On the Interannual Variations of the Summer Monsoon Onset Over the South China Sea

An Xie,Yong-Seung Chung,Xia Liu,Qian Ye 한국기상학회 1997 한국기상학회 학술대회 논문집 Vol.1997 No.-

Reinforcement Learning-Based Intelligent Decision-Making for Communication Parameters

Xia. Xie,Zheng Dou,Yabin Zhang 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.9

The core of cognitive radio is the problem concerning intelligent decision-making for communication parameters, the objective of which is to find the most appropriate parameter configuration to optimize transmission performance. The current algorithms have the disadvantages of high dependence on prior knowledge, large amount of calculation, and high complexity. We propose a new decision-making model by making full use of the interactivity of reinforcement learning (RL) and applying the Q-learning algorithm. By simplifying the decision-making process, we avoid large-scale RL, reduce complexity and improve timeliness. The proposed model is able to find the optimal waveform parameter configuration for the communication system in complex channels without prior knowledge. Moreover, this model is more flexible than previous decision-making models. The simulation results demonstrate the effectiveness of our model. The model not only exhibits better decision-making performance in the AWGN channels than the traditional method, but also make reasonable decisions in the fading channels.

On the role of surface diffusion in determining the shape or morphology of noble-metal nanocrystals

Xia, Xiaohu,Xie, Shuifen,Liu, Maochang,Peng, Hsin-Chieh,Lu, Ning,Wang, Jinguo,Kim, Moon J.,Xia, Younan National Academy of Sciences 2013 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.110 No.17

<P>Controlling the shape or morphology of metal nanocrystals is central to the realization of their many applications in catalysis, plasmonics, and electronics. In one of the approaches, the metal nanocrystals are grown from seeds of certain crystallinity through the addition of atomic species. In this case, manipulating the rates at which the atomic species are added onto different crystallographic planes of a seed has been actively explored to control the growth pattern of a seed and thereby the shape or morphology taken by the final product. Upon deposition, however, the adsorbed atoms (adatoms) may not stay at the same sites where the depositions occur. Instead, they can migrate to other sites on the seed owing to the involvement of surface diffusion, and this could lead to unexpected deviations from a desired growth pathway. Herein, we demonstrated that the growth pathway of a seed is indeed determined by the ratio between the rates for atom deposition and surface diffusion. Our result suggests that surface diffusion needs to be taken into account when controlling the shape or morphology of metal nanocrystals.</P>

Surface Modification of Poly(vinylidene fluoride) Ultrafiltration Membranes with Chitosan for Anti-Fouling and Antibacterial Performance

Weiwei Xia,Manman Xie,Xia Feng,Li Chen,Yiping Zhao 한국고분자학회 2018 Macromolecular Research Vol.26 No.13

A graft copolymer (PVDF-g-PAA) having poly(vinylidene fluoride) (PVDF) backbones and poly(acrylic acid) (PAA) side chains was synthesized using the radical polymerization method and the PVDF-g-PAA copolymer membrane was prepared via immersion phase inversion. Then the chitosan was immobilized on the surface of the copolymer membrane by covalent bond. The morphology, surface chemical structure and performance of the modified membranes were characterized by scanning electron microscopy, attenuated total reflection-Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, water contact angle, permeation measurement, antifouling and antibacterial tests. The results showed that the contact angle of the modified membrane decreased, and the water flux increased from 37.74Lm-2h-1 for pure PVDF membrane to 119.43 Lm-2h-1, which indicated that the modified membrane had higher hydrophilicity than unmodified membrane. The modified membrane has better antifouling properties than pure PVDF membrane due to the increase of surface hydrophilicity, and the highest water flux recovery ratio can achieve 93.2%. Furthermore, the modified membrane showed good antibacterial activity (E. coli), and the maximum antibacterial ratio of the modified membrane was 89.6%.

중국 진·한(秦·漢) 시대의 전통 와당 문양을 활용된 심벌 디자인에 관한 연구 -베이징 지역의 공공시설에 중심으로-

사무하 ( Xie Wu Xia ),박용진 ( Park Yong Jin ),김진성 ( Kim Jin Sung ) 한국기초조형학회 2017 기초조형학연구 Vol.18 No.4

