Harmless Measurement of Tree Root Distribution Using Electrical Resistivity Method

Wenlan Guo,Junshen Gao1,Yun Zhang 보안공학연구지원센터 2016 International Journal of u- and e- Service, Scienc Vol.9 No.11

The trees are of great meaning to the life and daily life of the human beings in various fields. However, the trees would disturb the normal activities of peoples. One of the problems is the growth of the tree roots close to the buildings or the roads can cause directly or indirectly structural damages. In this paper, a electrical measurement method based on resistivity is proposed The electrical property of tree root is analyzed. Finally, a tree root measurement system is built and practically tested.

Macroscopic Characterization of Flash Boiling Sprays using Laser Induced Exciplex Fluorescence from a Multi-Hole DI Injector

( Gao Ming Zhang ),( Min Xu ),( Yu Yin Zhang ),( Ming Zhang ),( David J. Cleary ) 한국액체미립화학회 2010 한국액체미립화학회 학술강연회 논문집 Vol.2010 No.-

Fuel temperature and the ambient pressure can dramatically influence spray characteristics such as the spray structure, spray penetration, and quantity of vaporized fuel. Higher fuel temperatures that occur in today`s direct-injection engines can reach superheated conditions, dramatically changing the spray due to flash boiling. In this paper, the spray structure and vaporization behaviors are examined for a multi-hole DI injector over a range of superheated conditions. Planer laser-induced-exciplex fluorescence (PLIEF) is used to characterize the spray, where fluorobenzene (FB) and diethyl-methyl-amine (DEMA) are added into n-hexane as vapor and liquid tracers, respectively. The temperature dependence of crosstalk signal intensity is examined using a quartz cell and necessary corrections are made to the spray image. The individual plumes from this multi-hole injector are determined to collapse with increasing superheat degree until the spray transforms into a single plume. The liquid component of the spray is more resistant to collapsing as comparing to the vapor component, where a vapor jet-like structure is formed near the centerline axis of the fuel spray once collapsed. The relative vapor quantity increases with fuel temperature in a near linear fashion until a step change is observed for the vapor signal when the two vapor plumes merge into a single structure.

Serum Insulin-Like Growth Factor Binding Protein 7 for Esophagogastric Junction Adenocarcinoma Diagnosis

Gao-Ming Zhang,Guo-Ming Zhang,Jian-Hua Zhang 거트앤리버 소화기연관학회협의회 2020 Gut and Liver Vol.14 No.4

Minus-C odorant binding protein TcasOBP7G contributes to reproduction and defense against phytochemical in the red flour beetle, Tribolium castaneum

Gao Shanshan,Zhang Xinyi,Zhou Can,Zhang Guangyan,Zhang Yong-lei,Li Rui-min,Zhang Kun-peng 한국응용곤충학회 2023 Journal of Asia-Pacific Entomology Vol.26 No.4

Insect odorant binding proteins (OBPs) paly an important role in the recognition and transmission signals. One odorant binding protein gene, TcasOBP7G, was significantly up-regulated after exposure to eucalyptol. Never theless, the causal role of TcasOBP7G in Tribolium castaneum is still unclear. Here, TcasOBP7G was cloned and characterized from T. castaneum, aligning with the typical characteristic of Minus-C OBPs. The analysis of gene expression profile showed that TcasOBP7G is highly expressed at late larval and adult stage, with particularly high expression levels in ovary and testis of adults, suggesting that TcasOBP7G might be associated with reproduction of T. castaneum. Furthermore, RNAi of TcasOBP7G led to a decrease in spawning, while the development of gonads was normal, suggesting that TcasOBP7G may medicate the reproduction of T. castaneum. Additionally, the mRNA level of TcasOBP7G was significantly increased after exposure to eucalyptol, and knockdown of TcasOBP7G resulted in an increased susceptibility of T. castaneum to eucalyptol, indicating that TcasOBP7G is associated with the tolerance of T. castaneum to eucalyptol. Altogether, these results indicate that TcasOBP7G is required for both reproduction and defense against phytochemical in T. castaneum. This study will provide a theoretical basis for the development of novel control strategies based on the olfaction of insects.

