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>

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.

Analysis on Lane Detection and Departure under IPM

Peng Li-xia,Tao Yong-qin 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.9

A method of structure lane detection and departure based on inverse perspective mapping (IPM) and effective gradient points is proposed. Firstly, road image is transformed into plan view using inverse perspective transform to eliminate perspective effect. Secondly, “Sobel” operator and morphological image processing are used to detect edge and eliminate noise. According to the actual lane width, effective gradient points are extracted. Finally, lane is fitted using the least square method. Experimental results show that the method can detect both sides lane and analyze departure and lane detection rate is 97.5%. The method can provide reference for lane departure warning system.

Mitochondrial DNA Levels in Blood and Tissue Samples from Breast Cancer Patients of Different Stages

Xia, Peng,Wang, Hui-Juan,Geng, Ting-Ting,Xun, Xiao-Jie,Zhou, Wen-Jing,Jin, Tian-Bo,Chen, Chao Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Aims: Alterations in mitochondrial DNA (mtDNA) have been implicated in carcinogenesis and tumor progression. We here evaluated the diagnostic and prognostic potential of mtDNA as a biomarker for breast cancer. Methods: Using multiplex real-time polymerase chain reaction, nuclear DNA (nDNA) and mtDNA levels in serum, buffy coat, tumor, and tumor-adjacent tissue samples from 50 breast cancer patients were determined and assessed for associations with clinicopathological features. To evaluate mtDNA as a biomarker for distinguishing between the four sample types, we created receiver operating characteristic (ROC) curves. Results: The mtDNA levels in buffy coat were significantly lower than in other sample types. Relative to tumor-adjacent tissue, reduced levels of mtDNA were identified in buffy coat and tumor tissue but not in serum. According to ROC curve analysis, mtDNA levels could be used to distinguish between buffy coat and tumor-adjacent tissue samples with good sensitivity (77%) and specificity (83%). Moreover, mtDNA levels in serum and tumor tissue were positively associated with cancer TMN stage. Conclusions: The mtDNA levels in blood samples may represent a promising, non-invasive biomarker in breast cancer patients. Additional, large-scale validation studies are required to establish the potential use of mtDNA levels in the early diagnosis and monitoring of breast cancer.

The impacts of Harmonia axyridis cues on foraging behavior of Aphidius gifuensis to Myzus persicae

Xia Peng-Liang,Yu Xing-Lin,Li Ze-Tao,Feng Yi 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

This study investigated the effect of adult associated cues of the multicolored Asian ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the foraging behavior of the aphid parasitoid, Aphidius gifuensis Ashmead (Hymenoptera: Aphididae) with three assays: 1) whole aphid leaf-disc with H. axyridis tracks; 2) aphid leaf-disc with only half contaminated with H. axyridis tracks; 3) aphid leaf-discs without H. axyridis tracks. Foraging behavior of A. gifuensis was recorded using the Observer® XT 11 and EthoVsion® XT 12. In addition, functional responses of A. gifuensis in patches with or without H. axyridis cues were also tested. Aphidius gifuensis females preferred oviposition in arenas where no adult tracks of H. axyridis were present. However, no significant dif ference between functional responses of A. gifuensis foraging in plants with and without H. axyridis cues was detected. Our study suggests that H. axyridis associated cues could influence the foraging behavior and activity of A. gifuensis under laboratory conditions. On the other hand, the foraging efficiency of A. gifuensis was not significantly affected by H. axyridis walking tracks in a single plant system. Aphidius gifuensis might exhibit flexible behavioral responses to predator associated cues. The risk of intraguild interactions and the possibility of mitigating such risks for parasitoids are important components for ultimately determining the compatibility of biological control agents.

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.2

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.

从动态语义格的角度看“去+VP”和“VP+去”

팽조하 ( Peng Zhao Xia ) 한국외국어대학교 중국연구소 2021 中國硏究 Vol.89 No.-

The two sentence patterns "Qu(去)+VP" and "VP+Qu(去)" are very similar, but the meanings expressed by the two are different. This article intends to analyze the meaning of these two sentence patterns from the semantic relation structure of "qu" and "VP", and strive to make a reasonable explanation for their pragmatic differences. At the same time, with the help of case grammar theory, the dynamic semantic case relationship structure is constructed, and the semantic case entering the expression level is screened through perspective, thereby revealing the cognitive internal causes of the formation of the two structures.

Fault Diagnosis of Wind Power Converters Based on Compressed Sensing Theory and Weight Constrained AdaBoost-SVM

Xiao-Xia Zheng,Peng Peng 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.2

As the core component of transmission systems, converters are very prone to failure. To improve the accuracy of fault diagnosis for wind power converters, a fault feature extraction method combined with a wavelet transform and compressed sensing theory is proposed. In addition, an improved AdaBoost-SVM is used to diagnose wind power converters. The three-phase output current signal is selected as the research object and is processed by the wavelet transform to reduce the signal noise. The wavelet approximation coefficients are dimensionality reduced to obtain measurement signals based on the theory of compressive sensing. A sparse vector is obtained by the orthogonal matching pursuit algorithm, and then the fault feature vector is extracted. The fault feature vectors are input to the improved AdaBoost-SVM classifier to realize fault diagnosis. Simulation results show that this method can effectively realize the fault diagnosis of the power transistors in converters and improve the precision of fault diagnosis.

A Weibo Topic Tracking System based on K-means

Yun Liu,Kun-Peng Xia,Jian-Xun Zhao 보안공학연구지원센터 2014 International Journal of Database Theory and Appli Vol.7 No.6

This article studied weibo text representation. For the weibo features such as short, real-time, colloquialism and originality, in the original vector space model, we propose a suitable method for weibo text representation. Make all the content words as feature words after participation. And we proposed T-TFIDF weight calculation method according to the features of weibo. According to the vector space model, we proposed a weibo adaptive topic tracking methods based on K-means clustering. Simulation analysis shows that, the method can by comparing the similarity micro-blog and sub topic vector set, determine whether weibo belonging to the topic.

Synthesis of Tailed Metalloporphyrins Modified with 2-Chloronicotinic Acid and Interactions with Human Serum Albumin

Shu-Jun Wang,Yu-Ling Peng,Cheng-Gen Zhang,Qi Peng Ma,Xiao Xia Peng,Li Lei Ren 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.7

Two kinds of free-base tailed porphyrins modified with 2-chloronicotinic acid and the corresponding Zn porphyrins have been synthesized. They have been characterized by elemental analysis and NMR, UV/Vis, fluorescence spectra, and infrared spectroscopies. Their configurations have been optimized through theoretical calculations. The fluorescence quantum yields were determined by a comparative method. The interactions between the Zn porphyrins and human serum albumin have been studied by means of fluorescence spectra. The experimental results showed that the interaction mechanism involved a combined fluorescence quenching process (static and dynamic quenching) and that the main driving force was hydrophobic in nature. Quenching constants, binding constants, thermodynamic parameters, and binding distances have been determined.