检索结果-南通市图书馆

Energy transfer, anticounterfeiting, white light emission and sensing in fine-regulating series of lanthanide metal-organic frameworks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第3期42卷 446-454,I0001页

作者： Juanjuan xue Yao Wang Guoping yang Yaoyu Wang Key Laboratory of Synthetic and Natural functional Molecule Chemistry of the Ministry of Education Shaanxi Key Laboratory of Physico-Inorganic ChemistryCollege of Chemistry&Materials ScienceNorthwest UniversityXi'an710127China

Three lanthanide ions and a rigid(1,1'-biphenyl)-2,4,6-tricarboxylic acid(H_(3)bptc) ligand led to the isostructural lanthanide metal-organic frameworks(Ln-Mofs) {[Ln(bptc)(H_(2)o)_(3)]·3H_(2)o}_n(Lnbptc, Ln = Eu,Tb, Gd, Eu_(x)Tb_(1—x), Eu_(x)Gd_(1-x), Tb_(x)Gd_(1-x), and Eu_(0.12)Tb_(0.52)Gd_(0.36)). The density functional theory(DfT) and time-dependent DfT calculation were expanded on H_3bptc, which point to the occurrence of “antenna effect”. The minor diameter samples of Eubptc, Tbbptc, and Gdbptc can also be attained via the microwave synthesis and employed for handwriting anticounterfeiting. Interestingly, the typical red emission of Eu^(3+) and green emission of Tb~(3+) could be fine-tuned by Gd^(3+) via chemical mixing to be full-color emissions bimetallic doped Eu_(x)Tb_(1-x)bptc, Eu_(x)Gd_(1-x)bptc, and Tb_(x)Gd_(1-x)bptc. The above synthetic bimetallic Mofs can be fixed in positioning boxes of quick response(QR) codes with diverse emission for anticounterfeiting. The message can be decoded under the irradiation of 365 nm ultraviolet lamp while invisible in the daylight. Notably, the trimetallic doped Eu_(0.12)Tb_(0.52)Gd_(0.36)bptc emits white light with the CIE color coordinate(0.34, 0.34). furthermore, Tbbptc is demonstrated to be a sensitive probe toward nitrobenzene and acetone with multiple mechanisms.

关键词： Metal-organic frameworks Anticounterfeiting White light-emitting Sensing Rare earths

Resonance mechanism of flapping wing based on fluid structure interaction simulation

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 243-262页

作者： Yueyang GUo Wenqing yang Yuanbo DoNG Dong xue National Key Laboratory of Science and Technology on Aerodynamic Design and Research School of AeronauticsNorthwestern Polytechnical UniversityXi'an 710072China Research&Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518063China yangtze River Delta Research Institute of Northwestern Polytechnical University Taicang 215400China

Certain insect species have been observed to exploit the resonance mechanism of their *** order to achieve resonance and optimize aerodynamic performance,the conventional approach is to set the flapping frequency of flexible wings based on the Traditional Structural Modal(TSM)***,there exists controversy among researchers regarding the relationship between frequency and aerodynamic *** that the structural response of wings can be influenced by the surrounding air vibrations,an analysis known as Acoustic Structure Interaction Modal(ASIM)is introduced to calculate the resonant *** this study,fluid Structure Interaction(fSI)simulations are employed to investigate the aerodynamic performance of flapping wings at modal frequencies derived from both TSM and ASIM *** performance is evaluated for various mass ratios and frequency ratios,and the findings indicate that the deformation and changes in vortex structure exhibit similarities at mass ratios that yield the highest aerodynamic ***,the flapping frequency associated with the maximum time-averaged vertical force coefficient at each mass ratio closely aligns with the ASIM frequency,as does the frequency corresponding to maximum ***,the ASIM analysis can provide an effective means for predicting the optimal flapping frequency for flexible ***,it enables the prediction that flexible wings with varying mass ratios will exhibit similar deformation and vortex structure *** paper offers a fresh perspective on the ongoing debate concerning the resonance mechanism of flexible flapping Wings(ffWs)and proposes an effective methodology for predicting their aerodynamic performance.

