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Designing Symmetric Gradient Honeycomb Structures with Carbon‑Coated Iron‑Based Composites for High‑Efficiency Microwave Absorption 被引量:1
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作者 Yu Zhang Shu‑Hao Yang +9 位作者 Yue Xin Bo Cai Peng‑Fei Hu Hai‑Yang Dai Chen‑Ming Liang Yun‑Tong Meng Ji‑Hao Su Xiao‑Juan Zhang Min Lu Guang‑Sheng Wang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第11期224-241,共18页
The impedance matching of absorbers is a vital factor affecting their microwave absorption(MA)properties.In this work,we controllably synthesized Material of Institute Lavoisier 88C(MIL-88C)with varying aspect ratios(... The impedance matching of absorbers is a vital factor affecting their microwave absorption(MA)properties.In this work,we controllably synthesized Material of Institute Lavoisier 88C(MIL-88C)with varying aspect ratios(AR)as a precursor by regulating oil bath conditions,followed by one-step thermal decomposition to obtain carbon-coated iron-based composites.Modifying the precursor MIL-88C(Fe)preparation conditions,such as the molar ratio between metal ions and organic ligands(M/O),oil bath temperature,and oil bath time,influenced the phases,graphitization degree,and AR of the derivatives,enabling low filler loading,achieving well-matched impedance,and ensuring outstanding MA properties.The MOF-derivatives 2(MD_(2))/polyvinylidene Difluoride(PVDF),MD_(3)/PVDF,and MD4/PVDF absorbers all exhibited excellent MA properties with optimal filler loadings below 20 wt%and as low as 5 wt%.The MD_(2)/PVDF(5 wt%)achieved a maximum effective absorption bandwidth(EAB)of 5.52 GHz(1.90 mm).The MD_(3)/PVDF(10 wt%)possessed a minimum reflection loss(RL_(min))value of−67.4 at 12.56 GHz(2.13 mm).A symmetric gradient honeycomb structure(SGHS)was constructed utilizing the high-frequency structure simulator(HFSS)to further extend the EAB,achieving an EAB of 14.6 GHz and a RL_(min) of−59.0 dB.This research offers a viable inspiration to creating structures or materials with high-efficiency MA properties. 展开更多
关键词 MIL-88c(Fe) Fe/Fe_(3)O_(4)/Fe_(3)c@c controllable preparation Symmetric gradient honeycomb structure Microwave absorbing
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Engineering the coordination structure of Cu for enhanced photocatalytic production of C_(1) chemicals from glucose
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作者 Lulu Sun Shiyang Liu +3 位作者 Taifeng Liu Dongqiang Lei Nengchao Luo Feng Wang 《Chinese Journal of Catalysis》 SCIE CAS CSCD 2024年第8期234-243,共10页
Photocatalytic decomposition of sugars is a promising way of providing H_(2),CO,and HCOOH as sus-tainable energy vectors.However,the production of C_(1) chemicals requires the cleavage of robust C−C bonds in sugars wi... Photocatalytic decomposition of sugars is a promising way of providing H_(2),CO,and HCOOH as sus-tainable energy vectors.However,the production of C_(1) chemicals requires the cleavage of robust C−C bonds in sugars with concurrent production of H_(2),which remains challenging.Here,the photo-catalytic activity for glucose decomposition to HCOOH,CO(C_(1) chemicals),and H_(2) on Cu/TiO_(2)was enhanced by nitrogen doping.Owing to nitrogen doping,atomically dispersed and stable Cu sites resistant to light irradiation are formed on Cu/TiO_(2).The electronic interaction between Cu and nitrogen ions originates valence band structure and defect levels composed of N 2p orbit,distinct from undoped Cu/TiO_(2).Therefore,the lifetime of charge carriers is prolonged,resulting in the pro-duction of C_(1) chemicals and H_(2) with productivities 1.7 and 2.1 folds that of Cu/TiO_(2).This work pro-vides a strategy to design coordinatively stable Cu ions for photocatalytic biomass conversion. 展开更多
关键词 cu photocatalyst coordination structure BIOMASS cc bond c_(1) chemicals
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Fine-tuning electronic structure of N-doped graphitic carbon-supported Co-and Fe-incorporated Mo_(2)C to achieve ultrahigh electrochemical water oxidation activity
