New Permeable Structure for Controlling Debris Flows in the Wenjiagou Gully

Yu-feng Liang,Chuan Liang,Hongwei Zhou,Feng-rong Yang,Miao Huo,Jia-wen Zhou 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

Aimed to control debris flows more effectively, we attempt to develop a new structure called a “sloping roof grill dam”, which consists of guidance walls, separation grills and lateral deposit areas. A series of flume tests were performed to verify the function of this new structure, focusing on the trapping efficiency (β ), deceleration efficiency (μ) and coarse-fine sediment separation extents (η) under different conditions of structure and debris flows. Experimental results show that both the trapping and deceleration efficiency increase with a decrease in permeability, whereas the separation extent shown the opposite effect. Multiple regression analysis indicates that β and η are linearly dependent on the permeability, deceleration efficiency and magnitudes of debris flow. In addition, an increase in beam gap can lead to an increase in the impact area downstream for the debris flow after the control of the structure. Finally, a two-level installation of the structure is tested to determine whether there is an enhancement of the debris control, which indicated that although the trapping effect of the two-level structure is considerably greater than that of a single-level structure (2.11 times at maximum), the separation extent of the two-level structure is not distinct and may be even lower.

Cu2ZnSnS4 Nanoparticles Synthesized by a Novel Diethylenetriamine-Assisted Hydrothermal Method

Feng Liang,Juan Gao,Changwei Zou,Lexi Shao 한국물리학회 2018 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.72 No.9

A diethylenetriamine (DETA)-assisted hydrothermal method was explored for the synthesis of kesterite Cu2ZnSnS4 (CZTS) nanoparticles. As complexing agent, DETA was employed to dissolve sulfur and to form complex with metal ions. By introducing DETA to the system, pure CZTS nanoparticles with bandgap of 1.54 eV could be successfully obtained and the agglomeration of samples could be restrained by increasing the concentration of DETA. From the discussion about the experimental results, the formation mechanism of CZTS nanoparticles was proposed. As the reagents used in this experiment is low-toxic and inexpensive, this method was considered as an effective and green route for the synthesis of CZTS nanoparticles.

Pharmacokinetics, Tissue Distribution, Metabolism, and Excretion of Ginsenoside Rg1 in Rats

Liang Feng,Ling Wang,Changjiang Hu,Xuehua Jiang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.12

The pharmacokinetics, tissue distribution, metabolism, and excretion of ginsenosides Rg1 were studied in Wistar rats, by measuring the concentrations of Rg1 and its metabolites in the blood, tissues, bile, urine, and feces after dosing. After intravenous (i.v.) administration, the elimination half-lives of Rg1 and its metabolites were 1.82, 5.87, and 6.87 h, and the area under the curves were 1595.7, 597.5, and 805.6 ng· h/mL, respectively. After oral administration, the elimination half-lives of Rg1 and its metabolites were 2.25, 6.73, 5.44, and 5.06 h, and the area under the curves were 2363.5, 4185.5, 3774.3, and 396.2 ng· h/mL, respectively. After i.v. administration, Rg1 and its metabolites were well distributed to the tissues analyzed except for the brain. The maximum concentration of Rg1 was reached in all tissues at 5 min post dose, and it was eliminated from most of the tissues except for the kidney faster than it was eliminated from the blood. The maximum concentration of the metabolites was reached in all tissues between 4 and 6 h post dose. After i.v. administration, the recovery of the Rg1 prototype in the urine and bile was 27.96% and 60.77%, respectively. The metabolism of Rg1 in the intestine was via a hydrolization pathway, with the 6-and 20-glucoside bond hydrolyzed gradually under the catalysis of β-glucosaccharase, and then the metabolites were reabsorbed into the blood. Finally, the total recovery of the Rg1 prototype and its metabolites in the urine and feces were 51.31% and 47.46%, respectively.

