75 results about "Holmium" patented technology

The invention provides a holmium and ytterbium co-doped mid-infrared microsphere Raman laser and a preparation method thereof, and relates to the technical field of laser preparation, the holmium and ytterbium co-doped mid-infrared microsphere Raman laser comprises an infrared transmission optical fiber, a pump light source, holmium and ytterbium co-doped tellurate glass microspheres and passive tellurate glass microspheres, pump light emitted by the pump light source is guided to a conical region through the infrared transmission optical fiber, and the holmium and ytterbium co-doped tellurate glass microspheres and the passive tellurate glass microspheres are arranged in the conical region; sequentially carrying out optical coupling with holmium and ytterbium co-doped tellurate glass microspheres and passive tellurate glass microspheres; in the holmium and ytterbium co-doped tellurate glass microspheres, the doping amount of the holmium element is 0.3%, and the doping amount of the ytterbium element is 0.45% according to the mass percentage. Compared with the prior art, through the cascade structure of the holmium-ytterbium co-doped microspheres and the passive microspheres, three-step wavelength conversion of pump light-rare earth ion lasing-Raman frequency shift is realized in a single system for the first time, and the wavelength limitation that a traditional single microsphere depends on a rare earth ion fixed energy level is broken through.

The invention discloses a method for improving performance of rare earth permanent magnet sintered neodymium iron boron grain boundary diffusion, and belongs to the technical field of rare earth permanent magnet materials. The method comprises the steps that a low-melting-point metal layer and a diffusion layer containing heavy rare earth elements are sequentially formed on the surface of a clean sintered neodymium-iron-boron magnet, and then vacuum diffusion heat treatment and tempering treatment are conducted. Wherein the low-melting-point metal layer comprises at least one of copper, aluminum, gallium and tin or an alloy of the copper, the aluminum, the gallium and the tin; the heavy rare earth element comprises at least one of dysprosium, terbium, holmium and gadolinium. The low-melting-point metal layer is preferentially diffused and wets the grain boundary in the heat treatment process, heavy rare earth elements are promoted to be deeply and uniformly diffused towards the interior of the magnet along the grain boundary, so that a heavy rare earth-rich shell layer is formed outside main phase grains of the magnet, and the intrinsic coercive force is improved; meanwhile, the low-melting-point metal forms a strengthening phase at the grain boundary, the brittleness of the magnet after diffusion is improved, the surface corrosion phenomenon is restrained, and collaborative optimization of the comprehensive performance of the magnet is achieved.

The invention discloses a dual-wavelength microsphere laser based on tri-doped rare earth ions and a preparation method thereof, the dual-wavelength microsphere laser based on tri-doped rare earth ions comprises a silica fiber, the middle part of the silica fiber is provided with a conical region; the pump light source is arranged at one end of the silica fiber; the erbium, holmium and ytterbium tri-doped tellurate glass microspheres are arranged in the conical region; pump light emitted by the pump light source is guided to the conical region through the single-mode optical fiber and is optically coupled with the erbium-holmium-ytterbium tri-doped tellurate glass microsphere; in the erbium-holmium-ytterbium triple-doped tellurate glass microspheres, infrared-transmitting tellurate glass is used as a matrix, and the doping amount of an erbium element is 0.11%, the doping amount of a holmium element is 0.22%, and the doping amount of an ytterbium element is 0.80% in percentage by mass. According to the dual-wavelength microsphere laser based on the three-doped rare earth ions, efficient and stable dual-wavelength laser output is achieved.

The invention discloses a method for determining the content of trace holmium, thulium and tungsten in rare earth erbium and a compound thereof, which comprises the following steps: placing a rare earth erbium and compound sample thereof in a beaker, and performing a blank test along with a sample; adding nitric acid, heating at low temperature until the sample is completely dissolved, and cooling; transferring into a volumetric flask, adding a cesium internal standard solution, diluting with water, and uniformly mixing; the holmium, the thulium and the tungsten are measured by using an oxygen mode of an inductively coupled plasma tandem mass spectrometer, and the contents of the holmium, the thulium and the tungsten are calculated according to a working curve method. According to the method, the inductively coupled plasma tandem mass spectrometry technology is used, and mass spectrum interference of an erbium matrix on holmium, thulium and tungsten is effectively eliminated by selecting a proper reaction mode and optimizing the flow of reaction gas.

