Effect of Plastocene Embedment in the Microperforated Plate on Its AcousticPerformance

Noise pollution is one of the contemporary environmental pollution, which seriously damages people’s green andhealthy life. In order to further improve the low frequency sound absorption performance of microperforatedpanel (MPP), a new plastocene coupled microperforated plate (PCMPP) is proposed. The acoustic propertiesof PCMPP with different apertures and perforation ratio were measured by transfer function method and compared with that of conventional MPPs. It is found that when the aperture was 0.8 mm, the peak value of soundabsorption coefficient of PCMPP decreased by 150 Hz compared with MPP. In a certain range, PCMPP with larger apertures showed a greater influence on sound absorption property in low frequency. In addition, higher perforation ratio led to a greater PCMPP bandwidth of sound absorption. On the other hand, the effect of PCMPPwith aperture of 0.2 mm on the performance of MPP was reduced, which could be compensated by increasing theperforation ratio. Furthermore, we found that the effect of aperture, perforation ratio and cavity on the soundabsorption performance of PCMPP was consistent with that of ideal rigid MPP. The step cooling curve showedthat the plastocene began to soften at about 50℃, representing a great potential for a non-high temperaturework environment.

Research on Feature Fusion Technology of Fruit and Vegetable Image Recognition Based on SVM

In order to improve the accuracy and stability of fruit and vegetable image recognition by single feature, this project proposed multi-feature fusion algorithms and SVM classification algorithms. This project not only introduces the Reproducing Kernel Hilbert space to improve the multi-feature compatibility and improve multi-feature fusion algorithm, but also introduces TPS transformation model in SVM classifier to improve the classification accuracy, real-time and robustness of integration feature. By using multi-feature fusion algorithms and SVM classification algorithms, experimental results show that we can recognize the common fruit and vegetable images efficiently and accurately.

Research on Technology of Twin Image Recognition Based on the Multi-feature Fusion

In order to improve the accuracy and stability of fruit and vegetable image recognition by single feature,this project proposed multi-feature fusion algorithms and SVM classification algorithms.This project not only introduces the Reproducing Kernel Hilbert space to improve the multi-feature compatibility and improve multi-feature fusion algorithm,but also introduces TPS transformation model in SVM classifier to improve the classification accuracy,real-time and robustness of integration feature.By using multi-feature fusion algorithms and SVM classification algorithms,experimental results show that we can recognize the common fruit and vegetable images efficiently and accurately.

Manipulation of the through-space interactions in diphenylmethane

Through-space interaction(TSI)has been proven to play an important role in the newly emerging clusteroluminescence(CL)phenomenon.However,it is still a big challenge to manipulate the TSI at the molecular level due to the unclear relationship between the non-conjugated structure and TSI properties.Herein,the TSI in diphenylmethane is manipulated by breaking its symmetric structures and changing the isolated subunits.Finally,the CL wavelength and efficiency of diphenylmethane are successfully regulated at the aggregate state.

Theory of the magnon Kerr effect in cavity magnonics

We develop a theory for the magnon Kerr effect in a cavity magnonics system, consisting of magnons in a small yttrium iron garnet(YIG) sphere strongly coupled to cavity photons, and use it to study the bistability in this hybrid system. To have a complete picture of the bistability phenomenon, we analyze two different cases in driving the cavity magnonics system, i.e.,directly pumping the YIG sphere and the cavity, respectively. In both cases, the magnon frequency shifts due to the Kerr effect exhibit a similar bistable behavior but the corresponding critical powers are different. Moreover, we show how the bistability of the system can be demonstrated using the transmission spectrum of the cavity. Our results are valid in a wide parameter regime and generalize the theory of bistability in a cavity magnonics system.

Visualizing Aβdeposits in live young AD model mice with a simple red/near-infrared-fluorescent AIEgen

Precise and early detection ofβ-amyloid(Aβ)deposits in situ and in real time is pivotal to the diagnosis and early intervention of Alzheimer’s disease(AD).Optical imaging stands out to be a promising technique for such a task;however,it still remains a big challenge,due to the lack of high-performance imaging contrast agent.Restricted by poor blood-brain barrier(BBB)penetrability,short-wavelength excitation and emission,as well as the aggregation-caused quenching effect,the widely used goldstandard probes cannot be used for early in-vivo imaging of Aβdeposits.Herein,we integrate the Aβdeposits-favored geometry,amphiphilic and zwitterionic molecular structure,extended D-π-A electronic structure,and 3 D conformation into one molecule,facilely establishing a simple and economic imaging contrast agent that enjoys high specificity and affinity to Aβdeposits,good BBB penetrability,bright red/near-infrared fluorescence,low interference from autofluorescence,aggregation-induced emission(AIE)feature,high signal-to-noise ratio(SNR),and high contrast.In-vitro,ex-vivo,and in-vivo experiments with different strains of mice indicate that AIE-CNPy-AD holds the universality to Aβdeposits identification.Noteworthily,AIE-CNPy-AD is even able to precisely trace the small and sparsely-distributed Aβdeposits in AD model mice as young as 4-month-old APP/PS1 mice,the youngest having Aβdeposits.Moreover,the present probe could clearly reveal the increase and enlargement of Aβdeposits as the mice grow.Therefore,AIE-CNPy-AD might be an ideal alternative for early AD diagnosis and highly reliable monitoring of AD progression.

Controllable Secondary Through-Space Interaction and Clusteroluminescence

Nonconjugated clusteroluminogens(CLgens),such as proteins and polystyrene,have become increasingly important in photophysics.They show many advantages over traditional conjugated dyes with fused aromatic rings in biological applications.However,CLgens have historically been unheeded because of their weak visible emissions in the aggregate state,namely clusteroluminescence(CL).Changing the electronic structures of CLgens by precisely regulating the intramolecular throughspace interaction(TSI)to improve their photophysical properties remains an enormous challenge.Herein,we propose a general strategy to construct a higher-level intramolecular TSI,namely secondary TSI constructed by the primary TSI and a TSI linker,in multi-aryl-substituted alkanes(MAAs).By introducing methyl and phenyl into 1,1,3,3-tetraphenylpropane,the modified MAAs show efficient CL with high luminescence quantum yield(-40%)and long emission wavelength(-530 nm).Then,comprehensive experiments and theoretical studies demonstrate that molecular rigidity and overlap of subunits play pivotal roles in improving these hierarchical TSIs.This work not only provides a feasible strategy to achieve controllable manipulation of hierarchical TSIs and CL but also establishes comprehensive TSI-based aggregate photophysics.