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Performance Enhancement of Chitosan for Food Packaging:Impact of Additives and Nanotechnology
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作者 Panji Setya Utama Putra Damar Rastri Adhika +1 位作者 Lia Amelia TresnaWulan Asri Suprijadi Suprijadi 《Journal of Renewable Materials》 2025年第6期1043-1070,共28页
The continuous increase in petroleum-based plastic food packaging has led to numerous environmental concerns.One effort to reduce the use of plastic packaging in food is through preservation using biopolymer-based pac... The continuous increase in petroleum-based plastic food packaging has led to numerous environmental concerns.One effort to reduce the use of plastic packaging in food is through preservation using biopolymer-based packaging.Among the many types of biopolymers,chitosan is widely used and researched due to its non-toxic,antimicrobial,and antifungal properties.Chitosan is widely available since it is a compound extracted from seafood waste,especially shrimps and crabs.The biodegradability and biocompatibility of chitosan also showed good potential for various applications.These characteristics and propertiesmake chitosan an attractive biopolymer to be implemented as food packaging in films and coatings.Chitosan has been tested in maintaining and increasing the shelf life of food,especially seafood such as fish and shrimp,and post-harvest products such as fruits and vegetables.In addition to its various advantages,the properties and characteristics of chitosan need to be improved to produce optimal preservation.The properties and characteristics of chitosan are improved by adding various types of additive materials such as biopolymers,plant extracts,essential oils,and metal nanoparticles.Research shows that material additives and nanotechnology can improve the quality of chitosan-based food packaging for various types of food by enhancing mechanical properties,thermal stability,antimicrobial activity,and antioxidant activity.This review provides a perspective on the recent development and properties enhancement of chitosan composite with additives and nanotechnology,as well as this material’s challenges and prospects as food packaging. 展开更多
关键词 BIOPOLYMER CHITOSAN essential oil plant extract metal nanoparticles food packaging NANOTECHNOLOGY
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On Discrete Hopf Fibrations, Grand Unification Groups, the Barnes-Wall, Leech Lattices, and Quasicrystals
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作者 Carlos Castro Perelman 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第4期1699-1712,共14页
A discrete Hopf fibration of S15 over S8 with S7 (unit octonions) as fibers leads to a 16D Polytope P16 with 4320 vertices obtained from the convex hull of the 16D Barnes-Wall lattice Λ16. It is argued (conjectured) ... A discrete Hopf fibration of S15 over S8 with S7 (unit octonions) as fibers leads to a 16D Polytope P16 with 4320 vertices obtained from the convex hull of the 16D Barnes-Wall lattice Λ16. It is argued (conjectured) how a subsequent 2-1 mapping (projection) of P16 onto a 8D-hyperplane might furnish the 2160 vertices of the uniform 241 polytope in 8-dimensions, and such that one can capture the chain sequence of polytopes 241,231,221,211in D=8,7,6,5dimensions, leading, respectively, to the sequence of Coxeter groups E8,E7,E6,SO(10)which are putative GUT group candidates. An embedding of the E8⊕E8and E8⊕E8⊕E8lattice into the Barnes-Wall Λ16 and Leech Λ24 lattices, respectively, is explicitly shown. From the 16D lattice E8⊕E8one can generate two separate families of Elser-Sloane 4D quasicrystals (QC’s) with H4 (icosahedral) symmetry via the “cut-and-project” method from 8D to 4D in each separate E8 lattice. Therefore, one obtains in this fashion the Cartesian product of two Elser-Sloane QC’s Q×Qspanning an 8D space. Similarly, from the 24D lattice E8⊕E8⊕E8one can generate the Cartesian product of three Elser-Sloane 4D quasicrystals (QC’s) Q×Q×Qwith H4 symmetry and spanning a 12D space. 展开更多
关键词 Division Algebras Hopf Fibrations Barnes-Wall Lattice Leech Lattice Exceptional Lie Algebras Grand Unification QUASICRYSTALS
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A Novel Derivation of Black Hole Entropy in all Dimensions from Truly Point Mass Sources
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作者 Carlos Castro Perelman 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2024年第3期1017-1028,共12页