The invention relates to the technical field of synthesis and processing of ceramic materials, and discloses a multiphase composite coated high-dielectric-constant ceramic material and a preparation method of the multiphase composite coated high-dielectric-constant ceramic material. 11%-13% of strontium titanate; 5%-7% of holmium oxide; 5%-6% of lead magnesium niobate; 6%-7% of titanium dioxide; 2%-3% of yttrium oxide; 3%-4% of magnesium oxide; 3%-4% of bismuth oxide; 2%-3% of lithium carbonate; 4%-5.5% of silicon dioxide; 1%-2% of zinc oxide; 2.5%-3.5% of manganese dioxide; 6%-7% of copper oxide; 3%-4% of glass powder; 0.05% to 0.08% of lanthanide series elements; through the steps of component pretreatment, ball milling and mixing, drying and sieving, forming, sintering and post-treatment, the component activity is improved through high-temperature calcination pretreatment, and directional growth of crystal grains in the components can be promoted by precisely controlled sintering temperature; the prepared ceramic material has the advantages of high dielectric constant, low dielectric loss, excellent densification effect and good mechanical property.

The invention belongs to the technical field of rare earth permanent magnet materials, and relates to a multi-component rare earth alloy diffusion source for improving the coercive force of a high-abundance neodymium-cerium-iron-boron magnet. The invention discloses a multi-component rare earth alloy diffusion source for improving the coercive force of a high-abundance neodymium-cerium-iron-boron magnet. The multi-component rare earth alloy diffusion source comprises rare earth elements and non-rare earth elements, the rare earth element is one or two of praseodymium element and holmium element; the non-rare earth element is a combination of an aluminum element and a copper element; the mass percent of rare earth elements in the multi-component rare earth alloy diffusion source is 80-95%, and the mass percent of non-rare earth elements in the multi-component rare earth alloy diffusion source is 5-20%. The invention further discloses a method for improving the coercive force of the high-abundance neodymium-cerium-iron-boron magnet and the prepared high-performance high-abundance neodymium-cerium-iron-boron magnet. The low-cost heavy rare earth element Ho is adopted as a diffusion source component, a Ho-rich (RE, Ho) 2Fe14B phase with a high magnetocrystalline anisotropy field is formed on the surface layer of main phase crystal grains, and the coercive force of the high-abundance neodymium-cerium-iron-boron magnet is improved.

This invention belongs to the field of surface modification technology for metallic materials, and discloses a steel-based laser cladding gradient transition layer and its application. The steel-based laser cladding gradient transition layer utilizes rare-earth holmium (Ho) and in-situ TiC nanoparticles for synergistic reinforcement, resulting in a uniform and dense TiC microstructure and significantly improved high-temperature stability. The gradient composite coating employs a three-layer gradient structure—a base layer, a transition layer, and a working layer—to achieve a smooth transition in hardness and high-temperature performance, eliminating interfacial thermal stress concentration and significantly improving interlayer bonding strength and anti-stripping ability. This invention employs a layered laser cladding process to achieve a smooth transition in coating hardness and performance, effectively eliminating interfacial thermal stress concentration and improving coating bonding strength and high-temperature stability. This invention is the first to use Ho in laser cladding gradient coatings, resulting in outstanding grain refinement and grain boundary purification effects, significantly improving coating microstructure uniformity, high-temperature strength, and thermal fatigue resistance. The process is stable and reliable, suitable for industrial strengthening applications in large aluminum alloy die-cast cups.