중국 고대 문화에는 전통 문양이 다양하게 형성 되어 있으며 이것이 중국 민족의 역사와 사회의 발전을 대표하는 상징일 뿐만 아니라 국가적 문화자산이며 세계적으로도 문화 예술적 가치가 있다. 중국 진·한(秦·漢) 시대의 통치자가 6개국을 통일한 후에 대규모 토목 공사를 통해 와당(기와)을 대량 사용하여 와당 문양의 형태 및 주제를 다양하게 발전시켰다. 와당문양은 장수와 부귀 등 여러 가지 의미를 상징하기 때문에 예로부터 사람들의 사랑을 많이 받아오고 있다. 관련된 선행연구를 살펴보면, 와당의 역사적 발전이나 건축 소재로 장식에 대한 연구를 많이 하였다. 그러나 그 시대의 문화 배경에서 와당문양은 독특한 예술 품격을 형성하여, 차별성을 보여주고 있기 때문에 현대의 디자인에 적용할 수 있는 요소가 많다. 그래서 문양의 풍부한 디자인 요소가 현대디자인 분야에 어떻게 적용하게 되는지 많은 연구가 필요하다. 본 연구는 중국 진·한(秦·漢) 시대의 전통 와당 문화 요소의 현대적 적용을 중심으로 베이징 지역에 있는 의료, 교육문화에 관한 공공시설 심벌디자인에 적용된 사례를 분석하였다. 이론적 고찰을 통해 와당 문양의 기원 및 발전을 파악하고 종류나 특징과 같은 표현 형식을 분석하였다. 와당 문양 및 공공시설 심벌디자인의 관계를 검토하고 와당문양이 공공시설 심벌디자인에 적용된 현황 분석을 통해 공공시설의 심벌디자인에 적용된 와당문양이 어떠한 특성을 가지는지에 대해서 연계하여 해석하고자 한다. 분석된 연구 결과를 토대로 와당 문양을 공공시설 심벌디자인에 적용하는 방법을 찾으려 하였으며, 현대 디자인에 전통 와당 문양을 잘 적용할 수 있는 디자인 가이드라인을 구축하는 것을 목적을 두고 연구하였다. In Chinese traditional culture, the traditional pattern, with full of variety and brilliance, represents not only Chinese nation`s long history as well as social development, but also a great treasure to global art and culture. Eaves tile began to be put into use widely, because the whole nation went in for large-scale construction after it was united as one in Qin and Han dynasties. Therefore, more and more decorative patterns and themes were created, when eaves tiles reached their greatest prosperity in that period. Different patterns corresponded to different wishes, such as longevity, wealth and safety. As a result, eaves tiles were popular among people in all ages. Most academic researches have focused on the history of tiles and their usage as building materials. However, influenced by the history and culture, eaves tile pattern in Qin and Han Dynasties has formed its unique artistic style which can be applied in the modern design. Therefore, the better application and combination of traditional art and modern culture is a valuable research worth studying. In order to study the method of applying eaves tile patterns to the modern design, this paper will analyze cases about the usage of tile patterns in public sings(logo) of medical and educational facilities in Beijing. Firstly, the origin , development, types and characteristics of eaves tiles will be studied according to theoretical research. Then, this paper will analyze the relationship between tile pattern and public facilities logo design. Through the analysis of the existing cases, the techniques and methods of using tile patterns in the design of public facilities can be concluded. Meanwhile, guidelines about how to apply eaves tile pattern could be better put forward in the future.

Mechanism underlying 2n male and female gamete formation in lemon via cytological and molecular marker analysis

Kai‑Dong Xie,Qiang‑Ming Xia,Jun Peng,Xiao‑Meng Wu,Zong‑Zhou Xie,Chun‑Li Chen,Wen‑Wu Guo 한국식물생명공학회 2019 Plant biotechnology reports Vol.13 No.2

The unreduced (2n) gametes have long been used in triploid breeding of citrus. In lemon, the previously reported mechanisms for 2n megagametophyte formation were controversial, whereas that for 2n pollen production is still unknown. Herein, the frequency of and mechanism underlying 2n megagametophyte and 2n pollen formation in ‘Eureka’ lemon were investigated based on cytological observation and genotyping of the triploid hybrids between ‘Eureka’ lemon and ‘Early gold’ sweet orange. As a result, 4.79% of the viable pollens of ‘Eureka’ lemon were identified as the 2n pollen with a larger diameter (70.16 ± 3.92 μm). The 2n pollen might be resulted from the formation of parallel spindles at meiosis stage II. Among the 204 plantlets regenerated from embryo rescue following the sexual cross, 12 were triploids as identified by flow cytometry. According to the analysis of heterozygosity transmission using 13 pericentromeric single nucleotide polymorphism (SNP) markers and 20 randomly distributed simple sequence repeat (SSR) markers, 11 triploids were identified to be originated from the fertilization of 2n megagametophytes of ‘Eureka’ lemon, with a frequency of 5.39%. Among them, nine 2n megagametophytes were supposed to be arisen from the second division restitution (SDR), whereas the other two were from postmeiotic genome doubling (PMD). These results to understand the mechanism underlying 2n gamete formation in lemon are valuable for its efficient polyploid breeding.