It is explicitly shown how the Schwarzschild Black Hole Entropy (in all dimensions) emerges from truly point mass sources at r=0due to a non-vanishing scalar curvature involving the Dirac delta distribution. In order ... It is explicitly shown how the Schwarzschild Black Hole Entropy (in all dimensions) emerges from truly point mass sources at r=0due to a non-vanishing scalar curvature involving the Dirac delta distribution. In order to achieve this, one is required to extend the domain of r to negative values −∞≤r≤+∞. It is the density and anisotropic pressure components associated with the point mass delta function source at the origin r=0which furnish the Schwarzschild black hole entropy in all dimensions D≥4after evaluating the Euclidean Einstein-Hilbert action. Two of the most salient results are i) that the observed spacetime dimension D=4is precisely singled out from all the other dimensions when the strong and weak energy conditions are met, and ii) the point mass source described in this work is not the result of a spherically symmetric gravitational collapse of a star as described by the Oppenheimer-Snyder model because we are not neglecting the pressure. As usual, it is required to take the inverse Hawking temperature βHas the length of the circle Sβ1obtained from a compactification of the Euclidean time in thermal field theory which results after a Wick rotation, it=τ, to imaginary time. This approach can be generalized to the Reissner-Nordstrom and Kerr-Newman metrics. The physical implications of this finding warrant further investigation since it suggests a profound connection between the notion of gravitational entropy and spacetime singularities. 展开更多
关键词 General Relativity Black Holes ENTROPY Strings
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New Alleles of Rice <i>ebisu dwarf</i>(<i>d</i>2) Mutant Show both Brassinosteroid-Deficient and -Insensitive Phenotypes 被引量:1
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作者 Tomoaki Sakamoto Yoichi Morinaka +1 位作者 Hidemi Kitano Shozo Fujioka 《American Journal of Plant Sciences》 2012年第12期1699-1707,共9页
ebisu dwarf (d2) is a mutant caused by mutation in a rice brassinosteroid biosynthetic enzyme gene, CYP90D2/D2, thereby conferring a brassinosteroid-deficient dwarf phenotype. Three newly isolated d2 alleles derived f... ebisu dwarf (d2) is a mutant caused by mutation in a rice brassinosteroid biosynthetic enzyme gene, CYP90D2/D2, thereby conferring a brassinosteroid-deficient dwarf phenotype. Three newly isolated d2 alleles derived from a Nippon- bare mutant library (d2-3, d2-4, and d2-6) produced more severe dwarf phenotypes than the previously characterized null allele from a Taichung 65 mutant library, d2-1. Linkage analysis and a complementation test clearly indicated that the mutant phenotypes in d2-6 were caused by defects in CYP90D2/D2, and exogenous treatment with brassinolide, a bioactive brassinosteroid, rescued the dwarf phenotype of three Nipponbare-derived d2 mutants. However, the content of endogenous bioactive brassinosteroid, castasterone, and the expression of brassinosteroid-response genes indicated that partial suppression of the brassinosteroid response in addition to a brassinosteroid deficiency has occurred in the Nipponbare-derived d2 mutants. Based on these results, we discuss the possibility that wild-type Nipponbare has some defects in an unknown factor or factors related to the brassinosteroid response in rice. 展开更多
关键词 Brassinosteroids BRASSINOSTEROID Biosynthetic Enzymes BRASSINOSTEROID Sensitivity Cytochrome P450 MONOOXYGENASE MUTANT Allele RICE
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Molecular Dissection of Bombyx mori Nucleopolyhedrovirus orf8 Gene
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作者 WonKyung Kang 《Virologica Sinica》 SCIE CAS CSCD 2009年第4期315-322,共8页
Viruses including baculoviruses are obligatory parasites, as their genomes do not encode all the proteins required for replication. Therefore, viruses have evolved to exploit the behavior and the physiology of their h... Viruses including baculoviruses are obligatory parasites, as their genomes do not encode all the proteins required for replication. Therefore, viruses have evolved to exploit the behavior and the physiology of their hosts and olden coevolved with their hosts over millions of years. Recent comparative analyses of complete genome sequences of baculoviruses revealed the patterns of gene acquisitions and losses that have occurred during baculovirus evolution. In addition, knowledge of virus genes has also provided understanding of the mechanism of baculovirus infection including replication, species-specific virulence and host range. The Bm8 gene of Bombyx mori nucleopolyhedrovirus (NPV) and its homologues are found only in group I NPV genomes. The Autographa californica NPV Ac 16 gene is a homologue of Bm8 and, encodes a viral structural protein. It has been shown that BmS/Ac 16 interacts with baculoviral and cellular proteins. BmS/Ac 16 interacts with baculoviral IE1 that is facilitated by coiled coil domains, and the interaction with IE1 is important for Bin8 function. Acl6 also forms a complex with viral FP25 and cellular actin and associates with membranes via palmitoylation. These data suggested that this gene family encodes a multifunctional protein that accomplishes specific needs of group I NPVs. 展开更多