IRE1α protects against osteoarthritis by regulating progranulin-dependent XBP1 splicing and collagen homeostasis

Liang Li,Zhang Fengmei,Feng Naibo,Kuang Biao,Fan Mengtian,Chen Cheng,Pan Yiming,Zhou Pengfei,Geng Nana,Li Xingyue,Xian Menglin,Deng Lin,Li Xiaoli,Kuang Liang,Luo Fengtao,Tan Qiaoyan,Xie Yangli,Guo Fen 생화학분자생물학회 2023 Experimental and molecular medicine Vol.55 No.-

Osteoarthritis (OA) is a full-joint, multifactorial, degenerative and inflammatory disease that seriously affects the quality of life of patients due to its disabling and pain-causing properties. ER stress has been reported to be closely related to the progression of OA. The inositol-requiring enzyme 1α/X-box-binding protein-1 spliced (IRE1α/XBP1s) pathway, which is highly expressed in the chondrocytes of OA patients, promotes the degradation and refolding of abnormal proteins during ER stress and maintains the stability of the ER environment of chondrocytes, but its function and the underlying mechanisms of how it contributes to the progression of OA remain unclear. This study investigates the role of IRE1α/ERN1 in OA. Specific deficiency of ERN1 in chondrocytes spontaneously resulted in OA-like cartilage destruction and accelerated OA progression in a surgically induced arthritis model. Local delivery of AdERN1 relieved degradation of the cartilage matrix and prevented OA development in an ACLT-mediated model. Mechanistically, progranulin (PGRN), an intracellular chaperone, binds to IRE1α, promoting its phosphorylation and splicing of XBP1u to generate XBP1s. XBP1s protects articular cartilage through TNF-α/ERK1/2 signaling and further maintains collagen homeostasis by regulating type II collagen expression. The chondroprotective effect of IRE1α/ERN1 is dependent on PGRN and XBP1s splicing. ERN1 deficiency accelerated cartilage degeneration in OA by reducing PGRN expression and XBP1s splicing, subsequently decreasing collagen II expression and triggering collagen structural abnormalities and an imbalance in collagen homeostasis. This study provides new insights into OA pathogenesis and the UPR and suggests that IRE1α/ERN1 may serve as a potential target for the treatment of joint degenerative diseases, including OA.

Joining Technology of Automotive Body using the Nano-Adhesives

Liang Feng(풍량),Dong-Ho Bae(배동호) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

In this paper, a new nano-adhesive which has been improved the conventional epoxy resin widely using in automobile industries was introduced. This nano-adhesive is organically composited with multi-walled carbon nano-tubes (MWCNT) (from 1%-4% by weight) as reinforcement. In order to optimize its quality and performance, electric and mechanical characteristics of the joints taking account the geometrical parameters of bonded layer into were assessed. The electric resistance of the nano-adhesive decreased with increase of the nano-tube weight percentage, and decrease of the thickness of the bonded layer. And in order to evaluate the overloading behaviors of the nano-adhesives and compare the results with the original epoxy resin, tensile tests were conducted on different bonded layer thickness and overlapped length of the bonded joints. From the results, the ultimate tensile strength remarkably increased at 2% weight percentage. Also surface treatment condition of the plates affected the ultimate tensile strength of the bonded joint.

Investigation of the relationship between arc-anode attachment mode and anode temperature for nickel nanoparticle production by a DC arc discharge

Liang, Feng,Tanaka, Manabu,Choi, Sooseok,Watanabe, Takayuki Institute of Physics Publishing Ltd. 2016 Journal of Physics. D, Applied Physics Vol.49 No.12

<P>Multiple and constricted arc-anode attachment modes were observed in helium arc discharge to prepare nickel nanoparticles. The electron overheating instability resulted in the formation of multiple attachment modes. The effects of hydrogen concentration and shield gas flow rate on the characteristics of nickel nanoparticles were investigated. The evaporation rate of anode material contributed to forming different arc-anode attachments. The surface temperature of the electrode was measured during the arc discharge by two-color pyrometry combined with a high-speed camera which employs appropriate band-pass filters. The relationship between the arc-anode attachment mode and the temperature behavior of the anode surface was investigated by using two synchronized high-speed cameras. The waveform of anode jet area variation with time follows that of the highest temperature variation of anode surface with time. The fluctuation of the highest anode temperature increased when the arc anode attachment changed from multiple into constricted mode. The highest temperature fluctuation and stability of the arc contributed to nanoparticle size distribution. Nickel nanoparticles with large productivity and narrow size distribution were obtained when shield gas was employed by controlling the residence time of nanoparticle growth. The formation mechanism of different arc-anode attachment modes was explained.</P>