关键词： flexible flapping Wing(ffW) Acoustic Structure Interaction Modal(ASIM) fluid Structure Interaction(fSI) Resonance mechanism Aerodynamic performance

Clinical prediction of insufficient vaults after implantable collamer lens implantation

在线全文

学校读者我要写书评

暂无评论

International Journal of ophthalmology(English edition) 2024年第7期17卷 1300-1306页

作者： Jun Zhu Dan cheng.xue-Ying Zhu fen-fen Li Ye yang Yu-feng Ye National Clinical Research Center for ocular Diseases Eye HospitalWenzhou Medical UniversityWenzhou 325027Zhejiang ProvinceChina

AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(<250μm)after implantable collamer lens(ICL V4c;STAAR Surgical)***:The participants underwent ICL surger... 详细信息

AIM:To determine the factors related to preoperative ocular characters that are predictive of insufficient vault(fter implantable collamer lens(ICL V4c;STAAR Surgical)***:The participants underwent ICL surgery and were divided into the low(ormal(250-1000μm)vault groups based on the postoperative vault at *** preoperative biometric parameters and clinical outcomes were compared between the two *** relationship between the 3-month vault values and preoperative ocular parameters were evaluated by Generalized estimating ***:Sixteen(23 eyes)and 36 patients(63 eyes)were in the low and normal vault groups,*** implantation procedures were uneventful with no cataract formation in the early postoperative *** sulcusto-sulcus lens rise(STSL)and iris ciliary angle(ICA)were correlated with vault at 3mo after *** 0.1 mm increase in STSL was associated with 38.9μm decrease in the postoperative 3-month vault.A rise of 1 degree in ICA is associated with a reduction of 4μm in ***:Eyes with a narrow ciliary sulcus are associated with a higher rate of low vault after ICL implantation,suggesting a need for adjustments to the ICL size in these *** the characteristics of the ciliary sulcus contributes valuable information to predict low vault after surgery.

关键词： insufficient vault implantable collamer lens ciliary body posterior chamber

Strengthening and control of second-phase particle precipitation in ferritic/austenitic/martensitic heat-resistant alloys:a review

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2024年第1期31卷 3-23页

作者： xue-cheng Peng Han-jie Guo Xin-fang Zhang Yi-wa Luo Ye Sun Jing Guo Rong-guang yang Xiao-dan Zheng School of Metallurgical and Ecological Engineering University of Science and Technology Beijing(USTB)Beijing100083China Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials University of Science and Technology Beijing(USTB)Beijing100083China Beijing Shougang Gitane New MATERIALS Co. Ltd.Beijing102206China

Heat-resistant alloys with excellent mechanical properties are widely used in various fields,and further improvement in their properties is essential to meet the requirements in new-generation advanced supercritical boilers,nuclear reactors,superheaters,and other new materials *** effectively enhance the comprehensive performance of heat-resistant alloys,second-phase particle strengthening has been widely studied,and in the face of different service envi-ronments of advanced heat-resistant steels,the selection of suitable second-phase particles is essential to maximize the performance of these *** this end,three major types of reinforcing phases in heat-resistant alloys such as carbides,rare earth oxides,and intermetallic compounds are summarized.A comparative analysis of the precipitation behavior of the reinforcing phases with different types as well as the risks and means of controlling their use in service,is *** parameters for the application of various types of second-phase particles in heat-resistant alloys are provided to support the design and preparation of new ultrahigh-performance heat-resistant alloys.

关键词： Heat-resistant alloy Second-phase particle Carbide Rare earth oxide Intermetallic compound Strengthening

Double Moving Extremes Ranked Set Sampling Design

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第1期40卷 75-90页

作者： Meng Chen Wang-xue Chen Rui yang Department of Mathematics and Statistics Jishou UniversityJishou416000China

The traditional simple random sampling(SRS)design method is inefficient in many *** proposed some new designs to increase *** this paper,as a variation of moving extremes ranked set sampling(MERSS),double MERSS(DMERSS)is proposed and its properties for estimating the population mean are *** turns out that,when the underlying distribution is symmetric,DMERSS gives unbiased estimators of the population ***,it is found that DMERSS is more efficient than the SRS and MERSS methods for usual symmetric distributions(normal and uniform).for asymmetric distributions considered in this study,the DMERSS has a small bias and it is more efficient than SRS for usual asymmetric distribution(exponential)for small sample sizes.

