Natural Sciences and Technology : [1126]

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Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1126
  • 7.pdf.jpg
  • Article


  • Authors: Le, Tung Son (2020)

  • In the context of the information society and knowledge economy, in order to meet the information access needs of organizations, individuals and businesses, it is essential to formulate policies for establishing scientific and technological information organization networks for scientific research and innovation in Vietnam. Based on the overview of experience in setting up scientific and technological information organization networks in some Asian countries, thereby the study has identified trends in setting up scientific and technological information organization networks and analyze the current situation of policies on establishing scientific and technological information organizat...

  • 6.pdf.jpg
  • Article


  • Authors: Le, Thi Thu Ha; Le, Thi Minh Huyen; Le, Thi Thu Huong; Le, Nguyen Hoang Linh (2020)

  • With the growth of the information technology industry, the literature exploring cloud computing, in particular, SaaS adoption has been developing considerably over the last few years. It is time to take stock of SaaS adoption’s determinant factors and its application to more specific contexts. This study endeavored to investigate the influence of three organizational factors (organizational size, organizational readiness, and top management support) to SaaS adoption in Vietnamese enterprises across sectors. Qualitative method was employed to analyze data gathered from 18 case-study companies. The findings reconfirmed that top management support is the strongest enabler for SaaS adopt...

  • 5.pdf.jpg
  • Article


  • Authors: Dang, Thi Anh Tuyet; Hoang, Thi Quyen (2020)

  • Along with the economic growth and development, people are facing challenges such as: the exhaustion of non-renewable resources, the natural environment is seriously destroyed, ecological balance is broken. Ensuring basic human rights is difficult because economic growth is not always accompanied by social progress and justice. Therefore, since the 1980s, "sustainable development" has become a strategy, that is mentioned by many countries and international organizations. Sustainable development is a relatively broad concept that covers all aspects and aspects of life, so sustainable development management requires the participation of many actors from state management institutions. to...

  • 3.pdf.jpg
  • Article


  • Authors: Le, Tuan Cuong (2020)

  • Chèo is a form of traditional folk art performance of Vietnam, originated about 10 centuries ago. Cheo derives from folk music and dance, especially parody. This form is the result of artistic creation of Vietnamese peasants in northern Vietnam to Nghe An and Ha Tinh. Since its introduction, Cheo has received the attention and love among people of all classes for centuries. Quan Am Thi Kinh, Luu Binh Duong Le, Truong Vien and Kim Nham together with famous chiếng chèo: chiếng chèo Doai, chiếng chèo Bac, chiếng chèo Dong, etc. showed intense vitality and the spread of Chèo. However, along with the history of national struggle, innovation, socio-economic development, especially internati...

  • 2.pdf.jpg
  • Article


  • Authors: Nguyen, Quynh Huy; Le, Vinh Trien (2020)

  • The Industrial Revolution 4.0 has brought about many changes including the higher education system. The main problem is how the education system could adapt to change and promote social innovation. This paper aims to describe the necessary changes and adjustments made in the education system, thereby better meeting the requirements of Industry 4.0, and creating a competitive education system, contributing to socio-economic development. With the research method based on the synthesis of documents, the research results show that, in the context of Industry Revolution 4.0 and the complexity of globalization, the philosophy in educational innovation needs to be changed so that universitie...

  • 1.pdf.jpg
  • Article


  • Authors: Pham, Minh Anh; Do, Van Quan (2020)

  • Urban development management is a global trend, and an urgent requirement in Vietnam today. In recent years, urban development in the southwestern region along the trend of adaptation to climate change has received the attention of the Party and the State; at the same time achieve certain results. However, the management of urban development in the southwestern region adapting to climate change is still inadequate, requiring more robust, systematic and synchronized measures in the development process and urban management in the Southwest region.

