Controllable synthesis of CuAlO_(2) via solid-phase method and its catalytic performance for methanol steam reforming to hydrogen

This study explores the controllable synthesis of CuAlO_(2) using copper hydroxide and pseudo-boehmite powders as raw materials via a simple solid-phase ball milling method,along with its catalytic performance investigation in methanol steam reforming(MSR).Various catalysts were prepared under different conditions,such as calcination temperature,calcination atmosphere,and heating rate.Characterization techniques including BET,XRD,XPS,SEM and H2-TPR were employed to analyze the samples.The results revealed significant effects of calcination temperature on the phase compositions,specific surface area,reduction performance,and surface properties of the CA-T catalysts.Based on the findings,a synthesis route of CuAlO_(2) via the solid-phase method was proposed,highlighting the importance of high calcination temperature,nitrogen atmosphere,and low heating rate for CuAlO_(2) formation.Catalytic evaluation data demonstrated that CuAlO_(2) could catalyze MSR without pre-reduction,with the catalytic performance of CA-T catalysts being notably influenced by calcination temperature.Among the prepared catalysts,the CA-1100 catalyst exhibited the highest catalytic activity and stability.The findings of this study might be useful for the further study of the catalytic material for sustained release catalysis,including the synthesis of catalytic materials and the regulation of sustained release catalytic performance.

基于STEAM理念联合PBL教学法在急诊医学教学中的应用研究

目的分析基于STEAM[S(science),T(technology),E(engineering),A(art),M(mathematics)]理念联合以问题为基础的教学法(problem base learning,PBL)在急诊医学教学中应用效果。方法选择2021年6月—2022年6月滨州医学院急诊科80名本临床医学专业实习生为研究对象,将其随机分为对照组、试验组,各40名。对照组接受传统教学,试验组接受基于STEAM理念联合PBL教学法。对比2组教学前后理论知识及实践操作考试成绩、实习生对教学的满意度、学习依从度及教学前后实习生职业特质评分。结果教学前,2组考核成绩对比,差异无统计学意义(P>0.05);教学3个月后,2组基础理论、实践操作考核成绩均明显提升,但试验组提升幅度更大,差异有统计学意义(P<0.001)。试验组实习生学习依从性(97.50%)高于对照组(85.00%),差异有统计学意义(P<0.001)。试验组教学方法、学术能力、带教态度管理质量评分高于对照组,差异有统计学意义(P<0.001)。教学前,2组实习生职业特质评分对比,差异无统计学意义(P>0.05);教学3个月后,试验组评分高于对照组,差异有统计学意义(P<0.001)。结论在急诊医学教学中,基于STEAM理念联合PBL教学法有利于提升实习生的综合能力,提高理论实践成绩和学习依从性。

Adaptive H-infinity control of synchronous generators with steam valve via Hamiltonian function method

Based on Hamiltonian formulation, this paper proposes a design approach to nonlinear feedback excitation control of synchronous generators with steam valve control, disturbances and unknown parameters. It is shown that the dynamics of the synchronous generators can be expressed as a dissipative Hamiltonian system, based on which an adaptive H-infinity controller is then designed for the systems by using the structure properties of dissipative Hamiltonian systems. Simulations show that the controller obtained in this paper is very effective.

Use of Perovskite-Type Lanthanum Nickelate Synthesized by the Polymeric Precursor Method in the Steam Reforming Reaction of Methane

In the current work, LaNiO3 perovskite was synthesized using the polymeric precursor method. The materials were thermally treated at 300°C for 2 hours, subsequently supported on alumina or zirconia and finally calcined at 800°C for 4 hours. The resulting samples were characterized by X-ray diffraction, thermogravimetry, BET surface area and thermo-programmed reduction. Steam reforming reactions were carried out at 750°C and 6 bar during 4 hours using a pilot reactor under a H2O:CH4 ratio of 2.5. The mass of catalysts was about 5.7 g. X-ray diffraction patterns confirmed the formation of the perovskite structure in all samples prepared. The results also showed that lanthanum nickelate was more efficient when supported on alumina than zirconia. Finally, it was observed that the methane conversion was approximately 94% and the selectivity to hydrogen was about 70%. In all cases low selectivity to CO and CO2 was verified.

