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Energy-transfer phenomenon and color-tunable properties of Ca2Al2SiO7: Dy3+/Eu3+ phosphors Ca2Al2SiO7: Dy3+/Eu3+荧光粉的能量转移现象和颜色可调性质
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6816
Do Thanh Tien, N. M. Sơn, Nguyen Dang Nhat, H. Tuyen, Le Xuan Diem Ngoc, T. Q. Toan
Ca2Al2SiO7 (CAS) doped with Eu3+ and Dy3+ was successfully synthesised with the solid-phase reaction method, in which the sample was sintered at 1,280 °C for one hour. The energy-transfer phenomenon from Dy3+ to Eu3+ was observed in the CAS matrix. The optimal doping concentration of Dy3+ and Eu3+ is 1.5 and 1% mol. In addition, the energy-transfer mechanism, CIE colour coordinate, and CCT colour temperature of CAS/Dy3+/Eu3+ were also presented and discussed.
采用固相反应法制备了掺有Eu3+和Dy3+的Ca2Al2SiO7 (CAS),将样品在1280℃下烧结1h。在CAS基体中观察到Dy3+向Eu3+的能量转移现象。Dy3+和Eu3+的最佳掺杂浓度分别为1.5 mol和1% mol。此外,还讨论了CAS/Dy3+/Eu3+的能量传递机理、CIE色坐标和CCT色温。
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引用次数: 0
Exciton quantum beats in GaAs/AlAs disk-shaped quantum dots GaAs/AlAs盘形量子点中的激子量子拍
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6909
Thi Dieu Hien Le, Thi Ngoc Bao Le, Nhu Thao Dinh
Using the renormalized wavefunction approach, we examined the excitonic quantum beat in a three-level system in disk-shaped quantum dots. The non-stationary electron wave function and the time-dependent exciton absorption intensity under the effect of an intensity pump laser that resonates with two excited electron states were also provided. Our numerical findings demonstrate that the time-dependent exciton absorption intensity takes the shape of a periodic oscillation when the quantum dot is subjected to a powerful resonant pump laser. This is clear evidence that quantum beats appears in the quantum disk. Additionally, the dot radius and the pump field detuning significantly affect the beat characteristics, such as frequency and amplitude.
利用重归一化波函数方法,研究了盘状量子点三能级系统中的激子量子拍。给出了与两个激发态共振的强度泵浦激光作用下的非平稳电子波函数和随时间变化的激子吸收强度。我们的数值研究结果表明,当量子点受到强共振泵浦激光时,激子吸收强度随时间的变化呈周期振荡的形式。这是量子拍在量子盘中出现的明显证据。此外,点半径和泵浦场失谐对频率和幅值等拍频特性有显著影响。
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引用次数: 0
Adsorption capacity of chitosan hydrogel beads fabricated from Penaeus monodon shrimp shell waste for safranin o dye 对虾壳废液制备壳聚糖水凝胶珠对红花素o染料的吸附性能
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6865
Thi Phuong Do, X. Nguyen
In this study, we extracted chitosan from Penaeus monodon shrimp shell waste and used it as a bio-sorbent to remove safranin O (SO) dye in aqueous solutions. The chitosan adsorbent was characterised by using SEM and FTIR techniques. Batch adsorption experiments were carried out to evaluate the influence of solution pH (3–10), chitosan dosage (0.1–3 g), contact time (1–720 min), and initial SO concentration (10–200 mg·L–1) on adsorption. The results show that the adsorption of SO with chitosan reached equilibrium after 120 min, and after that, an insignificant change in SO removal efficiency was observed. The maximum adsorption capacity of SO, calculated according to the Langmuir model, was 17.86 mg·g–1 under ambient temperature (25 ± 2 °C), pH 7, chitosan dose of 0.2 g, and SO concentration of 50 mg·L–1. The adsorption kinetics followed the pseudo-second-order model with a correlation coefficient R2 of 0.95. The Langmuir and Freundlich adsorption isotherm models described the SO’s adsorption well, with R2 higher than 0.95.
