Microstructure Evolution and Mechanical Properties of AA2099 Al–Li Alloy with Tailored Li‐Containing Precipitates in Uniaxial Compression at Medium Temperature

Li Hu,Mengdi Li,Weijiu Huang,Xusheng Yang,Fei Guo,Haipeng Dong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.5

Microstructure characteristics and mechanical behavior of AA2099 Al–Li alloy with no pre-existing Li-containing precipitates(AA2099-1 sample), pre-existing δ′ precipitates (AA2099-2 sample), pre-existing T1phase (AA2099-3 sample) andpre-existing T2phase (AA2099-4 sample) are systematically investigated via isothermal uniaxial compression at 250 °C inthe present study. Experimental results demonstrate that at the onset of plastic deformation, dynamic precipitation of smallsizedT1phase occurs rapidly within AA2099-1 sample, while it will be hindered within AA2099-2 sample. The increasingplastic strain benefits to dynamic precipitation of small-sized T1phase in AA2099-2 sample. Consequently, AA2099-1 andAA2099-2 samples possess similar and intermediate mechanical behaviors. In terms of AA2099-3 sample, the existence oflarge-sized T1phase results in the maximum yielding stress. However, some regions within these large-sized T1precipitatesare suspected to be sheared by cross-slip, leading to the destruction of crystallographic structure and the formation of Almatrix intervals. This aspect is responsible for the gradual degradation in true stress-strain curve after peak stress. As forAA2099-4 sample, dynamic precipitation rarely happens during plastic deformation and the interaction between dislocationand the pre-existing T2phase belongs to Orowan looping, resulting in the minimal mechanical response. Besides,AA2099-1 sample possesses the average minimum deviation angle (MDA) of ~ 16.5° between the loading direction and the<110> crystal direction, whereas AA2099-4 sample owns the average MDA of ~ 7.5°. The difference in MDA is mainlyattributed to δ′ phase and T1phase, which will separately accelerate and postpone the rotation of orientation towards the<110> crystal direction.

The Breed and Sex Effect on the Carcass Size Performance and Meat Quality of Yak in Different Muscles

Li Zhang,Baozhong Sun,Qun-li Yu,Qiumei Ji,Peng Xie,Haipeng Li,Li Wang,Yuchun Zhou,Yongpeng Li,Caixia Huang,Xuan Liu 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.2

The carcass size performances and the meat quality of Gannan and Sibu yak were determined using M. supraspinatus (SU), M. longissimus thoracis (LT) and M.quadriceps femoris (QF). It is found that Sibu yak had significantly higher carcass weight (CW) than Gannan yak with difference of nearly 40 kg, as well as significantly higher eye muscle area (EMA), carcass thorax depth (CTD), round perimeter (RP), etc. The carcass performances of steer yak were significantly higher than heifer yak except meat thickness at round (MTR) (p<0.05). The results show that both yak breed and gender had significant effects on carcass performances. It could be seen that the variation of carcass size performances from breeds is as large as from gender (50.22% and 46.25% of total variation, respectively) through principal component analysis (PCA). Sibu yak had significantly higher L*, b*, WBSF, cooking loss and Fat content, while Gannan yak had significantly higher a*, press loss, protein content and moisture (p<0.05). Yak gender and muscle had insignificant effects on meat colour and water holding capacity (p>0.05). The variation of meat quality of yak from breed is up to 59.46% of total variation according to PCA. It is shown that the difference between breeds, for Gannan yak and Sibu yak, plays an important role in carcass size performance and meat quality.

The Breed and Sex Effect on the Carcass Size Performance and Meat Quality of Yak in Different Muscles

Zhang, Li,Sun, Baozhong,Yu, Qunli,Ji, Qiumei,Xie, Peng,Li, Haipeng,Wang, Li,Zhou, Yuchun,Li, Yongpeng,Huang, Caixia,Liu, Xuan Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.2