基于小学科学课程的STEAM教具创新设计

本研究旨在探索基于小学科学课程的STEAM教具创新设计方法,以提升儿童在科学学习中的兴趣和学习质量。首先,通过文献综述和实地调研,分析了STEAM教育理念与小学科学课程的关系,并确定了STEAM教具设计的重要性;接着采用德尔菲方法和结构方程模型(SEM)相结合的方法,对儿童在科学课学习中的用户需求进行了深入研究;通过构建STEAM教具体验满意度结构方程模型,获得了各个变量的影响权重值排序,并根据影响权重值制定了设计原则。在此基础上,设计了一款儿童拼装显微镜,提升了教具的可玩性、互动性和美观度。本研究的创新点在于将德尔菲方法和SEM相结合,提高了用户需求获取的客观性和准确性,为STEAM教具的创新设计提供了新的思路和方法。

STEAM教育的基本内涵与发展路径研究

STEAM(Science,Technology,Engineering,Arts,Mathematics)教育是在真实的问题情境中以学科整合的方式培养学生STEAM素养的一种教育模式,其基本内涵主要体现于真实问题的解决、学科整合与技能培养三个方面。STEAM教育的本土化发展需要整合课程资源,创设教学环境;转变教学方式,培养学生的STEAM素养;加快师资培养,促进STEAM教师专业发展。

PLC课程融合STEAM教育的教学模式探究

随着“中国制造2025”的推进,探索制造类专业理实一体化课程的实践教学模式具有十分重要的现实意义。该文以PLC技术应用课程为例,通过对STEAM教育理念的内涵解读,探究基于STEAM教育理念的PLC技术应用课程教学模式。通过对教学模式的理论依据、教学目标、操作程序、实现条件和教学评价这五个元素进行STEAM教育与PLC课程教学模式的融合构建,本研究认为STEAM教育指向技能人才的培养,与制造类专业理实一体化课程在教育理念、教学内容和教学设计形式等层面深度契合。因此,基于STEAM教育的教学模式适用于PLC应用技术的实际教学,本研究对制造类专业人才培养具有很强的指导和借鉴作用。

价值共创视角的工程类STEAM课程设计研究——以智能蜗牛饲养箱课程为例

旨在探索在工程类STEAM课程设计中的设计方法并进行设计实践。通过价值共创的视角对工程类STEAM课程的分析解析其共创机理,由价值矩阵将工程类STEAM课程价值生成过程理解为产品生成过程,提出产品作为核心线索的设计方法,并通过设计实践验证该设计方法可行性。提出基于产品生成逻辑的“建构-解构-再建构”的课程设计方法,能够有效把握STEAM内涵要求的基础上进行课程设计开发。以小学三年级科学课教材中的蜗牛一节内容作为出发点进行工程类STEAM课程设计实践,创造出智能蜗牛饲养箱STEAM课程。以此为过去经验性的课程设计开发方法厘清设计思路与路径,以期帮助STEAM教育的本土化发展。

议幼儿阶段的Steam学习

文章简述了St eam教育与幼儿教育的特征,针对幼儿感官认识与直接经验的年龄段特色,构建了St eam教育框架。该框架以艺术教育为中心,紧密结合科学教育与技术教育这两个基本点,弱化工程、数学要素,强化逻辑思维训练,注重扩展教育思维,防止拔苗助长式教育。

Effect of drying methods on the discoloration of three major domestic softwood species in Korea

Japanese pine, Korean pine and larch are three major softwood species in Korea. Their colors are relatively light, thus easily discolored due to drying and UV irradiation. In this study, they were dried with five different drying methods, steam treated and exposed to weathering. Their colors were measured using a spectrophotometer and comparisons made both among species and drying methods. For Japanese and Korean pines, high temperature dried and steam-dried specimens showed distinct color differences compared with the controls. Steam treatment discolored the dried specimens of Japanese and Korean pines but did not discolor those of larch. After weathering for 144 days the specimens of Japanese pine showed slight color differences among drying methods.