Development of Nano-adhesives and Joining Technology

Liang Feng,Dong-Ho Bae 한국자동차공학회 2009 한국자동차공학회 학술대회 및 전시회 Vol.2009 No.11

In this paper, a new nano-adhesive which has been improved the conventional epoxy resin widely using in automobile industries was introduced. Multi-walled carbon nano-tubes (MWCNT) (from 1%-4% by weight) were mixed in epoxy resin through a high speed mechanical agitator. The trapped air and reaction volatiles were removed from the mixture using a high vacuum. In order to optimize its quality and performance, electric and mechanical characteristics of the joints taking account the geometrical parameters of bonded layer into were assessed. The electric resistance of the nano-adhesive decreased with increase of the nano-tube weight percentage, and decrease of the thickness of the bonded layer. And in order to evaluate the overloading behaviors of the nano-adhesives and compare the results with the original epoxy resin, tensile tests were conducted on different bonded layer thickness and overlapped length of the bonded joints. From the results, the ultimate tensile strength remarkably increased at 2% weight percentage. Also surface treatment condition of the plates also affected the ultimate tensile strength of the bonded joint.

Mechanical behavior of recycled fine aggregate concrete after high temperature

Liang, Jiong-Feng,Wang, En,He, Chun-Feng,Hu, Peng Techno-Press 2018 Structural Engineering and Mechanics, An Int'l Jou Vol.65 No.3

This paper reports mechanical behavior of recycled fine aggregate concretes after high temperatures. It is found that compressive strength of recycled fine aggregate concretes decline significantly as the temperature rises. The elastic modulus of recycled fine aggregate concretes decreases with the increase in temperature, and the decrease is much quicker than the decrease in compressive strength. The split tensile strength of recycled fine aggregate concrete decrease as the temperature rises. Through the regression analysis, the relationship of the mechanical behavior with temperature are proposed, including the compressive behavior, elastic modulus and split tensile strength, which are fitting the test data.

A parametric study on effects of pitting corrosion on stiffened panels' ultimate strength

Feng, Liang,Hu, Luocun,Chen, Xuguang,Shi, Hongda The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

Pitting corrosion commonly shaped in hull structure due to marine corrosive environment seriously causes the deterioration of structural performance. This paper deals with the ultimate strength behaviors of stiffened ship panels damaged by the pits subjected to uniaxial compression. A series of no-linear finite element analyses are carried out for three stiffened panels using ABAQUS software. Influences of the investigated typical parameters of pit degree (DOP), depth, location and distribution on the ultimate strength strength are discussed in detail. It is found that the ultimate strength is significantly reduced with increasing the DOP and pit depth and severely affected by the distribution. In addition, the pits including their distributions on the web have a slight effect on the ultimate strength. Compared with regular distribution, random one on the panel result in a change of collapse mode. Finally, an empirical formula as a function of corrosion volume loss is proposed for predicting the ultimate strength of stiffened panel.

Pharmacokinetics, Tissue Distribution and Excretion of Coumarin Components from Psoralea corylifolia L. in Rats

Liang Feng,Ling Wang,Xuehua Jiang 대한약학회 2010 Archives of Pharmacal Research Vol.33 No.2

Coumarin components from Psoralea corylifolia L. are novel drugs in which psoralen and isopsoralen are the active components. The pharmacokinetics, tissue distribution and excretion of the two compounds were studied by liquid chromatography-tandem mass spectrometry after intravenous administration to Wistar rats. The elimination half-lives of psoralen and isopsoralen were 4.88 and 5.35 h. After dosing, the area under the curves of the tissues decreased in the following order: liver > lung > heart > kidney > spleen > brain for psoralen; and kidney > lung > liver > heart > spleen > brain for isopsoralen. After dosing, 51.27% of psoralen and 56.25% of isopsoralen were excreted as prototype, and urine was the major excretion route. In addition, the pharmacokinetics of psoralen and isopsoralen after oral administration to Wistar rats were also studied. The elimination half-lives of psoralen and isopsoralen were 4.13 and 5.56 h, and their relative bioavailabilities were 61.45% and 70.35%. Overall, the results show that coumarin components from P. corylifolia L. have high oral bioavailability, they are rapidly and widely distributed into tissues after intravenous administration, but they are slowly cleared and excreted.