  • 10.pdf.jpg
  • Article


  • Authors: Nguyen, Thanh Liem; Nguyen, Pham Duy Linh; Nguyen, Huy Tung; Bach, Trong Phuc; Bui, Chuong; Nguyen, Thi Thuy (2020)

  • In this paper, the influence of paraffinic oil on the physical mechanical and thermal properties of three EPDM rubbers types Buna EP T.6465, Keltan 5260Q and Keltan 6160 D have been investigated. The results showed that the tensile strength and the elongation at break of Keltan 5260Q and Keltan 6160 D with 10 phr paraffinic oil represent the improvement of 57.8% to 57.6% and 71% to 81% respectively, compared to EPDM rubbers without paraffinic oil. The mean peel force of EPDM keltan 6260D with 10 phr paraffinic oil loaded is about 36% and 32.5% higher than that of keltan 5260Q and EP.T 6465 respectively. Beside that at the suitable paraffinic oil contents, the thermal resistance of Kel...

  • 9.pdf.jpg
  • Article


  • Authors: Luong, Xuan Dien; Nguyen, Xuan Truong; Ken-ichi, Yamashita; Ken-ichi, Sugiura, (2020)

  • An innovative π-expanded ligand derived from salicylaldimine ligand representing pyrene ring as a substitute for benzene ring was synthesized in 5 steps from commercially available pyrene. This unique bidentate ligand (1) was coordinated to Cu(II) metal centre for affording complex 2, which was characterized by IR, elemental, X-ray diffraction analyses, and magnetic susceptibility. Its coordination geometry is a trans-square plane with an obvious stair-step structure which is formed by two pyrene moieties and the coordination plane (CuN2O2). In addition, the dihedral angle between the coordination plane and the pyrene ring is 34.9o and the plane of seven carbon atoms of the long alkyl...

  • 8.pdf.jpg
  • Article


  • Authors: Tran, Thanh Thai; Pham, Thanh Luu; Ngo, Xuan Quang; Dao, Thanh Son (2020)

  • This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles (AgNPs) into the aquatic environment. To investigate the chronic toxicity of nanoparticles, freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of 0.2, 0.5 µg/l AgNPs, and control, for 21 days. Toxicological endpoints at different growing stages such as the maturation and reproduction were recorded. The reproduction rate of D. lumholtzi exposed to both AgNPs concentrations (0.2 and 0.5 µg/l ) was significantly lower than that of control. In turn, the maturation exposed to both AgNPs concentrations was not significantly different from the contr...

  • 7.pdf.jpg
  • Article


  • Authors: Do, Van Hai; Duong, Thi Hoan; Ritesh, Kumar Choudhary (2020)

  • Phlogacanthus geoffrayi is reported here as a newly recorded species from Vietnam. This species is morphologically allied to Phlogacanthus turgidus but differs in having a significantly bigger calyx and staminodes. The specimens were collected from Song Cau district of Phu Yen province. Description, line-drawing, photographs, and notes on ecology and distribution are provided.

  • 6.pdf.jpg
  • Article


  • Authors: Nguyen, Trung Thanh (2020)

  • The article introduces the effects of drying temperature on curing level, thermal endurance, thermal oxidation resistance, surface structure morphology of polymer composite material based on K-153 epoxy resin (K-153 epoxy resin is made from ED-20 epoxy resin modified by thiokol and oligomer acrylate), T-13 glass fiber and hardener polyethylenepolyamine. The results show that the thermal endurance, thermal oxidation resistance, surface structure morphology of polymer composite change much when the drying temperature changes. When the drying temperature increases from 60°C to about 80°C, the structure of the polymer composites are tighter, the thermal endurance, thermal oxidation resist...

  • 5.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Kim Lien; Le, Thi Thuy Trang; Vo, Nam Son (2020)

  • The objective of this study was to determine the diversity of zooplankton and using them as indicators for water quality monitoring in the Bun Xang canal of Can Tho City. The research was conducted at 3 sites (Canal begining, canal middle and canal end) from September to October 2018 with 3 sampling periods. At each stage, zooplankton samples were collected at the time of the highest and lowest water level. The results showed that a total of 82 zooplankton species were recorded, in which Rotifera had the most diversity composition with 50 species (61%), followed by Protozoa with 13 species (16%), others from 3-11 species (23%). Composition of zooplankton in tide up and tide down perio...