本研究以对虾壳为原料,提取壳聚糖作为生物吸附剂去除水中的红花素O (SO)染料。利用扫描电镜(SEM)和红外光谱(FTIR)对壳聚糖吸附剂进行了表征。通过批量吸附实验,考察了溶液pH(3-10)、壳聚糖用量(0.1-3 g)、接触时间(1-720 min)和初始SO浓度(10-200 mg·L-1)对吸附的影响。结果表明,壳聚糖对SO的吸附在120 min后达到平衡,之后对SO的去除率变化不大。在环境温度(25±2℃)、pH为7、壳聚糖用量为0.2 g、SO浓度为50 mg·L-1的条件下,根据Langmuir模型计算得到的最大吸附量为17.86 mg·g - 1。吸附动力学符合拟二阶模型,相关系数R2为0.95。Langmuir和Freundlich吸附等温线模型较好地描述了SO的吸附,R2均大于0.95。
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引用次数: 0
Non-doped phosphor for WLED with high CRI and R9 具有高显色比和R9的WLED用非掺杂荧光粉
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6838
Thi To Nhu Dang, Minh Thong Nguyen, M. Nguyen, Xuan-Viet Dao, Thao Vien Le
The effect of the ZnO/SnO2 ratio on phase formation and optical properties of the Zn-Sn-O compound was investigated by varying the ZnO/SnO2 molar ratio (ZnO/SnO2  = 1:2, 1:1, 2:1, 3:1, and 4:1). All samples were synthesised with high-energy planetary ball milling, followed by calcination at 1000 °C in the air. The result from X-Ray diffraction patterns (XRD) shows that the single-phase Zn2SnO4 is achieved at the ZnO/SnO2 ratio of 2:1. Whereas, the mixed phase of ZnO and Zn2SnO4 formed when ZnO is more than SnO2 (3:1 and 4:1). On the other hand, the XRD patterns of the products obtained at a ratio where SnO2 is more than ZnO present a mixture of SnO2 and Zn2SnO4. The photoluminescence of the two samples with the ratio of 2:1 and 1:3 gives full-visible range spectra from 400 to 800 nm, which are in the blue-far-red region centred at about 514, 580, and 690 nm. Temperature-dependent luminescence measurements were also carried out in this work, and the results indicate that the prepared phosphor Zn-Sn-O at the ZnO/SnO2 ratio of 1:2 has thermal stability. The obtained material was used to coat near UV LED chips, and the WLED possesses the highest CRI of 95. The SnO2-Zn2SnO4 powder can be used as a phosphor for WLED applications with high CRI and R9.
通过改变ZnO/SnO2的摩尔比(ZnO/SnO2 = 1:2, 1:1, 2:1, 3:1和4:1),研究了ZnO/SnO2比对Zn-Sn-O化合物相形成和光学性能的影响。所有的样品都是用高能行星球磨合成的,然后在1000℃的空气中煅烧。x射线衍射图(XRD)结果表明,ZnO/SnO2比为2:1时得到了单相Zn2SnO4。而ZnO和Zn2SnO4的混合相则在ZnO大于SnO2(3:1和4:1)时形成。另一方面,当SnO2比ZnO多时,产物的XRD谱图呈现出SnO2和Zn2SnO4的混合物。两种样品的光致发光比例分别为2:1和1:3,光谱范围为400 ~ 800 nm,位于蓝-远红色区域,集中在514、580和690 nm左右。实验结果表明,在ZnO/SnO2比为1:2的情况下,制备的荧光粉Zn-Sn-O具有热稳定性。将所得材料涂覆在近紫外LED芯片上,WLED的显色指数高达95。SnO2-Zn2SnO4粉末可以用作具有高CRI和R9的WLED应用的荧光粉。
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引用次数: 0
Modification of Phu Yen diatomite and its application to Cr(VI) removal in aqueous medium Phu Yen硅藻土的改性及其在水中去除Cr(VI)的应用
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6942
Vinh-Thien Tran
In this study, we successfully prepared a carboxyl-rich carbon nanomaterial from Phu Yen natural diatomite and used it as an effective adsorbent to remove Cr(VI) in aqueous media. The obtained nanomaterial was characterized by means of XRD, SEM, EDS, and FT-IR. The adsorption characteristics of Cr(VI) were investigated. pH has a significant influence on the adsorption process, and pH = 1 is optimal for Cr(VI) adsorption at ambient temperature. Three types of materials were prepared, including natural diatomite (DE), modified diatomite with carbon nanomaterial (DE/S), and modified diatomite with carboxyl-rich carbon nanomaterial (DE/C-S), and DE/C-S exhibits the highest adsorption capacity under the optimal conditions. The pseudo-second-order kinetic model and the Langmuir isotherm well describe the adsorption process of Cr(VI) onto DE/C-S with the maximum adsorption capacity of 58.82 mg·g–1, which is significantly higher compared with that of the natural diatomite (2.29 mg·g–1). Carboxyl-rich carbon-modified diatomite nanomaterials have great potential for use in removing Cr(VI) from wastewater.