关键词 Group I NPV Bm8 Early gene Structural protein Nuclear localization
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Effects of temperature and input energy on a quasi-three-level emission cross section of Nd^(3+):YAG pumped by a flashlamp
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作者 Seyed Ebrahim Pourmand Noriah Bidin Hazri Bakhtiar 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第9期328-331,共4页
The influence of temperature and input energy on the fluorescence emission cross section of Nd3+ :YAG crystal is studied. The stimulated emission cross sections of quasi-three-level systems are determined in a tempe... The influence of temperature and input energy on the fluorescence emission cross section of Nd3+ :YAG crystal is studied. The stimulated emission cross sections of quasi-three-level systems are determined in a temperature range from -30 to 60 ℃ and an input energy range from 18 to 75 J. The cross section is found to be decreased when the temperature and the input energy are increased. This is attributed to the thermal broadening mechanism of the emission line. This study is relevant for the development of laser design. 展开更多
关键词 emission cross section Nd:YAG laser flashlamp FLUORESCENCE
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Quantum Recoil Effects of Spontaneous Emission on Disentanglement
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作者 郑丽 杨垂平 +1 位作者 王雅红 郑泰玉 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第4期560-564,共5页
By taking into account spatial degrees of freedom of atoms, we study the internal-state disentanglement dynamics of two atoms interacting with a vacuum multi-mode noise field. We show that the complete internal-state ... By taking into account spatial degrees of freedom of atoms, we study the internal-state disentanglement dynamics of two atoms interacting with a vacuum multi-mode noise field. We show that the complete internal-state disentanglement of the two atoms, caused due to the atomic spontaneous emission can be achieved in a finite time. 展开更多
关键词 quantum back-action spontaneous emission DISENTANGLEMENT entanglement sudden death
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Temperature and Input Energy Dependence of the 946-nm Stimulated Emission Cross Section of Nd^(3+):YAG Pumped by a Flashlamp
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作者 Seyed Ebrahim Pourmand Noriah Bidin Hazri Bakhtiar 《Chinese Physics Letters》 SCIE CAS CSCD 2012年第3期104-106,共3页
The thermal effect on the laser transition at 946nm is investigated.The temperature of the cooling system is verified in the range 2-60℃.A Nd:YAG laser crystal is utilized as a gain medium and is pumped by a newly de... The thermal effect on the laser transition at 946nm is investigated.The temperature of the cooling system is verified in the range 2-60℃.A Nd:YAG laser crystal is utilized as a gain medium and is pumped by a newly developed flashlamp.The variable pumping energy is accomplished within the 5-40 d range.The stimulated emission cross section of the 946-nm line is estimated based on the fluorescence spectrum of the Nd:YAG laser.The stimulated emission cross section of the 946-nm line is found to be inversely proportional to the temperature and to the input energy due to the increase of the thermal population at the ground level. 展开更多
关键词 ND:YAG PUMPED PUMPING
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Genetic Background Influences Brassinosteroid-Related Mutant Phenotypes in Rice
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作者 Tomoaki Sakamoto Hidemi Kitano Shozo Fujioka 《American Journal of Plant Sciences》 2013年第2期212-221,共10页
