Vietnam Journal of Science and Technology最新文献_第10页

Developing solutions roadmaps for rice production in flooding area of the Vietnamese Mekong Delta adapting to uncertain changes in climate and surface water resources 制定越南湄公河三角洲洪涝地区水稻生产的解决方案路线图，以适应气候和地表水资源的不确定变化

Vietnam Journal of Science and Technology Pub Date : 2023-04-17 DOI: 10.15625/2525-2518/16432

H. Hoang, Nguyen Hong Tin, Dinh Diep Anh Tuan, Van Pham Dang Tri

{"title":"Developing solutions roadmaps for rice production in flooding area of the Vietnamese Mekong Delta adapting to uncertain changes in climate and surface water resources","authors":"H. Hoang, Nguyen Hong Tin, Dinh Diep Anh Tuan, Van Pham Dang Tri","doi":"10.15625/2525-2518/16432","DOIUrl":"https://doi.org/10.15625/2525-2518/16432","url":null,"abstract":"Climate change, hydro-power dams and socio-economic development in the upper Mekong River, have caused changes in surface water resources and agricultural transformation in the Vietnamese Mekong Delta (VMD). It is unpredictable and influences decision-making processes on water resource management. This study aims at applying the DAPP (Dynamic Adaptive Policy Pathways) approach to develop solution roadmaps supporting rice production in the Mekong Delta projection to 2030 under the context of uncertain changes on surface water resources. Data were collected from local officers, farmers, experts at Can Tho University, Technical University Delft, and Utrecht University using semi-structured interview techniques including workshops, group discussions, and in-depth interviews. The consolidated solutions from stakeholder’s opinions were evaluated at different socio-economic and environmental dimensions, specially focused on the time of tipping point of each solution. The study results show that two solution roadmaps were developed as sample scenarios to promote rice production in the upper area of the VMD. The determination of the solutions roadmaps based on the agreement of the stakeholders, which is a new feature of this approach in linking many stakeholders for the general development of the region. The DAPP approach could be suitable to support decision-making on surface water resources management in the context of uncertain changes. Therefore, further studies can apply this approach to other regions in the VMD which will support to reinforce and demonstrate the applicability of the DAPP approach on supporting decision-making in the face of increasingly uncertain changes in the VMD.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74048858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Green synthesis of graphene quantum dots from rice flour 用米粉绿色合成石墨烯量子点

Vietnam Journal of Science and Technology Pub Date : 2023-04-17 DOI: 10.15625/2525-2518/16847

Quyen, Thi Bich Tran, Phuong Thi Ngoe Huynh, My, Nguyen Tra Ngo, Thien, Van Hong Doan, T. H. Luong, L. Tran

{"title":"Green synthesis of graphene quantum dots from rice flour","authors":"Quyen, Thi Bich Tran, Phuong Thi Ngoe Huynh, My, Nguyen Tra Ngo, Thien, Van Hong Doan, T. H. Luong, L. Tran","doi":"10.15625/2525-2518/16847","DOIUrl":"https://doi.org/10.15625/2525-2518/16847","url":null,"abstract":"Graphene Quantum Dots (GQDs) were successfully synthesized by a green and eco-friendly synthetic method using abundant and naturally available raw materials from rice flour. This study suggested and compared two aggressive approaches to fabricate GQDs, which are hydrothermal method at 170 °C for 8 h and microwave irradiation method at 900 W with a short reaction time of 30 min. The results showed that the hydrothermal method produced GQDs with better nanoparticle size and properties than the microwave irradiation method. Furthermore, the products were only GQDs, water and carbide precipitate, thus avoiding complicated post-processing steps. The synthesized GQDs were determined for their morphology by Transmission electron microscope (TEM) showing spherical nanoparticles with an average size of ~5-7 nm and ~10-14 nm for hydrothermal and microwave irradiation methods, respectively. Besides, these GQDs were also analyzed for their characterizations, morphologies and compositions by UV-vis, XRD and FTIR. Thanks to their low cytotoxicity, good optical stability, and excellent photo-luminescence property, GQDs have become novel nanostructured materials in many application fields from energy to biomedicine and environment such as sensors, bio-imaging, drug carriers, and solar cells.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87984549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis and cytotoxic activity of some novel 2’-hydroxychalcones containing murrayafoline A 几种新型2′-羟查尔酮的合成及细胞毒活性研究

Vietnam Journal of Science and Technology Pub Date : 2023-04-17 DOI: 10.15625/2525-2518/16785

Le Duc Anh, Luu Van Chinh, Truong Ngoc Hung, Nguyen Manh Cuong, Pham Hong Ngoc

引用次数: 0

Prediction of the Distribution and Effect of Diameters of the Cylinder and the Piston Post-Manufacture on the Operation of Gas-Operated Automatic Rifles 气控自动步枪枪筒直径和活塞直径的分布及其制造后对操作影响的预测

Vietnam Journal of Science and Technology Pub Date : 2023-04-17 DOI: 10.15625/2525-2518/16627

N. Hung

引用次数: 0

Fabrication of polyglutamic acid-based sensor for electrochemical determination of a phenicol antibiotic in water environment 水环境中苯类抗生素电化学测定用聚谷氨酸传感器的制备

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/16865

Thi Tuyet Ngan Nguyen, Thi Thu Ha Vu, Van Thanh Dang, Tragiang Nguyen, Thi Hai Yen Pham

