Saturation impulses for dynamically loaded structures with finite-deflections

Zhao, Ya-Pu,Yu, T.X.,Fang, J. Techno-Press 1995 Structural Engineering and Mechanics, An Int'l Jou Vol.3 No.6

The concept of "Saturation Impulse" for rigid, perfectly plastic structures with finite-deflections subjected to dynamic loading was put forward by Zhao, Yu and Fang (1994a). This paper extends the concept of Saturation Impulse to the analysis of structures such as simply supported circular plates, simply supported and fully clamped square plates, and cylindrical shells subjected to rectangular pressure pulses in the medium load range. Both upper and lower bounds of nondimensional saturation impulses are presented.

Intersubband Transitions in Nonpolar GaN-based Resonant Phonon Depopulation Multiple-Quantum Wells for Terahertz Emissions

Ya-Feng Song,Xiong-Xiong Kong,Wei-Bin Tang,Zhong-Qiang Suo,Huan Zhang,Chen-Yang Li,Qian Jia,Cai-Xia Xue,Yan-Wu Lu,Chao-Pu Yang 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.11

We investigate the polarization effect in intersubband transitions in polar and nonpolar GaN-based multiple-quantum well (MQW) structures for terahertz (THz) emissions by using systematic comparisons and design a nonpolar GaN/Al$_{0.2}$Ga$_{0.8}$N two-well-based MQW structure with an emitting photon of 7.27 THz (30.07 meV). Its lower energy separation (92.7 meV) matches the resonant phonon depopulation condition for better population inversion. It shows a lower threshold current density $J\rm_{th}$ at all temperatures (1.548 kA/cm$^2$ at 90 K) and a higher output power of up to 86.1 mW at 5.8 K and 33.6 mW at 100 K. Our results for the polar GaN MQW are very close to the experimental data in the literature. We find that the $J\rm_{th}$ of the nonpolar GaN MQW increases more slowly than that of the polar GaN MQW as temperature increases, indicating the nonpolar GaN MQW may be a worth-trying direction for improving the operation temperature. These results can provide meaningful references for the design and fabrication of nonpolar GaN-based THz MQW or quantum cascade structures.

Adsorption thermodynamics and kinetics of disperse dye on poly(p-phenylene benzobisoxazole) fiber pretreated with polyphosphoric acid

Pu-xin Zhu,Yu Guan,Ya-hong Mao,Dong Wei,Xiu-xing Wang 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.9

Adsorption thermodynamic and kinetic studies of C. I. disperse dye 60 on PBO fiber pretreated with polyphosphoric acid (PPA) were carried out under the conditions of pH 6.0±0.2, initial dye concentration 0.05-1.0 g/L and liquor ratio 2,000 : 1. The results showed that the equilibrium adsorption isotherm of the disperse dye on the pretreated PBO fiber was a Langmuir-Nernst mixed Model and the saturated adsorption capacity of the turning point was 1.046mg/g. The thermodynamic parameters were calculated by the equilibrium adsorption isotherm, such as standard affinity,enthalpy change and entropy change, which indicated that the adsorption of disperse dye on the pretreated PBO fiber was an exothermic process. Based on the thermodynamic and kinetic data, the adsorption of the dye on the pretreated PBO fiber was a kinetics controlled process, and the disperse dye could only diffuse into the surface layer of pretreated PBO fiber. Meanwhile, the adsorption kinetics of disperse dye on pretreated PBO fiber well agreed with a pseudofirst-order kinetic model.

QTLs of Cold Tolerance-Related Traits at the Booting Stage for NIL-RILs in Rice Revealed by SSR

Ya Wen Zeng,Shu Ming Yang,Hong Cui,Xiao Juan Yang,Li Ming Xu,Juan Du,Xiao Ying Pu,Zi Chao Li,Zai Quan Cheng,Xing Qi Huang 한국유전학회 2009 Genes & Genomics Vol.31 No.2