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作者 Md.Selim Arif Sher Shah Hyeonjung Jung +3 位作者 Vinod K.Paidi Kug-Seung Lee Jeong Woo Han Jong Hyeok Park 《Carbon Energy》 SCIE EI CAS CSCD 2024年第7期134-149,共16页
Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated... Mo_(2)C is an excellent electrocatalyst for hydrogen evolution reaction(HER).However,Mo_(2)C is a poor electrocatalyst for oxygen evolution reaction(OER).Herein,two different elements,namely Co and Fe,are incorporated in Mo_(2)C that,therefore,has a finely tuned electronic structure,which is not achievable by incorporation of any one of the metals.Consequently,the resulting electrocatalyst Co_(0.8)Fe_(0.2)-Mo_(2)C-80 displayed excellent OER catalytic performance,which is evidenced by a low overpotential of 214.0(and 246.5)mV to attain a current density of 10(and 50)mA cm^(-2),an ultralow Tafel slope of 38.4 mV dec^(-1),and longterm stability in alkaline medium.Theoretical data demonstrates that Co_(0.8)Fe_(0.2)-Mo_(2)C-80 requires the lowest overpotential(1.00 V)for OER and Co centers to be the active sites.The ultrahigh catalytic performance of the electrocatalyst is attributed to the excellent intrinsic catalytic activity due to high Brunauer-Emmett-Teller specific surface area,large electrochemically active surface area,small Tafel slope,and low chargetransfer resistance. 展开更多
关键词 fine-tuning electronic structures heteronanostructures Mo_(2)c multimetal(co/Fe) oxygen evolution reaction
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基于C-STEM校本课程的初中化学项目式教学中核心素养的培育路径
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作者 马春秀 孙红杰 《唐山师范学院学报》 2024年第5期156-160,共5页
开发校本课程,有利于构建适合学校发展的课程教学体系,培养学生的科学思维、探究能力和创新意识。基于核心素养的初中化学校本课程建设目标,应有助于学生形成良好的素质能力。依托学校优势和学生的实际需求,科学设计课程内容,明确课程... 开发校本课程,有利于构建适合学校发展的课程教学体系,培养学生的科学思维、探究能力和创新意识。基于核心素养的初中化学校本课程建设目标,应有助于学生形成良好的素质能力。依托学校优势和学生的实际需求,科学设计课程内容,明确课程开发顺序,重视综合实践活动,开发创新作业任务,构建多元评价体系,是基于C-STEM校本课程的初中化学项目式教学核心素养培育的有效路径。 展开更多
关键词 c-stem 校本课程 初中化学 项目式教学 核心素养
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Atomically self-healing of structural defects in monolayer WSe_(2)
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作者 Kangshu Li Junxian Li +2 位作者 Xiaocang Han Wu Zhou Xiaoxu Zhao 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期49-55,共7页
Minimizing disorder and defects is crucial for realizing the full potential of two-dimensional transition metal dichalcogenides(TMDs) materials and improving device performance to desired properties. However, the meth... Minimizing disorder and defects is crucial for realizing the full potential of two-dimensional transition metal dichalcogenides(TMDs) materials and improving device performance to desired properties. However, the methods in defect controlcurrently face challenges with overly large operational areas and a lack of precision in targeting specific defects. Therefore,we propose a new method for the precise and universal defect healing of TMD materials, integrating real-time imaging withscanning transmission electron microscopy (STEM). This method employs electron beam irradiation to stimulate the diffusionmigration of surface-adsorbed adatoms on TMD materials grown by low-temperature molecular beam epitaxy (MBE),and heal defects within the diffusion range. This approach covers defect repairs ranging from zero-dimensional vacancydefects to two-dimensional grain orientation alignment, demonstrating its universality in terms of the types of samples anddefects. These findings offer insights into the use of atomic-level focused electron beams at appropriate voltages in STEMfor defect healing, providing valuable experience for achieving atomic-level precise fabrication of TMD materials. 展开更多
关键词 scanning transmission electron microscopy(stem) atom manipulation nanoscale materials and structures:fabrication and characterization new materials:theory design FABRIcATION
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Optimization and Characterization of Combined Degumming Process of Typha angustata L. Stem Fibers
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作者 Sana Rezig Foued Khoffi +2 位作者 Mounir Jaouadi Asma Eloudiani Slah Msahli 《Journal of Renewable Materials》 EI CAS 2024年第6期1071-1086,共16页
Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to... Plant derived natural fibers have been widely investigated as alternatives to synthetic fibers in reinforcing polymers.Researchers over the years have explored many plant fibers using different extraction processes to study their physical,chemical,and mechanical properties.In this context,the present study relates to the extraction,characterization,and optimization of Typha angustata L.stem fibers.For this purpose,desirability functions and response surface methodology were applied to simultaneously optimize the diameter(D),linear density(LD);yield(Y),lignin fraction(L),and tenacity(T)of Typha stem fibers.Typha stems have been subjected to both alkali(NaOH)and enzymatic(pectinex ultra-SPL)treatments.Three levels of process variables including enzyme concentration(10,15,and 20 ml/L)and treatment duration(10,15,and 20 days)were used to design the experiments according to the factorial design.Experimental results were examined by analysis of variance and fitted to second order polynomial model using multiple regression analysis.The Derringer’s desirability function released that the values of process variables generating optimized diameter,linear density,yield,lignin ratio and tenacity are 20 ml/L and 20 days for concentration of pectinex ultra-SPL enzyme and treatment duration,respectively.Confirmation was performed and high degree of correlation was found between the experimental and statistical values.Moreover,the morphological structure has been investigated by the scanning electron microscope,showing a crenelated structure of ultimate fiber bundles of cellulose composing the Typha fiber.Compared to Typha stem non-treated fibers(TSNTF),Typha stem combined treated fibers(TSCTF),brings to improve mechanical properties.This change in mechanical properties is affected by modifying the fiber structure showing alpha cellulose of(66.86%)and lignin ratio of(10.83%)with a crystallinity index of(58.47%). 展开更多
关键词 Typha angustata L.stems fibers combined treatment optimization process desirability function chemical and physical properties morphological structure
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Silencing of Jumonji domain-containing 1C inhibits the osteogenic differentiation of bone marrow mesenchymal stem cells via nuclear factor-κB signaling
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作者 Jing-Yi Li Ting-Ting Wang +2 位作者 Li Ma Yu Zhang Di Zhu 《World Journal of Stem Cells》 SCIE 2024年第2期151-162,共12页
BACKGROUND Osteoporosis is a common metabolic bone disorder induced by an imbalance between osteoclastic activity and osteogenic activity.During osteoporosis,bone mesenchymal stem cells(BMSCs)exhibit an increased abil... BACKGROUND Osteoporosis is a common metabolic bone disorder induced by an imbalance between osteoclastic activity and osteogenic activity.During osteoporosis,bone mesenchymal stem cells(BMSCs)exhibit an increased ability to differentiate into adipocytes and a decreased ability to differentiate into osteoblasts,resulting in bone loss.Jumonji domain-containing 1C(JMJD1C)has been demonstrated to suppress osteoclastogenesis.AIM To examine the effect of JMJD1C on the osteogenesis of BMSCs and the potential underlying mechanism.METHODS BMSCs were isolated from mouse bone marrow tissues.Oil Red O staining,Alizarin red staining,alkaline phosphatase staining and the expression of adipo-genic and osteogenic-associated genes were assessed to determine the differen-tiation of BMSCs.Bone marrow-derived macrophages(BMMs)were incubated with receptor activator of nuclear factor-kappaΒligand to induce osteoclast differentiation,and osteoclast differen-tiation was confirmed by tartrate-resistant acid phosphatase staining.Other related genes were measured via reverse transcription coupled to the quantitative polymerase chain reaction and western blotting.Enzyme-linked immunosorbent assays were used to measure the levels of inflammatory cytokines,including tumor necrosis factor alpha,interleukin-6 and interleukin-1 beta.RESULTS The osteogenic and adipogenic differentiation potential of BMSCs isolated from mouse bone marrow samples was evaluated.JMJD1C mRNA and protein expression was upregulated in BMSCs after osteoblast induction,while p-nuclear factor-κB(NF-κB)and inflammatory cytokines were not significantly altered.Knockdown of JMJD1C repressed osteogenic differentiation and enhanced NF-κB activation and inflammatory cytokine release in BMSCs.Moreover,JMJD1C expression decreased during BMM osteoclast differentiation.CONCLUSION The JMJD1C/NF-κB signaling pathway is potentially involved in BMSC osteogenic differentiation and may play vital roles in the pathogenesis of osteoporosis. 展开更多
