A new species of Stibadocerella Brunetti, 1918 from China (Diptera, Cylindrotomidae)

Zhang Bing,Gao Shang,Yang Qi-Cheng,Ren Jin-Long,Yang Ding 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

Four species of the genus Stibadocerella Brunetti, 1918 were previously known from the world. Here one new species, Stibadocerella shennongensis Zhang & Yang, sp. nov. is reported from Hubei, China. New record Stiba docerella pristina Brunetti, 1918 from Hainan, China is re-described and illustrated. A key to the known species of Stibadocerella is presented. www.zoobank.org/urn:lsid:zoobank.org:pub:45002F67-2C20-4F3C-A543-81F802EA3900.

A Study on Tooth Modification and Radiation Noise of a Manual Transaxle

Qi Zhang,류성기,강재화,Wei Dong 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

In recent years, there is a trend that lower gear noise levels are demanded for drivers to avoid annoyance and fatigue during operation. For the manual transaxle, meshing transmission error (T.E.) is the excitation that leads to the tonal noise known as gear whine, and radiated gear whine is also the dominant source of noise in the whole gearbox. This paper presents a method for the various interaction analysis of gear tooth profile and lead crowning modification, and the prediction of transmission error under the loaded torques for the 3rd gear pairs of two proposalsin the manual transaxle. And transmission error, root stress and contact stress are also calculated and compared before and after tooth micromodification under one torque. At last, the gear whine noise of the 3rd gear in WOT (Wide Open Throttle) and the coasting operation condition is investigated and compared between the two proposals. The simulation and test show that the transmission error and contact stress under the loaded torque can be minimized by the appropriate tooth modification. It is a good approach which the simulated result is used to improve the design in order to minimize the radiation gear whine noise.

Producing magnetite concentrate via self-magnetization roasting in N2 atmosphere: Phase and structure transformation, and extraction kinetics

Qi Zhang,Yongsheng Sun,Yuexin Han,Yanjun Li,Peng Gao 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

In this work, a green self-magnetization roasting technology for producing magnetite was proposed withoutadding additional. The regulatory mechanisms of the main factors (siderite dosage, roasting temperature,and roasting time) on the self-magnetization roasting process were investigated. In-situ kinetic ofthe self-magnetization roasting process was analyzed by the infrared gas analyzer, and the phase transformationwas investigated by in-situ X-ray diffraction and Mössbauer. Under the optimal roasting conditionsof 30% siderite dosage, 730 C, and 7.5 min, the iron concentrate with Fe grade 68.82% and Ferecovery 99.48% was obtained. The kinetic and phase transformation results indicated that the selfmagnetizationroasting process was divided into two stages: siderite pyrolysis in the prophase stage,and hematite reduced to magnetite by reductant (FeO and CO) from siderite pyrolysis in the anaphasestage. The SEM analyses showed that the newborn magnetite crystals were mainly coarse-grained andneedles, which fitted the kinetics characteristics for the Nucleation model. Using self-magnetizationroasting technology, siderite and hematite would promote mutual reduction to improve product magnetismand roasting efficiency without adding reductant. Also, self-magnetization roasting will enhancethe utilization rate of siderite, and it contributes to energy conservation and CO2 emission reduction.

Hexadecyltrimethylammonium Bromide-Modified Sericite Mica-Based Polyimide Composites: A Comparison Between In situ Polymerization and Solution Intercalation Processes

Qi Zhang,Duxin Li,Dengwang Lai,Baoli Ou 한국고분자학회 2015 Macromolecular Research Vol.23 No.9

In order to increase the spacing between clay layers and study the effects of processing on the morphology and properties of PI/organoclay composites, polyimide (PI) composites containing multi-step procedure-modified sericite mica were prepared via in situ polymerization and solution intercalation. The structure-property relationships of the composites were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS). The results of XRD patterns revealed d002-spacing of clay was expanded from 0.99 to 2.77 nm. TEM photographs indicated majority of the organoclay exhibited an exfoliated morphology in composites prepared by in situ polymerization. TGA summarized the composites prepared by solution intercalation and in situ polymerization had a 9 and 29 oC increment in T5 compared with pristine PI respectively. XPS indicated the interaction of organoclay and polymer matrix in composites prepared by in situ polymerization was stronger than other types of composites. The glass transition temperature (Tg) and storage modulus of the composites prepared via in situ polymerization was much higher. Especially the Tg of this composites revealed a 33 oC increase compared with pure PI.

