Bifurcations of A Third-Order Common-Base Transistor Circuit

Hou, Jian Jun,Wu, Jing Tang,Du, Xi Yu 대한전자공학회 1992 HICEC:Harbin International Conference on Electroni Vol.1 No.1

This paper reports the dynamics and a great variety of one parameter bifurcation phenomena observed in the laboratory and confirmed by extensive computer simulations for the circuit reported firstly in [2]. The circuit consists of five elements, where the only nonlinear element is a common-base transistor pair with the characteristics of a current-controlled nonlinear resistor. Several strange attractors, the intermittent attractor, periodic windows, cascades of period doubling, period plus two and period minus one phenomena are observed by adjusting the value of L₁. The computer simulation results agree with the experiment results quite nicely. Hopf bifurcation is proved mathematically and the Lyapunov dimensions of several chaotic attractors are derived to confirm the existence of chaos.

Transient microfluidic approach to the investigation of erythrocyte aggregation: comparison and validation of the method

Hou, Jian-Xun,Shin, Se-Hyun The Korean Society of Rheology 2008 Korea-Australia rheology journal Vol.20 No.4

A method based on transient shear flow dynamics of red cell aggregates was developed to investigate reversible re-aggregation processes with decreasing shear flow. In the microchannel-flow aggregometry, the aggregated red blood cells that are subjected to continuously decreasing shear stress in microchannel flow were measured with the use of a laser-scattering technique. Both the laser-backscattered intensity and pressure were simultaneously measured with respect to time, resulting in shear stress ranging from $0{\sim}35\;Pa$ for a time period of less than 30 seconds. The time dependent recording of the backscattered light intensity (syllectogram) yielded an upward convex curve with a peak point, which reflected the transition threshold of aggregation in the RBC suspensions. Critical-time and critical-shear stress corresponding to the peak point were examined by varying the initial pressure-differential and the micro channel depth, and these results showed good potential for being used as new aggregation indices. In the present study, these newly proposed indices were also validated by differentiating the effect of fibrinogen on RBC aggregation and then these indices were compared to the conventional indices that were measured by a rotational aggregometer.

Progressive Collapse Resistance of RC Frames under a Side Column Removal Scenario

Jian Hou,Li Song 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.2

Progressive collapse resistance of RC buildings can be analyzed by considering column loss scenarios. Using finite element analysis and a static test, the progressive collapse process of a RC frame under monotonic vertical displacement of a side column was investigated, simulating a column removal scenario. A single-story 1/3 scale RC frame that comprises two spans and two bays was tested and computed, and downward displacement of a side column was placed until failure. Our study offers insight into the failure modes and progressive collapse behavior of a RC frame. It has been noted that the damage of structural members (beams and slabs) occurs only in the bay where the removal side column is located. Greater catenary action and tensile membrane action are mobilized in the frame beams and slabs, respectively, at large deformations, but they mainly happen in the direction where the frame beams and slabs are laterally restrained. Based on the experimental and computational results, the mechanism of progressive collapse resistance of RC frames at different stages was discussed further. With large deformations, a simplified calculation method for catenary action and tensile membrane action is proposed.

The Current Membrane Industrial Situation in China and Introduction of “China Membrane Valley”

Jian Hou,Hongsik Byun,Sungil Jeon 한국막학회 2020 한국막학회 총회 및 학술발표회 Vol.2020 No.11

Bifurcations of A Third-Order Common-Base Transistor Circuit

Jian Jun Hou,Jing Tang Wu,Xi Yu Du 대한전자공학회 1992 대한전자공학회 Conference Vol.1992 No.2

Progressive Collapse Resistance of RC Frames under a Side Column Removal Scenario: The Mechanism Explained

Hou, Jian,Song, Li Korea Concrete Institute 2016 International Journal of Concrete Structures and M Vol.10 No.2

Progressive collapse resistance of RC buildings can be analyzed by considering column loss scenarios. Using finite element analysis and a static test, the progressive collapse process of a RC frame under monotonic vertical displacement of a side column was investigated, simulating a column removal scenario. A single-story 1/3 scale RC frame that comprises two spans and two bays was tested and computed, and downward displacement of a side column was placed until failure. Our study offers insight into the failure modes and progressive collapse behavior of a RC frame. It has been noted that the damage of structural members (beams and slabs) occurs only in the bay where the removal side column is located. Greater catenary action and tensile membrane action are mobilized in the frame beams and slabs, respectively, at large deformations, but they mainly happen in the direction where the frame beams and slabs are laterally restrained. Based on the experimental and computational results, the mechanism of progressive collapse resistance of RC frames at different stages was discussed further. With large deformations, a simplified calculation method for catenary action and tensile membrane action is proposed.