The carcass size performances and the meat quality of Gannan and Sibu yak were determined using M. supraspinatus (SU), M. longissimus thoracis (LT) and M.quadriceps femoris (QF). It is found that Sibu yak had significantly higher carcass weight (CW) than Gannan yak with difference of nearly 40 kg, as well as significantly higher eye muscle area (EMA), carcass thorax depth (CTD), round perimeter (RP), etc. The carcass performances of steer yak were significantly higher than heifer yak except meat thickness at round (MTR) (p<0.05). The results show that both yak breed and gender had significant effects on carcass performances. It could be seen that the variation of carcass size performances from breeds is as large as from gender (50.22% and 46.25% of total variation, respectively) through principal component analysis (PCA). Sibu yak had significantly higher L*, b*, WBSF, cooking loss and Fat content, while Gannan yak had significantly higher a*, press loss, protein content and moisture (p<0.05). Yak gender and muscle had insignificant effects on meat colour and water holding capacity (p>0.05). The variation of meat quality of yak from breed is up to 59.46% of total variation according to PCA. It is shown that the difference between breeds, for Gannan yak and Sibu yak, plays an important role in carcass size performance and meat quality.

Few-Layered MoS2 Nanostructures for Highly Efficient Visible Light Photocatalysis

Dan Li,Jianwei Li,Caiqin Han,Xinsheng Zhao,Haipeng Chu,Wenyan Lei,Xinjuan Liu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.10

Few-layered MoS2 nanostructures were successfully synthesized by a simple hydrothermal method without the addition of any catalysts or surfactants. Their morphology, structure and photocatalytic activity were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, transmission electron microscopy, electrochemical impedance spectra and UV-Vis absorption spectroscopy, respectively. These results show that the MoS2 nanostructures synthesized at 180℃ exhibit an optimal visible light photocatalytic activity (99%) in the degradation of Rhodamine B owing to the relatively easier adsorption of pollutants, higher visible light absorption and lower electron–hole pair recombination.

In situ IR studies on the mechanism of methanol synthesis from CO/H2 and CO2/H2 over Cu-ZnO-Al2O3 catalyst

Wei Li,Xiaojuan Wang,Haipeng Zhang 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.4

Methanol synthesis from CO/H2 and CO2/H2 was carried out at atmospheric pressure over Cu/ZnO/Al2O3catalyst. The formation and variation of surface species were recorded by in situ FT-IR spectroscopy. The result revealed that both CO and CO2 can serve as the primary carbon source for methanol synthesis. For CO/H2 feed gas, only HCOOZn was detected; however, for CO2/H2, both HCOO-Zn and HCOO-Cu were observed, and without CH3O-Cu. HCOOZn was the key intermediate. A scheme of methanol synthesis and reverse water-gas shift (RGWS) reaction was proposed.

Optimal Energy Management Strategy for an Islanded Microgrid with Hybrid Energy Storage

Chen Haipeng,Gao Lin,Zhang Zhong,Li He 대한전기학회 2021 Journal of Electrical Engineering & Technology Vol.16 No.3

Due to the randomness and volatility of light intensity and wind speed, renewable generation and load management are facing new challenges. This paper proposes a novel energy management strategy to extend the life cycle of the hybrid energy storage system (HESS) based on the state of charge (SOC) and reduce the total operating cost of the islanded microgrid (MG). In this paper, a demand response (DR) optimization model of independent MG is introduced considering the total cost of MG operation, carbon emission and new energy consumption penalty. Meanwhile, by analyzing the SOC of the HESS, starting and stopping criteria (SSC) of diesel generator (DG), residential load classifi cation, an optimal energy management strategy for island grid operation of HESS based on DR is proposed. Then, the particle swarm optimization (PSO) algorithm with improved acceleration factor is applied to solve the optimization scheme. The simulation results show that a novel energy management strategy has improved the economical and reliable performance of the independent MG via setting the charging and discharging criteria of HESS and SSC of DG. Moreover, fl exible scheduling of part controllable loads can be used to improve the renewable energy consumption rate and reduce the loss of load rate.

Assessment of supervision monitoring for radiation environment around the typical research reactors in China

Sa Li,Haipeng Wang,Yanxia Zhang 한국원자력학회 2021 Nuclear Engineering and Technology Vol.53 No.12

The supervision mode, monitoring basis and monitoring scheme of radiation environment monitoringconcerning typical research reactors in China were investigated in this study. Summary and analysis wereconcluded of the present situation of supervised monitoring of radiation environment, such as monitoring objects, points, frequency and so on, based on the relevant data of monitoring points of fourtypical research reactors in China. Some experiences and existing problems were analyzed concerningthe supervised monitoring of China's research reactors. Tips on topics related to strengthen the monitoring of radiation environment around the research reactors has noted.

