Optoelectronic Characteristics of UV Photodetector Based on GaN/ZnO Nanorods p-i-n Heterostructures

Qingshan Li,Lichun Zhang,Fengzhou Zhao,Caifeng Wang,Feifei Wang,Ruizhi Huang 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.4

We demonstrate an efficient ultraviolet (UV) photodetector operating at room temperature based on n-ZnO nanorods/i-ZnO/p-GaN heterojunctions. We employ x-ray diffraction and field-emission scanning electron microscopy to confirm the high quality of the ZnO nanorods using an undoped ZnO film as the interlayer. Then, we investigate the photoelectric properties of the fabricated photodetector with UV light illumination under a different reverse bias. Based on the current-voltage curve, the photocurrent to dark current ratio is approximately 73.3 at −4 V. At zerobias voltage, the peak responsivity was 138.9 mA/W at 362 nm under front-illumination conditions. Time-varying measurements indicate the reproducibility and stability of the heterojunction photodetector.

Research on a Demand Response Interactive Scheduling Model of Home Load Groups

Qingshan Xu,Xiaoquan Jiao 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.3

In order to solve the problem that the potential between electrical appliances and each power supply is not timely in the current scheduling model, which may leads to high energy consumption and poor interaction performance, the research of interactive scheduling model for demand response of home load group is proposed. Four types of household appliances are obtained from the home load group structure diagram: core electrical appliances, electrical appliances capable of providing storing energy, electrical appliances of any use time, and load aggregators. By selecting multiple indicators, a load group response potential index system is constructed to measure the household based on the impacts of electrical and power response potentials; and two load-aggregate demand response models are established by integrating demand response resources through load aggregation. Furthermore, By combining the above two models with home load aggregation, the improved tabu search algorithm is used to determine the objective function and constraints, such that an interactive scheduling model for the family load group demand response is constructed. The experimental results show that the energy consumption of this model can be low after dispatching household load group. It can reduce household electricity consumption, and have good application performance. The model can efectively complete the interactive scheduling of the demand response of the home load group. It solves the problem of electricity wasting so as to save energy. In the meantime, it improves the user’s real-time and convenient experience.

Irradiation-Induced Hardening and Softening of CLAM Steel Under Fe Ion Irradiation

Qingshan Li,Yinzhong Shen,Xi Huang,Zhiqiang Xu,Jun Zhu 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.6

The irradiation-induced hardening and softening of CLAM steel irradiated with 3.5 MeV Fe13+ions at temperaturesof 300 °C and 550 °C were investigated by nanoindentation tests in combination with microstructures. Irradiation-induced hardening occurred in the steel irradiated at 300 °C to doses of 0.46 dpa, 0.94 dpa, and 2.79 dpa. The hardening occurred at 300 °C is mainly attributed to the formation of irradiation-produced dislocation loopsand a network of tangled dislocations in the irradiated steel samples. Significant hardening was found in the steelirradiated at 550 °C to 0.38 dpa. On the contrary, irradiation-induced softening occurred in the steel irradiated at550 °C to both 0.76 dpa and 2.75 dpa. Irradiation-produced dislocation loops are not dominant effect on the irradiationhardening of the steel samples irradiated at 550 °C. The hardening and softening of the irradiated steel wereexplained in terms of the irradiation-produced defects and recovery process occurred during the irradiation.

Expression and Purification of Lacticin Q by Small Ubiquitin-Related Modifier Fusion in Escherichia coli

Qingshan Ma,Zhanqiao Yu,Bing Han,Qing Wang,Rijun Zhang 한국미생물학회 2012 The journal of microbiology Vol.50 No.2

Lacticin Q is a broad-spectrum class II bacteriocin with potential as an alternative to conventional antibiotics. The objective of this study was to produce recombinant lacticin Q using a small ubiquitin-related modifier (SUMO) fusion protein expression system. The 168-bp lacticin Q gene was cloned into the expression vector pET SUMO and transformed into Escherichia coli BL21(DE3). The soluble fusion protein was recovered with a Ni-NTA Sepharose column (95% purity); 130 mg protein was obtained per liter of fermentation culture. The SUMO tag was then proteolytically cleaved from the protein, which was re-applied to the column. Finally, about 32 mg lacticin Q (≥96% purity) was obtained. The recombinant protein exhibited antimicrobial properties similar to that of the native protein, demonstrating that lacticin Q had been successfully expressed by the SUMO fusion system.