A 2 GS/s, 6-bit DAC for UWB Applications In 0.18 ㎛ CMOS Technology

Yi Zhang,Zhonghua Liu,Changchun Zhang,Yufeng Guo,Ying Zhang,Xiaopeng Li,Youtao Zhang,Hao Gao 대한전자공학회 2019 Journal of semiconductor technology and science Vol.19 No.6

To satisfy higher and higher transmission rate and broadband requirement of modern communication, high-speed, low-resolution Digital-to-Analog Converters (DACs) becomes the key element. In this paper, the design of a 2 GS/s, 6 bit DAC without calibration for Ultra-wideband (UWB) applications, is presented. The DAC is based on current steering architecture and is segmented with 4 bit unary and 2 bit binary. To realize larger linear range and fast switching, the source degeneration switch is designed instead of the traditional differential switch. The DAC is designed and taped-out in SMIC 0.18 ㎜ CMOS technology and the area is 975 ㎛´ 775 ㎛. The wafer bonding measurement results shows that the DNL is 0.11 LSB, INL is 0.25 LSB. Under a clock frequency of 2 ㎓, the DAC can achieve a SFDR of 51 ㏈ for input signal of 6㎒, and a SFDR of 32.4 ㏈ for Nyquist input while the power consumption is 79 ㎽.

The Numerical Simulation Analysis of Flow Field in Level Control Valve of Water Storage Tank

Yaping Wang,Lei Gao,Jianghua Ge,Han Gao,Jing Zhang 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.10

Level control valve of water storage tank is installed in the outlet of tank, which control the water level of water storage tank by adjusting the water emissions, which make great significance for the safe operation of the super (super) criticality thermal power unit boiler . Complete the simulation analysis of internal flow field by the method of numerical simulation ,in order to achieve structure improvements of level control valve of water storage tank, that make level control valve of water storage tank better meet the work requirements. Establish flow channel model and mesh models of level control valve of water storage tank in various stages of the open process. Make three dimensional viscous numerical simulation of the internal complex flow field by the computational fluid dynamics software of ANSYS CFX. The error between the simulation values of the flow coefficient and the theoretical values , trial values is less than 5% ,which verifies the correctness of the simulation results . Get pressure contour , velocity streamline diagrams and outlet mass flow of level control valve of water storage tank in various stages of the open process. According to the pressure contours and velocity streamline diagrams, make detailed analysis of the flow field of level control valve of water storage tank. According to the dates of outlet mass flow, fit the flow characteristic curve of level control valve of water storage tank. Provide a theoretical basis for the structural design of level control valve of water storage tank.

Degradation of roller compacted concrete subjected to low-velocity fatigue impacts and salt spray cycles

Gao, Longxin,Lai, Yong,Zhang, Huigui,Zhang, Jingsong,Zhang, Wuman Techno-Press 2021 Advances in concrete construction Vol.12 No.5

Roller compacted concrete (RCC) used in the island reef airport runway will be subjected to the coupling actions of the fatigue impacts and the salt spray cycles, which will accelerate the deterioration of runway concrete and even threaten the flight safety. A cyclic impact testing machine and a climatic chamber were used to simulate the low-velocity fatigue impact and the salt spray cycles, respectively. The physical properties, the microstructures and the porosity of RCC were investigated. The results show the flexural strength firstly increases and then decreases with the increase of the fatigue impacts and the salt spray cycles. However, the decrease in the flexural strength is significantly earlier than the compressive strength of RCC only subjected to the salt spray cycles. The chlorine, sulfur and magnesium elements significantly increase in the pores of RCC subjected to 30000 fatigue impacts and 300 salt spray cycles, which causes the decrease in the porosity of RCC. The coupling effects of the fatigue impacts and the salt spray cycles in the later period accelerates the deterioration of RCC.