  • 4.pdf.jpg
  • Article


  • Authors: Huynh, Dang Chinh; Trinh, Viet Dung; Nguyen, Thi Tuyet Mai (2020)

  • LiMnxFe(1-x)PO4 olivine cathode material (x= 0.1; 0.2; 0.3 and 0.8) fabricated according to hydrothermal route. Micro-Raman spectroscopy, SEM scanning electron microscopy, UV-Vis absorption spectra and reflectance spectra methods were performed to study the characteristics of materials. The results showed that LiMnxFe(1-x)PO4 prepared materials were nano-meter in size (60- 100 nm) and distorted sphere-like shape. The material has bands in the Raman spectrum corresponding to the position of the bands of the pure LiFePO4 and shift slightly. The band position at 410 cm-1 (corresponding to the position of the 2 band of the pure LiFePO4 sample) was attenuated of the sample in which Mn2+ i...

  • 3.pdf.jpg
  • Article


  • Authors: Nguyen, Hoai Nam; Nguyen, Huu Tho; Nguyen, Minh Ngoc; Pham, Quang Trung (2020)

  • In this work, we studied the applicability of diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR) as an alternative method in determination of polystyrene molecular weight. DOSY NMR spectroscopy allows measuring the diffusion coefficient of molecule which directly depend on hydrodynamic radius and so on, average molar mass in weight (Mw). By using commercial polystyrene (PS) standards, an external calibration curve was established.

  • 2.pdf.jpg
  • Article


  • Authors: Hoang, Thi Thu Yen; Nguyen, Thuy Linh; Huynh, Thi Thu Hue; Nguyen, Hai Dang (2020)

  • In plants, flavonol synthase (FLS) is a multifunctional enzyme that converts dihydroflavonol into flavonols and naringenin into dihydrokaempferol. FLS from tea has been shown to metabolize dihydroquercetin to quercetin. In this study, we conducted studying on the relationship between quercetin content and the expression level of FLS in two traditional tea cultivars of Vietnam, TrungDuxanh and TrungDutim tea grown in tea garden of Thai Nguyen University of Agriculture and Forestry. Tea shoots with one apical bud and two to three young leaves using as research materials which collected in September 2017. The using of HPLC technique did not detect the quercetin content from the these tea...

  • 1.pdf.jpg
  • Article


  • Authors: Le, Thi Huong; Trinh, Thi Huong; Nguyen, Thi Thanh Huong; Ly, Ngoc Sam (2020)

  • Zingiber mekongense Gagnep., which found in the Central Vietnam, is here reported as a new record for the flora of Vietnam. Voucher specimens collected in the Binh Thuan, Nghe An and Thanh Hoa provinces and deposited in the major herbaria: the herbarium of the Biology (Vinh University), HN, VNM. A detailed morphological description and a coloured photographs of this species along with data on distribution, ecology, phenology and notes to its allies are given.

  • document (1).pdf.jpg
  • Article


  • Authors: Trần, Đình Trinh; Nguyễn, Thị Hoài Phương (2020)

  • Vật liệu biochar từ tính được tổng hợp bằng phương pháp nung vỏ trấu ở 500°C trong môi trường nitơ, sau đó cố định các oxit sắt lên bề mặt biochar sử dụng phương pháp thủy nhiệt hỗn hợp Fe(OH)2 và Fe(OH)3 được tạo ra từ tiền chất Fe2+ và Fe3+ trong môi trường kiềm. Sự có mặt của các oxit sắt trên bề mặt biochar và các đặc trưng bề mặt của vật liệu composite biochar-oxit sắt được nghiên cứu bằng các phương pháp SEM/EDX, BET, FT-IR, XRD. Vật liệu biochar từ tính có nhiều lỗ xốp, diện tích bề mặt đạt 62,1 m2, kích thước mao quản trung bình khoảng 17,2 nm, với các hạt oxit sắt có kích thước khoảng 15 nm phủ trên bề mặt vật liệu. Hiệu suất hấp phụ xanh methylen phụ thuộc vào khối lượng chấ...