In two cases, mutations in the same brassinosteroid-related genes caused different phenotypes in japonica varieties Nipponbare and Taichung 65. The mutant phenotypes were less severe in the Taichung 65 background than... In two cases, mutations in the same brassinosteroid-related genes caused different phenotypes in japonica varieties Nipponbare and Taichung 65. The mutant phenotypes were less severe in the Taichung 65 background than in the Nipponbare background. Three newly isolated brassinosteroid-insensitive mutants (d61-1N, d61-11, and d61-12) derived from a Nipponbare mutant library were found to be alleles of d61, which represent defects in the OsBRI1 gene. Although the Nipponbare-derived mutant d61-1N had the same nucleotide substitution as the previously characterized Taichung 65-derived mutant d61-1T, these two mutants showed different phenotypes for plant stature, internode elongation pattern, and seed shape;in each case, d61-1N (in the Nipponbare genetic background) had the more severe mutant phenotype. Similar trends were seen for phenotypes caused by mutants of d2, a brassinosteroid biosynthesis gene. Consistent with these phenotypes, the expression of brassinosteroid-responsive genes was lower in the Nipponbare-derived mutants. These results can be explained by our findings that feed-forward up-regulation of OsBRI1 did not occur in the Nipponbare-derived mutants and that an mPing transposon is inserted into the promoter region of Nipponbare OsBRI1. Based on these results, we conclude that the expression of OsBRI1, especially its feed-forward up-regulation, is misregulated in wild-type Nipponbare and in brassinosteroid-related mutants in a Nipponbare genetic background. Although Nipponbare is a model rice genotype, it can be categorized as an OsBRI1 mutant that has reduced sensitivity to brassinosteroid. 展开更多
关键词 BRASSINOSTEROID BRASSINOSTEROID Receptor BRASSINOSTEROID Sensitivity miniature PING (mPing) MUTANT Nipponbare RICE
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Reflection Profile of Iron Due to Corrosion Activity Using Fiber Optic
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作者 Asiah Yahaya Noor A'in A.Rahman +1 位作者 Rosly A .Rahman M. Asmu'i M. Akil 《材料科学与工程(中英文B版)》 2011年第5期626-629,共4页
关键词 光纤测量系统 腐蚀损伤 铁金属 反射剖面 反射光谱 腐蚀性环境 经济损失 腐蚀环境
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Impact of vaccination on the dynamics of COVID-19:A mathematical study using fractional derivatives
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作者 Shraddha Ramdas Bandekar Mini Ghosh C.Rajivganthi 《International Journal of Biomathematics》 SCIE 2024年第2期201-232,共32页
Arrival of a new disease marks a yearlong destruction of human lives and economy in general,and if the disease turns out to be a pandemic the loss is frightening.COVID-19 is one such pandemic that has claimed millions... Arrival of a new disease marks a yearlong destruction of human lives and economy in general,and if the disease turns out to be a pandemic the loss is frightening.COVID-19 is one such pandemic that has claimed millions of lives till date.There is a suffering throughout the world due to various factors associated with the pandemic,be it loss of livelihoods because of sudden shutdown of companies and lockdown,or loss of lives due to lack of medical aid and inadequate vaccination supplies.In this study,we develop a six-compartmental epidemiological model incorporating vaccination.The motivation behind the study is to analyze the significance of higher vaccination efficacy and higher rate of population getting vaccinated in controlling the rise in infectives and thereby the untimely demise of various individuals.The work begins with an ordinary differential equation model followed by stability analysis of the same,after which a fractional-order derivative model of the same is formulated and the existence of uniformly stable solution for the system is proved.In addition to this,we present the stability of the equilibria in general for the fractional model framed.The sensitivity analysis of the basic reproduction number along with its correlation with various parameters is presented.In addition to this,sensitivity of certain state variables in the fractional model with respect to different.fractional orders as well with respect to different infection rate is exhibited in this work.Factors related to lockdown and usage of face shields are incorporated in the entire study,and importance of these is highlighted in the study as well.The major takeaway from the study is that mere vaccination will not sufice in eradication of the virus.The vaccine efficacy plays a major role along with other intervention included in the model.The numerical simulations are carried out in MATLAB software using ode45 and fdel2. 展开更多
关键词 Caputo fractional derivative basic reproduction number stability analysis SENSITIVITYANALYSIS VACCINATION
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An analytical approach for the fractional-order Hepatitis B model using new operator
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作者 Surath Ghosh 《International Journal of Biomathematics》 SCIE 2024年第1期177-198,共22页
