Shanghai’s Urban Integrated Meteorological Observation Network (SUIMON) : Some Case Studies of Applications

Jianguo Tan,Sue Grimmond 한국기상학회 2016 한국기상학회 학술대회 논문집 Vol.2016 No.10

A free-jet experimental study on the performance of a cavity-type ramjet

Jianguo Tan,Yu Pan,Jianhan Liang,Zhenguo Wang 대한기계학회 2011 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.25 No.11

Free jet experiments have been conducted to evaluate the performance of a cavity-type ramjet. To prevent uncertainty of combustion parameters, a method to calculate internal thrust from cold flow parameters is brought forward. According to this analysis method, the internal thrust of the cavity-type ramjet increases linearly with the stoichiometric ratio while the specific impulse decreases squarely. The aero-propulsive balance of a conceptive missile is also examined, focusing on the effect of attack angle. Considering both efficiency and performance, an attack angle of 3~6 degrees is recommended. And the free-jet experimental results show that the cavity-type ramjet can supply sufficient thrust for the missile under cruise conditions.

Inhibition of ERK and Activation of p38 are Involved in Diallyl Disulfide Induced Apoptosis of Leukemia HL-60 Cells

Tan, Hui,Ling, Hui,He, Jie,Yi, Lan,Zhou, Jianguo,Lin, Min,Su, Qi 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.6

We investigated the effects of diallyl disulfide (DADS) on the induction of apoptosis in human Leukemia cell line HL-60 and explored the roles of mitogen-activated protein kinase (ERK and p38 MAPK) pathways in the growth inhibition and apoptosis induced by DADS. MTT assay was used to determine the DADS induced cell growth inhibition in HL-60 cells. Flow cytometry and DNA fragmentation were used to examine the roles of apoptosis in DADS-mediated cell death. Western blot analysis of the expression of phospho-MAPKs (ERK and p38) was employed to elucidate the possible mechanisms of DADS induced apoptosis. We found that growth inhibition of HL-60 cells treated with DADS exhibited a dose-dependent response (P<0.05) and DADS induced significant apoptosis. DADS at the concentration of 10 mg/L persistently activated p38 and simultaneously reduced ERK activity. PD98059, an inhibitor of ERK upstream activators MAPK kinase MKK1 and MKK2, promoted cytotoxicity and apoptosis in HL-60 cells treated with DADS. In contrast, SB203580, an inhibitor of p38, decreased cytotoxicity and apoptosis induced by DADS. Therefore, DADS can effectively inhibit the proliferation and induce apoptosis of human leukemia cell line HL-60. Inhibition of ERK signaling pathways and activation of p38 signaling pathways are likely involved in DADS induced apoptosis in HL-60 cells.

Inhibition of ERK and Activation of p38 are Involved in Diallyl Disulfide Induced Apoptosis of Leukemia HL-60 Cells

Hui Tan,Hui Ling,Jie He,Lan Yi,Jianguo Zhou,Min Lin,Qi Su 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.6

We investigated the effects of diallyl disulfide (DADS) on the induction of apoptosis in human Leukemia cell line HL-60 and explored the roles of mitogen-activated protein kinase (ERK and p38 MAPK) pathways in the growth inhibition and apoptosis induced by DADS. MTT assay was used to determine the DADS induced cell growth inhibition in HL-60 cells. Flow cytometry and DNA fragmentation were used to examine the roles of apoptosis in DADS-mediated cell death. Western blot analysis of the expression of phospho-MAPKs (ERK and p38) was employed to elucidate the possible mechanisms of DADS induced apoptosis. We found that growth inhibition of HL-60 cells treated with DADS exhibited a dose-dependent response (P<0.05) and DADS induced significant apoptosis. DADS at the concentration of 10 mg/L persistently activated p38 and simultaneously reduced ERK activity. PD98059, an inhibitor of ERK upstream activators MAPK kinase MKK1 and MKK2, promoted cytotoxicity and apoptosis in HL-60 cells treated with DADS. In contrast, SB203580, an inhibitor of p38, decreased cytotoxicity and apoptosis induced by DADS. Therefore, DADS can effectively inhibit the proliferation and induce apoptosis of human leukemia cell line HL-60. Inhibition of ERK signaling pathways and activation of p38 signaling pathways are likely involved in DADS induced apoptosis in HL- 60 cells.