The invention discloses a modification method of a ternary positive electrode material. The modification method comprises the following steps: S1, carrying out a co-precipitation reaction on a solution of transition metal sulfate in an inert gas atmosphere; a sulfate solution of rare earth elements is synchronously added in the coprecipitation process, and a ternary precursor with the surface coated with rare earth hydroxide is formed; and S2, mixing the ternary precursor obtained in the step S1 with a lithium source, calcining in an air atmosphere, and cooling to obtain the fast ion conductor coated ternary positive electrode material, the rare earth elements are selected from one or more of lanthanum, cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium; the transition metal sulfate is soluble salt of Ni, Co and Mn. The rare earth element sulfate is added in the coprecipitation process, the rare earth element hydroxide is precipitated on the surface of the precursor, the lithium source is removed after filtering and drying, uniform mixing is performed, and the ternary positive electrode material which contains the rare earth element and is uniformly coated with the fast ion conductor is obtained after calcination, so that side reactions on the surface of the material are reduced; and the cycling stability of the positive electrode material is improved.

Aspects are provided for a UV-Vis calibration solution, composed of a lanthanide and an ionic liquid. In particular, the UV-Vis calibration solution may contain 4 to 12% by weight of Holmium (III), dissolved in an aqueous chloride solution. The disclosure also includes a calibration standard created from this calibrated solution, by placing the solution in a cuvette and capping it. The disclosure additionally includes a method of using the calibration standard to obtain a UV-Vis spectrum in the wavelength range of about 250 nm to 700 nm.

The application belongs to the technical field of laser materials, and relates to a holmium-praseodymium-scandium doped composite calcium fluoride single crystal as well as a preparation method and application thereof. 0.01 Pr x Sc y Ca 0.99‑x‑y F 2.01+x+y , wherein 0.005 <= x <= 0.015, 0.005 <= y <= 0.05; the crystal is obtained by growing the crystal in a vacuum environment through a temperature gradient method. Compared with the prior art, the application can realize high-efficiency laser output in a 2-3 mu m mid-infrared wave band, the grown crystal has the characteristics of high thermal conductivity, high chemical stability, high transmittance and high quality, and has the advantages of high gain bandwidth, high gain cross section, high power and high slope efficiency in the mid-infrared wave band, and has significant advantages in the fields of environmental monitoring, industrial processing, national defense and safety.

The application relates to the technical field of target production, and discloses a low-resistance and high-mobility indium oxide doped target material, wherein metal elements in the target material are composed of indium, titanium, holmium and cerium; the molar ratio of the indium, titanium, holmium and cerium is 92.4-95.2:3-4:0.7-0.9:1.5-1.8; the target material is prepared through a degreasing operation and an oxygen-rich sintering operation of a target precursor containing indium oxide powder, titanium oxide powder, holmium oxide powder and cerium oxide powder; the process parameters of the degreasing operation are as follows: a degreasing temperature is 500-600 DEG C, and an oxygen pressure is 0.02-0.05 MPa; and the process parameters of the oxygen-rich sintering operation are as follows: a sintering temperature is 1300-1550 DEG C, and an oxygen pressure is 0.09-0.12 MPa.

The application relates to the technical field of target production, and discloses a preparation method of high-purity indium cerium tantalum holmium oxide target material, which comprises the following steps: step 1: soluble metal salts of indium, cerium, tantalum and holmium are weighed according to a molar ratio of In:Ce:Ta:Ho=90-94:0.8-1.2:4-6:1.2-2.8, and are dissolved in deionized water; step 2: a precipitant urea is added to the mixture in step 1 and is mixed; step 3: the mixture in step 2 is placed in a sealed container and is heated at 190-200 DEG C, and after heating is completed, a precursor powder is separated; and step 4: the precursor powder is calcined and shaped to obtain the indium cerium tantalum holmium oxide target material. The content of indium in the target material is relatively low, the use of cerium, tantalum and holmium is beneficial to control of high conductivity, and the purity of the target material can be effectively maintained through a wet precipitation process, which is also an important factor for improvement of the conductivity. In addition, the application also discloses the target material.