In this work,the main goal is to implement Homotopy perturbation transform method(HPTM)involving Katugampola fractional operator.As an example,a fractional order Hepatitis model is considered to analyze the solutions.... In this work,the main goal is to implement Homotopy perturbation transform method(HPTM)involving Katugampola fractional operator.As an example,a fractional order Hepatitis model is considered to analyze the solutions.At first,the integer order model is converted to fractional order model in Caputo sense.Then,the new operator Katugampola fractional derivative is used to present the model.The new such kind of operator is illustrated in Caputo sense.HPTM is described to get the solution of the proposed model using the new kind of operator.Also,there are some analyses about the new kind of operator to prove the efficiency of the operator. 展开更多
关键词 Caputo derivative Katugampola fractional derivative homotopy perturbation transform method Hepatitis B model
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Neuromodulation of the peripheral nervous system:Bioelectronic technology and prospective developments
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作者 Hayoung Song Moohyun Kim +7 位作者 Enji Kim Jakyoung Lee Inhea Jeong Kyeonghee Lim Seoung Young Ryu Myoungjae Oh Younhee Kim Jang-Ung Park 《BMEMat(BioMedical Engineering Materials)》 2024年第1期88-114,共27页
The peripheral nervous system(PNS)is a fascinatingly complex and crucial component of the human body,responsible for transmitting vital signals throughout the body's intricate network of nerves.Its efficient funct... The peripheral nervous system(PNS)is a fascinatingly complex and crucial component of the human body,responsible for transmitting vital signals throughout the body's intricate network of nerves.Its efficient functioning is paramount to our health,with any dysfunction often resulting in serious medical conditions,including motor disorders,neurological diseases,and psychiatric disorders.Recent strides in science and technology have made neuromodulation of the PNS a promising avenue for addressing these health issues.Neuromodulation involves modifying nerve activity using a range of techniques,such as electrical,chemical,optical,and mechanical stimulation.Bioelectronics plays a critical role in this effort,allowing for precise,controlled,and sustained stimulation of the PNS.This paper provides an overview of the PNS,discusses the current state of neuromodulation devices,and presents emerging trends in the field,including advances in wireless power transfer and materials,that are shaping the future of neuromodulation. 展开更多
关键词 BIOELECTRONICS NEUROMODULATION peripheral nervous system
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Homeostasis of Brassinosteroids Regulated by DRL1, a Putative Acyltransferase in Arabidopsis 被引量:7
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作者 Wenjiao Zhu Haijiao Wang +4 位作者 Shozo Fujioka Tao Zhou Hailong Tian Weisheng Tian Xuelu Wang 《Molecular Plant》 SCIE CAS CSCD 2013年第2期546-558,共13页
Brassinosteroids (BRs) play essential roles in regulating various aspects of plant growth and development and in responding to diverse environmental cues, and their metabolism is an important way to regulate their h... Brassinosteroids (BRs) play essential roles in regulating various aspects of plant growth and development and in responding to diverse environmental cues, and their metabolism is an important way to regulate their homeosta-sis in plants. Here, we identified a dominant mutant, dwarf and round leaf-1 (drll-D), which exhibits weak BR-deficient or BR-insensitive mutant phenotypes, including short and round leaves, prolonged senescence, dwarfed shape, and altered expression levels of the BR-responsive genes. Hypocotyl length and root inhibition assays suggest that the drll-D mutant responds to BRs normally, but has decreased BR signaling outputs. The endogenous levels of several BRs, includ-ing typhasterol (TY), 6-deoxotyphasterol (6-deoxoTY), and 6-deoxocastasterone (6-deoxoCS), are significantly lower in the drll-D mutant than in the wild-type. The DRL1 gene encodes an acyltransferase and is widely expressed in leaves, roots, flowers, and siliques. Plants without DRL1 and its homologs are larger with an enhanced BR signaling. The expres-sion of DRL1 was induced by eBL and inhibited by ABA. DRL1 is involved in the BR metabolism likely by catalyzing the BR conjugation through esterification, which plays important roles in regulating the BR homeostasis and responding to abiotic stresses in Arabidopsis. 展开更多
关键词 DRL1 (dwarf and round leaf 1) BRASSINOSTEROID ACYLTRANSFERASE 6-deoxoCS metabolism.