Mascot Design- “Kun”

Zhang Qi 한국디자인학회 2023 한국디자인학회 국제초대전도록 Vol.2023 No.10

The evaluation of online course of Traditional Chinese Medicine for Medical Bachelor, Bachelor of Surgery international students during the COVID-19 epidemic period

Zhang Qing,He Yi-Jing,Zhu Yu-Hang,Dai Min-Chen,Pan Man-Man,Wu Jia-Qi,Zhang Xian,Gu Ying-Er,Wang Fang-Fang,Xu Xiang-Rong,Qu Fan 한국한의학연구원 2020 Integrative Medicine Research Vol.9 No.3

Background: During the COVID-19 epidemic period, Traditional Chinese Medicine (TCM) course for international students of Medical Bachelor, Bachelor of Surgery (MBBS) program in Zhejiang University has shifted from traditional classroom to online environment. This study aimed to investigate MBBS international students’ perception on online TCM course, and to assess the online learning efficacy. Methods: A total of 84 MBBS international students attending course of “Basic Traditional Chinese Medicine” during 2020 academic years at Zhejiang University were enrolled in this study. A quantitative questionnaire was respectively completed before and after the TCM course using a pretest–post-test design. By means of two online learning platforms, Learning in ZJU and DingTalk, TCM course was broadcast in both live and archived format to students. Results: A total of 48 participants completed both baseline and follow-up questionnaires. The majority of participants preferred face-to-face classroom learning (26, 54.17% of total) when compared with online learning. Students felt that the course had brought in much benefits (mean 3.88, SD 0.87), and they were satisfied with the course content (mean 3.83, SD 0.95). Students’ TCM related knowledge and their behaviors of discussion and consulting were significantly improved by online TCM course (all P < 0.001). Students’ awareness of the necessity of TCM education and their feeling of difficulty in learning TCM were significantly strengthened (P = 0.042, 0.025, respectively). Conclusion: Online learning is a good alternative for TCM course of MBBS international students when classroom learning is suspended, whereas it cannot replace the need for onsite and face-to-face learning.

Influence of Static and Repeated Surface Surcharge Loadings on Tunnel Displacement Considering Small-Strain Stiffness of Soft Clay

Qi Zhang,Bin Yan,Wenxuan Zhu,Guanlin Ye 대한토목학회 2024 KSCE Journal of Civil Engineering Vol.28 No.2

With the rapid development of urban metro tunnels, the effect of surface surcharge loading on existing tunnels is unavoidable. Accurate evaluation of soil deformation and tunnel displacement under surface surcharge loading is of great significance for practical engineering. In this research, the effect of static and repeated surface surcharge loadings on tunnel displacement in soft clay was investigated numerically. The hardening soil model with small-strain stiffness (HSS model) was adopted to simulate the soil response. The parameters of the HSS model were obtained through geotechnical tests. The result indicates that Shanghai layer 4 soft clay exhibits large soil shear stiffness in the small strain range. Tunnel displacement is closely related to parameters of surface surcharge loading width, burial depth of tunnel, and the horizontal distance from the centerline. The overlapping influence range of tunnel displacement was proposed. Under repeated surface surcharge loadings, the first cycle of the repeated surface surcharge loading has the greatest effect on the tunnel displacement, and the subsequent cycles of loadings still cause further increases in the tunnel displacement. The effect of repeated surface surcharge loadings on tunnel displacement gradually decreases as the burial depth of tunnel and the number of cycles increase.