在本研究中,我们成功地从Phu Yen天然硅藻土中制备了富含羧基的碳纳米材料,并将其作为有效的吸附剂去除水中的Cr(VI)。采用XRD、SEM、EDS、FT-IR等手段对所制得的纳米材料进行了表征。研究了其对Cr(VI)的吸附特性。pH对吸附过程有显著影响,常温下pH = 1对Cr(VI)的吸附效果最优。制备了天然硅藻土(DE)、碳纳米材料修饰硅藻土(DE/S)和富羧基碳纳米材料修饰硅藻土(DE/C-S)三种材料,在最佳条件下,DE/C-S的吸附能力最高。拟二级动力学模型和Langmuir等温线较好地描述了Cr(VI)在DE/C-S上的吸附过程,最大吸附量为58.82 mg·g-1,明显高于天然硅藻土的吸附量(2.29 mg·g-1)。富羧基碳改性硅藻土纳米材料在去除废水中铬(VI)方面具有很大的应用潜力。
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引用次数: 0
Imaginary part of microscopic optical potential at negative energies 负能量下微观光学势的虚部
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6871
Tam Do Quang, Vinh Phu Nguyen, Minh Hoa Nguyen, Hong Nguyen Thi, Quynh Nhu Tran Duy, Nhan Hao Tran Viet, Le Uyen Vo
In this paper, we calculate the diagonal contributions W(R, s = 0) of the imaginary part of the microsopic optical potential at negatives energies, where W(R, s) =Σlj(2j+1)/4π Im∆Σlj(r, r′, ω), with R = 1/2.(r + r′) corresponding to the radius and shape ofIm∆Σ, and s = r - r′. To do it, the microscopic optical potential has been calculatedby using the nuclear structure approach which is based on the Green function method. The coupling between the particle and collective phonon has been performed to calculate the dynamic part of the optical potential. It has been found that the imaginary part at negative energies is very small as expected. The calculated W(R, 0) is maximum on the surface and deacreases to zero in the interior.
本文计算了负能量下微观光势虚部的对角线贡献W(R, s = 0),其中W(R, s) =Σlj(2j+1)/4π Im∆Σlj(R, R ', ω), R = 1/2。(r + r ')对应m∆Σ的半径和形状,s = r - r '。为此,采用基于格林函数法的核结构方法计算了微观光势。利用粒子与集体声子之间的耦合计算了光势的动态部分。已经发现,在负能量的虚数部分是非常小的预期。计算得到的W(R, 0)在表面最大,在内部逐渐减小到零。
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引用次数: 0
Synthesis and physical properties of multiferroic BaDyFeO4 多铁性BaDyFeO4的合成及物理性质
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.6912
T. T. Le, Danh Bich Do, Thanh Khan Dinh, T. Tran, Vu Truong Son Le, N. Dang, T. Nguyen
Materials exhibiting magnetoelectric effects have drawn great interest because of their intriguing physical phenomena and potential applications in electronic devices. The magnetoelectric (ME) coupling makes the materials promising for use in multifunctional devices with electric-field-tunable magnetism and magnetic-field-controlled ferroelectricity. Very recently, a strong ME effect has been found in the BaRFeO4 system (R is a rare-earth element), in which the ferroelectricity is driven by the onset of a long-range cycloidal antiferromagnetic order of Fe spins. However, previous studies have shown how complicated the synthesis procedure is to obtain single-phase samples of the materials. In this work, we present a simple and easy fabrication process to synthesise high-quality BaDyFeO4 using the conventional solid-state reaction method. The structural, morphological, and optical properties of the synthesised sample were investigated by means of X-ray diffraction, scanning electron microscopy, and UV-Vis spectroscopy, respectively. The sample was formed from high-quality microparticles. The X-ray diffraction study reveals the single-phase nature of the sample adopting the Pnma orthorhombic structure without any impurity phases. The detailed structural parameters were refined with Rietveld refinement. The sample demonstrates a direct gap semiconducting behaviour. The experimental results of the structural and electronic properties of BaDyFeO4 are complemented by density functional theory (DFT) calculations.