基于STEAM教育的儿童益智玩具设计

益智玩具有助于儿童的智力发育,而STEAM教育是一种跨学科、重实践的教育理念。将STEAM教育理念运用于儿童益智玩具设计可以使益智功能更全面,使玩具有更高的教育意义。本文从STEAM教育的内涵、其与儿童益智玩具的关系、STEAM玩具的分类、STEAM玩具的设计要求这几方面探讨STEAM教育在儿童益智玩具设计中的应用,最后基于这一理念设计了一款名为DRIFT COLOR PLATE的儿童益智玩具,结合科学和艺术两方面的知识,完成了设计实践,希望为儿童益智玩具的设计提供新思路。

Hydrogen production from steam reforming of ethanol over Ni/MgO-CeO_2 catalyst at low temperature

MgO,CeO2 and MgO-CeO2 with different mole ratio of Mg:Ce were prepared by solid-phase burning method.Catalysts Ni/MgO,Ni/CeO2 and Ni/MgO-CeO2 were prepared by impregnation method.The catalytic properties were evaluated in ethanol steam reforming(ESR) reaction.Specific surface areas of the supports were measured by nitrogen adsorption-desorption at 77 K,and the catalysts were characterized with X-ray diffraction(XRD),temperature programmed reduction(TPR) and thermogravimetric(TG).The results showed that well...

Calculation of Thermal Stress and Fatigue Life of 1000 MW Steam Turbine Rotor

The paper calculated the temperature and stress fields of 1000 MW ultra-supercritical steam turbine rotors which start in cold condition using the finite element calculation program (ANSYS). After getting rotor stress field, the paper use the general slope method to estimate the low cycle fatigue life loss, the rest of the conditions can be calculated in this method.

核心素养视域下STEAM教育的课堂教学变革

STEAM教育与我国深化教育改革的方向具有高度一致性,核心素养的养成与STEAM教育的出发点是完全吻合的,都是为了在社会转型期培养未来全面发展的人才。该文在分析核心素养体系的基础上,分析了STEAM教育在教学目标上由学科素养向核心素养转变、教学内容由单一性项目向专题性项目转变、教学方式由特定方式到多样化转变、学习结果由问题解决向内涵理解转变、教学评价从过程评价向动态评价五个方面的课堂教学变革,期望通过课堂变革得以提升学生核心素养和综合实践能力,加速学生全面发展的进程,培育更多的21世纪创新型复合人才。

The riddles of number nine in Chinese medicine processing method

The“nine cycles of steaming and shining”,“nine making”,“nine turns”and“nine cycles of calcining and quenching”methods that are recorded and used since ancient times are merely one aspect of the unique processing methods of traditional Chinese medicine.Inducing the Chinese medicine processing method“nine cycles of steaming and shining”from historical review and summarizing the practical wisdom based on the canonical aspects of traditional Chinese medicine and the experiences of ancient Chinese medicine sages to promote the new development of traditional Chinese medicine.After the long-term and multiple“nine”processing,the materials of traditional Chinese medicine exhibit significant beneficial changes in terms of taste,efficacy,and chemical composition contents,thus emphasizing that Chinese medicine processing plays a significant role in their efficacy enhancement and toxicity reduction.Heshouwu(Polygoni Multiflori Radix),Dihuang(Rehmanniae Radix),Huangjing(Rhizoma Polygonati),Dahuang(Radix et Rhizoma Rhei),and Xixiancao(Herba Siegesbeckiae)are representatives of Chinese medicinal materials prepared using the“nine-system”processing method.This review discovers the aim and the molecular mechanism of“nine”processing of the abovementioned herbs from the viewpoints of modern pharmacochemistry and pharmacology to provide a theoretical support for the“nine”processing method of traditional Chinese medicine and to promote the international market of traditional Chinese medicine.

Preparation of Hierarchically Trimodal-Porous ZSM-5 Composites through Steam-assisted Conversion of Macroporous Aluminosilica Gel with Two Different Quaternary Ammonium Hydroxides

This article presents a detailed structural study of a new spherical Mg Cl2-supported Ti Cl4 Ziegler-Natta catalyst for isotactic propylene polymerization, and researches on the relationship between catalyst structure and polymer properties. The spherical support with the chemical composition of CH3CH2 OMg OCH(CH2Cl)2 has been synthesized from a new dispersion system and is used as the supporting material to prepare Ziegler-Natta catalyst. The XRD analysis indicates that the catalyst is fully activated with δ-Mg Cl2 in the active catalyst. The far-IR spectrometric results confirm again the presence of δ-Mg Cl2 in the active catalyst. Textural property of the active catalyst exhibits high surface area coupled with high porosity. The high activity in propylene polymerization is mainly ascribed to the full activation and the porous structure of the catalyst. Scanning electron microscopy/energy dispersive spectrometer mapping results indicate a uniform titanium distribution throughout the catalyst particles. Particle size analysis shows that the catalyst has a narrow particle size distribution. The perfect spherical shape, uniform titanium distribution and narrow particle size distribution of the catalyst confirm the advantage of polymer particles production with less fines. The solid state 13 C NMR and mid-IR spectroscopic analyses indicate that there exists strong complexation between diisobutyl phthalate and Mg Cl2, which leads to the high isotacticity of polypropylene.