  • document (3).pdf.jpg
  • Article


  • Authors: Hoàng, Văn Mạnh; Phạm, Mạnh Thắng (2020)

  • Trong báo cáo này, chúng tôi sẽ trình bày một phương pháp phát hiện chứng nhồi máu cơ tim sử dụng tín hiệu ECG tần số cao. Trước tiên, thuật toán sẽ xác định vị trí, điểm bắt đầu và kết thúc của các phức bộ QRS trong tín hiệu ECG. Tiếp theo, sự tương quan giữa các phức bộ QRS trong mỗi chuyển đạo sẽ được xác định nhằm loại bỏ nhiễu và các dao động ngoại vị nhờ sử dụng ma trận tương quan. Kế tiếp, phân tích nhóm được sử dụng để phát hiện các phức bộ QRS chiếm ưu thế. Kết quả nhận được sẽ được trung bình hóa để có một phức bộ QRS đại diện duy nhất cho mỗi chuyển đạo. Sau đó, phức bộ QRS trung bình được lọc bởi bộ lọc thông dải để có được các thành phần tần số cao của phức bộ QRS. Cuối c...

  • document (2).pdf.jpg
  • Article


  • Authors: Trần, Huy Thái; Nguyễn, Thị Hiền; Lê, Ngọc Diệp; Nguyễn, Trung Thành; Đinh, Thị Thu Thủy (2020)

  • Tinh dầu từ lá của loài Dẻ tùng vân nam (Amentotaxus yunnanensis H.L. Li), thu tại Hoàng Su Phì, Hà Giang nhận được bằng phương pháp chưng cất lôi cuốn hơi nước sử dụng thiết bị Clevenger. Hàm lượng tinh dầu từ lá loài Dẻ tùng vân nam đạt 0,01% (theo nguyên liệu khô không khí). Bằng phương pháp sắc ký khối phổ (GC/MS), 50 thành phần hóa học của tinh dầu từ lá loài Dẻ tùng vân nam chiếm 88,96% tổng lượng tinh dầu đã được xác định. Thành phần chính của tinh dầu gồm: α-pinene (21,91%), kaur-16-ene (13,03%), α-calacorene (9,42%), δ-cadinene (6,23%) và β-caryophyllene (4,9%). Đây là dẫn liệu mới về thành phần hóa học của tinh dầu loài Dẻ tùng vân nam ở Việt Nam.

Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1126

Natural Sciences and Technology : [1126]

Follow this collection to receive daily e-mail notification of new additions
Collection's Items (Sorted by Submit Date in Descending order): 1 to 20 of 1126
  • 7.pdf.jpg
  • Article


  • Authors: Le, Tung Son (2020)

  • In the context of the information society and knowledge economy, in order to meet the information access needs of organizations, individuals and businesses, it is essential to formulate policies for establishing scientific and technological information organization networks for scientific research and innovation in Vietnam. Based on the overview of experience in setting up scientific and technological information organization networks in some Asian countries, thereby the study has identified trends in setting up scientific and technological information organization networks and analyze the current situation of policies on establishing scientific and technological information organizat...

  • 6.pdf.jpg
  • Article


  • Authors: Le, Thi Thu Ha; Le, Thi Minh Huyen; Le, Thi Thu Huong; Le, Nguyen Hoang Linh (2020)

  • With the growth of the information technology industry, the literature exploring cloud computing, in particular, SaaS adoption has been developing considerably over the last few years. It is time to take stock of SaaS adoption’s determinant factors and its application to more specific contexts. This study endeavored to investigate the influence of three organizational factors (organizational size, organizational readiness, and top management support) to SaaS adoption in Vietnamese enterprises across sectors. Qualitative method was employed to analyze data gathered from 18 case-study companies. The findings reconfirmed that top management support is the strongest enabler for SaaS adopt...

  • 5.pdf.jpg
  • Article


  • Authors: Dang, Thi Anh Tuyet; Hoang, Thi Quyen (2020)

  • Along with the economic growth and development, people are facing challenges such as: the exhaustion of non-renewable resources, the natural environment is seriously destroyed, ecological balance is broken. Ensuring basic human rights is difficult because economic growth is not always accompanied by social progress and justice. Therefore, since the 1980s, "sustainable development" has become a strategy, that is mentioned by many countries and international organizations. Sustainable development is a relatively broad concept that covers all aspects and aspects of life, so sustainable development management requires the participation of many actors from state management institutions. to...