具有磁电效应的材料由于其有趣的物理现象和在电子器件中的潜在应用而引起了人们的极大兴趣。磁电耦合使该材料有望用于具有电场可调谐磁性和磁场控制铁电的多功能器件。最近,在BaRFeO4体系(R是稀土元素)中发现了强ME效应,其中铁电性是由铁自旋的长周期摆线反铁磁序的开始驱动的。然而,先前的研究表明,要获得材料的单相样品,合成过程是多么复杂。在本研究中,我们提出了一种简单易行的制备方法,利用传统的固相反应方法合成高质量的BaDyFeO4。通过x射线衍射、扫描电子显微镜和紫外可见光谱对合成样品的结构、形态和光学性质进行了研究。样品是由高质量的微粒组成的。x射线衍射分析表明,样品采用Pnma正交结构,为单相,无杂质相。采用Rietveld细化法对结构参数进行细化。样品显示出直接间隙半导体行为。BaDyFeO4的结构和电子性能的实验结果与密度泛函理论(DFT)的计算结果相吻合。
{"title":"Synthesis and physical properties of multiferroic BaDyFeO4","authors":"T. T. Le, Danh Bich Do, Thanh Khan Dinh, T. Tran, Vu Truong Son Le, N. Dang, T. Nguyen","doi":"10.26459/hueunijns.v132i1b.6912","DOIUrl":"https://doi.org/10.26459/hueunijns.v132i1b.6912","url":null,"abstract":"Materials exhibiting magnetoelectric effects have drawn great interest because of their intriguing physical phenomena and potential applications in electronic devices. The magnetoelectric (ME) coupling makes the materials promising for use in multifunctional devices with electric-field-tunable magnetism and magnetic-field-controlled ferroelectricity. Very recently, a strong ME effect has been found in the BaRFeO4 system (R is a rare-earth element), in which the ferroelectricity is driven by the onset of a long-range cycloidal antiferromagnetic order of Fe spins. However, previous studies have shown how complicated the synthesis procedure is to obtain single-phase samples of the materials. In this work, we present a simple and easy fabrication process to synthesise high-quality BaDyFeO4 using the conventional solid-state reaction method. The structural, morphological, and optical properties of the synthesised sample were investigated by means of X-ray diffraction, scanning electron microscopy, and UV-Vis spectroscopy, respectively. The sample was formed from high-quality microparticles. The X-ray diffraction study reveals the single-phase nature of the sample adopting the Pnma orthorhombic structure without any impurity phases. The detailed structural parameters were refined with Rietveld refinement. The sample demonstrates a direct gap semiconducting behaviour. The experimental results of the structural and electronic properties of BaDyFeO4 are complemented by density functional theory (DFT) calculations.","PeriodicalId":13004,"journal":{"name":"Hue University Journal of Science: Natural Science","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74534854","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
Additional data on species diversity of gobies (Actinopteri: Gobiiformes) in Xuan Thuy National Park, Nam Dinh province 南定省宣翠国家公园虾虎鱼物种多样性的补充资料(放线鱼目:虾虎目)
Pub Date : 2023-06-30 DOI: 10.26459/hueunijns.v132i1b.7050
Van Long Pham, Hoang Nam Chu, Thi Thanh Huyen Dang, H. Nguyen, Duc Hau Tran
Xuan Thuy National Park in the Red River Delta Biosphere Reserve is a biodiverse area that supports a variety of flora, fauna, and fishery resources. This study aims to provide new data on goby fish in this area by conducting monthly collections from 2018 to 2019. Based on morphological analysis, we identified 43 species of gobies, 27 of which were tropical fish. We added three new goby records to the fish fauna of Vietnam, three to northern Vietnam, and eight to the study site. The goby community was dominated by two species, namely Glossogobius olivaceus and Glossogobius giuris. Besides, the goby community of Xuan Thuy National Park is nearest to that of Tien Hai Wetland Nature Reserve but is far different from that of Ha Long Bay. This study area has a more diverse goby community than other locations in northern Vietnam. These findings further suggest the importance of this mangrove forest for gobies, and they are fundamental data for conservation and sustainable exploitation.
