高清演播室音频系统设计、延时解决方法及应用

通过对东视高清系统的设计和应用实践,利用"延时图"和实际应用举例试图回答在各种情况下延时问题的解决,及相应点上图像与声音监视监听上的关系,对各种情况下高清视音频系统同步问题的解决方案进行了分析和探讨。

Varying of up-conversion nanoparticles luminescence from the muscle tissue depth during the compression

The current work is focused on the study of optical clearing of skeletal muscles under local compression.The experiments were performed on in vitro bovine skeletal muscle.The time dependence of optical clearing was studied by monitoring the luminescence intensity of NaYF_(4)∶Er,Yb upconverting particles located under tissue layers.This study shows the possibility to use upconverting nanoparticles(UCNPs)both for studying the dynamics of the optical clearing of biological tissue under compression and to detect moments of cell wall damage under excessive pressure.The advantage of using UCNPs is the presence of several bands in their luminescence spectra,located both at close wavelengths and far apart.

Two-photon Pumped Up-conversion Lasing Properties of A Series of Organic Salts with Different Side-chains

The synthesis and upconverted fluorescent properties of a series of organic compounds with the structure: donor/bridge/acceptor, and different side-chains are reported. The results show that the compounds with different side-chains exhibit different two-photon induced fluorescent properties, although they have the same main donor/bridge/acceptor structure.

Artificial intelligence reinforced upconversion nanoparticle-based lateral flow assay via transfer learning

The combination of upconverting nanoparticles(UCNPs)and immunochromatography has become a widely used and promising new detection technique for point-of-care testing(POCT).However,their low luminescence efficiency,non-specific adsorption,and image noise have always limited their progress toward practical applications.Recently,artificial intelligence(AI)has demonstrated powerful representational learning and generalization capabilities in computer vision.We report for the first time a combination of AI and upconversion nanoparticle-based lateral flow assays(UCNP-LFAs)for the quantitative detection of commercial internet of things(IoT)devices.This universal UCNPs quantitative detection strategy combines high accuracy,sensitivity,and applicability in the field detection environment.By using transfer learning to train AI models in a small self-built database,we not only significantly improved the accuracy and robustness of quantitative detection,but also efficiently solved the actual problems of data scarcity and low computing power of POCT equipment.Then,the trained AI model was deployed in IoT devices,whereby the detection process does not require detailed data preprocessing to achieve real-time inference of quantitative results.We validated the quantitative detection of two detectors using eight transfer learning models on a small dataset.The AI quickly provided ultra-high accuracy prediction results(some models could reach 100%accuracy)even when strong noise was added.Simultaneously,the high flexibility of this strategy promises to be a general quantitative detection method for optical biosensors.We believe that this strategy and device have a scientific significance in revolutionizing the existing POCT technology landscape and providing excellent commercial value in the in vitro diagnostics(IVD)industry.

One-Pot Synthesis and Strong Near-Infrared Upconversion Luminescence of Poly(acrylic acid)-Functionalized YF3:Yb^(3+)/Er^(3+) Nanocrystals

This paper describes the synthesis of new upconverting luminescent nanoparticles that consist of YF_(3):Yb^(3+)/Er^(3+)functionalized with poly(acrylic acid)(PAA).Unlike the upconverting nanocrystals previously reported in the literature that emit visible(blue-green-red)upconversion fluorescence,these as-prepared nanoparticles emit strong near-infrared(NIR,831 nm)upconversion luminescence under 980 nm excitation.Scanning electron microscopy,transmission electron microscopy,and powder X-ray diffraction were used to characterize the size and composition of the luminescent nanocrystals.Their average diameter was about 50 nm.The presence of the PAA coating was confirmed by infrared spectroscopy.The particles are highly dispersible in aqueous solution due to the presence of carboxylate groups in the PAA coating.By carrying out the synthesis in the absence of PAA,YF_(3):Yb^(3+)/Er^(3+)nanorice materials were obtained.These nanorice particles are larger(~700 nm in length)than the PAA-functionalized nanoparticles and show strong typical visible red(668 nm),rather than NIR(831 nm),upconversion fluorescence.The new PAA-coated luminescent nanoparticles have the pottential be used in a variety of bioanalytical and medical assays involving luminescence detection and fluorescence imaging,especially in vivo fluorescence imaging,due to the deep penetration of NIR radiation.

Up-converting NaYF4:0.1%Tm^(3+), 20%Yb^(3+) nanoparticles as luminescent labels for deep-tissue optical imaging

Optical imaging plays an important role in biomedical research being extremely useful for early detection, screening and image-guided therapy. Lanthanide-doped up-converting nanoparticles were ideally suited for bioimaging because they could be ex- cited in near infrared （NIR） and emit in NIR or visible （VIS）. Here, we compared lanthanide doped up-converting NaYF4 and organic fluorophores for application in deep-tissue imaging. For that purpose - tissue phantoms mimicking the natural properties of light scat- tering by living tissues were prepared. The studies allowed to quantitatively compare optical resolution of different fluorescent com- pounds, revealing that the NIR photoexcitation was favorable over conventional UV photoexcitation.

