EFFECT OF THE STRUCTURE OF ISOMERS OF MERCAPTOVALERIC ACID ON OPTICAL PROPERTIES OF CdTe QUANTUM DOTS

KAI-GUO MA,JIN-YI BAI,TAN FANG,Haiqing Guo 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.5

4-Mercaptovaleric acid (4MVA) and 3-mercaptovaleric acid (3MVA), two branched isomers of 5-mercaptovaleric acid (MVA), were designed and synthesized. They were used as capping agents in the aqueous synthesis of CdTe quantum dots (QDs) by a modified hydrothermal method with sodium tellurite as Te source. Compared with MVA-CdTe, either 4MVA-QDs or 3MVA-QDs exhibited higher fluorescent quantum yield (QY) and sharper absorption peak, which confirmed the superiority of using branched mercapto acids in the aqueous synthesis of QDs for improved optical properties. The fluorescence of QDs capped with 4MVA was higher than that of QDs capped with 4-mercaptobutyric acid (MBA) but lower than that of QDs capped with 3-mercaptobutyric acid (3MBA), which further confirmed the advantage of designing methyl side group rather than methylene group in the main chain for desired optical properties. However, the lower fluorescence, less sharp absorption peak and faster growth rate of 3MVA-QDs than that of 3MBA-QDs indicated adverse effect of side group on the aqueous synthesis of QDs if the size of side group is very bulky. Our results are helpful for selecting and designing appropriate capping agents for QDs with excellent properties.

Research on Tagging Recommendation Algorithm Based on Relevance and Diversity

Guo Zheng-Hong,Ma Xinhua,Zhao Kai 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.10

The traditional recommendation algorithms of image tagging ignore the diversity between the visual content information and the tags recommended, which causes the recommended results have the problem of tag ambiguity, tag redundancy and so on. Therefore, this paper proposes the recommendation algorithm of image tagging based on relevance and diversity. The algorithm defines the relevance and diversity of a label set, and selects a label set which can reasonably balance the relevance and diversity to recommend to the user. The experimental results show that this algorithm improves the relevance between the recommended results and the image, and makes the recommended results be able to reflect the image content thoroughly at the same time.

Dynamic Compliance and its Compensation Control of HIVC Force Control System

Kai-xian Ba,Bin Yu,Wen-feng Li,Dong-kun Wang,Ya-liang Liu,Guo-liang Ma,Xiang-dong Kong 대한전기학회 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, the dynamic compliance and its compensation control of the force control system on the highly integrated valve-controlled cylinder (HIVC), the joint driver of the hydraulic drive legged robot, is researched. During the robot motion process, the outer loop dynamic compliance control is applied on the base of hydraulic control inner loop and most inner loop control are the force or torque closed loop control. While the dynamic compliance control effectiveness of outer loop can be affected by the inner loop self-dynamic-compliance. Based on this problem, the dynamic compliance series composition theory of HIVC force control system as well as the analysis of its self-dynamiccompliance is proposed. And then the paper comes up with the compliance-enhanced control, which is a compound compensation control method of dynamic compliance with multiple series branches. Finally, the experiment results indicate that the control method mentioned above can enhance the dynamic compliance of HIVC force control system observably. This provides the compensation control method of inner loop dynamic compliance for the outer loop compliance control requiring the high accuracy and high robustness for the robot.

Power control of CiADS core with the intensity of the proton beam

Kai Yin,Wenjing Ma,Wenjuan Cui,Zhiyong He,Xinxin Li,Shiwu Dang,Feng Yang,Yuhui Guo,Limin Duan,Meng Li,Yikai Hou 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.4

