Pyrene-based bisboronic sensors for multichannel enantioselective recognition of tartaric acid

Xiao, Ting,Wang, Fang,Chen, Yahui,Yang, Xiao,Wei, Tingwen,Liu, Chuantao,Chen, Shuangjun,Xu, Zhijun,Yoon, Juyoung,Chen, Xiaoqiang Elsevier 2019 Dyes and pigments Vol.163 No.-

<P><B>Abstract</B></P> <P>New chiral bisboronic receptors based on pyrene-excimer were synthesized and applied for the determination of absolute configuration and enantiomeric composition of tartaric acid. The distinction was visualized by portable UV lamp in certain concentration range. There were three ways for the sensors to enantioselectively recognize tartaric acid, including the fluorescence spectrum, UV–vis spectrum, and CD spectrum. The enantiomeric excess of tartaric acid was measured quantitatively by using fluorescence analytical technique. Compared with the previous chiral boronic acid sensors, sensor <B>1</B> showed weaker background fluorescence and excellent chiral recognition ability of D/<SMALL>L</SMALL>-tartaric acid throughout the whole pH range.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Two pyrene-based sensors for enantioselective recognition of tartaric acid were synthesized. </LI> <LI> Three ways to recognize tartaric acid, including the fluorescence spectrum, UV–vis spectrum, and CD spectrum. </LI> <LI> Sensor <B>1</B> showed weaker background fluorescence and recognized tartaric acid throughout wider pH range. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Pyrene-based chiral discrimination of tartaric acid including the fluorescence spectrum and CD spectrum.</P> <P>[DISPLAY OMISSION]</P>

Study of the sympathetic detonation reaction behavior of a fuze explosive train under the impact of blast fragments

Youcai Xiao,Xiangdong Xiao,Chenyang Fan,Yanyi Xiong,Zhijun Wang,Yi Sun 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.6

Insensitive munitions (IM) assessments are required to carry out the sympathetic detonation (SD) experiments. The impact of blast fragments or strong shock waves is the cause of sympathetic detonation. In this paper, a numerical simulation method is developed to predict the sympathetic detonation behavior of fuze explosive trains under the impact of blast fragments, which includes the ignition and growth (I&G) model, the JonesWilkins-Lee (JWL) equations of state, and a constitutive relationship. The experimental and numerical results were compared and analyzed, and the validity of the numerical simulation method was proven. The sympathetic detonation behavior of a fuze was studied for a single donor and multiple acceptors. The critical distance was obtained with the presence of fragments using numerical simulation. A critical distance model was developed, which provides a theoretical model for relating the detonation sequence and the placement distance of the fuze explosive train. The simulated results agreed with the theoretical calculations, and thus the model can provide the support for sympathetic detonation experiments.

Quantitative trait locus mapping and genomic selection of tobacco (Nicotiana tabacum L.) based on high-density genetic map

Tong Zhijun,Xiu Zhihui,Ming Yao,Fang Dunhuang,Chen Xuejun,Hu Yafei,Zhou Juhong,He Weiming,Jiao Fangchan,Zhang Chi,Zhao Shancen,Jin Han,Jian Jianbo,Xiao Bingguang 한국식물생명공학회 2021 Plant biotechnology reports Vol.15 No.6

Tobacco ( Nicotiana tabacum L.) is an economic crop and a model organism for studies of plant biology and genetics. As an allotetraploid plant generated from interspecific hybridization, tobacco has a massive genome (4.5 Gb). Recently, a genetic map with 45,081 single nucleotide polymorphism (SNP) markers was constructed using whole-genome sequencing data for a tobacco population including 274 individuals. This provides a basis for quantitative trait locus (QTL) mapping and genomic selection, which have been widely applied to other crops but have not been feasible in tobacco. Based on this high-density genetic map, we identified QTLs associated with important agronomic traits, chemical compounds in dry leaves, and hazardous substances in processed cigarettes. The LOD values for major QTLs were highest for agronomic traits, followed by chemical compounds and hazardous substances. In addition to the identification of molecular markers, we evaluated genomic selection models and found that BayesB had the highest prediction accuracy for the recombinant inbred line population. Our results offer new insights into the genetic mechanism underlying important traits, such as agronomic traits and quality-related chemical compounds in tobacco, and will be able to support the application of molecular breeding to tobacco.

