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IMPACTS OF SHELLFISH CULTURE ON THE ECOSYSTEM IN SEMI-ENCLOSED BAYS
Ming Yuan Zhu,Ru Bao Ji,Shang Chen,Xue Lei Zhang 한국해안해양공학회 1999 학술강연회 발표논문초록집 Vol.1 No.1
Stimulated by high economic profits, the industries of shellfish culture have grown rapidly during the last two decades. The expansion of mariculture adds pressure on the environment and associated ecosystem. The potential impacts of the cultivation include reduction of primary productivity due to the consumption of large quantities of phytoplankton, changes of water current movement resulted from the semi-permeation 'Island' effects of the suspended culture, and production of a large amount of faeces and pseudofaeces which may enhance the importance of benthic ecosystem in geo-biological cycling.
Transverse vibration of flexible hoisting rope with time-varying length
Ji-hu Bao,Peng Zhang,Chang-Ming Zhu,Wei Sun 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.2
The nonlinear vibration of a flexible hoisting rope with time-varying length is investigated. The governing equations of the flexible hoistingrope are developed based on Hamilton’s principle. Experiments performed evaluated the theoretical model and found that the experimentaldata agree well with the theoretical prediction, which validates the mathematical model of the flexible hoisting system. The resultsof the simulations and experiments show that the flexible hoisting system dissipates energy during downward movement (thus is stabilized)and gains energy during upward movement (thus is unstabilized). In addition, a passage through resonance in the hoisting system withperiodic external excitation is analyzed. Due to the time-varying length of the hoisting rope the natural frequencies of the system varyslowly, and transient resonance may occur when one of the frequencies coincides with the frequency of an external excitation.
A 4th-Order Low-distortion Low-pass ΣΔ Modulator Using Timing-Sharing Technique
Hong-guo Zhang,Ji-bao Zhang,Ming-yuan Ren 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.9
A 4th-Order low-distortion low-pass ΣΔ modulator structure is proposed in this paper, which uses the timing-sharing between the 3rd and 4th integrators during one clock phase. Compared with conventional cascade of integrators with distributed feed-forward (CIFF) sigma-delta modulator structure, the proposed structure not only solves the critical timing issue for the quantizer and feedback DAC path, but also eliminates an extra active adder to sum up the input feed-forward. By methods of delay redistribution structure, the time for quantization and feedback dynamic element match (DEM) operation can be extended from a non-overlapping interval for a conventional low-distortion structure to half of the sampling clock period. Capacitive input feed-forward (CIF) methodology eliminates the adder in front of the quantizer. Further, the op-amp of the last integrator is used as an active adder by op-amp sharing. Therefore, the power consumption can be reduced and the linearity of the feedback DAC is improved because of the increasing time which used for implementation of DEM algorism. The proposed 4th-Order low-distortion low-pass ΣΔ modulator with 4-bit quantizer is simulated in MATLAB. From the simulation results, the proposed structure can achieve a peak SNR (signal- to-noise ratio) of 87dB with 2.5MHz bandwidth under 32 oversampling ratio at 160MHz sampling frequency and the ENOB of 14.234bits in non-ideal condition.
Grain Size Effect on Multi-Stage Micro Deep Drawing of Micro Cup with Domed Bottom
Wen Ting Li,Ming Wang Fu,Ji Lai Wang,Bao Meng 한국정밀공학회 2016 International Journal of Precision Engineering and Vol.17 No.6
A two-stage micro deep drawing system was designed and developed to manufacture a micro cup with domed bottom. The copper blank was annealed at three different conditions to obtain different grain sizes in such a way to study the grain size effect on the deformation behavior and thickness variation of the micro part. To investigate the instantaneous effect and deformation behavior, finite element simulation was used to simulate the whole drawing process. It revealed that the fracture in the place with the thinnest thickness in the micro part drawn from a circle blank with residual stress induced in blanking can be easily happen and the deformation load in the first-stage decreases more than that in the second-stage with the increase of grain size. Moreover, the micro part with a larger grain size has more nonuniform thickness and severer thinning around the punch corner. The surface roughness at the bottom of micro part increases with the grain size. The surface roughness at the wall of it, however, decreases with the deformation stage mainly due to the ironing effect. The research promotes the understanding of grain size effect on multi-stage micro deep drawing and facilitates the development of microforming process.
