A New ent-Kaurane type Diterpenoid Glycoside from Inula japonica Thunb

Jiang Jiang Qin,Jia Xian Zhu,Wei Dong Zhang1,2,Yan Zhu,Jian Jun Fu,Xiao Hua Liu,Hui Zi Jin 대한약학회 2009 Archives of Pharmacal Research Vol.32 No.10

A new ent-kaurane type diterpenoid glycoside, 17-O-β-D-glucopyranosyl-16α-ent-kauran-19-oic acid (1), together with 17-hydroxy-16α-ent-kauran-19-oic acid (2), 16α,17-dihydroxyl-ent-kauran-19-oic acid (3), and 16α-hydroxy-17-acetoxy-ent- kauran-19-oic acid (4) were isolated from the aerial parts of Inula japonica Thunb. The structure of 1 was determined mainly by use of 1D and 2D NMR spectroscopic techniques including HSQC, 1H-1H COSY, HMBC, and NOESY. In addition, 4 exhibited significant inhibitory activity on NO production in LPS-stimulated RAW264.7 cells with IC50 value of 14.3 μg/mL.

A GENERALIZATION OF LOCAL SYMMETRIC AND SKEW-SYMMETRIC SPLITTING ITERATION METHODS FOR GENERALIZED SADDLE POINT PROBLEMS

Jian-Lei Li,Dang Luo,Zhi-Jiang Zhang 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.5

In this paper, we further investigate the local Hermitian and skew-Hermitian splitting (LHSS) iteration method and the modified LHSS (MLHSS) iteration method for solving generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. When A is non-symmetric positive definite, the convergence conditions are obtained, which generalize some results of Jiang and Cao [M.-Q. Jiang and Y. Cao, On local Hermitian and Skew-Hermitian splitting iteration methods for generalized saddle point problems, J. Comput. Appl. Math., 2009(231): 973-982] for the generalized saddle point problems to generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. Numerical experiments show the effectiveness of the iterative methods.

Efficient Elicitation of Ginsenoside Biosynthesis in Cell Cultures of Panax notoginseng by Using Self-chemically-synthesized Jasmonates

Jian-Jiang Zhong,Wei Wang,Zhen-Jiang Zhao,Yufang Xu,Xuhong Qian 한국생물공학회 2005 Biotechnology and Bioprocess Engineering Vol.10 No.2

A series of fluorine and hydroxyl containing jasmonate derivatives, which were chemically synthesized in our institute, were investigated for their effects on the biosynthesis and heterogeneity of ginsenosides in suspension cultures of Panax notoginseng cells. Compared to the control (without addition of elicitors), 100 M of each of the jasmonate was added on day 4 to the suspension cultures of P. notoginseng cells. It was observed that, jasmonates greatly enhanced the ginsenoside content and the ratio of Rb group to Rg group (i.e. (Rb1 + Rd)/(Rg1 + Re)) in the P. notoginseng cells. Some of the synthetic jasmonates, such as pentafluoropropyl jasmonate (PFPJA), 2-hydroxyethyl jasmonate (HEJA) and 2-hydroxye-thoxyethyl jasmonate (HEEJA), could promote the ginsenoside content to 2.55 0.11, 3.65 0.13 and 2.94 0.06 mg/100 mg DW, respectively, compared to that of 0.64 0.06 mg/100 mg DW for the control and 2.17 0.04 mg/100 mg DW by the commercially available methyl jasmonate (MJA); and they could change the respective Rb:Rg ratio to 1.60 0.04, 1.87 0.01 and 1.56 0.05, compared to that of 0.47 0.01 for the control and 1.42 0.06 by MJA. The results suggest that suitable esterification of MJA with fluorine or hydroxyl group could increase the elicitation activity to induce plant secondary metabolism. The information obtained from this study is useful for hyper-production of heterogeneous products by plant cell cultures.

