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Pan Z.,Xi'an Jiaotong University | Zhang Y.,Xi'an Jiaotong University | Cheng Z.,Xi'an Jiaotong University | Liang B.,Xi'an Jiaotong University | And 7 more authors.
Sensors and Actuators, B: Chemical | Year: 2017

Measuring the concentration of oxynitride NOx (including NO and NO2) can provide a scientific basis for determining its potential harm to the human body. The existing metal oxide semiconductor sensor arrays are greatly limited by high operating temperature and low integration. In this article, we report on a high-integration carbon nanotubes sensor array with two different electrode separations sensitive to oxynitride mixture at low temperature. The triple-electrode sensor array is comprised of a large carbon nanotube array cathode, two extracting electrodes and two collecting electrodes and worked at non-self-sustaining discharge state, which was determined by the study on current-voltage characteristic of a double-electrode structure sensor. Through studying the relationship between gas concentration and discharge current at 1 atm, we obtained the distinct sensitivities of the binary mixture in the concentration ranges of 0–1166 ppm NO and 0–712 ppm NO2 using the sensor array at low operating voltages and 60 °C. Collecting currents of the two sensors in the array decreased with increasing NO and NO2 concentration in the gas mixture. The repeatable characteristics and dynamical response tests of the sensors were also conducted. The proposed sensor array has potential for the direct detection of a NO-NO2 mixture without separating the mixed gases. © 2017 Elsevier B.V.

Tengfei Q.,China Electric Power Research Institute | Bangwen S.,China Electric Power Research Institute | Xiaolong W.,Huanghe Hydropower Development Co | Hui L.,Nanjing Southeast University
Proceedings - 2015 6th International Conference on Intelligent Systems Design and Engineering Applications, ISDEA 2015 | Year: 2015

In recent years, photovoltaic (PV) power generation is developing rapidly on account of its environment friendliness. However, the PV devices between different manufacturers could hardly interoperate because of different model and protocols they applied. This paper built the information model for PV power generation based on IEC61850, which is more normative and convenient for PV plant configuring. The method abstract functions of PV devices to Logic Nodes (LN), and assembling related LNs into Intelligent Electronic Device (IED). This object-oriented model is strong in commonality and practicability, and is beneficial for devices interoperating. The model in this paper is suitable, and has been applied in practical PV project in Qinghai province, China. © 2015 IEEE.

Cao Y.,Hubei University | Guo Q.,Hubei University | Shu Z.,Hubei University | Zhuang Y.,Hubei University | And 6 more authors.
Applied Clay Science | Year: 2016

Unlike the other family members of anion clay, iowaite, a Mg-Fe based layered double hydroxide, was seldom used in removing undesirable constituents from natural or contaminated waters. In this study, iowaite as well as its calcination product were employed to treat arsenic-spiked solutions, taking into account that anion clays exhibited great capacity to incorporate anionic pollutants as a result of their relatively weak interlayer bonding, and Fe-bearing minerals had high affinity to both arsenate and arsenite. The thermal decomposition process and structural memory effect of synthetic iowaite were investigated over a wide temperature range of 300-1000. °C for the first time, based on which the calcination product obtained at 450. °C was finally selected to be used in solution dearsenication experiments. The experimental results showed that the content of Fe in pristine iowaite significantly affected its arsenite sorption behavior, whereas the calcination process weakened the effect of Fe content on arsenite uptake. The calcined iowaite was generally characterized with higher arsenic uptake capacity as compared to some other sorbents commonly used for arsenic removal from solution in recent years as well as the pristine iowaite synthesized in this study. A contrast experiment suggested that magnoferrite in the calcination products of iowaite made no contribution to the enhanced arsenic uptake capacity of calcined iowaite. Hence, calcined iowaite performed better in arsenic removal because of the high availability of arsenic oxyanions to the interlayer regions during its structural restoration. The arsenic oxyanions did not need to diffuse into the interlayers to replace the original chloride ions as they did for pristine iowaite. © 2016 Elsevier B.V.

Cui W.J.,CAS Zhengzhou Research Institute | Li L.Q.,CAS Zhengzhou Research Institute | Zhang W.,Huanghe Hydropower Development Co.
Applied Mechanics and Materials | Year: 2014

Calculation of seepage stability is important method in selection and justification of reinforcing dike seepage control measures. In the reinforcement design of the Qinhe river dike downstream, the finite element method of AutoBank is used to calculate the seepage stability of the dike reinforced before and after, and an economic and reasonable reinforcement scheme is selected then. © (2014) Trans Tech Publications, Switzerland.

Liu M.,Hubei University | Guo Q.,Hubei University | Zhang X.,Hubei University | Luo J.,Hubei University | And 5 more authors.
Environmental Earth Sciences | Year: 2016

The Gonghe geothermal region, located in the northeastern part of Qinghai–Tibet Plateau, is the most geothermally active in Qinghai Province. The geothermal waters from three hydrothermal areas (Qiabuqia, Guide and Xinghai) of Gonghe are characterized with different hydrochemical types. Nevertheless, their δD and δ18O data suggest that they are all of meteoric origin. Most Gonghe samples are far away from the full equilibrium line in Na–K–Mg triangular diagram, implying that Na–K geothermometer is generally not suitable for calculating the reservoir temperatures. In comparison, silica geothermometers perform much better and give more accurate temperature estimations. The hydrochemistry of the Gonghe geothermal waters is distinctively different from that of the hot springs from Rehai, a well-known magmatic hydrothermal area located in the Tengchong volcanic region of Yunnan Province, southwestern China, indicating that the geothermal anomaly in Gonghe is not related to an underlying magma chamber. Instead, the strong hydrothermal manifestation there is more likely to be supported by the intense deep tectonic activities. Moreover, the possible existence of radioactive heat source can not be ruled out at this stage. © 2016, Springer-Verlag Berlin Heidelberg.