Preliminary Correlation Between Warm Needling Treatment for Knee Osteoarthritis of Deficiency-Cold Syndrome and Metabolic Functional Genes and Pathways

Conge Tan,Weijun Ding,Wenzhe Feng,Jianguo Wang,Miqu Wang 사단법인약침학회 2010 Journal of Acupuncture & Meridian Studies Vol.3 No.3

The warm needling technique used in traditional Chinese medicine has been shown to be effective in the treatment and prevention of knee osteoarthritis (OA), but the biological mechanisms behind this action have not been well explored. This study investigated the molecular mechanisms behind warm needling using cDNA microarray technology, thus providing further scientific evidence for its efficacy. Ten patients with knee OA of deficiency-cold syndrome were selected for 2 weeks of warm needling treatment. This treatment involved stimulating the selected acupoints using needles with a burning moxa stick on their handle for 40 minutes per session. Pain intensity and accumulated clinical scores of deficiency-cold syndrome were assessed pretreatment and posttreatment using a 40-factor questionnaire of OA with deficiency-cold syndrome. Four patients with the best therapeutic efficacy were selected for cDNA microarray testing. Among the four patients, 41, 246,57 and 70 differentially expressed genes were obtained, with more than 50% of these differentially expressed genes functionally linked to primary, cellular and energy metabolism pathways. This work demonstrates that the molecular mechanism behind warm needling treatment may be associated with the regulation of metabolism-related genes and pathways.

In situ investigations into mining-induced overburden failures in close multiple-seam longwall mining: A case study

Ning, Jianguo,Wang, Jun,Tan, Yunliang,Zhang, Lisheng,Bu, Tengteng Techno-Press 2017 Geomechanics & engineering Vol.12 No.4

Preventing water seepage and inrush into mines where close multiple-seam longwall mining is practiced is a challenging issue in the coal-rich Ordos region, China. To better protect surface (or ground) water and safely extract coal from seams beneath an aquifer, it is necessary to determine the height of the mining-induced fractured zone in the overburden strata. In situ investigations were carried out in panels 20107 (seam No. $2-2^{upper}$) and 20307 (seam No. $2-2^{middle}$) in the Gaojialiang colliery, Shendong Coalfield, China. Longwall mining-induced strata movement and overburden failure were monitored in boreholes using digital panoramic imaging and a deep hole multi-position extensometer. Our results indicate that after mining of the 20107 working face, the overburden of the failure zone can be divided into seven rock groups. The first group lies above the immediate roof (12.9 m above the top of the coal seam), and falls into the gob after the mining. The strata of the second group to the fifth group form the fractured zone (12.9-102.04 m above the coal seam) and the continuous deformation zone extends from the fifth group to the ground surface. After mining Panel 20307, a gap forms between the fifth rock group and the continuous deformation zone, widening rapidly. Then, the lower portion of the continuous deformation zone cracks and collapses into the fractured zone, extending the height of the failure zone to 87.1 m. Based on field data, a statistical formula for predicting the maximum height of overburden failure induced by close multiple seam mining is presented.

Relationship of box counting of fractured rock mass with Hoek-Brown parameters using particle flow simulation

Ning, Jianguo,Liu, Xuesheng,Tan, Yunliang,Wang, Jun,Tian, Chenglin Techno-Press 2015 Geomechanics & engineering Vol.9 No.5

Influenced by various mining activities, fractures in rock masses have different densities, set numbers and lengths, which induce different mechanical properties and failure modes of rock masses. Therefore, precisely expressing the failure criterion of the fractured rock influenced by coal mining is significant for the support design, safety assessment and disaster prevention of underground mining engineering subjected to multiple mining activities. By adopting PFC2D particle flow simulation software, this study investigated the propagation and fractal evolution laws of the micro cracks occurring in two typical kinds of rocks under uniaxial compressive condition. Furthermore, it calculated compressive strengths of the rocks with different confining pressures and box-counting dimensions. Moreover, the quantitative relation between the box-counting dimension of the rocks and the empirical parameters m and s in Hoek-Brown strength criterion was established. Results showed that with the increase of the strain, the box-counting dimension of the rocks first increased slowly at the beginning and then exhibited an exponential increase approximately. In the case of small strains of same value, the box-counting dimensions of hard rocks were smaller than those of weak rocks, while the former increased rapidly and were larger than the latter under large strain. The results also presented that there was a negative correlation between the parameters m and s in Hoek-Brown strength criterion and the box-counting dimension of the rocks suffering from variable mining activities. In other words, as the box-counting dimensions increased, the parameters m and s decreased linearly, and their relationship could be described using first order polynomial function.