This paper reports the control method for the core power of the China initiative Accelerator DrivenSystem (CiADS) facility. In the CiADS facility, an intense external neutron source provided by a protonaccelerator coupled to a spallation target is used to drive a sub-critical reactor. Without any control rodinside the sub-critical reactor, the core power is controlled by adjusting the proton beam intensity. Inorder to continuously change the beam intensity, an adjustable aperture is considered to be used at theLow Energy Beam Transport (LEBT) line of the accelerator. The aperture size is adjusted based on theProportional Integral Derivative (PID) controllers, by comparing either the setting beam intensity or thesetting core power with the measured value. To evaluate the proposed control method, a CiADS coremodel is built based on the point reactor kinetics model with six delayed neutron groups. The simulations based on the CiADS core model have indicated that the core power can be controlled stably byadjusting the aperture size. The response time in the adjustment of the core power depends mainly onthe adjustment time of the beam intensity

Analysis and Optimization of Energy Consumption for Multi-part Printing Using Selective Laser Melting and Considering the Support Structure

Zhilin Ma,Mengdi Gao,Kai Guo,Qingyang Wang,Lei Li,Conghu Liu,Guang Zhu,Zhifeng Liu 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.3

Selective laser melting (SLM) can form complex and precise metal parts simultaneously and is widely used in medical and aerospace fields. The support structure plays an important role in SLM process, including supporting the overhanging structure, dissipating heat, and minimizing geometric deformation caused by internal stress. However, a non-optimal support structure causes increased energy and material consumption during processing and must be removed afterward to allow for utilization of the parts. Existing support structure design methods only consider reducing the support of a single part, and research on the support and energy consumption of simultaneous multi-part printing is lacking. Therefore, to reduce the energy and material consumption of simultaneous multi-part printing by SLM and improve processing efficiency, an energy consumption analysis and optimization method is proposed in this study from the perspective of the support structure. Based on previous studies on energy consumption distribution of the additive manufacturing process, a multi-component SLM energy consumption and material consumption model was established. Furthermore, a shared-support optimization strategy for simultaneous multi-part processing is proposed. For optimization, the method selects the appropriate printing direction of one part, and then combines multiple parts to form a shared support structure to minimize energy consumption. Finally, under the constraint of minimizing the mass, an optimization strategy of the SLM multi-part shared support combination is established, and the purpose of reducing the energy consumption and material consumption of the SLM is achieved under the premise of ensuring the geometric accuracy of the parts. The method was applied to the manufacturing process of a group of parts with a beam structure. Compared with the printing method using independent support, the shared support structure method reduced energy consumption more than 5.5%, material consumption for the support structure more than 17.2%, and printing time to a certain extent. This method effectively improves SLM production efficiency and sustainability and provides strategic support for additive manufacturing designers and producers.

Dynamic Compliance and its Compensation Control of HIVC Force Control System

Ba, Kai-xian,Yu, Bin,Li, Wen-feng,Wang, Dong-kun,Liu, Ya-liang,Ma, Guo-liang,Kong, Xiang-dong The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.2

In this paper, the dynamic compliance and its compensation control of the force control system on the highly integrated valve-controlled cylinder (HIVC), the joint driver of the hydraulic drive legged robot, is researched. During the robot motion process, the outer loop dynamic compliance control is applied on the base of hydraulic control inner loop and most inner loop control are the force or torque closed loop control. While the dynamic compliance control effectiveness of outer loop can be affected by the inner loop self-dynamic-compliance. Based on this problem, the dynamic compliance series composition theory of HIVC force control system as well as the analysis of its self-dynamic-compliance is proposed. And then the paper comes up with the compliance-enhanced control, which is a compound compensation control method of dynamic compliance with multiple series branches. Finally, the experiment results indicate that the control method mentioned above can enhance the dynamic compliance of HIVC force control system observably. This provides the compensation control method of inner loop dynamic compliance for the outer loop compliance control requiring the high accuracy and high robustness for the robot.

Two new neolignans from Patrinia scabra with potent cytotoxic activity against HeLa and MNK-45 cells

Lei Di,Guo-Qing Yan,Ling-Yu Wang,Wei Ma,Kai-Jin Wang,Ning Li 대한약학회 2013 Archives of Pharmacal Research Vol.36 No.10

Two new neolignans, patrineolignan A (1) andpatrineolignan B (2), together with seven known lignans,were isolated from the 90 % aqueous EtOH extract of theroots of Patrinia scabra. Their structures were elucidatedon the basis of spectroscopic data (HRESIMS, IR, 1D and2D NMR) and comparison with literature data. The twonew neolignans were evaluated in vitro for cytotoxicproperties against human cervical carcinoma HeLa cell lineand gastric carcinoma MNK-45 cell line using the microculturetetrazolium assay, and both 1 and 2 exhibitedstrongly cytotoxic activity against the two tumor cell lines.