A facile ＂ship-in-a-bottle＂ approach to construct nanorattles based on upconverting lanthanide-doped fluorides

Rattle structure is a topic of great interest in design and application of nano- materials due to the unique core@void@shell architecture and the integration of functions. Herein, we developed a novel ＂ship-in-a-bottle＂ method to fabricate upconverting （UC） luminescent nanorattles by incorporating lanthanide-doped fluorides into hollow mesoporous silica. The size of nanorattles and the filling amount of fluorides can be well controlled. In addition, the modification of silica shell （with phenylene and amine groups） and the variation of efficient UC fluorides （NaYF4：Yb, Er, NaLuF4：Yb, Er, NaGdF4：Yb, Er and LiYF4：Yb, Er） were readily achieved. The resulting nanorattles exhibited a high capacity and pH-dependent release of the anti-cancer drug doxorubicin （DOX）. Furthermore, we employed these nanorattles in proof-of-concept UC-monitoring drug release by utilizing the energy transfer process from UC fluorides to DOX, thus revealing the great potential of the nanorattles as efficient cancer theranostic agent.

Sub-10 nm lanthanide-doped SrFCl nanoprobes:Controlled synthesis,optical properties and bioimaging

Alkaline-earth dihalide nanocrystals(NCs) such as SrFCl, owing to their high chemical stability and low phonon energy, are excellent host materials for lanthanide(Ln3+) doping to achieve desirable optical properties for various bioapplications, Herein, we report a novel strategy for the synthesis of sub-10 nm Ln3+-doped SrFCl NCs with efficient upconverting and downshifting luminescence through a facile onestep hot-injection method. Utilizing the temperature-dependent upconverting luminescence(UCL) from the thermally coupled 2H11/2 and 4S3/2 levels of Er3+, we showed the potential of SrFCl:Yb,Er NCs as sensitive UCL nanoprobes for non-contact thermal sensing with a maximum detection sensitivity of 0.0066 K-1, which is among the highest values for thermal sensing based on Er3+-activated UCL nanoprobes. Furthermore, by employing the intense downshifting luminescence from Tb3+ and Eu3+, we demonstrated the successful use of biotinylated SrFCl:Ce,Tb and SrFCl:Eu3+ nanoprobes for biotin receptor-targeted cancer cell imaging, thus revealing the great promise of SrFCl:Ln3+ nanoprobes for versatile bioapplications.

A new strategy to achieve enhanced upconverted circularly polarized luminescence in chiral perovskite nanocrystals

Achieving large luminescence dissymmetry factors(pium)is challenging in the research field of circularly polarized luminescence(CPL).While various approaches have been developed to construct organic systems with CPL activity,there is still a lack of effective methods for fabricating CPL active inorganic materials.Herein,we propose an approach for endowing upconversion nanoparticles(UCNPs)and perovskite nanocrystal(PKNC)hybrid nanomaterials with upconverted circularly polarized luminescence(UC-CPL)activity.Chiral cesium lead bromides(CsPbBr_(3))PKNCs were synthesized by a chiral-ligand-assistant method.Meanwhile,UCNP could be embedded into the chiral PKNC,enabling a photon upconvesion feature to the PKNC.The embedded UCNPs in PKNCs were confirmed by electron tomography.Consequently,various CPL activities,including prompt CPL,UC-CPL,and energy transfer enhanced circularly polarized luminescence(ET-CPL),were realized.The chiral perovskite nanocrystals could reabsorb the chiral energy generated from UCNPs,showing energy transfer enhanced CPL activity with four times magnification of the circular polarization.These findings provide a meaningful strategy for designing chiral photon upconversion inorganic nanomaterials with highly efficient UC-CPL activity.

Composite particles with magnetic properties,near-infrared excitation,and far-red emission for luminescence-based oxygen sensing

Oxygen sensing,magnetic,and upconversion luminescence properties are combined in multi-functional composite particles prepared herein by a simple mixing,baking,and grinding procedure.Upconverting nanocrystals are used as an excitation source and an oxygen indicator with far-red emission.The composite particles are excited with near infrared(NIR)laser light(980 nm).The visible upconversion emission is converted into an oxygen concentration-dependent far-red emission(<750 nm)using an inert mediator dye and a platinated benzoporphyrin dye.This concept combines the advantages of NIR excitation and far-red emissive indicator dyes,offering minimized auto-fluorescence and enhanced membrane permeability.Additional functionality is obtained by incorporating magnetic nanoparticles into the composite particles,which enables easy manipulation and separation of the particles by the application of an external magnetic field.