QTLs for cold tolerance-related traits at the booting stage using balanced population for 1525 recombinant inbred lines of near-isogenic lines (viz. NIL-RILs for BC5F3 and BC5F4 and BC5F5) over 3 years and two locations by backcrossing the strongly cold-tolerant landrace (Kunmingxiaobaigu) and a cold-sensitive cultivar (Towada) was analyzed. In this study, 676 microsatellite markers were employed to identify QTLs conferring cold tolerance at booting stage. Single marker analysis revealed that 12 markers associated with cold tolerance on chromosome 1, 4 and 5. Using a LOD significance threshold of 3.0, compositive interval mapping based on a mixed linear model revealed eight QTLs for 10 cold tolerance-related traits on chromosomes 1, 4, and 5. They were tentatively designated qCTB-1-1, qCTB-4-1, qCTB-4-2, qCTB-4-3, qCTB-4-4, qCTB-4-5, qCTB-4-6, and qCTB-5-1. The marker intervals of them were narrowed to 0.3-6.8 cM. Genetic distances between the peaks of the QTL and nearest markers varied from 0 to 0.04 cM. We were noticed in some traits associated cold tolerance, such as qCTB-1-1 for 5 traits (plant height, panicle exsertion, spike length, blighted grains per spike and spikelet fertility), qCTB-4-1 for 8 traits (plant height, node length under spike, leaf length, leaf width, spike length, full grains per spike, total grains per spike and spikelet fertility), qCTB-4-2 for 3 traits (spike length, full grains per spike and spikelet fertility), qCTB-5-1 for 5 traits (plant height, panicle exsertion, blighted grains per spike, full grains per spike and spikelet fertility). The variance explained by a single QTL ranged from 0.80 to 16.80%. Three QTLs (qCTB-1-1, qCTB-4-1, qCTB-4-2) were detected in two or more trials. Our study sets a foundation for cloning cold-tolerance genes and provides opportunities to understand the mechanism of cold tolerance at the booting stage.

Coevolution between Human's Anticancer Activities and Functional Foods from Crop Origin Center in the World

Zeng, Ya-Wen,Du, Juan,Pu, Xiao-Ying,Yang, Jia-Zhen,Yang, Tao,Yang, Shu-Ming,Yang, Xiao-Meng Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.6

Cancer is the leading cause of death around the world. Anticancer activities from many functional food sources have been reported in years, but correlation between cancer prevalence and types of food with anticancer activities from crop origin center in the world as well as food source with human migration are unclear. Hunger from food shortage is the cause of early human evolution from Africa to Asia and later into Eurasia. The richest functional foods are found in crop origin centers, housing about 70% in the world populations. Crop origin centers have lower cancer incidence and mortality in the world, especially Central Asia, Middle East, Southwest China, India and Ethiopia. Asia and Africa with the richest anticancer crops is not only the most important evolution base of humans and origin center of anticancer functional crop, but also is the lowest mortality and incidence of cancers in the world. Cancer prevention of early human migrations was associated with functional foods from crop origin centers, especially Asia with four centers and one subcenter of crop origin, accounting for 58% of the world population. These results reveal that coevolution between human's anticancer activities associated with functional foods for crop origin centers, especially in Asia and Africa.

Strategies of Functional Food for Cancer Prevention in Human Beings

Zeng, Ya-Wen,Yang, Jia-Zheng,Pu, Xiao-Ying,Du, Juan,Yang, Tao,Yang, Shu-Ming,Zhu, Wei-Hua Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

Functional food for prevention of chronic diseases is one of this century's key global challenges. Cancer is not only the first or second leading cause of death in China and other countries across the world, but also has diet as one of the most important modifiable risk factors. Major dietary factors now known to promote cancer development are polished grain foods and low intake of fresh vegetables, with general importance for an unhealthy lifestyle and obesity. The strategies of cancer prevention in human being are increased consumption of functional foods like whole grains (brown rice, barley, and buckwheat) and by-products, as well some vegetables (bitter melon, garlic, onions, broccoli, and cabbage) and mushrooms (boletes and Tricholoma matsutake). In addition some beverages (green tea and coffee) may be protective. Southwest China (especially Yunnan Province) is a geographical area where functional crop production is closely related to the origins of human evolution with implications for anticancer influence.

A Study of Urodynamic Parameters at Different Bladder Filling Stages for Predicting Upper Urinary Tract Dilatation

Lei Lyu,Ya Xiong Yao,Er Peng Liu,Yan Ping Zhang,Hui Jie Hu,Feng Ping Ji,Qing Song Pu,Xing Huan Yang,Qing Wei Wang,Yan Wang,Jian Guo Wen 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.1

Purpose: To identify more accurate predictors of upper urinary tract dilatation (UUTD) in neurogenic bladder (NB) children, we studied the relationship among urodynamic parameters at different bladder filling stages, detrusor leak point pressure (DLPP) and UUTD. Methods: A total of 158 children (3–16 years) with NB were included and then divided into 2 groups according to whether their NB diagnosis was complicated with UUTD: the UUTD group (39 patients) and those without UUTD group (control group, 119 patients). The bladder filling phase was divided into 3 equal parts: the early, middle, and end filling stages. The bladder compliance (BC) and detrusor pressure (△Pdet) at each phase and DLPP at the end filling stage were recorded. Results: A BC<8 mL/cm H2O both in the middle and end stages is more specific than a BC<9 mL/cm H2O in the end stage (72%, 73%, vs. 66%), and △Pdet >8 cm H2O in the early stage, 20 cm H2O in the middle stage and 25 cm H2O in the end stage are more sensitive than △Pdet >40 cm H2O in the end stage (82%, 85%, 85%, vs. 49%). A DLPP cutoff value of 20 cm H2O showed higher sensitivity for predicting UUTD than 40 cm H2O. Conclusions: Low BC and a high △Pdet in the middle and end filling stages are more accurate factors than classic indicators for predicting UUTD. In addition, a DLPP value of >20 cm H2O in the end bladder filling stage shows high sensitivity.