关键词 OSTEOPOROSIS Mesenchymal stem cells OSTEOGENESIS Jumonji domain-containing 1c Nuclear factor-κB
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TPACK理论视角下STEM教师的知识结构及其量表的开发与验证
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作者 刘唤 杨晓娟 《现代教育技术》 CSSCI 2024年第4期122-131,共10页
STEM教育是落实创新人才培养模式的重要举措,研究STEM教师知识结构,开展STEM教师知识测评,是持续、深入提升STEM教育质量的关键。为此,文章基于TPACK理论模型,通过文献研究、访谈和专家咨询进行STEM教师知识结构理论维度的构建与优化,... STEM教育是落实创新人才培养模式的重要举措,研究STEM教师知识结构,开展STEM教师知识测评,是持续、深入提升STEM教育质量的关键。为此,文章基于TPACK理论模型,通过文献研究、访谈和专家咨询进行STEM教师知识结构理论维度的构建与优化,并通过项目分析、因子分析和信效度检验等步骤,编制STEM教师知识测评量表。研究结果表明,量表具有良好的信效度;量表各题项内部一致性较好,符合拟合接受的标准;量表7个维度彼此之间是相互影响的关系。文章通过研究,期望为测量STEM教师知识水平和促进STEM教师专业成长提供参考。 展开更多
关键词 TPAcK stem教师 知识结构 量表开发
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Binary molten salt in situ synthesis of sandwich-structure hybrids of hollowβ-Mo2C nanotubes and N-doped carbon nanosheets for hydrogen evolution reaction
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作者 Tianyu Gong Yang Liu +6 位作者 Kai Cui Jiali Xu Linrui Hou Haowen Xu Ruochen Liu Jianlin Deng Changzhou Yuan 《Carbon Energy》 SCIE EI CAS CSCD 2023年第12期111-124,共14页
Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction(HER)performance is very important for large-scale and efficient electrolysis of water... Focused exploration of earth-abundant and cost-efficient non-noble metal electrocatalysts with superior hydrogen evolution reaction(HER)performance is very important for large-scale and efficient electrolysis of water.Herein,a sandwich composite structure(designed as MS-Mo2C@NCNS)ofβ-Mo2C hollow nanotubes(HNT)and N-doped carbon nanosheets(NCNS)is designed and prepared using a binary NaCl–KCl molten salt(MS)strategy for HER.The temperature-dominant Kirkendall formation mechanism is tentatively proposed for such a three-dimensional hierarchical framework.Due to its attractive structure and componential synergism,MS-Mo2C@NCNS exposes more effective active sites,confers robust structural stability,and shows significant electrocatalytic activity/stability in HER,with a current density of 10 mA cm-2 and an overpotential of only 98 mV in 1 M KOH.Density functional theory calculations point to the synergistic effect of Mo2C HNT and NCNS,leading to enhanced electronic transport and suitable adsorption free energies of H*(ΔGH*)on the surface of electroactive Mo2C.More significantly,the MS-assisted synthetic methodology here provides an enormous perspective for the commercial development of highly active non-noble metal electrocatalysts toward efficient hydrogen evolution. 展开更多
关键词 binary molten-salt synthesis hydrogen evolution reaction Mo2c hollow nanotubes N-doped carbon nanosheets sandwich structure
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Genetic diversity and population structure of the sea star Asterias amurensis in the northern coast of China
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作者 Quanchao WANG Ying LIU +2 位作者 Zirui PENG Linlin CHEN Baoquan LI 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2023年第4期1593-1601,共9页