Zhu, Hai-Li,Bao, Ji-Ming,Lin, Pei-Xin,Li, Wen-Xia,Zou, Zhen-Ning,Huang, Ye-En,Chen, Qing,Shen, Hong Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.16
Background: Numerous studies have explored the influence of XPD Lys751Gln and/or Asp312Asn polymorphisms on skin cancer susceptibility. However, the results remain inconclusive. To derive a more precise estimation, we conducted a comprehensive search to identify all available published studies and performed a meta-analysis. Materials and Methods: Electronic literature searches of the PubMed, CBM and CNKI databases were performed up to March 2014. Odds ratios (ORs) with 95% confidence intervals (CIs) were applied to assess the strength of associations. Results: Seventeen case-control studies were included with a total sample size of 6, 113 cases and 11, 074 controls for the XPD Lys751Gln polymorphism, and 10 studies (3, 840cases and 7, 637 controls) for the XPD Asp312Asn polymorphism were pooled for analysis. Overall, no significant associations were found between the XPD Lys751Gln polymorphism and skin cancer risk in any genetic model. On stratified analysis by tumor type, XPD Lys751Gln polymorphism was not associated with increased risk of non-melanoma skin cancer, but was significantly related with increased risk of cutaneous melanoma (Gln/Gln vs Lys/Lys: OR=1.15, 95%CI=1.02-1.29, p=0.023; dominant model: OR=1.09, 95%CI=1.01-1.18, p=0.036). For the XPD Asp312Asn polymorphism, no significant association with skin cancer risk was observed in overall or subgroup analyses. Conclusions: The present meta-analysis suggests that the XPD Lys751Gln polymorphism may contribute to the risk of cutaneous melanoma from currently available evidence. Further investigations are needed to obtain more insight into possible roles of these two polymorphisms in skin carcinogenesis.
Duan Feng,Jin Bao-Sheng,Huang Ya-Ji,Li Bin,Sun Yu,Wu Yiming,Zhang Ming-Yao 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6
High temperature preheated air and steam as gasifying agent and coal gasification was performed in a pressurized turbulent circulating fluidized bed (CFB) gasification pilot plant to investigate the pressurized gasification process and estimate its potential. Within the scope of this paper this test facility as well as its operation behavior was described. Furthermore, the parameter pressure has been investigated regarding its influence on the syngas composition and was presented and discussed in the following. The results show that the gasification quality is improved at higher pressure because of the better fluidization in the reactor. Coal gasification at a higher pressure shows advantages in lower heat value and carbon conversion. With the gasifier pressure increased from 0.1MPa to 0.3MPa, the gas heating value is increased by 15%. Increasing the gasifier pressure would increase the carbon conversion from 57.52% to 76.76%. Also, the dry gas yield and efficiency of cold gas increase little with the increase of the gasifier pressure. The operating parameter of pressure exists at optimum operating range for this specific CFB coal gasification process.
( Jia-yi Dou ),( Yu-chen Jiang ),( Zhong-he Hu ),( Kun-chen Yao ),( Ming-hui Yuan ),( Xiao-xue Bao ),( Mei-jie Zhou ),( Yue Liu ),( Zhao-xu Li ),( Li-hua Lian ),( Ji-xing Nan ),( Yan-ling Wu ) 한국응용약물학회 2022 Biomolecules & Therapeutics(구 응용약물학회지) Vol.30 No.3
The present study focused on the potential mechanism of betulin (BT), a pentacyclic triterpenoid isolated from the bark of white birch (Betula pubescens), against chronic alcohol-induced lipid accumulation and metaflammation. AML-12 and RAW 264.7 cells were administered ethanol (EtOH), lipopolysaccharide (LPS) or BT. Male C57BL/6 mice were fed Lieber-DeCarli liquid diets containing 5% EtOH for 4 weeks, followed by single EtOH gavage on the last day and simultaneous treatment with BT (20 or 50 mg/kg) by oral gavage once per day. In vitro, MTT showed that 0-25 mM EtOH and 0-25 μM BT had no toxic effect on AML-12 cells. BT could regulate sterolregulatory-element-binding protein 1 (SREBP1), lipin1/2, P2X7 receptor (P2X7r) and NOD-like receptor family, pyrin domains-containing protein 3 (NLRP3) expressions again EtOH-stimulation. Oil Red O staining also indicated that BT significantly reduced lipid accumulation in EtOH-stimulated AML-12 cells. Lipin1/2 deficiency indicated that BT might mediate lipin1/2 to regulate SREBP1 and P2X7r expression and further alleviate lipid accumulation and inflammation. In vivo, BT significantly alleviated histopathological changes, reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and triglyceride (TG) levels, and regulated lipin1/2, SREBP1, peroxisome proliferator activated receptor α/γ (PPARα/γ) and PGC-1α expression compared with the EtOH group. BT reduced the secretion of inflammatory factors and blocked the P2X7r-NLRP3 signaling pathway. Collectively, BT attenuated lipid accumulation and metaflammation by regulating the lipin1/2-mediated P2X7r signaling pathway.