Multi-Scale Simulation of an Immobilizing F1-ATPase Molecular Motor

Zhenyu Yang,Ya-Pu Zhao 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.4

Immobilization, including specific attachment, positioning and orientation, is essential for the integration of F₁-ATPase molecular motors into nanoelectromechanical systems (NEMS). The stability of the immobilization is a very critical technology to prolong the functional lifetime of the molecular motor. Hybrid quantum mechanics and molecular mechanics (QM/MM) and classical molecular dynamics (MD) simulations were separately implemented to investigate the immobilization of the F₁-ATPase molecular motor on different substrates. The QM/MM simulation was employed to give insight into the interaction between the (Histidine)6-tagged peptide and the nickel-nitrilotriacetate (Ni-NTA). The analysis of the charge redistribution revealed that the Ni ion increased the negative charge on the nitrogen atoms of imidazoles, resulting in a strong chemical bonding. The maximum torque that the His-tagged peptide could apply to the rotary molecular motor was estimated from the results of the MD simulation. The immobilization stability was analyzed and is discussed. Immobilization, including specific attachment, positioning and orientation, is essential for the integration of F₁-ATPase molecular motors into nanoelectromechanical systems (NEMS). The stability of the immobilization is a very critical technology to prolong the functional lifetime of the molecular motor. Hybrid quantum mechanics and molecular mechanics (QM/MM) and classical molecular dynamics (MD) simulations were separately implemented to investigate the immobilization of the F₁-ATPase molecular motor on different substrates. The QM/MM simulation was employed to give insight into the interaction between the (Histidine)6-tagged peptide and the nickel-nitrilotriacetate (Ni-NTA). The analysis of the charge redistribution revealed that the Ni ion increased the negative charge on the nitrogen atoms of imidazoles, resulting in a strong chemical bonding. The maximum torque that the His-tagged peptide could apply to the rotary molecular motor was estimated from the results of the MD simulation. The immobilization stability was analyzed and is discussed.

New disperse dyeing method of poly(p-phenylene benzobisoxazole) fiber pretreated with polyphosphoric acid

Yu Guan,Ya-hong Mao,Pu-xin Zhu 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.10

Poly(p-phenylene benzobisoxazole) fiber is considered as a high-performance fiber because of its high strength and excellent thermal and chemical stability. It has been used in industrial reinforcement, body armor and military camouflage. But the application of poly(p-phenylene benzobisoxazole) fiber used for protective clothing is limited because it is difficult to dye with conventional dyeing processes. In this work, a carrier dyeing method with disperse dyes was first used to dye the fiber after a pretreatment with polyphosphoric acid. The effects of the carrier structure and dyeing conditions on the color strength of dyed samples were investigated. In addition, the crystallinity and orientation degree of the poly(p-phenylene benzobisoxazole) fibers before and after pretreatment with phthalimide and benzyl benzoate were measured by X-ray diffraction and velocity-oriented test, respectively. The results suggested phthalimide and benzyl benzoate, as carrier, could effectively promote disperse dyeing of the PBO fiber pretreated with polyphosphoric acid. Meanwhile, the optimal conditions for the carrier dyeing were obtained, that is, concentration of carrier 4%, dyeing temperature 150 oC and time 120 min. By way of the carrier dyeing, the K/S value of dyed sample and the percentage of dye exhaustion were greatly improved, while the crystalline structure and orientation degree of the pretreated samples hardly changed. Furthermore, the decreases of the tensile strength and the limiting oxygen index of dyed poly(p-phenylene benzobisoxazole) sample were very little, and the color fastness was also satisfactory.

Low temperature oxidation characteristics analysis of ultra-heavy oil by thermal methods

Yi-Bo Li,Ya-Fei Chen,Wan-Fen Pu,Hong Dong,Hao Gao,Fa-yang Jin,Bing Wei 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.48 No.-

To study the oxidation behavior of heavy oils, low temperature oxidation experiments under differentialtemperature and pressure conditions were carried out for both heavy oils (ordinary heavy and ultraheavyoils) with thermogravimetry (TG–DTG)/differential scanning calorimeter (DSC) analyses. And theresults indicated that the differences of physical properties and oxidation reactions for the heavy oilsascribe to the SARA compositions, H/C ratio and specific oxidation path. Owing to the asphaltenescontent, the ultra-heavy oil after the oxidation has more obvious coke deposition with lower activationenergy demand to make it possible for the in-situ combustion without combustion adjuvants.