{"title":"Fabrication of polyglutamic acid-based sensor for electrochemical determination of a phenicol antibiotic in water environment","authors":"Thi Tuyet Ngan Nguyen, Thi Thu Ha Vu, Van Thanh Dang, Tragiang Nguyen, Thi Hai Yen Pham","doi":"10.15625/2525-2518/16865","DOIUrl":"https://doi.org/10.15625/2525-2518/16865","url":null,"abstract":"In this study, a graphite electrode (GrE) modified with polyglutamic acid was used to determine chloramphenicol (CAP), a phenicol antibiotic, in a water environment using adsorptive stripping linear sweep voltammetry. The pGA modification process involved electropolymerization via cyclic voltammetry, resulting in a significantly enlarged electrochemical active area of the pGA/GrE interface (1.5 times greater than that of the unmodified GrE). The highest CAP signal was obtained on the electrode fabricated by scanning 50 cycles in the potential range of -1.2 V to +2.0 V. The CAP signal recorded on the pGA/GrE electrode was nine times higher than that on the GrE, which was due to the larger electrochemical active area of the pGA/GrE and its good adsorption capacity with CAP. Analysis conditions including the pH of electrolyte and accumulation time, were optimized. Under optimal conditions, the calibration curve was built with two linear regions in the concentration ranges of 0.5-20 µmol L-1 (R2 = 0.987) and 20-100 µmol L-1 (R2 = 0.996), and the detection limit for CAP was 0.28 µmol L-1.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78758156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesis of highly stable silver nanoparticles as computed tomography contrast agents 合成高度稳定的银纳米颗粒作为计算机断层造影剂

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/16892

Tam The Le, Linh Nguyen Thi Ngoc

引用次数: 0

In silico studies on potential MCF-7 inhibitors of alkaloid and phenolic compounds isolated from Zanthoxylum nitidum: A combination of molecular docking and ADMET analysis 从镍花椒中分离的生物碱和酚类化合物的潜在MCF-7抑制剂的硅研究:分子对接和ADMET分析的结合

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/16945

Q. Pham, Thi-Hong-Minh Pham

引用次数: 0

Synthesis, structure and antibacterial, antifungal activities of some hydrazones synthesized from 4-hydroxy-3-nitrobenzaldehyde 4-羟基-3-硝基苯甲醛合成的几种腙的合成、结构及抑菌抑菌活性

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/17073

引用次数: 0

Bert Adapter and Contrastive Learning for Continual Classification of Aspect Sentiment Task Sequences 面向面向情感任务序列连续分类的Bert适配与对比学习

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/17395

{"title":"Bert Adapter and Contrastive Learning for Continual Classification of Aspect Sentiment Task Sequences","authors":"","doi":"10.15625/2525-2518/17395","DOIUrl":"https://doi.org/10.15625/2525-2518/17395","url":null,"abstract":"Task incremental learning, a setting of Continual learning, isan approach to exploit the knowledge from previous tasks for currentlynew task. Task incremental learning aims to solve two big challengesof continual learning: catastrophic forgetting and knowledge transfer orsharing between previous tasks and current task. This paper improveTask incremental learning by (1) transferring the knowledge (not thetraining data) learned from previous tasks to a new task (contrast ofmulti-task learning); (2) to maintain or even improve performance oflearned models from previous tasks with avoid forgetting; (3) to developa continual learning model based on result from (1) and (2) to applyfor aspect sentiment classification. Specifically, we combine two loss baseon contrastive learning modules from Contrastive Knowledge Sharing(CKS) for encouraging knowledge sharing between old and current tasksand improve the performance of the current task by Contrastive Super-vised learning (CSC) module. The experimental results show that ourmethod could get rid of previous learned tasks catastrophic forgettingphenomenon and outperform the previous study for aspect sentimentclassification.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79989907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study of corrosion behavior of arc thermal sprayed Al-Mg alloy coating 电弧热喷涂铝镁合金涂层的腐蚀行为研究

Vietnam Journal of Science and Technology Pub Date : 2023-04-05 DOI: 10.15625/2525-2518/16768

{"title":"Study of corrosion behavior of arc thermal sprayed Al-Mg alloy coating","authors":"","doi":"10.15625/2525-2518/16768","DOIUrl":"https://doi.org/10.15625/2525-2518/16768","url":null,"abstract":"In this study, Al-Mg alloy coatings were deposited on a C45 steel substrate by using the electric arc spray technique. The corrosion behavior of the coating was studied by electrochemical measurements and salt spray tests. The electrochemical tests were performed in 3.5 wt.% NaCl solution. Polarization tests indicated that the corrosion potential of the coating is significantly more negative than that of steel substrate after 240 hours of immersion. EIS measurements showed that after 24 hours of immersion, the total impedance increased with increasing the immersion time. This could be due to sealing of pores by corrosion products which hinder further penetration of the solution through the coating. Red rust spots did not appear on the surface of the coating after 1360 hours of salt spray test. The corrosion rate of the coating decreased with the increase in salt spray test time. After the salt spray test, the coating surface pitted and the cross section of the coating appeared with many long voids. In addition, XRD analysis proved that the main corrosion product was Al(OH)3. The results obtained indicated that arc thermal sprayed Al-Mg alloy coatings can reliably protect steel structures against corrosion in chloride-containing aqueous solutions.","PeriodicalId":23553,"journal":{"name":"Vietnam Journal of Science and Technology","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87246841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0