The invention relates to a novel functional material for X-ray protection, in particular to a liquid metal flexible shielding material and a preparation method and application thereof. The material comprises liquid metal and solid metal, the liquid metal serves as a solvent to be filled in gaps of the solid metal, the liquid metal is gallium, gallium indium, gallium indium tin, gallium indium tin zinc or mercury, and the solid metal is selected from one or more of indium, tin, gold, platinum, iridium, zirconium, niobium, molybdenum, ruthenium, osmium, rhenium, rhodium, tungsten, antimony, palladium, tantalum, hafnium, lutetium, lead, ytterbium, thulium, bismuth, silver, erbium, holmium, dysprosium, terbium, gadolinium, samarium, neodymium, lanthanum, praseodymium, cerium and europium. On the basis of compounding of the liquid metal solvent and the solid metal solute based on the liquid metal combinatology, the liquid metal and the solid metal are jointly used for protecting X-ray radiation, the comprehensive performance of X-ray protection is improved, and meanwhile the variety and number range of selectable metal elements is widened.

The application provides a high-thermal-conductivity radiation refrigeration coating for a 5G communication base station cabinet and a preparation method thereof, and belongs to the technical field of coatings. A SiC@BN / TiB2 three-phase fiber framework obtained through three-stage calcination is bonded with methylphenyl silicone resin through a silane coupling agent to form a longitudinal high-speed thermal conduction framework. Starburst calcium titanate and edge in-situ magnesium fluoride form a refractive index ladder and a rough multi-faceted structure, which not only reflects ultraviolet-near infrared light, but also endows weather resistance. Holmium / ytterbium co-doped calcium fluoride nanosheets are transversely overlapped to scatter near infrared light and convert the near infrared light into medium-far infrared radiation which can penetrate the atmospheric window, thereby further dissipating heat. Through mutual cooperation of a longitudinal continuous heat conduction path, a transverse heat dissipation network, optical multiple scattering and energy downshift radiation, stable chemical bond network support is achieved to realize high-efficiency, long-term reliable heat dissipation performance.

The present application relates to the technical field of optical fibers, in particular to a dual-wavelength femtosecond fiber laser. The laser comprises a pumping light source, which is used for outputting first-wavelength femtosecond pulse laser and a first excitation light source; a double-clad nonlinear optical fiber, which is connected to an output end of the pumping light source and is used for converting part of the first-wavelength femtosecond pulse laser into second-wavelength femtosecond pulse laser by means of using the soliton self-frequency shift effect, and outputting the remaining first-wavelength femtosecond pulse laser, the second-wavelength femtosecond pulse laser and the first excitation light source; and a holmium-doped gain fiber, which is connected to the output end of the double-clad nonlinear optical fiber and is used for amplifying the first-wavelength femtosecond pulse laser and the second-wavelength femtosecond pulse laser under the excitation of the first excitation light source. Therefore, the present application achieves the output of dual-wavelength high-energy femtosecond pulse laser in full-fiber mid-infrared lasers, achieves a compact and portable structure, good environmental adaptability and wavelength and energy advantages in practical applications such as medicine and material processing, and is applicable to vehicle-mounted scenarios, airborne scenarios, etc.

The invention discloses an intracavity resonance ESA pumping enhanced thulium-doped laser, which comprises a 0.8 [mu] m pumping source, an input mirror, a thulium-doped laser medium, a holmium-doped laser medium and an output mirror, the thulium-doped laser medium and the holmium-doped laser medium are placed in the same cavity, 1.9 [mu] m, 2.1 [mu] m and 2.3 [mu] m laser resonant cavities are formed between the input mirror and the output mirror, the 0.8 [mu] m pumping source emits 0.8 [mu] m wave band pumping light, and the output mirror emits holmium-doped laser light. The laser is emitted to the thulium-doped laser medium through the input mirror, the generated 1.9 [mu] m and 2.1 [mu] m wave band laser oscillates in the cavity but is not output to the outside of the laser resonant cavity, and the generated 2.3 [mu] m laser is output to the outside of the laser resonant cavity through the output mirror. The thulium-doped laser is based on 2.1 [mu] m intra-cavity resonance ESA pumping enhancement, and the thulium-doped laser intra-cavity pumping holmium-doped laser is utilized to realize enhancement of thulium-doped laser medium 2.3 [mu] m wave band laser radiation by regulating and controlling the number of 3H5 energy level particles.