Multi-channel analyzer based on a novel pulse fi tting analysis method

Qingshan Wang,Xiongjie Zhang,Xiangting Meng,Bao Wang,Dongyang Wang,Pengfei Zhou,Renbo Wang,Bin Tang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

A novel pulse fitting analysis (PFA) method is presented for the acquisition of nuclear spectra. Thecharging process of the feedback capacitor in the resistive feedback charge-sensitive preamplifier isequivalent to the impulsive pulse, and its impulse response function (IRF) can be obtained by non-linearfitting of the falling edge of the nuclear pulse. The integral of the IRF excluding the baseline representsthe energy deposition of the particles in the detector. In addition, since the non-linear fitting process inPFA method is difficult to achieve in the conventional architecture of spectroscopy system, a new multichannel analyzer (MCA) based on Zynq SoC is proposed, which transmits all the data of nuclear pulsesfrom the programmable logic (PL) to the processing system (PS) by high-speed AXI-Stream in order toimplement PFA method with precision. The linearity of new MCA has been tested. The spectrum of 137Cswas obtained using LaBr3(Ce) scintillator detector, and was compared with commercial MCA by ORTEC. The results of tests indicate that the MCA based on PFA method has the same performance as thecommercial MCA based on pulse height analysis (PHA) method and excellent linearity for g-rays withdifferent energies, which infers that PFA method is an effective and promising method for the acquisitionof spectra. Furthermore, it provides a new solution for nuclear pulse processing algorithms involvingregression and iterative processes

Comprehensive analysis of acid gases on mercury removal by CuCl2 modified char exposure to oxy-fuel environment: Experiment and XPS perception

Zeng Qingshan,Wang Hui,Wu Jingmao,Ran Hengyuan,Yang Kang,Wu Jianfei 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.12

In this work, 0.15 mol/L CuCl2 solution was used to impregnate rice husk char. Experiments were conducted in a laboratory-scale fixed-bed reactor to investigate the oxidation mechanism of Hg0 by acidic gases. The effects of acid gases (SO2, HCl and NO) atmospheres on the mercury removal efficiency of the adsorbent were studied by FTIR, XPS and experiments. The FTIR results showed that the surface of the prepared rice husk char adsorbent contained a large amount of Cu2+ and chlorine-containing functional groups. The XPS results showed that the Cu+ on the surface of the adsorbent increased after mercury adsorption. This work shows that the inhibitory effect of SO2 on Hg removal is reflected in the blockage of the pore structure on the adsorbent surface; the competitive adsorption of O2 needed for the generation of C-O*, the formation of an acid mist by SO2 hinders the contact of Hg0 with the active site. The promotion of HCl is due to the production of active chlorine substances (Cl*) to promote the oxidation of Hg0 to HgCl, HgCl2 and HgO. And introduction of NO will react with O2, while generation of NO2 is beneficial to the oxidation of Hg0 to HgO and Hg(NO3)2. The optimum mercury removal efficiency of the adsorbent is nearly 100% under certain conditions.

Relationship of mineral elements in sheep grazing in the highland agro-ecosystem

Fan, Qingshan,Wang, Zhaofeng,Chang, Shenghua,Peng, Zechen,Wanapat, Metha,Bowatte, Saman,Hou, Fujiang Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.1