Identification, fine mapping and characterization of Rht-dp, a recessive wheat dwarfing (reduced height) gene derived from Triticum polonicum

Hou-Yang Kang,Li-Juan Lin,Zhi-Jian Song,Jing-Ya Yuan,Mei-Yu Zhong,Hai-Qin Zhang,Xing Fan,Li-Na Sha,Yi Wang,Li-Li Xu,Jian Zeng,Yong-Hong Zhou 한국유전학회 2012 Genes & Genomics Vol.34 No.5

Semi-dwarfism is an agronomically important trait in breeding for resistance to damage by wind and rain (lodging resistance)and for stable high yields. Dwarf Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB AS304) is a potential donor of dwarfing and other traits for common wheat improvement. A genetic analysis using an F2 population derived from a cross of AS304 and tall cultivar AS302 and derived F2:3 lines indicated that AS304 carries a recessive dwarfing gene, temporarily designated Rht-dp. Molecular markers and bulked segregant analysis were used to characterize and map the gene. Eight polymorphic SSR markers (Xwmc511, Xgwm495, Xgwm 113, Xgwm192, Xgpw7026, Xgpw3017, Xgpw1108 and Xgpw7521) on chromosome arm 4BS and two AFLP markers (M8/E5 and M4/E3) were mapped relative to the dwarfing locus. The closest linked markers, Xgpw3017 and M8/E5 at 0.5 and 3.5 cM, respectively, from Rht-dp will enable its marker assisted transfer to wheat breeding populations. Allelic tests indicated that Rht-dp was allelic to Rht-B1b; hence it may be an alternative allele at the Rht-B1 locus.

Transient microfluidic approach to the investigation of erythrocyte aggregation: comparison and validation of the method

Jian-Xun Hou,Sehyun Shin 한국유변학회 2008 Korea-Australia rheology journal Vol.20 No.4

A method based on transient shear flow dynamics of red cell aggregates was developed to investigate reversible re-aggregation processes with decreasing shear flow. In the microchannel-flow aggregometry, the aggregated red blood cells that are subjected to continuously decreasing shear stress in microchannel flow were measured with the use of a laser-scattering technique. Both the laser-backscattered intensity and pressure were simultaneously measured with respect to time, resulting in shear stress ranging from 0~35 Pa for a time period of less than 30 seconds. The time dependent recording of the backscattered light intensity (syllectogram) yielded an upward convex curve with a peak point, which reflected the transition threshold of aggregation in the RBC suspensions. Critical-time and critical-shear stress corresponding to the peak point were examined by varying the initial pressure-differential and the microchannel depth, and these results showed good potential for being used as new aggregation indices. In the present study, these newly proposed indices were also validated by differentiating the effect of fibrinogen on RBC aggregation and then these indices were compared to the conventional indices that were measured by a rotational aggregometer

리튬이차전지 전해액의 고온 안정성을 위한 PVA-CN 첨가제 합성 및 평가

후건(Jian Hou),장원기(Wongi Jang),변홍식(Hongsik Byun) 한국고분자학회 2018 폴리머 Vol.42 No.5

현재 리튬이차전지에는 이온전도도나 전기화학적 안정성이 좋은 액체 전해액을 사용하고 있으나, 고온 열적 안정성에 문제가 노출되고 있다. 본 연구에서는 전해액의 열 안정성을 향상시키기 위해 리튬이차전지 전해액용 cyanoethyl polyvinyl alcohol(PVA-CN) 첨가제를 합성하였으며, 합성은 polyvinyl alcohol(PVA) 원료를 용해하는 공정(Step 1)과 PVA-CN을 합성하는 공정(Step 2)으로 나누어서 진행하였다. 합성된 PVA-CN 첨가제의 열적 안정성을 확인하기 위하여 TGA 측정을 진행하였다. 전기적 특성평가에서 PVA-CN이 첨가된 전해액의 이온전도도가 기존 상용의 전해액보다 약 6% 감소하였다. 하지만, PVA-CN 첨가된 전해액을 활용한 리튬이차전지는 고온에서 swelling 특성이 매우 우수한 결과, 즉 29%의 swelling 감소 효과를 보여주었으며, 리튬이차전지의 가장 큰 사고 원인인 고온 swelling 문제를 해결할 수 있다는 결과를 얻었다. Currently liquid electrolyte having good ion-conductivity and high electrochemical stability has been used for the lithium secondary battery. But it has been reported there was a serious problem in the high temperature stability. In this study, the development of PVA-CN cyanoethyl polyvinyl alcohol additive which is used in lithium secondary battery electrolyte was carried out with two steps; the first step was the dissolution of PVA raw materials, and the second step was the synthesis of PVA-CN. The thermal property of the prepared PVA-CN was quantitatively analyzed using TGA. The significantly improved thermal stability of the electrolytes containing PVA-CN additives was also confirmed by monitoring swelling behavior of the membranes at high temperature, i.e. 29% less swelling effect, although they exhibited slightly lower ion conductivity, about 6% lower than commercially available electrolytes. This finding clearly suggests the possibility of preventing the swelling issue at high temperature which is the main cause of dangerous accidents from secondary battery systems.

Low-temperature solution selective growth of zinc oxide nanorods on different substrates

Jian Zhang,Lijuan Wan,Xuejiao Chen,Chunran Liu,Huina Hou 한양대학교 세라믹연구소 2010 Journal of Ceramic Processing Research Vol.11 No.3

In this paper, regular ZnO nanorods with excellent reproducibility were grown by a simple solution method at low temperature. The growth parameters, which can affect the ZnO nanostructures were studied, including the substrate types, the growth temperature, the growth time and the concentration of the solution. Among these conditions, the influence of different substrates on the resulting nanostructures was investicated carefully. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology and microstructure of the as-grown ZnO nanorods. It is concluded that the substrates can affect the ZnO growth remarkably and the selective growth of ZnO is possible through the choice of the substrates.