Provided is an aluminum alloy powder comprising 0.1-2.0 mass% or one or more metal elements from among rare earth metal elements comprising the lanthanide elements and yttrium, wherein the iron content is suppressed to not more than 2.0 mass%. The rare earth metal element is preferably one of praseodymium, neodymium, europium, samarium, terbium, gadolinium, dysprosium, holmium, erbium, thulium, ytterbium, and lutetium.

The present invention discloses a HoMOF material, its preparation method and its application, which comprises: (1) mixing a holmium source, organic ligand and solvent, sonicating to obtain the first mixture; (2) Placing the first mixture in the condensation reflux device for heating and stirring to obtain the second mixture; (3) Post treating the second mixture to obtain HoMOF material. Therefore, the preparation method is facile, and the obtained HoMOF material has a uniform pore structure, fewer impurity peaks, a single structure, good crystal structure and good magnetism, which can be further applied to adsorb methylene blue from waste water.

A laser apparatus for generating a sub- 190 nanometer laser beam includes a deep-ultraviolet solid-state laser source to generate an initial deep-ultraviolet laser beam, at least one mid-infrared solid-state laser source to generate at least one respective mid-infrared laser beam, and at least one lithium triborate crystal to generate an output deep-ultraviolet laser beam from the initial deep-ultraviolet and mid-infrared laser beams via sum-frequency generation. Each mid-infrared solid- state laser source includes (a) a holmium-, thulium-, or chromium-doped gain crystal or gain fiber or (b) an optically-pumped semiconductor gain material to generate the respective mid-infrared laser beam. The laser apparatus may be configured for continuous-wave and pulsed operation, thus offering versatile solutions for applications requiring DUV laser radiation below 190 nanometers. Advantageously, the present approach relies on lithium triborate. Lithium triborate crystals can be grown with the quality and dimensions needed for industrial applications.

The application relates to the technical field of nanometer materials, and particularly discloses a bismuth titanate nanometer material, a preparation method thereof and a sewage treatment method. The preparation method of the bismuth titanate nanometer material comprises the following steps: uniformly mixing bismuth oxide, titanium oxide, holmium oxide, sodium chloride and potassium chloride according to a molar ratio of Bi:Ti:Ho:NaCl:KCl=(3.5-3.92):(2.8-3.2):(0.1-0.5):(40-55):(40-55) to obtain a precursor; calcining the precursor to obtain an intermediate product; and removing sodium chloride and potassium chloride in the intermediate product. By implementing the application, the polarity and piezoelectric response of the bismuth titanate nanometer material can be improved, and the piezoelectric-optical catalytic performance of the bismuth titanate nanometer material can be improved.

This invention discloses a holmium ion-doped yttrium gadolinium oxide single-crystal optical fiber, its preparation method, and its applications, belonging to the field of laser materials and laser technology. The chemical formula of the single-crystal optical fiber is Ho. 3+ YGdO3, wherein the Ho ion doping concentration is 0.2-1.0 at.%, is a cubic C-type sesquioxide crystal structure with space group Ia-3. This crystal exhibits characteristic absorption peaks at wavelengths of 1100-1200 nm and Ho-derived absorption peaks at 2.80-2.90 μm. 3+ ion 5 I6→ 5 Broad-spectrum mid-infrared fluorescence emission with I7 level transition; this crystal possesses a wide gain bandwidth, a large emission cross section, and excellent thermal properties, making it less prone to thermal lensing and thermal depolarization under continuous or high-repetition-rate pumping of single-crystal fibers, thus ensuring high stability of laser output. It is particularly suitable for realizing broadband tunable and ultrafast mode-locked mid-infrared lasers, and has broad application prospects in laser surgery, environmental monitoring, remote sensing, and other fields.