Objective: Minerals are one of the important nutrients for supporting the growth of sheep grazing in the highland, northwest of China. The experiment was conducted to investigate the relationship of both macro and micro minerals in sheep grazing in the highlands of six districts located in the Qilian Mountain of China. Methods: Samples of herbage (n = 240) and soil (n = 240) were collected at random in a "W" shape across the area designated for harvesting from 24 farms, where the sheep commonly graze in October (winter) for mineral analyses. In addition, serum samples were taken via jugular vein from 20 sheep per farm from 24 farms (n = 480 samples in total) for serum minerals analyses. Mean values of macro and micro minerals were statistically compared among districts and the correlations among soil-plant-animal were statistically analyzed and correlations were regressed, as well. Results: The results revealed that there were variations for both macro and micro minerals among districts. Statistical analysis of the correlation coefficients between herbage and sheep were significantly different for most of the minerals but not for P, Cu, and Se. Many correlation regression coefficients were found significantly different among minerals of herbage, soil, and sheep serum especially those of K, Na, Fe, Mn, and Zn (between herbage and sheep serum), and Fe and Mn (between herbage and soil), Na, Fe, Mn, and Zn (between soil and sheep serum), respectively. The regression coefficient equations derived under this experiment for prediction of Ca (R² = 0.618), K (R² = 0.803), Mg (R² = 0.767), Na (R² = 0.670), Fe (R² = 0.865),Zn (R² = 0.950), Mn (R² = 0.936), and Se (R² = 0.630), resulted in significant R² values. Conclusion: It is inferred that the winter herbage minerals in all the districts were below the recommended levels for macro minerals which indicated there would be some mineral deficiencies in sheep grazing the herbage in these regions. Supplemental minerals may therefore play an important role in balancing the minerals available from the herbage in winter and would lead to increased productivity in sheep on the highland areas of China. These findings could be potentially applied to the other regions for improving the livestock productivity.

Rumen bacteria influence milk protein yield of yak grazing on the Qinghai-Tibet plateau

Fan, Qingshan,Wanapat, Metha,Hou, Fujiang Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.9

Objective: Ruminants are completely dependent on their microbiota for rumen fermentation, feed digestion, and consequently, their metabolism for productivity. This study aimed to evaluate the rumen bacteria of lactating yaks with different milk protein yields, using high-throughput sequencing technology, in order to understand the influence of these bacteria on milk production. Methods: Yaks with similar high milk protein yield (high milk yield and high milk protein content, HH; n = 12) and low milk protein yield (low milk yield and low milk protein content, LL; n = 12) were randomly selected from 57 mid-lactation yaks. Ruminal contents were collected using an oral stomach tube from the 24 yaks selected. High-throughput sequencing of bacterial 16S rRNA gene was used. Results: Ruminal ammonia N, total volatile fatty acids, acetate, propionate, and isobutyrate concentrations were found to be higher in HH than LL yaks. Community richness (Chao 1 index) and diversity indices (Shannon index) of rumen microbiota were higher in LL than HH yaks. Relative abundances of the Bacteroidetes and Tenericutes phyla in the rumen fluid were significantly increased in HH than LL yaks, but significantly decreased for Firmicutes. Relative abundances of the Succiniclasticum, Butyrivibrio 2, Prevotella 1, and Prevotellaceae UCG-001 genera in the rumen fluid of HH yaks was significantly increased, but significantly decreased for Christensenellaceae R-7 group and Coprococcus 1. Principal coordinates analysis on unweighted UniFrac distances revealed that the bacterial community structure of rumen differed between yaks with high and low milk protein yields. Furthermore, rumen microbiota were functionally enriched in relation to transporters, ABC transporters, ribosome, and urine metabolism, and also significantly altered in HH and LL yaks. Conclusion: We observed significant differences in the composition, diversity, fermentation product concentrations, and function of ruminal microorganisms between yaks with high and low milk protein yields, suggesting the potential influence of rumen microbiota on milk protein yield in yaks. A deeper understanding of this process may allow future modulation of the rumen microbiome for improved agricultural yield through bacterial community design.

An alternative method for estimation of annual extreme wind speeds

Yi Hui,Qingshan Yang,Zhengnong Li 한국풍공학회 2014 Wind and Structures, An International Journal (WAS Vol.19 No.2

This paper presents a method of estimation of extreme wind. Assuming the extreme wind follows the Gumbel distribution, it is modeled through fitting an exponential function to the numbers of storms over different thresholds. The comparison between the estimated results with the Improved Method of Independent Storms (IMIS) shows that the proposed method gives reliable estimation of extreme wind. The proposed method also shows its advantage on the insensitiveness of estimated results to the precision of the data. The volume of extreme storms used in the estimation leads to more than 5% differences in the estimated wind speed with 50-year return period. The annual rate of independent storms is not a significant factor to the estimation.

Decision-making Study on Mechanism and Priority of Functional Objective of the Manufacturing System

Wei Xu,Qingshan Zhang,Yue Cao,Haijun Wang 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.8

The aim of this paper established priority level determines method of manufacturing system functional objective based QFD theory, priority sequence presented and the functional objective priority weights, advised manufacturing system functional objective decisions, provides technology support and application reference for system functional objective decisions.