Abscisic acid synthesis and root water uptake contribute to exogenous methyl jasmonate-induced improved tomato drought resistance

Yan Jiakun,Li Haipeng,Li Yu,Zhang Nan,Zhang Suiqi 한국식물생명공학회 2022 Plant biotechnology reports Vol.16 No.2

In rain-fed semi-arid agricultural areas, unevenly distributed seasonal rainfall influences tomato production. Meanwhile, jasmonic acid, an essential plant hormone, enhances plant resistance to biotic and abiotic stresses; however, its effect on tomato drought resistance remains unclear. In this study, a series of pot experiments were conducted to investigate the effects elicited via addition of exogenous methyl jasmonate (MeJA), an active ingredient of jasmonic acid, on tomato physiology, biochemistry, and transcription under two water conditions. The results indicate that 100 μM MeJA application significantly improved drought resistance in tomato and increased the biomass. Moreover, water deficiency significantly decreased the tomato plant photosynthetic rate, stomatal conductance, and root exudation and increased the leaf abscisic acid (ABA) con- tent. Meanwhile, MeJA application increased root exudation and whole plant transpiration rate to maintain relatively high leaf water content. In leaves, specifically, MeJA increased the expression of carotenoid cleavage dioxygenases and reduced ABA content, which might contribute to the maintenance of a high stomatal conductance. In addition, many genes involved in photosynthetic carbon metabolism and sugar transport were upregulated by MeJA, resulting in a low soluble sugar-to- starch ratio, to maintain plant growth. Collectively, these findings indicate that exogenous MeJA decreases ABA content to maintain high stomatal conductance and enhance root water uptake capacity to maintain improved leaf relative water status, consequently improving tomato drought resistance.

Enhancement of CO2 desorption using ultrasound and vacuum in water scrubbing biogas upgrading system

Fuqiang Jin,Haipeng Xu,Dongliang Hua,Lei Chen,Yan Li,Yuxiao Zhao,Bin Zuo 한국화학공학회 2021 Korean Journal of Chemical Engineering Vol.38 No.1

Ultrasound and vacuum were respectively employed to enhance CO2 desorption in a water scrubbing biogas upgrading system. Results showed that incomplete CO2 desorption could cause a high CO2 content in the water and seriously affect the purity of the product gas. Vacuum had a strong enhancement effect on CO2 desorption. When a vacuum of 0.04MPa was used to enhance CO2 desorption, the amount of the stripping air could be reduced to 1/16- th of that without enhancement, indicating that vacuum could greatly enhance CO2 desorption and significantly decrease the amount of the stripping air, which was expected to reduce a large amount of energy consumption. In contrast, the enhancement effect of ultrasound was not so obvious for CO2 desorption in the desorption column with air stripping, since the solution could be well desorbed by gas stripping, though ultrasound could strongly affect the static CO2 desorption.

Efficient Post-Quantum Secure Network Coding Signatures in the Standard Model

( Dong Xie ),( Haipeng Peng ),( Lixiang Li ),( Yixian Yang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

In contrast to traditional “store-and-forward” routing mechanisms, network coding offers an elegant solution for achieving maximum network throughput. The core idea is that intermediate network nodes linearly combine received data packets so that the destination nodes can decode original files from some authenticated packets. Although network coding has many advantages, especially in wireless sensor network and peer-to-peer network, the encoding mechanism of intermediate nodes also results in some additional security issues. For a powerful adversary who can control arbitrary number of malicious network nodes and can eavesdrop on the entire network, cryptographic signature schemes provide undeniable authentication mechanisms for network nodes. However, with the development of quantum technologies, some existing network coding signature schemes based on some traditional number-theoretic primitives vulnerable to quantum cryptanalysis. In this paper we first present an efficient network coding signature scheme in the standard model using lattice theory, which can be viewed as the most promising tool for designing post-quantum cryptographic protocols. In the security proof, we propose a new method for generating a random lattice and the corresponding trapdoor, which may be used in other cryptographic protocols. Our scheme has many advantages, such as supporting multi-source networks, low computational complexity and low communication overhead.