及课程满意度的主观评价等。结果:课程开始前,8成以上学生在把握度分析、偏倚控制、偏倚识别、样本量估算、统计分析设计等环节存在困难。课程结束后,9成以上学生已掌握上述内容。96.19%的学生认为课程设计的科学性与实用性较好;仅有48.89%认为课程具有趣味性。结论:临床研究设计与实施课程已获得广泛认可,但仍需在课程内容及时间设置上予以改进,并进一步提升趣味性。

断点回归方法及应用实现

目的完整、系统介绍断点回归设计(RDD)原理及统计方法,为其在公共卫生领域应用提供参考。方法在介绍断点回归设计原理基础上,用室内甲醛干预的实例演示了利用Stata软件实现断点回归统计方法的过程,介绍和比较属于参数法的多项式回归和属于非参数法的局部线性回归的分析方法和结果。结果RDD是一种准实验设计,对研究对象没有随机分组,而是选择一个与干预措施有关的变量,根据该变量的取值选择切点划分干预组和对照组。RDD在内部有效性方面优于其他准实验设计,但外部有效性受到一定限制。基于观察性资料的RDD不仅可控制可观测的混杂因素,还可控制无法观测的混杂因素,也更符合伦理道德。在本文实例中,多项式回归和局部线性回归两种分析方法的结果基本一致。结论RDD在公共卫生领域的真实世界研究中有广阔的应用前景,为科学评估干预政策和提供高质量决策依据提供新的思路和方法。

中高能重离子束全径迹辐照材料和细胞的实验装置设计及效应分析

中高能重离子束注入生物材料的径迹显著深于生物靶,且不同径迹点上的剂量分布、理化效应等又大不相同,所以,同一靶点通常不可能接受所有理化因子的作用(即全径迹辐照)。本实验设计思路:基于CR-39核径迹探测手段,在纯水介质中验证全径迹辐照综合效应特征;通过沿径迹上连续逆向移动靶材料或细胞培养液,以探究全径迹的辐照效应。最后,与对照组相比较,揭示重离子束全径迹的辐照效应及其潜在的分子改性、细胞改良和发酵工程等方面的应用价值。