Effect of compressible membrane’s nonlinear stress-strain behavior on spiral case structure

Qi-Ling Zhang,He-Gao Wu 국제구조공학회 2012 Structural Engineering and Mechanics, An Int'l Jou Vol.42 No.1

With an active structural involvement in spiral case structure (SCS) that is always the design and research focus of hydroelectric power plant (HPP), the compressible membrane sandwiched between steel spiral case and surrounding reinforced concrete was often assumed to be linear elastic material in conventional design analysis of SCS. Unfortunately considerable previous studies have proved that the foam material serving as membrane exhibits essentially nonlinear mechanical behavior. In order to clarify the effect of membrane (foam) material’s nonlinear stress-strain behavior on SCS, this work performed a case study on SCS with a compressible membrane using the ABAQUS code after a sound calibration of the employed constitutive model describing foam material. In view of the successful capture of fitted stress-strain curve of test by the FEM program, we recommend an application and dissemination of the simulation technique employed in this work for membrane material description to structural designers of SCS. Even more important, the case study argues that taking into account the nonlinear stress-strain response of membrane material in loading process is definitely essential. However, we hold it unnecessary to consider the membrane material’s hysteresis and additionally, employment of nonlinear elastic model for membrane material description is adequate to the structural design of SCS. Understanding and accepting these concepts will help to analyze and predict the structural performance of SCS more accurately in design effort.

Experiment and molecular simulation for liquid phase adsorption of triethylenetetramine on activated carbon: equilibrium, kinetics, thermodynamics and molecular behavior

Qi Zhang,Xiang C. Ma,Chang He,Qing L. Chen,Bing J. Zhang 한국탄소학회 2023 Carbon Letters Vol.33 No.7

Modification of the surface of raw activated carbon using chemical solvents can significantly improve the adsorption performance of activated carbon. Triethylenetetramine is one of the most important chemical solvents used to modify raw activated carbon for formaldehyde removal indoor. We conducted the liquid impregnation experiments at different initial concentrations, temperatures, adsorbent dosage and time ranges to fully investigate the adsorption of triethylenetetramine on the surface of raw activated carbon for modification. We found that the Langmuir isotherm model and pseudo-first-order kinetic model fit quite well with the experimental data and the R2 are 0.9883 and 0.9954, respectively. The theoretical maximum adsorption capacity is 166.67 mg/g. The change in Gibbs free energy (ΔG0), enthalpy change (ΔH0) and entropy change (ΔS0) were also calculated to study the direction and driving force of the liquid adsorption process. In order to understand the adsorption process at the molecular level, a new activated carbon model based on the actual physical and chemical properties of activated carbon was carefully established in the Materials Studio to simulate the liquid-phase adsorption. The pore structure, elemental composition, functional group content, density, pore volume, and porosity of the activated carbon model converge close to the actual activated carbon and the adsorption isotherms obtained from the simulation agree well with the experimental results. The results show that the adsorption of triethylenetetramine on activated carbon is a spontaneous, endothermic and monolayer physical adsorption process.

Study on Signal De-Noising for Multi-Channel Automatic Ultrasonic Testing System

Qi Zhang,Li Hou 보안공학연구지원센터 2016 International Journal of Signal Processing, Image Vol.9 No.8

To ensure the quality of thick-walled seamless steel pipe, the defects in thick-walled seamless steel pipe should be detect. This paper has developed PC-based microcomputer water immersion, digital multi-channel automatic ultrasonic testing system based on the principle of ultrasonic flaw detection of thick-walled seamless steel pipe. The hardware and software of this detection system were designed. To improve detection efficiency and accuracy, all sorts of effective anti-interference measures were proposed. They could effectively remove interference signals in ultrasonic echo signal by analyzing interference source and dissemination way of automatic ultrasonic flaw detection system for small-diameter steel pipe with thick wall. An improved wavelet threshold was proposed to remove mixed noise in the echo signal to improve the echo signal-to-noise ratio at the same time. Experimental results show that the ultrasonic flaw detection system can achieve defect detection of the Small-Diameter Steel Pipe with Thick Wall, the wavelet threshold de-noising method can effectively remove mixed noise in the ultrasonic echo signal and the echo signal-to-noise ratio was improved greatly.