Effect of Xeroderma Pigmentosum Complementation Group F Polymorphisms on Gastric Cancer Risk and Associations with H.pylori Infection

Zhang, Ji-Shun,Zhang, Chuan,Yan, Xue-Yan,Yuan, Zhi-Fang,Duan, Zhuo-Yang,Gao, Hui Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.3

We conducted a hospital case-control study by genotyping four potential functional single nucleotide polymorphisms (SNPs) to assess the association of Xeroderma pigmentosum complementation group F (XPF) with gastric cancer susceptibility, and role of XPF polymorphisms in combination with H.pylori infection in risk definition. A total of 331 patients with gastric cancer and 355 controls were collected. Four SNPs of XPF, rs180067, rs1799801, rs2276466 and rs744154, were genotyped by Taqman real-time PCR method with a 7900 HT sequence detector system. The gastric cancer patients were more likely to have smoking habit, a family history of cancer and H.pylori infection. We did not find any significant difference in the genotype distributions of XPF rs180067, rs1799801, rs2276466 and rs744154 between cases and controls. However, multivariate logistic analysis showed a non-significant decreased risk in patients carrying rs180067 G allele, rs1799801 T allele or rs2276466 T allele genotypes. A non-significant increased risk of gastric cancer was found in individuals carrying the rs744154 GG genotype. Stratification by H.pylori infection and smoking was not significantly different in polymorphisms of XPF rs180067, rs1799801, rs2276466 and rs744154. The four XPF SNPs did not show significant interaction with H.pylori infection and smoking status (P for interaction was 0.35 and 0.18, respectively). Our study indicated that polymorphisms in rs180067, rs1799801, rs2276466 and rs744154 may affect the risk of gastric cancer but further large sample size studies are needed to validate any association.

Model Predictive Power Control of a PWM Rectifier for Electromagnetic Transmitters

Zhang, Jialin,Zhang, Yiming,Guo, Bing,Gao, Junxia The Korean Institute of Power Electronics 2018 JOURNAL OF POWER ELECTRONICS Vol.18 No.3

Model predictive direct power control (MPDPC) is a widely recognized high-performance control strategy for a three-phase grid-connected pulse width modulation (PWM) rectifier. Unlike those of conventional grid-connected PWM rectifiers, the active and reactive powers of permanent magnet synchronous generator (PMSG)-connected PWM rectifiers, which are used in electromagnetic transmitters, cannot be calculated as the product of voltage and current because the back electromotive force (EMF) of the generator cannot be measured directly. In this study, the predictive power model of the rectifier is obtained by analyzing the relationship among flux, back EMF, active/reactive power, converter voltage, and stator current of the generator. The concept of duty cycle control in the proposed MPDPC is introduced by allocating a fraction of the control period for a nonzero vector and rest time for a zero vector. When nonzero vectors and their duration in the predefined cost function are simultaneously evaluated, the global power ripple minimization is obtained. Simulation and experimental results prove that the proposed MPDPC strategy with duty cycle control for the PMSG-connected PWM rectifier can achieve better control performance than the conventional MPDPC-SVM with grid-connected PWM rectifier.

A Novel Procedure for Protection Setting in an HVDC System Based on Fault Quantities

Gao, Benfeng,Zhang, Ruixue,Zhang, Xuewei The Korean Institute of Electrical Engineers 2017 Journal of Electrical Engineering & Technology Vol.12 No.2

HVDC protection setting is difficult to be calculated analytically because of its strong nonlinearity. The currently used setting method is based on the empirical setting of previous projects and then verified by digital simulation. It entails a huge workload and low efficiency. To facilitate protection setting, this paper systematically summarizes the HVDC protection characteristics and then presents a classification of HVDC protections according to the protection principles. On the basis of the fault quantities, a novel setting procedure suitable for travelling wave protection, derivative and level protection, and differential protection is proposed. The proposed procedure is illustrated and verified in detail with the example of travelling wave protection. An HVDC protection setting system that has the functions of automatic protection setting and data management is developed utilizing the C# programming language.