宣翠国家公园位于红河三角洲生物圈保护区,是一个生物多样性的地区,支持各种动植物和渔业资源。该研究旨在通过2018年至2019年的月度收集,提供该地区虾虎鱼的新数据。在形态学分析的基础上,共鉴定出43种虾虎鱼,其中热带鱼27种。我们在越南的鱼类动物群中增加了3条新的虾虎鱼记录,在越南北部增加了3条,在研究地点增加了8条。虾虎鱼群落以两种虾虎鱼(Glossogobius olivaceus和Glossogobius giuris)为主。此外,宣翠国家公园的虾虎鱼群落最接近天海湿地自然保护区,但与下龙湾的虾虎鱼群落差异较大。与越南北部其他地区相比,该研究区域的虾虎鱼群落更为多样化。这些发现进一步表明了这片红树林对虾虎鱼的重要性,它们是保护和可持续开发的基础数据。
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引用次数: 1
The local uniform convergence of positive harmonic function sequence 正调和函数序列的局部一致收敛性
Pub Date : 2023-05-09 DOI: 10.26459/hueunijns.v131i1d.6663
Dang Thinh Do, Le Dieu Linh Tran, Nhat Quy Hoang
The Harnack distance on space  and its conformal invariance were constructed and studied by Herron. In this paper, we obtain the Harnack distance on domains  in . Then, we use this concept to investigate some properties of the positive harmonic function class. These results are obtained in the complex plane, so it is advantageous to take some tools of the complex analysis. The main result of this paper is the property of the local uniform convergence of the positive harmonic sequences on a domain in the complex plane.
Herron构造并研究了空间上的Harnack距离及其共形不变性。在本文中,我们得到了域上的哈纳克距离。然后,我们利用这一概念研究了正调和函数类的一些性质。这些结果都是在复平面上得到的,因此利用复分析的一些工具是有利的。本文的主要结果是复平面上正调和数列局部一致收敛的性质。
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引用次数: 0
Sample decomposition to determine microplastics in parts of mullets 样品分解以测定鲻鱼部分的微塑料
Pub Date : 2023-03-31 DOI: 10.26459/hueunijns.v132i1a.7095
Thi Ai My Tran, T. H. Phan, A. Tran, Q. D. Luong, Van Quy Vo
In this study, a 10% KOH solution was used to decompose the meat, skin, and digestive system of mullets. The factors in each experiment are as follows: 1) VKOH:mmeat is 10/1 (mL·g–1), incubated at 25 °C for 72 h; VKOH:mskin is 15/1 (mL·g–1), incubated at 40 °C for 72 h; VKOH:mdigestive system is 20/1 (mL·g–1), incubated at 40 °C for 72 h. The actual sample images display microplastics in the surveyed parts of the mullets with different shapes and colours.
本研究采用10% KOH溶液对鲻鱼的肉、皮和消化系统进行分解。各实验影响因素如下:1)VKOH:mmeat = 10/1 (mL·g-1), 25℃孵育72h;VKOH:mskin为15/1 (mL·g-1), 40℃孵育72 h;VKOH:消化系统为20/1 (mL·g-1),在40°C下孵育72小时。实际样品图像显示,鲻鱼被调查部位的微塑料具有不同的形状和颜色。
{"title":"Sample decomposition to determine microplastics in parts of mullets","authors":"Thi Ai My Tran, T. H. Phan, A. Tran, Q. D. Luong, Van Quy Vo","doi":"10.26459/hueunijns.v132i1a.7095","DOIUrl":"https://doi.org/10.26459/hueunijns.v132i1a.7095","url":null,"abstract":"In this study, a 10% KOH solution was used to decompose the meat, skin, and digestive system of mullets. The factors in each experiment are as follows: 1) VKOH:mmeat is 10/1 (mL·g–1), incubated at 25 °C for 72 h; VKOH:mskin is 15/1 (mL·g–1), incubated at 40 °C for 72 h; VKOH:mdigestive system is 20/1 (mL·g–1), incubated at 40 °C for 72 h. The actual sample images display microplastics in the surveyed parts of the mullets with different shapes and colours.","PeriodicalId":13004,"journal":{"name":"Hue University Journal of Science: Natural Science","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84840153","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
期刊
Hue University Journal of Science: Natural Science
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