Asymmetry of Cloud Vertical Structures and Associated Radiative Effects in Typhoon over the Northwest Pacific Based on CloudSat Tropical Cyclone Dataset

Yan Yafei,Tan Jianguo,Cui Linli,Yu Wei,Hu Yan 한국기상학회 2020 Asia-Pacific Journal of Atmospheric Sciences Vol.56 No.4

The clouds’ macro-, microphysical vertical structures and radiative effects in 4 shear-relative quadrants of typhoon over the northwest Pacific during development, maturity and extinction stages are studied based on CloudSat Tropical Cyclone dataset and China Meteorological Administration tropical cyclone dataset from 2nd June 2006 to 31th December 2015. The typhoon cloud is in an asymmetric “mushroom” shape, with the downshear quadrants (in particular of the downshear left quadrant (DL)) have denser clouds than the upshear quadrants. Cloud ice water content mainly distributes near typhoon center with wide vertical range (6–17 km). A large number of ice particles with small sizes are gathering in high levels, while small amount of ice particles with large sizes are gathering in low levels. As typhoon matures, the number concentration and size of cloud ice particles in inner ring increases, especially in the DL quadrant; while in the upshear left (UL) quadrant, a larger amount of ice particles with bigger sizes are transport to high levels (above 16 km) by deeper convection near storm center. The shortwave (longwave) cloud radiative effects (CRE) is mainly heating (cooling) upper layer atmosphere between 10 km and 17 km (between 14 km and 17 km), and the net CRE on atmosphere is heating almost at any levels in typhoon. The strongest heating of shortwave CRE and net CRE, as well as the strongest cooling of longwave CRE are in the DL quadrant at development stage and in the UL quadrant at maturity stage in inner core of storms. The existences of typhoon clouds mainly decrease solar radiation penetrating to the earth surface and increase longwave radiation absorbed by the whole atmosphere in typhoon’s inner core, and they are generally stronger in downshear (especially in DL) quadrants, except the maturity stage when the UL quadrant performs the strongest shortwave CRE on the surface and longwave CRE on the atmosphere in typhoon’s inner core.

Damage constitutive model of brittle rock considering the compaction of crack

Gu, Qingheng,Ning, Jianguo,Tan, Yunliang,Liu, Xuesheng,Ma, Qing,Xu, Qiang Techno-Press 2018 Geomechanics & engineering Vol.15 No.5

The deformation and strength of brittle rocks are significantly influenced by the crack closure behavior. The relationship between the strength and deformation of rocks under uniaxial loading is the foundation for design and assessment of such scenarios. The concept of relative crack closure strain was proposed to describe the influence of the crack closure behavior on the deformation and strength of rocks. Considering the crack compaction effect, a new damage constitutive model was developed based on accumulated AE counts. First, a damage variable based on the accumulated AE counts was introduced, and the damage evolution equations for the four types of brittle rocks were then derived. Second, a compaction coefficient was proposed to describe the compaction degree and a correction factor was proposed to correct the error in the effective elastic modulus instead of the elastic modulus of the rock without new damage. Finally, the compaction coefficient and correction factor were used to modify the damage constitutive model obtained using the Lemaitre strain equivalence hypothesis. The fitted results of the models were then compared with the experimental data. The results showed that the uniaxial compressive strength and effective elastic modulus decrease with an increase in the relative crack closure strain. The values of the damage variables increase exponentially with strains. The modified damage constitutive equation can be used to more accurately describe the compressive deformation (particularly the compaction stage) of the four types of brittle rocks, with a coefficient of determination greater than 0.9.

Elastic Foundation Beam Solution of Tensile Flexible Retaining Wall

Xu Jianqiang,Xu Jiangbo,Yang Xiaohua,Yan Zhaobai,Li Haiping,Wang Huoming,Tan Ling,Fei Dongyang,Li Jianguo,Luo Yongzhen 한국강구조학회 2022 International Journal of Steel Structures Vol.22 No.2

The application of fl exible retaining walls in foundation pit engineering is gradually increasing. At present, many practical engineering problems need to be solved. This article takes a corrugated steel retaining wall with tensile reinforcement, for example, assuming that it is an elastic foundation beam model. A typical vertical thin layer unit is taken on the retaining wall for analysis. It uses the waveform integration method to calculate the moment of inertia, deriving the diff erential equation of fl exural deformation of corrugated steel retaining wall and establishing the theoretical formula for deformation of corrugated steel retaining wall under fi lling pressure behind the wall. Finally, a FLAC3D model was established to simulate the deformation of corrugated steel retaining walls in practical engineering, and the fi nal numerical simulation results were consistent with the theoretical formula. Thus, providing a theoretical basis for the deformation of such fl exible retaining structures.