The sea star Asterias amurensis is widely viewed as a severe“marine pest”because of its broad feeding habits.Over the past few decades,A.amurensis undergoes massive and sporadic population outbreaks worldwide,causin... The sea star Asterias amurensis is widely viewed as a severe“marine pest”because of its broad feeding habits.Over the past few decades,A.amurensis undergoes massive and sporadic population outbreaks worldwide,causing extensive economic and ecological losses to the local aquaculture industry and marine ecosystem.Understanding the genetic diversity and population structure of A.amurensis can provide vital information for resource management.By analyzing the polymorphism of the mitochondrial cytochrome C oxidase subunit I(COI)gene and ten simple sequence repeat(SSR)microsatellites markers,the genetic diversity and population structure of A.amurensis of four populations along the northern coast of China was uncovered.A total of 36 haplotypes were identified,and a main haplotype was found in four populations.The Qingdao(QD)population displayed the highest genetic diversity among all the populations.The AMOVA and pairwise F_(st)showed that there was small but statistically significant population differentiation among the four populations,especially between QD and Weihai(WH).Moreover,the principal component analysis(PCA)and admixture analysis showed that several individuals in Yantai(YT)and Dalian(DL)had little genetic association with other individuals.Overall,this study provided useful information of the genetic diversity and population structure of A.amurensis and will contribute to the resource management of A.amurensis in China. 展开更多
关键词 Asterias amurensis cytochrome c oxidase subunit I(cOI) simple sequence repeat(SSR) population structure china seas
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Mapping theme trends and knowledge structures for human neural stem cells:a quantitative and co-word biclustering analysis for the 2013-2018 period 被引量:5
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作者 Wen-Juan Wei Bei Shi +3 位作者 Xin Guan Jing-Yun Ma Ya-Chen Wang Jing Liu 《Neural Regeneration Research》 SCIE CAS CSCD 2019年第10期1823-1832,共10页
Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends a... Neural stem cells,which are capable of multi-potential differentiation and self-renewal,have recently been shown to have clinical potential for repairing central nervous system tissue damage.However,the theme trends and knowledge structures for human neural stem cells have not yet been studied bibliometrically.In this study,we retrieved 2742 articles from the PubMed database from 2013 to 2018 using "Neural Stem Cells" as the retrieval word.Co-word analysis was conducted to statistically quantify the characteristics and popular themes of human neural stem cell-related studies.Bibliographic data matrices were generated with the Bibliographic Item Co-Occurrence Matrix Builder.We identified 78 high-frequency Medical Subject Heading(MeSH)terms.A visual matrix was built with the repeated bisection method in gCLUTO software.A social network analysis network was generated with Ucinet 6.0 software and GraphPad Prism 5 software.The analyses demonstrated that in the 6-year period,hot topics were clustered into five categories.As suggested by the constructed strategic diagram,studies related to cytology and physiology were well-developed,whereas those related to neural stem cell applications,tissue engineering,metabolism and cell signaling,and neural stem cell pathology and virology remained immature.Neural stem cell therapy for stroke and Parkinson’s disease,the genetics of microRNAs and brain neoplasms,as well as neuroprotective agents,Zika virus,Notch receptor,neural crest and embryonic stem cells were identified as emerging hot spots.These undeveloped themes and popular topics are potential points of focus for new studies on human neural stem cells. 展开更多
关键词 nerve REGENERATION human NEURAL stem cells PubMed bibliometric ANALYSIS biclustering ANALYSIS co-word ANALYSIS strategic diagram ANALYSIS social network ANALYSIS hot research topics mapping THEME TRENDS knowledge structures NEURAL REGENERATION
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The Inner Structure of the Intrinsic Electron and the Origin of Self-Mass
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作者 Victor Vaguine 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期174-189,共16页
