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1

Impact of the evolution of Plateau Lake landscape pattern on ecosystem service value in the Pearl River basin: a case study of Yilong Lake Basin in Yunnan Province, China

Ma Guoqiang, Xiao Jianping, Li Qiujie, Zhang Lixun, An Bei, Sun Guojun, Cheng Hua, Tang Jiaqi, Li Hong

Acta Geophysica

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2023

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Vol. 71, no. 3

1391--1407

EN

Yilong Lake is the southernmost plateau freshwater lake in China. The health of its watershed ecosystem is of special strategic significance to maintain the ecological security and ensure the sustainable development of regional economy and society. This paper analyzed the characteristics of landscape type in Yilong Lake Basin of 1990, 1995, 2000, 2005, 2010, 2015 and 2018 and discussed the impact of landscape pattern type changes and its effect on ecosystem services values (ESV). The results showed that: (1) The landscape types of Yilong Lake are mainly forest land and the largest dynamic degree of comprehensive 1andscape type in the six stages is 2010–2015 and the smallest is 2015–2018. (2) Spatially, the most frequent conversion was arbor forest land, which turned to shrub forest land and garden land. The rapid expansion of construction land and transportation land were turned by cultivated land area. (3) Temporally, from 1990 to 2018, the total ESV also increases year by year, and the regional distribution of high ESV is consistent with the distribution of water areas and gardens. The comprehensive analysis shows that the implementation of governance projects such as ecological protection and governance of Yilong Lake surface mountain are conducive to increase the landscape types and the total ESV.

2

Entire and meromorphic solutions for systems of the differential difference equations

Xu Hong Yan, Li Hong, Ding Xin

Demonstratio Mathematica

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2022

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Vol. 55, nr 1

676--694

EN

With the help of the Nevanlinna theory of meromorphic functions, the purpose of this article is to describe the existence and the forms of transcendental entire and meromorphic solutions for several systems of the quadratic trinomial functional equations: {f(z)2+2αf(z)g(z+c)+g(z+c)2=1,g(z)2+2αg(z)f(z+c)+f(z+c)2=1, {f(z+c)2+2αf(z+c)g'(z)+g'(z)2=1,g(z+c)2+2αg(z+c)f'(z)+f'(z)2=1, and {f(z+c)2+2αf(z+c)g′′(z)+g′′(z)2=1,g(z+c)2+2αg(z+c)f′′(z)+f′′(z)2=1. We obtain a series of results on the forms of the entire solutions with finite order for such systems, which are some improvements and generalizations of the previous theorems given by Gao et al. Moreover, we provide some examples to explain the existence and forms of solutions for such systems in each case.

3

Dual-parameter sensing characteristics of a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing

Li Hong, Zhang Haoyue, Song Yanming, Meng Fanyong, Zhu Lianqing

Optica Applicata

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2021

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Vol. 51, nr 3

391--406

EN

A novel technology for the simultaneous and independent measurement of dual parameters is proposed and experimented. By using a single fiber Bragg grating half-pasted by 1C-LV epoxy under different curing conditions, the sensor structure is designed such that the reflective single-peak spectrum splits into a twin-peak spectrum, which makes the FBG spectrum form a natural spectral peak splitting bias. A measurement limitation exists in the FBG sensor packaging at room temperature, which can be solved by the high-temperature cured packaging method. To verify the validity of the theory and methodology, the experimental system is used. In the range from –1000 to +1000 με and from 35 to 75°C, the Bragg wavelength change is relative linear to the strain and temperature. The temperature and strain variations can be independently and simultaneously measured using the split peak, and the deviations of the FBG sensor are ±1°C and ±5 με, respectively. This single FBG sensor can realize dual-parameter measurement, which is valuable for narrow-space health monitoring.

4

Microstructure and properties of ZrO2 ceramic and Ti-6A-4V alloy vacuum brazed by Ti-28Ni filler metal

Li Hong, Liu Xuan, Huang Haixin

Welding Technology Review

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2019

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R. 91, nr 10

35--41

EN

Reliable ceramics/metal joints have an extensive application in the aerospace and biomedical area. However, ZrO2 ceramic has not been investigated systematically compared to the Si3N4 and Al2O3 ceramic. Therefore, successful brazing of ZrO2 ceramic and Ti-6A-4V alloy was achieved by using a binary active Ti-28Ni filler metal in this paper. The effect of holding time on the microstructure of ZrO2 ceramic/filler metal interface and mechanical properties of brazed joints was investigated. The results indicated that the representative interfacial microstructure was ZrO2 ceramic/Ti2O/Ni2Ti4O/Ti-rich phase/ Ti2Ni+α-Ti. With the increase of holding time, the thickness of Ti-rich layer in the interface of ZrO2/Ti-6Al-4V joint decreased obviously due to the diffusion of Ti atoms. Substantial brittle intermetallic compounds Ti2Ni and Ni2Ti4O were formed in the joint, which were detrimental to the mechanical properties of the brazed joints. The maximum shear strength of joint was 112.7 MPa when brazed at 1060 °C for 10 min.

PL

Niezawodne połączenia ceramiki/metalu mają szerokie zastosowanie w przemyśle lotniczym i biomedycznym. Jednak ceramika Zr02 nie była badana systematycznie w porównaniu z ceramiką Si3N4 i Al2O3. W niniejszym artykule przeprowadzono udany proces lutowania ceramiki Zr02 i stopu Ti-6A-4V, który został osiągnięty dzięki zastosowaniu binarnie aktywnego metalu wypełniającego Ti-28Ni. Zbadano wpływ czasu trwania połączenia na mikrostrukturę powierzchni ceramicznej/metalu wypełniającego ZrO2 oraz właściwości mechaniczne lutowanych połączeń. Wyniki wskazują, że reprezentatywną mikrostrukturą międzyfazową była ceramika ZrO2/Ti2O/Ni2Ti4O/faza bogata w Ti/Ti2Ni+α-Ti. Wraz ze wzrostem czasu trwania połączenia, grubość warstwy bogatej w Ti w interfejsie złącza ZrO2/Ti-6AI-4V zmniejszyła się z powodu dyfuzji atomów Ti. W spoinie powstały znaczne kruche związki międzymetaliczne Ti2Ni i Ni2Ti4O, które były szkodliwe dla właściwości mechanicznych lutowanych połączeń. Maksymalna wytrzymałość złącza na ścinanie wynosiła 112,7 MPa po lutowaniu w 1060 °C przez 10 min.

5

Impact of particle density on the classification efficiency of the static air classifier in Vertical Spindle Mill

Li Hong, He Yaqun, Yang Jinshan, Zhu Xiangnan, Peng Zhen, Xie Weining

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 2

494--503

EN

In order to investigate the impact of density on the classification behavior of particles in the static classifier of Vertical Spindle Mill, the sensitivity of overflow yield to the increase of air amount for narrowly sized pyrite, carborundum, quartz and coal samples were compared in a lab-scale classifier, respectively. Response surface methodology is used to analyze the combined effect of size and density on the classification. Wide size classification was also conducted and results show that both the yield and R90 of overflow increase with the decreasing of density, and the growth of air amount would also lead them to rise. The Whiten’s model was applied to illustrate the influence of density on the sharpness of classification, corrected cut size and fishhook effect. Results show that material with a lower density would have a higher fishhook effect parameter, classification sharpness and corrected cut size. The increase of air amount would result in a more evident fishhook effect for the high density material. Based on the Whiten’s model, a new classification efficiency model with the addition of particle density in various forms was established. This new model could describe the classification efficiency of materials with different density in the identical experiment conditions.