Steam turbine rotor crack detection using sifting process of EMD and B-spline wavelet on the interval element model

A high-precision identification method for steam turbine rotor crack is presented. By providing me nrst three measured natural frequencies, contours for the specified natural frequency are plotted in the same coordi- nate, and the intersection of the three curves predicts the crack location and size. The cracked rotor system is mod- eled using B-spline wavelet on the interval （BSWI） finite element method, and a method based on empirical mode decomposition （EMD） and Laplace wavelet is implemented to improve the identification precision of the first three measured natural frequencies. Compared with the classical nondestructive testing, the presented method shows its effectiveness and reliability. It is feasible to apply this method to the online health monitoring for rotor structure.

基于瞬时热处理的虾夷扇贝精准开壳方法及品质分析

针对生鲜虾夷扇贝人工开壳存在开壳难和效率低,传统热处理开壳易影响生鲜品质等问题,提出了基于瞬时热处理的虾夷扇贝精准开壳方法。为了探明虾夷扇贝瞬时热处理的精准开壳方法,通过测定虾夷扇贝的体型特征参数,构建精准化蒸汽喷射开壳方法;对比不同瞬时热处理条件下虾夷扇贝的开壳完整率、色差、汁液损失率等,结合感官评价分析,确定最优的瞬时开壳参数。结果显示:相对于140℃蒸汽,在160℃蒸汽作用下,虾夷扇贝的开口宽度更大,开壳拉力值更小,开壳完整率更高,因此确定瞬时热处理的热源温度为160℃;蒸汽喷射时间越长,虾夷扇贝的开壳难度越小,开口宽度越大,综合感官评定,确定瞬时热处理的蒸汽喷射时间2 s。壳长110~120 mm,壳厚22~25 mm,质量为100~125 g/枚的虾夷扇贝,采用蒸汽喷射(160℃、2 s),虾夷扇贝开壳后的开壳完整率100%,汁液流失率0.86%。研究表明,采用瞬时热处理精准开壳能够较好地保持虾夷扇贝生鲜品质,为其自动化加工提供理论依据。

蒸汽浴-流动分析仪法测定土壤有机碳含量的方法

为了准确高效批量测定土壤有机碳含量,采用比色管代替消煮管,蒸汽加热消煮土壤,利用流动分析仪法测定有机碳。并将此方法与重铬酸钾氧化-外加热法(常规通用)进行了比较,探讨方法的可行性。结果表明,蒸汽浴-流动分析仪法测定土壤有机碳含量重复性试验的相对标准偏差为3.19%~9.41%,回收率为92.21%~97.63%。方法精密度及准确性良好。所测结果与重铬酸钾氧化-外加热法无显著性差异(P>0.05),两种方法拟合的回归方程:y(蒸汽浴-流动分析仪法)=0.947x(重铬酸钾氧化-外加热法)+1.621(r^(2)=0.933),两者呈良好的相关性。用两种方法测定200个土壤有机碳,蒸汽浴-流动分析仪法的检测用时是重铬酸钾氧化-外加热法用时的68%,人工操作用时是重铬酸钾氧化-外加热法用时的44%,蒸汽浴-流动分析仪法无需使用硫酸亚铁,重铬酸钾、硫酸和水用量为重铬酸钾氧化-外加热法的40%。蒸汽浴-流动分析仪法省工省时,人员工作强度低,试剂用量少,环境危害降低,检测准确高效,经济安全,可推荐为大批量土壤有机碳含量测定的方法。

直播电商模式下农产品直播供应链风险识别与测度研究

电子商务作为一种新的经济形态,如今在提升区域竞争力并获得优质资源方面发挥重要作用,通过电商渠道购买农产品为农村经济提供了新的发展空间。而农产品以其特有属性,加上直播供应链的独特性,使供应链体系复杂化。文章对农产品直播电商供应链风险因素进行分层归类,并对构建农产品直播电商供应链风险指数进行评价、分析和预警,运用DEMATEL探讨因素之间的相互作用,建立因素的“原因—结果”归集,并依据因素的原因度和中心度对因素的权重进行修正,界定其在系统中关键综合重要度的优先改善顺序,基于ABC分类法分析直播电商供应链风险的关键因素,最后以某农产品直播电商作为算例进行验证。