The effect of lanthanum on the solidification curve and microstructure of Al-Mg alloy during eutectic solidification

Xie, Shikun,Yi, Rongxi,Guo, Xiuyan,Pan, Xiaoliang,Xia, Xiang Techno-Press 2015 Advances in materials research Vol.4 No.2

The influence of rare earth lanthanum (La) on solidification cooling range, microstructure of aluminum-magnesium (Al-Mg) alloy and mechanical properties were investigated. Five kinds of Al-Mg alloys with rare earth content of La (i.e., 0, 0.5, 1.0, 1.5 and 2.0 wt.%) were prepared. Samples were either slowly cooled in furnace or water cooled. Results indicate that the addition of the rare earth (RE) La can significantly influence the solidification range, the resultant microstructure, and tensile strength. RE La can extend the alloy solidification range, increase the solidification time, and also greatly improve the flow performance. The addition of La takes a metamorphism effect on Al-Mg alloy, resulting in that the finer the grain is obtained, the rounder the morphology becomes. RE La can significantly increase the mechanical properties for its metamorphism and reinforcement. When the La content is about 1.5 wt.%, the tensile strength of Al-Mg alloy reaches its maximum value of 314 MPa.

A New Pyrrolizidine Alkaloid from Senecio vulgaris

Xie, Wei-Dong,Li, Xia,Row, Kyung-Ho Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.9

Effect of temperature on survival and immature development of Arma chinensis

Xia Peng-Liang,Wang Bo,Xie Xiao-Fei,Feng Yi,Huang Yong 한국응용곤충학회 2022 Journal of Asia-Pacific Entomology Vol.25 No.3

Arma chinensis (Fallou) is a predaceous pentatomid with the potential to control a wide range of insect pests. In this study, the stage-specific temperature-dependent development and survival of A. chinensis was investigated under seven constant temperatures (range 18–35 ◦ C) when fed with yellow mealworm (Tenebrio molitor L.). Developmental times (in days) for the immature stage, entire nymphal stage, and egg-to-adult development were inversely proportional to temperatures between 18 and 33 ◦ C (30 ◦ C for eggs and 1st instar nymphs). The lowest survival rate of A. chinensis was observed at 18 ◦ C (6.7%), whereas it was the highest (80–93.3%) at temperatures ranging from 21 to 24 ◦ C. The low temperature thresholds for the egg, entire nymph stage, and egg-to-adult development were 14.3, 12.28, and 12.8 ◦ C, respectively, while the thermal constants for these stages were estimated to be 85.47, 334.9, and 423.8 ◦ days. Among the three non-linear models examined, the Taylor model showed the best fit for the egg data, the Briére1 model was the best fit for the 1st instar nymph stage, and the Lactin1 model was more approprate for all the other instar stages, the entire nymphal stage, and overall development. The upper temperature thresholds estimated using the Lactin1 model for eggs, overall nymphal stage, and egg-to-adult development were 38.57, 38.9, and 40.0 ◦ C. The optimal temperature for the overall eggto-adult period was estimated to be 33.5 ◦ C. The results of this study can be used for the mass rearing of this natural pest enemy and development of phenology models of its seasonal progress.

Bond Behavior of Basalt Fiber-Reinforced Polymer Bars Embedded in Concrete Under Mono-tensile and Cyclic Loads

Xia Liu,Xin Wang,Kangyu Xie,Zhishen Wu,Feng Li 한국콘크리트학회 2020 International Journal of Concrete Structures and M Vol.14 No.3

This study evaluates the static and fatigue bond behavior in basalt fiber-reinforced polymer (BFRP) bars embedded in concrete. For bond behavior under a mono-tensile load, BFRP bars with four types of surface patterns (round, rectangular, cross-winding, and spiral-winding) were adopted, and 20 groups of rib parameters were introduced for round-type BFRP bars. The bond-slip relationships and the influences of the above parameters on bond behavior were investigated. An analytical model for simulating the relationships of full bond slip was studied by data fitting. For bond behavior under cyclic loads, the relationship between stress levels and the number of cycles was investigated, and the slip of round-ribbed BFRP bars was studied with respect to the number of cycles. The results showed that the rectangular, cross-winding, and spiral-winding ribbed bars experienced serious wear, and that the average bond strength was approximately 80.6% of that of the round-ribbed bars. Thus, the bond behavior of the round rib is superior to those of the other surfaces. In addition, a bond–slip constitutive model for a BFRP bar is proposed, representing four main stages: a micro-slip stage, a slip stage, a descending stage, and a residual stage. Under cyclic loads, an equation was proposed for predicting fatigue life with a regression coefficient of 0.880, and a development law of slip was characterized as three stages: the linear increase stage, the steady increase stage, and the sharp increase stage, respectively.