  • 3.pdf.jpg
  • Article


  • Authors: Le, Tuan Cuong (2020)

  • Chèo is a form of traditional folk art performance of Vietnam, originated about 10 centuries ago. Cheo derives from folk music and dance, especially parody. This form is the result of artistic creation of Vietnamese peasants in northern Vietnam to Nghe An and Ha Tinh. Since its introduction, Cheo has received the attention and love among people of all classes for centuries. Quan Am Thi Kinh, Luu Binh Duong Le, Truong Vien and Kim Nham together with famous chiếng chèo: chiếng chèo Doai, chiếng chèo Bac, chiếng chèo Dong, etc. showed intense vitality and the spread of Chèo. However, along with the history of national struggle, innovation, socio-economic development, especially internati...

  • 2.pdf.jpg
  • Article


  • Authors: Nguyen, Quynh Huy; Le, Vinh Trien (2020)

  • The Industrial Revolution 4.0 has brought about many changes including the higher education system. The main problem is how the education system could adapt to change and promote social innovation. This paper aims to describe the necessary changes and adjustments made in the education system, thereby better meeting the requirements of Industry 4.0, and creating a competitive education system, contributing to socio-economic development. With the research method based on the synthesis of documents, the research results show that, in the context of Industry Revolution 4.0 and the complexity of globalization, the philosophy in educational innovation needs to be changed so that universitie...

  • 1.pdf.jpg
  • Article


  • Authors: Pham, Minh Anh; Do, Van Quan (2020)

  • Urban development management is a global trend, and an urgent requirement in Vietnam today. In recent years, urban development in the southwestern region along the trend of adaptation to climate change has received the attention of the Party and the State; at the same time achieve certain results. However, the management of urban development in the southwestern region adapting to climate change is still inadequate, requiring more robust, systematic and synchronized measures in the development process and urban management in the Southwest region.

  • 10.pdf.jpg
  • Article


  • Authors: Nguyen, Thanh Liem; Nguyen, Pham Duy Linh; Nguyen, Huy Tung; Bach, Trong Phuc; Bui, Chuong; Nguyen, Thi Thuy (2020)

  • In this paper, the influence of paraffinic oil on the physical mechanical and thermal properties of three EPDM rubbers types Buna EP T.6465, Keltan 5260Q and Keltan 6160 D have been investigated. The results showed that the tensile strength and the elongation at break of Keltan 5260Q and Keltan 6160 D with 10 phr paraffinic oil represent the improvement of 57.8% to 57.6% and 71% to 81% respectively, compared to EPDM rubbers without paraffinic oil. The mean peel force of EPDM keltan 6260D with 10 phr paraffinic oil loaded is about 36% and 32.5% higher than that of keltan 5260Q and EP.T 6465 respectively. Beside that at the suitable paraffinic oil contents, the thermal resistance of Kel...

  • 9.pdf.jpg
  • Article


  • Authors: Luong, Xuan Dien; Nguyen, Xuan Truong; Ken-ichi, Yamashita; Ken-ichi, Sugiura, (2020)

  • An innovative π-expanded ligand derived from salicylaldimine ligand representing pyrene ring as a substitute for benzene ring was synthesized in 5 steps from commercially available pyrene. This unique bidentate ligand (1) was coordinated to Cu(II) metal centre for affording complex 2, which was characterized by IR, elemental, X-ray diffraction analyses, and magnetic susceptibility. Its coordination geometry is a trans-square plane with an obvious stair-step structure which is formed by two pyrene moieties and the coordination plane (CuN2O2). In addition, the dihedral angle between the coordination plane and the pyrene ring is 34.9o and the plane of seven carbon atoms of the long alkyl...

  • 8.pdf.jpg
  • Article


  • Authors: Tran, Thanh Thai; Pham, Thanh Luu; Ngo, Xuan Quang; Dao, Thanh Son (2020)

  • This study aimed to enhance our insight on the potential toxicological effects of silver nanoparticles (AgNPs) into the aquatic environment. To investigate the chronic toxicity of nanoparticles, freshwater micro-crustacean Daphnia lumholtzi was exposed to different concentrations of 0.2, 0.5 µg/l AgNPs, and control, for 21 days. Toxicological endpoints at different growing stages such as the maturation and reproduction were recorded. The reproduction rate of D. lumholtzi exposed to both AgNPs concentrations (0.2 and 0.5 µg/l ) was significantly lower than that of control. In turn, the maturation exposed to both AgNPs concentrations was not significantly different from the contr...