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Recent advances in electronic devices for monitoring and modulation of brain 被引量:3
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作者 Yong Won Kwon Yoon Sun Jun +2 位作者 Young-Geun Park Jiuk Jang Jang-Ung Park 《Nano Research》 SCIE EI CSCD 2021年第9期3070-3095,共26页
The brain is actuated by billions of neurons with trillions of interconnections that regulate human behaviors.Understanding the mechanisms of these systems that induce sensory reactions and respond to disease remains ... The brain is actuated by billions of neurons with trillions of interconnections that regulate human behaviors.Understanding the mechanisms of these systems that induce sensory reactions and respond to disease remains one of the greatest challenges in science,engineering,and medicine.Recent advances in nanomaterials and nanotechnologies have led to the extensive research of electronic devices for brain interfaces to better understand the neural activities of the brains complex nervous system.The development of sensor devices for monitoring the physiological signals of the brain related to traumatic injury status has accompanied by the progress of electronic neural probes in parallel.In addition,these neurological and stereotactic surgical revolutions hold immense potential for clinical analysis of pharmacological systems within cerebral tissues.Here,we review the progress of electronic devices interfacing with brain in terms of the materials,fabrication technologies,and device designs.Neurophysiological activity can be measured and modulated by brain probes based on newly developed nanofabrication methodologies.Furthermore,in vivo pathological monitoring of the brain and pharmacological assessment has been developed in miniaturized and wireless form.We also consider the key challenges and prospects for further development,and explore the future directions emerging in the latest research. 展开更多
关键词 neural interfaces neural recording NEUROMODULATION intracranial pressure monitoring microfluidic drug delivery
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Comparison Study of Two Commercial Spectrometers for Heavy Metal Analysis of Laser Induced Breakdown Spectroscopy (LIBS) 被引量:3
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作者 M.Arab N.Bidin +2 位作者 Z.H.Rizvi S.Safie M.A.Alsaedi 《Photonic Sensors》 SCIE EI CAS 2014年第1期63-69,共7页
The purpose of this paper is to compare the performance of two spectrometers that are manufactured from the same company. In this work, heavy metals like lead Pb and copper Cu in the KBr matrix were analyzed using the... The purpose of this paper is to compare the performance of two spectrometers that are manufactured from the same company. In this work, heavy metals like lead Pb and copper Cu in the KBr matrix were analyzed using the laser induced breakdown spectroscopic technique. A Q-switched Nd:YAG laser with 90mJ per pulse operating at the fundamental wavelength of 1064nm and pulse duration of 10 ns was used to generate plasma at the focal region. The important experimental parameters such as the laser energy, integration time, distance between the lens and sample, distance and angle of the optical fiber from the target were optimized. Two spectrometers manufactured by Ocean Optics namely as Maya2000Pro and USB 4000 were employed for anlyzing the spectral lines. The experimental setup and conditions were remained the same for both experiments. The production of spectral lines from each of the interested elements was analyzed and compared with the NIST (National Institute of Standards and Technology) database. The sensitivity, repeatability and limit of detection for each of the systems are discussed in detail. 展开更多
关键词 Heavy metal SPECTROMETER LIBS LOD
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Rare-earth dialkyl and dihydride complexes bearing monoanionic ancillary ligands 被引量:1
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作者 CHENG JianHua HOU ZhaoMin 《Science China Chemistry》 SCIE EI CAS 2011年第12期2032-2037,共6页
Rare-earth elements, including scandium, yttrium, and the lanthanides (La-Lu), possess unique chemical and physical properties, and constitute one of the last frontiers in the periodic table. Rare-earth elements are... Rare-earth elements, including scandium, yttrium, and the lanthanides (La-Lu), possess unique chemical and physical properties, and constitute one of the last frontiers in the periodic table. Rare-earth elements are vital for many high-tech industry products such as smartphones and electric cars. However, 展开更多
关键词 稀土元素 复合物 轴承 配体 二氢 烷基 化学性质 香格里拉
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Plasma preparation method and tribological properties of diamond-like carbon coating on magnesium alloy AZ31 substrate 被引量:1