Systematic influence of different building spacing, height and layout on mean wind and turbulent characteristics within and over urban building arrays

Jiang, Dehai,Jiang, Weimei,Liu, Hongnian,Sun, Jianning Techno-Press 2008 Wind and Structures, An International Journal (WAS Vol.11 No.4

Large eddy simulations have been performed within and over different types of urban building arrays. This paper adopted three dimensionless parameters, building frontal area density (${\lambda}_f$) the variation degree of building height (${\sigma}_h$), and the staggered degree of building range ($r_s$), to study the systematic influence of building spacing, height and layout on wind and turbulent characteristics. The following results have been achieved: (1) As ${\lambda}_f$ decrease from 0.25 to 0.18, the mean flow patterns transfer from "skimming" flow to "wake interference" flow, and as ${\lambda}_f$ decrease from 0.06 to 0.04, the mean flow patterns transfer from "wake interference" flow to "isolated roughness" flow. With increasing ${\lambda}_f$, wind velocity within arrays increases, and the vortexes in front of low buildings would break, even disappear, whereas the vortexes in front of tall buildings would strengthen and expand. Tall buildings have greater disturbance on wind than low buildings do. (2) All the wind velocity profiles and the upstream profile converge at the height of 2.5H approximately. The decay of wind velocity within the building canopy was in positive correlation with ${\lambda}_f$ and $r_s$. If the height of building arrays is variable, Macdonald's wind velocity model should be modified through introducing ${\sigma}_h$, because wind velocity decreases at the upper layers of the canopy and increases at the lower layers of the canopy. (3) The maximum of turbulence kinetic energy (TKE) always locates at 1.2 times as high as the buildings. TKE within the canopy decreases with increasing ${\lambda}_f$ and $r_s$ but the maximum of TKE are very close though ${\sigma}_h$ varies. (4) Wind velocity profile follows the logarithmic law approximately above the building canopy. The Zero-plane displacement $z_d$ heighten with increasing ${\lambda}_f$, whereas the maximum of and Roughness length $z_0$ occurs when ${\lambda}_f$ is about 0.14. $z_d$ and $z_0$ heighten linearly with ${\sigma}_h$ and $r_s$, If ${\sigma}_h$ is large enough, $z_d$ may become higher than the average height of buildings.

A GENERALIZATION OF LOCAL SYMMETRIC AND SKEW-SYMMETRIC SPLITTING ITERATION METHODS FOR GENERALIZED SADDLE POINT PROBLEMS

Li, Jian-Lei,Luo, Dang,Zhang, Zhi-Jiang The Korean Society for Computational and Applied M 2011 Journal of applied mathematics & informatics Vol.29 No.5

In this paper, we further investigate the local Hermitian and skew-Hermitian splitting (LHSS) iteration method and the modified LHSS (MLHSS) iteration method for solving generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. When A is non-symmetric positive definite, the convergence conditions are obtained, which generalize some results of Jiang and Cao [M.-Q. Jiang and Y. Cao, On local Hermitian and Skew-Hermitian splitting iteration methods for generalized saddle point problems, J. Comput. Appl. Math., 2009(231): 973-982] for the generalized saddle point problems to generalized nonsymmetric saddle point problems with nonzero (2,2) blocks. Numerical experiments show the effectiveness of the iterative methods.

Systematic influence of different building spacing, height and layout on mean wind and turbulent characteristics within and over urban building arrays

Dehai Jiang,Weimei Jiang,Hongnian Liu,Jianning Sun 한국풍공학회 2008 Wind and Structures, An International Journal (WAS Vol.11 No.4

Large eddy simulations have been performed within and over different types of urban building arrays. This paper adopted three dimensionless parameters, building frontal area density (λf), the variation degree of building height (σh), and the staggered degree of building range (rs), to study the systematic influence of building spacing, height and layout on wind and turbulent characteristics. The following results have been achieved: (1) As λf decrease from 0.25 to 0.18, the mean flow patterns transfer from “skimming” flow to “wake interference” flow, and as λf decrease from 0.06 to 0.04, the mean flow patterns transfer from “wake interference” flow to “isolated roughness” flow. With increasing σh, wind velocity within arrays increases, and the vortexes in front of low buildings would break, even disappear, whereas the vortexes in front of tall buildings would strengthen and expand. Tall buildings have greater disturbance on wind than low buildings do. (2) All the wind velocity profiles and the upstream profile converge at the height of 2.5H approximately. The decay of wind velocity within the building canopy was in positive correlation with λf and rs. If the height of building arrays is variable, Macdonald’s wind velocity model should be modified through introducing σh, because wind velocity decreases at the upper layers of the canopy and increases at the lower layers of the canopy. (3) The maximum of turbulence kinetic energy (TKE) always locates at 1.2 times as high as the buildings. TKE within the canopy decreases with increasing λf and rs but the maximum of TKE are very close though σh varies. (4) Wind velocity profile follows the logarithmic law approximately above the building canopy. The Zero-plane displacement zd heighten with increasing λf, whereas the maximum of and Roughness length z0 occurs when λf is about 0.14. zd and z0 heighten linearly with σh and rs, If σh is large enough, zd may become higher than the average height of buildings.