A brief review and analysis of two historical models of the electron, the charged spinning sphere and Goudsmit and Uhlenbeck’s concept, is presented. It is shown that the enormous potential of classical electrodynami... A brief review and analysis of two historical models of the electron, the charged spinning sphere and Goudsmit and Uhlenbeck’s concept, is presented. It is shown that the enormous potential of classical electrodynamics has been underutilized in particle physics. Such observation leads to discovery of a principal component in the electron inner structure—the charged c-ring. The intrinsic (fundamental) electron model based on the charged c-ring successfully explains the ontology of the charge fractionation in quantum chromodynamics and the formation of Cooper pairs in superconductivity. The c-ring properties are explained on the basis of the General Compton Conditions as defined. Properties of the charged c-ring include the explanation of the boundary conditions, electro-magnetostatic field configuration, self-mass, spin, magnetic moment, and the gyromagnetic ratio. The self-mass of the intrinsic electron is 100% electro-magnetostatic and it is shown how to compute its value. The classical-quantum divide no longer exists. Relation between the intrinsic electron and the electron is fundamentally defined. The electron is the composite fermion consisting of the intrinsic electron and the neutrino. The ontology of the anomaly in the electron magnetic moment is demonstrated—it is due to the addition of the neutrino magnetic moment to the overall electron magnetic moment. The intrinsic electron replaces the W? boson in particle physics, resulting in a fundamental implication for the Standard Model. 展开更多
关键词 Intrinsic Electron Inner structure Electro-Magnetostatic Self-Mass General compton conditions charged c-Ring Visualization c-Ring Length constant
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The Intrinsic Electron with Its Properties Such as Inner Structure and Self-Mass Is in Conflict with Quantum Field Theory
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作者 Victor Vaguine 《Journal of High Energy Physics, Gravitation and Cosmology》 2023年第3期583-595,共13页
The quantum field theory (QFT) is one of branches of the Standard Model. According to QFT, quantum fields are the primary entities and particles are the excitations of these fields, coming in discrete lumps with no in... The quantum field theory (QFT) is one of branches of the Standard Model. According to QFT, quantum fields are the primary entities and particles are the excitations of these fields, coming in discrete lumps with no inner structures and with properties assigned by declaration. Such view is in conflict with the observed vacuum energy density, 140 orders of magnitudes less than required by the QFT. In addition, such view is challenged by Aphysical Quantum Mechanics (AQM), a deeper quantum theory. According to AQM, the fundamental understanding of quantum reality is expanded by the addition of two fundamental categories, aphysical and elementary consciousness of elementary particles. Based on AQM and as an example, the total ontology of the intrinsic (fundamental) electron is presented with its inner structure of perfect geometry consisting of the physical charged c-ring and aphysical cylinder, and with its properties such as self-mass, spin, magneto-electrostatic field configuration and magnetic moment. The position parameter in the inner structure demonstrates that there are no two identical intrinsic electrons in the Universe thus placing a question mark over the QFT principle of indistinguishability. 展开更多
关键词 Quantum Reality Physical-Aphysical Intrinsic Electron charged c-Ring Aphysical cylinder Elementary consciousness Position Parameter constant U Ontology Self-Mass Indistinguishable Inner structure
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Structure and electrochemical properties of La-Mg-Ni system hydrogen storage alloys with different Co contents 被引量:2
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作者 王建辉 钟凯 +3 位作者 丁慧 李锐 高明霞 潘洪革 《中国有色金属学会会刊:英文版》 EI CSCD 2005年第6期1351-1355,共5页