关键词： double moving extremes ranked set sampling symmetric distribution efficiency

The response of structure and nitrogen removal function of the biofilm on submerged macrophytes to high ammonium in constructed wetlands

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第8期142卷 129-141页

作者： xue Jiang Mengmeng Wang Shunqing yang Di He fei fang Liuyan yang State Key Laboratory of Pollution Control and Resource Reuse School of the EnvironmentNanjing UniversityNanjing 210023China School of Resources and Environment Anqing Normal UniversityAnqing 246133China

The ammonium exceedance discharge from sewage treatment plants has a great risk to the stable operation of subsequent constructed wetlands(CWs).The effects of high ammonium shocks on submerged macrophytes and epiphytic biofilms on the leaves of submerged macrophytes in CWs were rarely mentioned in previous *** this paper,the 16S rRNA sequencing method was used to investigate the variation of the microbial communities in biofilms on the leaves of Vallisneria natans plants while the growth characteristics of *** plants were measured at different initial ammonium *** results demonstrated that the total chlorophyll and soluble sugar synthesis of *** plants decreased by 51.45%and 57.16%,respectively,and malondialdehyde content increased threefold after8 days if the initial NH_(4)^(+)-N concentration was more than 5 mg/*** density,bacterial quantity,dissolved oxygen,and pH increased with high ammonium *** average removal efficiencies of total nitrogen and NH_(4)^(+)-N reached 73.26%and 83.94%,*** heat map and relative abundance analysis represented that the relative abundances of phyla Proteobacteria,Cyanobacteria,and Bacteroidetes *** numbers of autotrophic nitrifiers and heterotrophic nitrification aerobic denitrification(HNAD)bacteria expanded in *** particular,HNAD bacteria of flavobacterium,Hydrogenophaga,Acidovorax,Acinetobacter,Pseudomonas,Aeromonas,and Azospira had higher abundances than autotrophic nitrifiers because there were organic matters secreted from declining leaves of *** *** analysis of the nitrogen metabolic pathway showed aerobic denitrification was the main nitrogen removal ***,the nitrification and denitrification bacterial communities increased in epiphytic biofilms on submerged macrophytes in constructed wetlands while submerged macrophytes declined under ammonium shock loading.

关键词： Ammonium shock loading Biofilm Autotrophic nitrifiers Heterotrophic nitrification aerobic denitrification bacteria Submerged macrophyte

Room-temperature ferrimagnetism and size-modulated electronic structures in two-dimensional cluster-based metal-organic frameworks

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第4期67卷 1334-1340页

作者： Jing cheng Xingxing Li Jinlong yang Key Laboratory of Precision and Intelligent Chemistry University of Science and Technology of ChinaHefei 230026China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Hefei National Research Center for Physical Sciences at the Microscale University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Cluster-assembled materials have attracted particular attention for their complex hierarchical structures and unique ***,the majority of cluster-based assemblies developed so far are either non-magnetic or only exhibit magnetic ordering with a relatively low Curie temperature,limiting their applications in ***,two-dimensional(2D)cluster-assembled materials with room-temperature magnetism remain highly *** this purpose,based on first principles calculations,we design a series of thermodynamically stable 2D cluster-based metal-organic frameworks(Mofs)fe_(n)-(pyz)(n=1-6)by utilizing fenmetal clusters as nodes and nitrogen-containing pyrazine ligands as organic *** 2D cluster-based Mofs exhibit robust ferrimagnetic ordering due to the strong d-p direct exchange interaction between d-electron spin of fe_(n)(n=1-6)clusters and charge transfer-induced p-electron spin of pyrazine *** particular,the ferrimagnetic Curie temperatures are well above room temperature(up to 836 K).Additionally,altering the size of fe_(n)clusters in fe_(n)-(pyz)(n=1-6)Mofs results in diverse functional spintronic properties,including bipolar magnetic semiconductors,half semiconductors and Dirac half ***,these 2D assembled Mofs possess sizable magnetic anisotropy energies,up to 9.16 me V per formula.