Two New Monoterpene Alkaloid Derivatives from the Roots of Incarvillea arguta

Jian Jun Fu,Hui Zi Jin,Jiang Jiang Qin,Qi Zeng,Ying Huang,Wei Dong Zhang 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.2

Two new monoterpene alkaloid derivatives, incargutosines C (1) and D (2), together with a known compound, argutine A (3) have been isolated from the roots of Incarvillea arguta Royle. The structures of 1 and 2 were established on the basis of 1D and 2D NMR spectroscopic analysis, while the absolute configurations of 1 and 2 were determined by a synthetic method. In addition, the cytotoxicity of 3 was evaluated using four tumor cell lines, A549, LOVO, 6TCEM, and MDA-MB-435 (MDA) by the MTT assay.

One-Dimensional Transient Wave Propagation in a Dry Overlying Saturated Ground

Jiang Tao Yi,Lei Zhang,Fei Jian Ye,Siang Huat Goh 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.10

While the propagation of stress wave generated by dynamic compaction in dry or saturated granular soil has received much coverage in the research literature, attention to situations with dry soil overlying saturated soil, or mixed-phase ground, is limited. In such cases, the compressional waves have to propagate from a dry layer above the groundwater table to saturated soil below the groundwater table. In this paper, the transient wave propagation characteristics in a mixed-phase ground with an idealized interface between the dry and saturated layer is studied. As the time domain solutions for such problems are often unavailable using analytical methods, a numerical approach based on a dual-phase coupled finite element method implemented on a commercial software platform is adopted. The wave behaviour across the interface is studied and the energy transmission and reflection mechanism from dry to saturated layer is examined. The amplitude, speed and attenuation of the compressional waves and their dependencies on the soil permeability, skeleton stiffness and load duration are quantitatively evaluated via a comprehensive parametric study. As a precursor to the numerical investigation of wave propagation in a mixed-phase ground due to dynamic compaction, the results presented in this study are likely to help in providing a better understanding of the ground improvement effect of dynamic compaction in soil involving a groundwater table.

Progressive Collapse of Steel High-Rise Buildings Exposed to Fire: Current State of Research

Jiang, Jian,Li, Guo-Qiang Council on Tall Building and Urban Habitat Korea 2018 International journal of high-rise buildings Vol.7 No.4

This paper presents a review on progressive collapse mechanism of steel framed buildings exposed to fire. The influence of load ratios, strength of structural members (beam, column, slab, connection), fire scenarios, bracing systems, fire protections on the collapse mode and collapse time of structures is comprehensively reviewed. It is found that the key influencing factors include load ratio, fire scenario, bracing layout and fire protection. The application of strong beams, high load ratios, multi-compartment fires will lead to global downward collapse which is undesirable. The catenary action in beams and tensile membrane action in slabs contribute to the enhancement of structural collapse resistance, leading to a ductile collapse mechanism. It is recommended to increase the reinforcement ratio in the sagging and hogging region of slabs to not only enhance the tensile membrane action in the slab, but to prevent the failure of beam-to-column connections. It is also found that a frame may collapse in the cooling phase of compartment fires or under travelling fires. This is because that the steel members may experience maximum temperatures and maximum displacements under these two fire scenarios. An edge bay fire is more prone to induce the collapse of structures than a central bay fire. The progressive collapse of buildings can be effectively prevented by using bracing systems and fire protections. A combination of horizontal and vertical bracing systems as well as increasing the strength and stiffness of bracing members is recommended to enhance the collapse resistance. A protected frame dose not collapse immediately after the local failure but experiences a relatively long withstanding period of at least 60 mins. It is suggested to use three-dimensional models for accurate predictions of whether, when and how a structure collapses under various fire scenarios.

Cooperation in Port Economy and Maritime Logistics under the „New Normal‟

Jian Li,Bao Jiang 한국해운물류학회 2018 The Asian journal of shipping and Logistics Vol.34 No.3