PubMed | Friedrich - Alexander - University, Erlangen - Nuremberg, Wuhan University and Huanghe Hydropower Development CO.
Type: | Journal: Scientific reports | Year: 2017

In this paper, the hydraulic and heat-transfer properties of two sets of artificially fractured granite samples are investigated. First, the morphological information is determined using 3D modelling technology. The area ratio is used to describe the roughness of the fracture surface. Second, the hydraulic properties of fractured granite are tested by exposing samples to different confining pressures and temperatures. The results show that the hydraulic properties of the fractures are affected mainly by the area ratio, with a larger area ratio producing a larger fracture aperture and higher hydraulic conductivity. Both the hydraulic apertureand the hydraulic conductivity decrease with an increase in the confining pressure. Furthermore, the fracture aperture decreases with increasing rock temperature, but the hydraulic conductivity increases owing to a reduction of the viscosity of the fluid flowing through. Finally, the heat-transfer efficiency of the samples under coupled hydro-thermal-mechanical conditions is analysed and discussed.

Hong D.,Xi'an University of Technology | Hong D.,Huanghe Hydropower Development Co. | Niu Z.-M.,Xi'an University of Technology | Nan J.-H.,Xi'an University of Technology | And 2 more authors.
Shuidonglixue Yanjiu yu Jinzhan/Chinese Journal of Hydrodynamics Ser. A | Year: 2010

In this paper, the results of the inversion model test are compared with that of the prototype observation of Gongboxia horizontal swirl discharge tunnel. Based on it, the characteristics of fluctuating pressure of this new type energy dissipater in the process of the gates' open-and-close were analyzed. The research results show that in both the prototype and the model, the pressure change with time is approximately consistent in the shaft upper ring-form aerators, in the spiral starter and horizontal swirl tunnel, and it accords with the gravity similarity principle. At the same time, due to the model scale effect, their cavity lengths of the ring-form aerators are different and the differences of pressure are also larger. Pressure changes on the wall of the spiral starter may be classified into four steps in the process of the gates' open. The dominant frequencies corresponding measuring points in the prototype and the model of horizontal swirl tunnel all belong to low frequencies, are far less than the inherent frequency of the building.

An Y.,Xi'an University of Technology | Fang W.,Xi'an University of Technology | Huang Q.,Xi'an University of Technology | Xie X.,Huanghe Hydropower Development CO. | And 2 more authors.
Taiyangneng Xuebao/Acta Energiae Solaris Sinica | Year: 2016

Taking the world's largest hydro/solar power combination-Longyangxia project as the research object, the characteristics of hydropower generation and solar PV generation were analyzed, the new concept and connotation of supplementary power of hydropower were presented, and the principle of hydro/solar complementary operation was revealed. In short term scheduling, hydropower generation can improve PV generation via the first compensation for PV's zigzag output and the second compensation for PV's interim, fluctuant and random output. The hydropower generation can support capacity of PV generation in short term scheduling, the PV generation is able to support hydropower generation by its compensatory electricity generation in mid-long term scheduling and peak-load regulating operation. Meanwhile, the compensation ability of hydropower generation for PV generation in short term scheduling was discussed;the formulae for hydro/solar compensation calculation were theoretically derived to explore the cause and condition on water spillage and solar PV spillage during hydro/solar complementary operation. Finally, a calculation model for hydro/solar complementary operation was formulated on the basis of Longyangxia hydro/solar power combination. The results show that hydro/solar complementary operation can remarkably improve the quality of PV power, effectively prevent or reduce solar power curtailment, and provide stronger peak-load regulating capacity than a single hydropower plant. © 2016, Editorial Board of Acta Energiae Solaris Sinica. All right reserved.

Tengfei Q.,China Electric Power Research Institute | Bangwen S.,Huanghe Hydropower Development Co. | Hui L.,Huanghe Hydropower Development Co.
Proceedings - 2015 6th International Conference on Intelligent Systems Design and Engineering Applications, ISDEA 2015 | Year: 2015

There are many existing problems in the traditional photovoltaic power plant. For example, the application functions of the devices and monitoring system are not clear and definite, the communication standards among the devices vary a lot, the interactivity with the dispatching system is poor and there are very less wise auxiliary decision ways in the plant. In order to solve these problems, digital photovoltaic power plant is proposed in this paper. The specific characteristics and definition of the digital photovoltaic power plant are given and the overall framework and hierarchical division of the digital photovoltaic power plant are given as well. In addition, the application functions of the digital photovoltaic power plant are analyzed concretely at last, which provides some supports and guidelines for the practical application of the digital photovoltaic power plant. © 2015 IEEE.

Wang J.,University of Sichuan | Huang W.,University of Sichuan | Ma G.,University of Sichuan | Bai Y.,Huanghe Hydropower Development Co. | And 2 more authors.
Shuili Fadian Xuebao/Journal of Hydroelectric Engineering | Year: 2015

Based on the relationship between annual power generation and year-end energy storage, a multi-objective prediction model for the optimal year-end water level of carryover storage reservoir is developed, which gives a full consideration to maximizing the hydro energy and least output of the hydro plant at such a reservoir. The model was validated with the case of Longyangxia reservoir on the upper Yellow, and the essence in obtaining its optimal year-end level was revealed through analysis of the impacts of water inflow and year-start level on this optimal level. The operation results simulated by the model are further compared with the prototype operation case of this reservoir from 1990 to 2012. This shows that since 2006 it has run at a higher level than before 2006, which improves its own benefits and indicates that the multi-objective model is reasonable and feasible. ©, 2015 All right reserved.

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