  • 7.pdf.jpg
  • Article


  • Authors: Do, Van Hai; Duong, Thi Hoan; Ritesh, Kumar Choudhary (2020)

  • Phlogacanthus geoffrayi is reported here as a newly recorded species from Vietnam. This species is morphologically allied to Phlogacanthus turgidus but differs in having a significantly bigger calyx and staminodes. The specimens were collected from Song Cau district of Phu Yen province. Description, line-drawing, photographs, and notes on ecology and distribution are provided.

  • 6.pdf.jpg
  • Article


  • Authors: Nguyen, Trung Thanh (2020)

  • The article introduces the effects of drying temperature on curing level, thermal endurance, thermal oxidation resistance, surface structure morphology of polymer composite material based on K-153 epoxy resin (K-153 epoxy resin is made from ED-20 epoxy resin modified by thiokol and oligomer acrylate), T-13 glass fiber and hardener polyethylenepolyamine. The results show that the thermal endurance, thermal oxidation resistance, surface structure morphology of polymer composite change much when the drying temperature changes. When the drying temperature increases from 60°C to about 80°C, the structure of the polymer composites are tighter, the thermal endurance, thermal oxidation resist...

  • 5.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Kim Lien; Le, Thi Thuy Trang; Vo, Nam Son (2020)

  • The objective of this study was to determine the diversity of zooplankton and using them as indicators for water quality monitoring in the Bun Xang canal of Can Tho City. The research was conducted at 3 sites (Canal begining, canal middle and canal end) from September to October 2018 with 3 sampling periods. At each stage, zooplankton samples were collected at the time of the highest and lowest water level. The results showed that a total of 82 zooplankton species were recorded, in which Rotifera had the most diversity composition with 50 species (61%), followed by Protozoa with 13 species (16%), others from 3-11 species (23%). Composition of zooplankton in tide up and tide down perio...

  • 4.pdf.jpg
  • Article


  • Authors: Huynh, Dang Chinh; Trinh, Viet Dung; Nguyen, Thi Tuyet Mai (2020)

  • LiMnxFe(1-x)PO4 olivine cathode material (x= 0.1; 0.2; 0.3 and 0.8) fabricated according to hydrothermal route. Micro-Raman spectroscopy, SEM scanning electron microscopy, UV-Vis absorption spectra and reflectance spectra methods were performed to study the characteristics of materials. The results showed that LiMnxFe(1-x)PO4 prepared materials were nano-meter in size (60- 100 nm) and distorted sphere-like shape. The material has bands in the Raman spectrum corresponding to the position of the bands of the pure LiFePO4 and shift slightly. The band position at 410 cm-1 (corresponding to the position of the 2 band of the pure LiFePO4 sample) was attenuated of the sample in which Mn2+ i...

  • 3.pdf.jpg
  • Article


  • Authors: Nguyen, Hoai Nam; Nguyen, Huu Tho; Nguyen, Minh Ngoc; Pham, Quang Trung (2020)

  • In this work, we studied the applicability of diffusion ordered nuclear magnetic resonance spectroscopy (DOSY NMR) as an alternative method in determination of polystyrene molecular weight. DOSY NMR spectroscopy allows measuring the diffusion coefficient of molecule which directly depend on hydrodynamic radius and so on, average molar mass in weight (Mw). By using commercial polystyrene (PS) standards, an external calibration curve was established.

  • 2.pdf.jpg
  • Article


  • Authors: Hoang, Thi Thu Yen; Nguyen, Thuy Linh; Huynh, Thi Thu Hue; Nguyen, Hai Dang (2020)

  • In plants, flavonol synthase (FLS) is a multifunctional enzyme that converts dihydroflavonol into flavonols and naringenin into dihydrokaempferol. FLS from tea has been shown to metabolize dihydroquercetin to quercetin. In this study, we conducted studying on the relationship between quercetin content and the expression level of FLS in two traditional tea cultivars of Vietnam, TrungDuxanh and TrungDutim tea grown in tea garden of Thai Nguyen University of Agriculture and Forestry. Tea shoots with one apical bud and two to three young leaves using as research materials which collected in September 2017. The using of HPLC technique did not detect the quercetin content from the these tea...