Immune Reconstitution of CD4⁺T Cells after Allogeneic Hematopoietic Stem Cell Transplantation and its Correlation with Invasive Fungal Infection in Patients with Hematological Malignancies

Peng, Xin-Guo,Dong, Yan,Zhang, Ting-Ting,Wang, Kai,Ma, Yin-Jian Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Objective: To explore the immune reconstitution of $CD4^+T$ cells after allogeneic hematopoietic stem cell transplantation (Allo-HSCT) and its relationship with invasive fungal infection (IFI) in patients with hematological malignancies. Materials and Methods: Forty-seven patients with hematological malignancies undergoing Allo-HSCT in Binzhou Medical University Hospital from February, 2010 to October, 2014 were selected. At 1, 2 and 3 months after transplantation, the immune subpopulations and concentration of cytokines were assessed respectively using flow cytometry (FCM) and enzyme linked immunosorbent assay (ELISA). The incidence of IFI after transplantation and its correlation with immune reconstitution of $CD4^+T$ cells were investigated. Results: The number of $CD4^+T$ cells and immune subpopulations increased progressively after transplantation as time went on, but the subpopulation cell count 3 months after transplantation was still significantly lower than in the control group (p<0.01). In comparison to the control group, the levels of interleukin-6 (IL-6) and IL-10 after transplantation rose evidently (p<0.01), while that of transforming growth factor-${beta}$ (TGF-${beta}$) was decreased (p<0.01). There was no statistically significant difference level of interferon-${\gamma}$ (IFN-${\gamma}$) (p>0.05). The incidence of IFI was 19.2% (9/47), and multivariate logistic regression revealed that IFI might be related to Th17 cell count (p<0.05), instead of Th1, Th2 and Treg cell counts as well as IL-6, IL-10, TGF-${beta}$ and IFN-${\gamma}$ levels (p>0.05). Conclusions: After Allo-HSCT, the immune reconstitution of $CD4^+T$ cells is delayed and Th17 cell count decreases obviously, which may be related to occurrence of IFI.

Two Androstane Derivatives from the Cultures of Fungus Marasmiellus ramealis (Bull.) Singer

Yang, Ning-Ning,Ma, Qing-Yun,Huang, Sheng-Zhuo,Dai, Hao-Fu,Guo, Zhi-Kai,Yu, Zhi-Fang,Zhao, You-Xing Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.11

A new androstane derivative, $4{\beta}$-methyl-15-oxa-$14{\beta}$-androstane-7-ene-$4{\alpha}$-carboxylic acid (1) and a known one $4{\beta}$-methyl-15-oxa-$14{\beta}$-androstane-7-ene-$4{\alpha}$-hydroxyl (2) were isolated from the EtOAc extract of the cultures of the fungus Marasmiellus ramealis (Bull.) Singer. Their structures were elucidated on the basis of 1D and 2D NMR as well as MS spectroscopic data analysis. The inhibitory activity of two isolates against acetylcholinesterase (AChE) revealed that compound 1 exhibited definitely inhibitory activity.

Two New Phenolic Compounds from the Fruiting Bodies of Ganoderma tropicum

Hu, Li-Li,Ma, Qing-Yun,Huang, Sheng-Zhuo,Guo, Zhi-Kai,Guo, Jian-Chun,Dai, Hao-Fu,Zhao, You-Xing Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

Chemical investigation of the fruiting bodies of Ganoderma tropicum led to the isolation of two new phenolic compounds, ganodermatropins A (1) and B (2). Their structures were elucidated by spectroscopic techniques (MS, 1D and 2D NMR). Ganodermatropin A exhibited antimicrobial activity against Staphylococcus aureus.