关键词： metal-organic framework two-dimensional material half metal bipolar magnetic semiconductor magnet

Interplay between Microscopic Structures and Macroscopic Viscoelastic Properties of Polyampholyte Gels

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第9期42卷 1360-1367,I0008页

作者： You-Cai xue Yi-Ming yang Di Jia Beijing National Laboratory for Molecular Sciences Laboratory of Polymer Physics and ChemistryInstitute of ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing100049China

Polyampholyte gels,which have hierarchical structures,exhibit excellent self-healing properties and have great promise for biomaterials and *** investigated the relationship between microscopic structures and macroscopic viscoelastic properties of polyampholyte gels and found three factors influencing their viscoelastic properties,including the chemical crosslinking bonds,topological entanglements controlled by monomer concentration,and the ionic *** strength plays a major role on the strength of ionic bonds.A crossover point of elastic modulus and loss modulus was observed in the dynamic frequency sweeps at low monomer concentration or low chemical crosslinking density for gels with intermediate strength of ionic *** solid-liquid transition signaled by the crossover point is a typical feature of dynamic associated gels,representing the dynamical association-dissociation of the ionic bonds and full relaxation of the topological entanglements in the gel *** the crossover point disappears when the ionic bonds are too weak or too strong to form“permanent”***,in the non-linear yielding measurement,gels with intermediate strength of the ionic bonds are ductile and yield at very large shear strain due to the self-healing properties and the dynamic association-dissociation of the ionic *** the self-healing properties disappear when the ionic bond strength is too weak or too *** work reveals the mechanism of how the dynamic association-dissociation of ionic bonds influences both the linear and non-linear viscoelastic properties of the polyampholyte gels.

关键词： Polyampholyte gel Ionic bond Topological entanglement Self-healing Hierarchical structure

Performance of Gas-Steam Combined Cycle Cogeneration Units Influenced by Heating Network Terminal Steam Parameters

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2024年第6期121卷 1495-1519页

作者： Guanglu Xie Zhimin xue Bo Xiong Yaowen Huang Chaoming Chen Qing Liao cheng yang Xiaoqian Ma Zhongshan Jiaming Electric Power Co. Ltd.CNOOC Gas&Power GroupZhongshan528403China School of Electric Power South China University of TechnologyGuangzhou510640China

The determination of source-side extracted heating parameters is of great significance to the economic operation of cogeneration *** paper investigated the coupling performance of a cogeneration heating and power system multidimensionally based on the operating characteristics of the cogeneration units,the hydraulic and thermodynamic characteristics of the heating network,and the energy *** a steam network supported by a gas-steam combined cycle cogeneration system as the research case,the interaction effect among the source-side prime movers,the heating networks,and the terminal demand thermal parameters were investigated based on the designed values,the plant testing data,and the validated *** operating maps of the gas-steam combined cycle cogeneration units were obtained using THERMofLEX,and the minimum source-side steam parameters of the steam network were solved using an inverse solution procedure based on the hydro-thermodynamic coupling *** cogeneration operating maps indicate that the available operating domain considerably narrows with the rise of the extraction steam pressure and flow *** heating network inverse solution demonstrates that the source-side steam pressure and temperature can be optimized from the originally designed 1.11 MPa and 238.8°C to 1.074 MPa and 191.15°C,*** the operating strategy with the minimum source-side heating parameters,the power peak regulation depth remarkably increases to 18.30%whereas the comprehensive thermal efficiency *** operation under the minimum source-side heating steam parameters can be superior to the originally designed one in the economy at a higher price of the heating *** a fuel price of$0.38/kg and the power to fuel price of 0.18 kg/(kW·h),the critical price ratio of heating steam to fuel is 119.1 kg/*** influence of the power-fuel price ratio on the economic deviation appears relatively weak.

关键词： Gas-steam combined cycle cogeneration of heating and power steam network inverse problem operating performance