  • 1.pdf.jpg
  • Article


  • Authors: Le, Thi Huong; Trinh, Thi Huong; Nguyen, Thi Thanh Huong; Ly, Ngoc Sam (2020)

  • Zingiber mekongense Gagnep., which found in the Central Vietnam, is here reported as a new record for the flora of Vietnam. Voucher specimens collected in the Binh Thuan, Nghe An and Thanh Hoa provinces and deposited in the major herbaria: the herbarium of the Biology (Vinh University), HN, VNM. A detailed morphological description and a coloured photographs of this species along with data on distribution, ecology, phenology and notes to its allies are given.

  • document (1).pdf.jpg
  • Article


  • Authors: Trần, Đình Trinh; Nguyễn, Thị Hoài Phương (2020)

  • Vật liệu biochar từ tính được tổng hợp bằng phương pháp nung vỏ trấu ở 500°C trong môi trường nitơ, sau đó cố định các oxit sắt lên bề mặt biochar sử dụng phương pháp thủy nhiệt hỗn hợp Fe(OH)2 và Fe(OH)3 được tạo ra từ tiền chất Fe2+ và Fe3+ trong môi trường kiềm. Sự có mặt của các oxit sắt trên bề mặt biochar và các đặc trưng bề mặt của vật liệu composite biochar-oxit sắt được nghiên cứu bằng các phương pháp SEM/EDX, BET, FT-IR, XRD. Vật liệu biochar từ tính có nhiều lỗ xốp, diện tích bề mặt đạt 62,1 m2, kích thước mao quản trung bình khoảng 17,2 nm, với các hạt oxit sắt có kích thước khoảng 15 nm phủ trên bề mặt vật liệu. Hiệu suất hấp phụ xanh methylen phụ thuộc vào khối lượng chấ...

  • document (3).pdf.jpg
  • Article


  • Authors: Hoàng, Văn Mạnh; Phạm, Mạnh Thắng (2020)

  • Trong báo cáo này, chúng tôi sẽ trình bày một phương pháp phát hiện chứng nhồi máu cơ tim sử dụng tín hiệu ECG tần số cao. Trước tiên, thuật toán sẽ xác định vị trí, điểm bắt đầu và kết thúc của các phức bộ QRS trong tín hiệu ECG. Tiếp theo, sự tương quan giữa các phức bộ QRS trong mỗi chuyển đạo sẽ được xác định nhằm loại bỏ nhiễu và các dao động ngoại vị nhờ sử dụng ma trận tương quan. Kế tiếp, phân tích nhóm được sử dụng để phát hiện các phức bộ QRS chiếm ưu thế. Kết quả nhận được sẽ được trung bình hóa để có một phức bộ QRS đại diện duy nhất cho mỗi chuyển đạo. Sau đó, phức bộ QRS trung bình được lọc bởi bộ lọc thông dải để có được các thành phần tần số cao của phức bộ QRS. Cuối c...

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  • Article


  • Authors: Trần, Huy Thái; Nguyễn, Thị Hiền; Lê, Ngọc Diệp; Nguyễn, Trung Thành; Đinh, Thị Thu Thủy (2020)

  • Tinh dầu từ lá của loài Dẻ tùng vân nam (Amentotaxus yunnanensis H.L. Li), thu tại Hoàng Su Phì, Hà Giang nhận được bằng phương pháp chưng cất lôi cuốn hơi nước sử dụng thiết bị Clevenger. Hàm lượng tinh dầu từ lá loài Dẻ tùng vân nam đạt 0,01% (theo nguyên liệu khô không khí). Bằng phương pháp sắc ký khối phổ (GC/MS), 50 thành phần hóa học của tinh dầu từ lá loài Dẻ tùng vân nam chiếm 88,96% tổng lượng tinh dầu đã được xác định. Thành phần chính của tinh dầu gồm: α-pinene (21,91%), kaur-16-ene (13,03%), α-calacorene (9,42%), δ-cadinene (6,23%) và β-caryophyllene (4,9%). Đây là dẫn liệu mới về thành phần hóa học của tinh dầu loài Dẻ tùng vân nam ở Việt Nam.

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