RGB-D Sensor-based Visual Target Detection and Tracking for an Intelligent Wheelchair Robot in Indoors Environments

Hanzhen Xiao,Zhijun Li,Chenguang Yang,Wang Yuan,Liyang Wang 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.3

The ability to follow or move alongside a person is a necessary skill for an autonomous mobile agent that works with human users. To accomplish such tasks, we develop a new scheme of visual-target de-tection and tracking for a wheelchair robot equipped with Microsoft Kinect that captures RGB images along with per-pixel depth information (RGB-D camera). The speeded-up semi-supervised on-line boosting algorithm is employed to provide the robust description of feature for environments and the target person from RGB images. Based on the environmental Haar-like features, we utilize an ex-tended Kalman filter (EKF) based localization to estimate robot pose. Then obstacle avoidance navigation approach based on η3 spline trajectory planning and optimization are proposed for the wheelchair robot. Finally, the experimental results are provided to demonstrate the effectiveness and feasibility in real world environments.

Periparturient stocking density affects lying and ruminating behavior and one-week-calf performance of Holstein cows

Jiang Mingming,Alugongo Gibson Maswayi,Xiao Jianxin,Li Congcong,Ma Yulin,Li Tingting,Cao Zhijun,Liu Dasen 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.4

Objective: This study aimed to investigate the effect of stocking density on the behavior, productivity, and metabolism of periparturient Holstein cows as well as calf performance. Methods: A total of 48 periparturient cows were randomly assigned into three groups at 28 days (±3 days) before their expected calving date. The stocking densities of the groups, relative to the standard cubicle and feed bunk number, were i) 80% (13 cows), ii) 100% (16 cows), and iii) 120% (19 cows). Lying and rumination behavior was recorded using electronic data loggers and HR-Tags from d -21 (“d-” means days before calving) until the calving date, d 0. Lying time was assessed to determine the diurnal total hours spent lying per day. Rumination time was averaged in 2 hours interval periods over 24 hours during the experimental period. Results: Cows in the 80% group spent more time lying and ruminating between d -21 and d -7 and tended to ruminate more between d -14 and d 0. Calcium levels tended to be higher for cows in the 80% group, no other observable differences were found in monitored blood parameters. Moreover, 3.5% fat corrected milk and energy corrected milk yields were higher in 80% group in the first month of lactation. No other observable differences were found in the yield and composition of colostrum and milk in the first 10 months of lactation. The growth and performance of calves in the first week of life was not affected by stocking density of the dams. Conclusion: We concluded that lower stocking density may increase lying and ruminating behavior of prepartum Holstein cows. However, this did not translate into improved productivity and metabolism. Objective: This study aimed to investigate the effect of stocking density on the behavior, productivity, and metabolism of periparturient Holstein cows as well as calf performance.Methods: A total of 48 periparturient cows were randomly assigned into three groups at 28 days (±3 days) before their expected calving date. The stocking densities of the groups, relative to the standard cubicle and feed bunk number, were i) 80% (13 cows), ii) 100% (16 cows), and iii) 120% (19 cows). Lying and rumination behavior was recorded using electronic data loggers and HR-Tags from d -21 (“d-” means days before calving) until the calving date, d 0. Lying time was assessed to determine the diurnal total hours spent lying per day. Rumination time was averaged in 2 hours interval periods over 24 hours during the experimental period.Results: Cows in the 80% group spent more time lying and ruminating between d -21 and d -7 and tended to ruminate more between d -14 and d 0. Calcium levels tended to be higher for cows in the 80% group, no other observable differences were found in monitored blood parameters. Moreover, 3.5% fat corrected milk and energy corrected milk yields were higher in 80% group in the first month of lactation. No other observable differences were found in the yield and composition of colostrum and milk in the first 10 months of lactation. The growth and performance of calves in the first week of life was not affected by stocking density of the dams.Conclusion: We concluded that lower stocking density may increase lying and ruminating behavior of prepartum Holstein cows. However, this did not translate into improved productivity and metabolism.

Memory characteristics and tunneling mechanism of Pt nano-crystals embedded in HfAlOx films for nonvolatile flash memory devices

Guangdong Zhou,BoWu,Zhiling Li,Zhijun Xiao,Shuhui Li,Ping Li 한국물리학회 2015 Current Applied Physics Vol.15 No.3

A non-volatile flash memory device based on metal oxide semiconductor (MOS) capacitor structure hasbeen fabricated using platinum nano-crystals(PteNCs) as storage units embedded in HfAlOx high-ktunneling layers. Its memory characteristics and tunneling mechanism are characterized by capacitanceevoltage(CeV) and flat-band voltage-time(ΔVFB-T) measurements. A 6.5 V flat-band voltage(memory window) corresponding to the stored charge density of 2.29 × 1013 cm-2 and about 88% storedelectron reserved after apply ±8 V program or erase voltage for 105 s at high frequency of 1 MHz wasdemonstrated. Investigation of leakage currentevoltage(JeV) indicated that defects-enhanced Pool-Frenkel tunneling plays an important role in the tunneling mechanism for the storage charges. Hence,the PteNCs and HfAlOx based MOS structure has a promising application in non-volatile flash memorydevices.