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作者 HAN BeiBei JU DongYing +1 位作者 SATO Susumu ZHAO HuiJun 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2019年第11期1939-1947,共9页
Magnesium alloys are light weight and exhibit good recyclability but suffer from low hardness and wear resistance.In this study,the hardness and wear resistance of AZ31 magnesium alloy were improved by depositing diam... Magnesium alloys are light weight and exhibit good recyclability but suffer from low hardness and wear resistance.In this study,the hardness and wear resistance of AZ31 magnesium alloy were improved by depositing diamond-like carbon(DLC)films as hard protective coatings using ion-beam-enhanced deposition with various CH4/H2 ratio,gas flow rates and accelerating voltages.The supporting effect of the magnesium alloy was enhanced by the production of a graded interfacial layer which is composed of film atoms and substrate atoms.The composition and mechanical properties of the DLC coatings were characterized using scanning electron microscopy(SEM),Raman spectroscopy,Rockwell test and nano-indentor.The tribological properties of the coating were also investigated using a frictional surface microscope with an in situ observation system and friction force measurements.The DLC films were characterized by a lower intensity ratio of the D-peak to G-peak(ID/IG),higher hardness,and improved tribological properties when deposited at a lower accelerating voltage(6 kV).At the CH4/H2 ratio of 1:99 and 6 sccm/6 kV,minimum ID/IG values of 0.62,relatively low friction force value of 0.12 N,and a maximum hardness of 4056HV were attained respectively.In addition,the DLC film exhibited improved wear resistance and a shallower wear track at this condition. 展开更多
关键词 DLC film magnesium alloy PLASMA preparation HARDNESS wear resistance
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Q-switched ytterbium doped fiber laser using multi-walled carbon nanotubes saturable absorber 被引量:1
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作者 N.Kasim A.H.H.Al-Masoodi +3 位作者 F.Ahmad Y.Munajat H.Ahmad S.W.Harun 《Chinese Optics Letters》 SCIE EI CAS CSCD 2014年第3期41-44,共4页
A Q-switched ytterbium-doped fiber laser (YDFL) is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide (MWCNTs-PEO) film as a passive saturable absorber (SA). The s... A Q-switched ytterbium-doped fiber laser (YDFL) is proposed and demonstrated using a newly developed multi-walled carbon nanotubes polyethylene oxide (MWCNTs-PEO) film as a passive saturable absorber (SA). The saturable absorber is prepared by mixing the MWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and integrated into the laser cavity for Q-switching pulse generation. The laser generates a stable pulse operating at wavelength of 1060.2 nm with a threshold pump power of 53.43 mW. The YDFL generates a stable pulse train with repetition rates ranging from 7.92 to 24.27 kHz by varying 980-nm pump power from 53.42 to 65.72 mW. At 59.55-mW pump power, the lowest pulse width and the highest pulse energy are obtained at 12.18 μs and 143.5 n J, respectively. 展开更多
关键词 MWCNTS PEO length SA Q-switched ytterbium doped fiber laser using multi-walled carbon nanotubes saturable absorber
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Design of Mach-Zehnder Interferometer and Ring Resonator for Biochemical Sensing 被引量:2
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作者 Dedi IRAWAN Toto SAKTIOTO +1 位作者 Jalil ALI Preecha YUPAPIN 《Photonic Sensors》 SCIE EI CAS CSCD 2015年第1期12-18,共7页
We proposed a compact design of an optical biochemical sensor based on the Mach-Zehnder interferometer (MZI), which was coupled by a ring resonator (RR) as a sensing tool. The sensor sensitivity has been determine... We proposed a compact design of an optical biochemical sensor based on the Mach-Zehnder interferometer (MZI), which was coupled by a ring resonator (RR) as a sensing tool. The sensor sensitivity has been determined by power difference at the output ports. The sensor enhancement has been optimized by numerically evaluating the geometrical parameters of the MZ! and RR. A great sensor sensitivity depicted by Fano resonance characteristic has been demonstrated as a function of the round trip phase in the range of 4×10^-4 - 4×10^-4, which was changed by the presence of the sample solution in the sensing area. This optimum sensitivity has been obtained for the values of two coupling coefficients of the MZI k1 =k2 =0.5/mm and the coupling coefficient between the MZI arm and RR KR = 0.5/ram. Furthermore, a good profile of sensitivity exchange has been exhibited by inducing the direct current voltage to the coupling region of k R. Finally, the output power transmission of the ring-coupled arm was depicted as a function of tunable k R. 展开更多
关键词 Mach-Zehnder interferometer ring resonator biochemical sensor tunable sensitivity Fano resonance
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