The structure and electrochemical properties of the La0.7Mg0.3Ni3.4-xMn0.1Cox (x=01.05) hydrogen storage alloys were investigated. The crystal structure and the lattice parameters of the alloys were analyzed by X-ra... The structure and electrochemical properties of the La0.7Mg0.3Ni3.4-xMn0.1Cox (x=01.05) hydrogen storage alloys were investigated. The crystal structure and the lattice parameters of the alloys were analyzed by X-ray diffractometry and Rietveld method. Electrochemical properties of the alloys including p—c—t curves, discharge capacity, discharge capacity retention were studied. The results show that (La, Mg)Ni3 and LaNi5 are the main phases of all the alloys. The plateau pressure for hydrogen absorption/desorption decreases and the hydrogen storage capacity firstly increases and subsequently decreases with increasing Co content. The values of the maximum discharge capacity of the alloy electrodes remain in range of 395.3403.1mA·h/g in spite of the change of Co content. The cycling stability of the alloy electrodes is greatly improved with increasing Co content, which is attributed to the suppression of the cell volume expansion during hydriding, leading the pulverization of the alloy particles lowered and the oxidation/corrosion of the active elements reduced. 展开更多
关键词 储氢合金 La-Mg-Ni 结构 电化学性能 P-c-T曲线
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Study on Underground Stem Tissue Structure and Agronomic Traits of Different Populations of Wild Houttuynia cordata Thumb
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作者 Can CHEN Huang HUANG +2 位作者 Huabin ZHENG Guangxiang DENG Tianxi WANG 《Medicinal Plant》 2017年第6期51-55,共5页
[Objectives] To study the underground stem tissue structure and agronomic traits of different populations of wild Houttuynia cordata Thumb. [Methods] 8 different populations of wild Houttuynia cordata Thumb. in southe... [Objectives] To study the underground stem tissue structure and agronomic traits of different populations of wild Houttuynia cordata Thumb. [Methods] 8 different populations of wild Houttuynia cordata Thumb. in southern China were selected,the preliminary study was carried out about underground stem tissue structure( stem wall thickness,underground stem cross section diameter,medullary cavity,large vascular bundle area,small vascular bundle area,and number of vascular bundles),and main agronomic traits of aboveground and underground parts. [Results]There were significant differences in the underground stem tissue structure and agronomic traits of some populations of wild Houttuynia cordata Thumb. [Conclusions] From comparison,it reached the conclusion that the populations of wild Houttuynia cordata Thumb. in Kunming of Yunnan,Hechuan of Chongqing,and Nanning of Guangxi showed better underground stem tissue structure and agronomic traits. The results are expected to provide certain guidance for cultivation,reasonable development,and utilization of wild populations of Houttuynia cordata Thumb. 展开更多
关键词 Different populations WILD Houttuynia cordata THUMB UNDERGROUND stem Tissue structure AGRONOMIc traits comparison
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Computational analysis of genetic loci required for amphid structure and functions and their possibly corresponding microRNAs in C. elegans 被引量:1
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作者 胡亚欧 孙阳 +1 位作者 叶波平 王大勇 《Neuroscience Bulletin》 SCIE CAS CSCD 2007年第1期9-20,共12页
Objective To examine the important roles of microRNAs (miRNAs) in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their po... Objective To examine the important roles of microRNAs (miRNAs) in regulating amphid structure and function, we performed a computational analysis for the genetic loci required for the sensory perception and their possibly corresponding miRNAs in C. elegans. Methods Total 55 genetic loci required for the amphid structure and function were selected. Sequence alignment was combined with E value evaluation to investigate and identify the possible corresponding miRNAs. Results Total 30 genes among the 55 genetic loci selected have their possible corresponding regulatory miRNA(s), and identified genes participate in the regulation of almost all aspects of amphid structure and function. In addition, our data suggest that both the amphid structure and the amphid functions might be regulated by a series of network signaling pathways. Moreover, the distribution of miRNAs along the 3' untranslated region (UTR) of these 30 genes exhibits different patterns. Conclusion We present the possible miRNA-mediated signaling pathways involved in the regulation of chemosensation and thermosensation by controlling the corresponding sensory neuron and interneuron functions. Our work will be useful for better understanding of the miRNA-mediated control of the chemotaxis and thermotaxis in C. elegans. 展开更多
