Assessing the effectiveness of learning solid geometry by using an augmented reality-assisted learning system

This study integrates augmented reality (AR) technology into teaching activities to design a learning system that assists junior high-school students in learning solid geometry. The following issues are addressed: (1) the relationship between achievements in mathematics and performance in spatial perception; (2) whether system-assisted learning can improve the spatial perceptions of students; (3) whether students with high, average and low academic achievement learn effectively after taught with system assistance; (4) system usability; (5) system task load; and (6) the relationship among various factors. Study participants were 76 students from Tainan City, Taiwan. Qualitative and quantitative data are obtained using pre- and post-system-assisted learning paper–pencil tests, a system usability scale, National Aeronautics & Space Administration Task Load indeX, and observations and focus group interviews. Analysis results indicate that students' math scores and spatial perception during the test closely correspond to each other. Additionally, system-assisted can improve the spatial perceptions of student. Regarding group differences related to the significance of impact, students with average and low academic achievements exhibit small and medium levels of effectiveness, but are insignificant in high academic achievement students. As for system usability, students with low academic achievements demonstrate a positive attitude toward the intensive programs provided by the system. However, the correlation between students’ learning effectiveness and system usability/task load is low.     

凉州熏醋大曲中细菌区系研究

研究了凉州熏醋传统酿造大曲中细菌区系,对大曲中的细菌总数、醋酸菌、乳酸菌及耐热菌进行计数、分离纯化和鉴定,通过显微镜镜检、革兰氏染色、接触酶反应、需氧型、产酸产气、发酵性等特性测定,对分离的菌株进行了具体菌属鉴定.结果表明,大曲表面与大曲中心细菌区系差异明显;大曲中共分离到5株醋酸菌、8株乳酸菌和4株耐热菌;醋酸菌分属为醋杆菌属和葡糖杆菌属;乳酸菌分属为糖球菌属、链球菌属、魏斯氏菌属、乳球菌属和索丝菌属;耐热菌分属为微球菌属和芽孢杆菌属.     

Investigation on the application of reformed coke oven gas in direct reduction iron production with a mathematical model

To investigate the application of reformed coke oven gas （COG） in producing the direct reduction iron （DRI）, we simulated a countercurrent gas solid moving bed reactor in which the iron ore pellet was reduced by reformed COG. An ordinary differential equation （ODE） was set based on the unreacted shrinking core model considering both mass and energy balances of the reactor. The concentration and temperature profiles of all species within the reactor were obtained by solving the ODE sys tem. The solid conversion and gas utilization were studied by changing gas flow rate, solid flow rate, reactor length, and the ratio of O/CHa to guide the practical application of COG in DRI production. Model results showed that COG was suitable for the DRI production. In order to meet the requirement of the industrial production, the minimum gas flow rate was set as 130,000 Nm3/h, and the maximum production was 90 t/h. The reactor length and the mole ratio x（O）： x（CH4） were depended on the actual industrial situations.     

消费与浪费

消费与浪费是两个对经济增长有强制约作用的因素。消费与浪费在人类社会的不同发展阶段又各处不同的地位。树立正确的消费观 ,对我国扩大内需 ,促进宏观经济增长和提高微观经济效益具有极其重要的意义。     

可调式服装人体标准模型的研发

服装人体模型在立体裁剪中充当人体的替代品。立体裁剪是将面料直接铺覆在人体模型上根据服装款式的需要进行裁剪，有些平面较难表现的褶皱、曲线、浪势和复杂的线条在立体裁剪中都能较容易的表现出来。立体裁剪注重表现人体三雏的立体性。而用立体裁剪手段生产出的服装品质高低与人体模型有着极重要的关系。因此研发高品质的人体模型是立体裁剪实践教学的重要保证。     

城市道桥景观功能分析

景观是指在“观”的角度上,以审美的意识,在工程技术的基础上,通过可视的手法,对人们生存所处的自然环境和人文构造物进行论证和设计,使之达到和谐统一。城市基础设施景观问题是道桥工程美学、城市规划学、环境美学、人文地理、民族心理、历史文化传统、民族经济等方面知识在工程建设上的综合体现。     

哈萨克毡房及其几何体结构

哈萨克毡房是根据长期游牧生活需要而制造的传统住房,其历史悠久。首先介绍了哈萨克毡房的传统结构,然后从数学和力学的角度研究了哈萨克毡房的整体科学结构。     

Preparation and adsorption behaviors of Cu(II) ion-imprinted polymers

Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furalls(PCDD/Fs)emissions in flue gas from two types of municipal solid waste incinerators(MSWIs)most commonly used in China were investigated in this study.The selected incinerators include two grate-type MSWIs:MSWl-A(350 t/d)and MSWI-B(150 t/d),and two fluidized bed MSWIs:MSWI-C(400 t/d) and MSWI-D (400 t/d),which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber(WS)as air pollutant conffol device(APCD).Results indicated that the emission concentration and the international toxic equivalents(I-TEQs)of the PCDD/Fs from the stacks were in the range of 1.210～10.273 ng/Nm3 and 0.019～0.201 ngI-TEQ/Nm3,respectively.They were greatly lower than the emission regulation standard of PCDD/FS in China(1.0 ng I-TEQ/Nm3).However,only the PCDD/Fs emission Ievel from MSWI-C Was below 0.1 ng I-TEQ/Nm3.Although the homologue profiles were distinct,the contributions of the 2,3,7,8-subsituted congenem to the total I-TEQ were similar among all the investigated MSWIs.Two major 2,3,7,8-substituted congeners,2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD,account for 47% and 9%(average values)of the total I-TEQ values,respectively.The correlation between PCDD/Fs levels and composition of flue gas Was also discussed.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.