关键词 microRNA cilia structure sensory neuron INTERNEURON computational analysis c. elegans
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核壳结构C-TiO_(2)纳米复合材料用于高效光催化降解有机染料 被引量:1
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作者 王文静 汤晶 +2 位作者 刘维刚 程晓丽 徐英明 《黑龙江大学工程学报(中英俄文)》 2024年第1期1-11,F0002,共12页
化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于... 化工、纺织印染与农药化肥等产业的蓬勃发展推动着人类社会的进步,但同时也给环境治理带来了巨大难题。目前,光催化降解局限于在特定波长下针对单一有机污染物进行降解,然而现实中的情况往往更复杂。因此,开发一种多功能光催化材料用于光催化降解不同有机污染物显得尤为重要。采用一步无模板溶剂热法合成了核壳结构的C-TiO_(2)复合材料前驱体,并在氩气气氛下煅烧得到高结晶度的C-TiO_(2)复合光催化材料。运用SEM、TEM、XRD和TG等表征手段对材料进行表征,结论如下:550℃煅烧时的样品为包含少量碳的高结晶度的锐钛矿相TiO 2,且550℃煅烧时的样品依然保持了完整的核壳结构。此外,C-TiO_(2)复合材料的比表面积高达85.69 m 2·g^(-1),平均孔径为16.4 nm以及孔体积为0.423 m 3·g^(-1)。在UV-Vis光照射下,C-TiO_(2)复合材料分别对罗丹明B(RhB)、亚甲基蓝(MB)和刚果红(CR)3种染料显示出增强的光催化降解活性。 展开更多
关键词 光催化 c-TiO_(2) 溶剂热 核壳结构
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基于线粒体COⅠ基因序列的梭鲈野生群体遗传结构
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作者 鲁翠云 孙志鹏 +4 位作者 曹顶臣 耿龙武 那荣滨 吴学工 郑先虎 《水产学报》 CSCD 北大核心 2024年第1期82-92,共11页
为了解梭鲈种群的遗传结构,实验利用线粒体细胞色素c氧化酶Ⅰ亚基(COⅠ)基因部分序列分析了中国6个和中亚2个群体的遗传差异,并与欧洲群体的单倍型序列进行了比较。结果在640 bp的COⅠ基因序列中检测到5个变异位点,定义了7种单倍型,发现... 为了解梭鲈种群的遗传结构,实验利用线粒体细胞色素c氧化酶Ⅰ亚基(COⅠ)基因部分序列分析了中国6个和中亚2个群体的遗传差异,并与欧洲群体的单倍型序列进行了比较。结果在640 bp的COⅠ基因序列中检测到5个变异位点,定义了7种单倍型,发现Hap1为8个梭鲈群体的共享单倍型,且与欧洲群体的HapA相同,在中国群体所占比例(93.36%)高于中亚群体(72.58%)和欧洲群体(53.85%);Hap2和Hap3是中国群体的特异单倍型,而Hap4~Hap7为中亚群体的特异单倍型。单倍型序列的聚类图和网络图均显示Hap1/A为梭鲈群体的原始单倍型,中国和中亚群体的特异单倍型相对于原始单倍型仅有1~2个位点的变异,属于Hap1/A的亚型,与欧洲群体的特异单倍型具有较大的差异。每个群体检测到1~4种单倍型,斋桑湖(ZS)群体单倍型最多,而中国的腾格里湖(NX)、兴凯湖(XK)和鸭绿江(YJ)群体仅有1个单倍型(Hap1);塔什干(TS)群体的单倍型多样性(Hd)和核苷酸多样性(π)最高(Hd=0.514±0.069;π=0.00079±0.00011),其次是ZS群体,而中国梭鲈群体的多样性参数较低。AMOVA分析结果显示,梭鲈群体间遗传变异占20.74%,群体间遗传分化程度较高(0.15≤F_(st)=0.20736<0.25),TS群体与ZS群体和中国群体间的遗传分化极大(F_(st)>0.25),中国群体中仅黑河(HH)群体与其他群体的遗传分化较大,而中国其他5个群体间无遗传分化。基于群体间遗传距离的系统进化树显示,来自中国的6个梭鲈群体与哈萨克斯坦的ZS群体聚为一支,而乌兹别克斯坦的TS群体独立为一支。研究结果为梭鲈群体的繁殖及放流管理提供了参考。 展开更多
关键词 梭鲈 线粒体cOⅠ基因 野生群体 遗传结构
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氮含量对Ti-B-C-N薄膜微观结构和性能的影响
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作者 陈向阳 张瑾 +1 位作者 马胜利 胡海霞 《机械工程材料》 CAS CSCD 北大核心 2024年第5期62-66,共5页
采用反应磁控溅射法在高速钢基体上制备氮原子分数分别为10.8%,15.6%,28.1%,36.4%的Ti-B-C-N薄膜,研究了氮含量对薄膜微观结构、硬度和摩擦磨损性能的影响。结果表明:Ti-B-C-N薄膜均由α-Fe和Ti(C,N)纳米晶组成,具有Ti(C,N)纳米晶镶嵌... 采用反应磁控溅射法在高速钢基体上制备氮原子分数分别为10.8%,15.6%,28.1%,36.4%的Ti-B-C-N薄膜,研究了氮含量对薄膜微观结构、硬度和摩擦磨损性能的影响。结果表明:Ti-B-C-N薄膜均由α-Fe和Ti(C,N)纳米晶组成,具有Ti(C,N)纳米晶镶嵌在非晶基体相中的纳米复合结构;随着氮含量增加,非晶相含量增加,Ti(C,N)纳米晶的含量和晶粒尺寸减小;随着氮含量增加,Ti-B-C-N薄膜的显微硬度增大,摩擦因数和磨损率均减小,表面磨痕变浅,磨损机制由剥落和微观犁削转变为微观抛光。 展开更多
关键词 反应磁控溅射 Ti-B-c-N薄膜 纳米复合结构 硬度 摩擦磨损性能
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不同溶剂预处理煤在ScCO_(2)作用下的谱学差异及其机制
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作者 张小东 亢红东 +2 位作者 李冰辉 张硕 韩磊 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2024年第9期2657-2666,共10页
为了探究溶剂预处理后超临界二氧化碳(ScCO_(2))对煤化学结构的影响,以长治霍尔辛赫贫煤为研究对象,分别用四氢呋喃(THF)、盐酸(HCI)和氢氟酸(HF)对煤样进行预处理,采用傅里叶红外光谱(FTIR)、固体核磁共振(^(13)C-NMR)和X射线衍射(XRD... 为了探究溶剂预处理后超临界二氧化碳(ScCO_(2))对煤化学结构的影响,以长治霍尔辛赫贫煤为研究对象,分别用四氢呋喃(THF)、盐酸(HCI)和氢氟酸(HF)对煤样进行预处理,采用傅里叶红外光谱(FTIR)、固体核磁共振(^(13)C-NMR)和X射线衍射(XRD)测试,探讨了ScCO_(2)对预处理煤的化学组成和结构的影响机理。研究表明:①FITR分峰拟合谱图实验曲线基本一致,而各官能团吸收峰位置及峰强度仍出现一定的偏差,酸(HCI、HF)预处理后部分波段脂肪族峰位消失。两类酸预处理顺序不同,对煤中含氧官能团、脂肪结构及芳烃结构作用效果也不相同。HF-HCI处理后芳烃C=C结构和含氧官能团峰强度均增强,而HCI-HF处理后芳烃C=C结构强度减弱,含氧官能团结构峰强度变化不明显。THF预处理后煤样芳烃C=C结构峰强度增强,含氧官能团结构峰强度降低。总体芳烃C=C结构峰强度远大于脂肪族结构和含氧官能团结构的峰强度。②^(13)C-NMR谱中主要官能团谱峰的化学位移出现了一定程度的偏移,芳香碳f_(a)^(B)化学位移向增大的方向偏移。大分子结构参数中,芳香碳含量远大于脂肪碳含量,说明煤大分子结构中芳香碳占主要组成部分。③XRD谱中002峰与101峰衍射强度明显增大,芳香微晶层网面间距d_(002)呈现升高趋势,说明THF、酸(HF、HCI)处理和ScCO_(2)对煤大分子结构产生了一定程度的改造作用,使煤的大分子网络结构变得疏松,进而使微晶结构参数d_(002)整体增大。研究认为,溶剂作用后煤的谱学特征变化不仅与溶剂性质有关,还与无机酸处理顺序有关,由此使得官能团组成和大分子结构不同程度改变,进而影响ScCO_(2)对预处理煤的萃取效果。 展开更多
关键词 超临界二氧化碳(SccO_(2)) 溶剂预处理 傅里叶变换红外光谱 固体核磁共振(^(13)c-NMR) 化学结构
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