The invention discloses a screening method and device for holmium-copper alloy spherical particles applied to quantum computing, and relates to the classified screening technology, the device comprises four stages of screening devices, the first screening device and the second screening device screen the holmium-copper alloy spherical particles according to the size by setting the upper limit and the lower limit of the specification, then impurities are removed through slope screening, and the holmium-copper alloy spherical particles are obtained. And finally, irregular particles are removed through bouncing separation of the separation balls, and finally the holmium-copper alloy spherical particles meeting the requirements are obtained. According to the method, screening of the holmium-copper alloy spherical particles is achieved through five steps. The holmium-copper alloy spherical particle screening device can rapidly and efficiently screen out holmium-copper alloy spherical particles with the size meeting the requirement and the intact spherical shape, impurities in the holmium-copper alloy spherical particles are removed, and the requirements of scientific research and production are met.

The invention discloses an implementation method of a tunable palladium diselenide mode-locked fiber laser, which belongs to the technical field of laser, and comprises the following steps: preparing an integrated tuning mode-locked component integrating a tunable band-pass filtering function and a palladium diselenide saturable absorption function; the integrated tuning mode-locking assembly is embedded into an optical fiber laser cavity, a thulium-holmium co-doped optical fiber is adopted as a gain medium, and a tunable mode-locking laser system is formed. External control voltage is applied to the integrated tuning mode-locking assembly to adjust the light-passing wavelength, cooperative mode-locking operation is triggered, and an intracavity mode-locking light field is generated; exporting an intracavity mode-locked light field, and outputting mode-locked laser pulses; wavelength tuning operation is carried out on the tunable mode-locked laser system, spectrum and pulse width measurement is carried out on mode-locked laser pulses, and broadband tunable ultrashort pulse characteristic data are generated. According to the invention, the integrated tuning mode-locking assembly is adopted, and the electronic control wavelength tuning and passive mode-locking mechanism is combined, so that broadband tunable ultrashort pulse laser output can be realized.

The application belongs to the technical field of Nd-Fe-B magnets, and relates to a high-coercivity Nd-Fe-B magnet and a preparation method thereof. The grain boundary triple point of the magnet is enriched with oxides of M and / or R. R is at least one of dysprosium, terbium, holmium and praseodymium. M is at least one of zirconium, titanium, tungsten, molybdenum, ruthenium, vanadium and manganese. The Nd-Fe-B magnet is added with metal salt powder of rare earth elements, and the rare earth element metal oxides are enriched at the grain boundary triple point. Since the oxides have a large number of oxygen vacancy type point defects, the grain boundary of the magnet is thickened, the flipping of magnetic domains is hindered under an external magnetic field, the rare earth element metal oxides play a pinning role, and thus the coercivity of the Nd-Fe-B magnet is improved.

The invention relates to a holmium and praseodymium doped disordered high-entropy fluoride mid-infrared laser crystal and a preparation method thereof, the chemical formula of the crystal is Ho, Pr: Me1Me2CaSrBaF12, the doping concentration of holmium is 0.5-1.5 at.%, the doping concentration of praseodymium is 0.05-0.15 at.%, and Me1 and Me2 are respectively selected from one of lanthanum, yttrium, gadolinium, scandium, lutetium, aluminum and gallium. Compared with the prior art, the invention has the advantages of wide absorption range, high transmittance and mid-infrared laser output capability with high fluorescence intensity.

This invention discloses a rare-earth metal fluoride superionic conductor dielectric film and its preparation method. The dielectric film is prepared from a rare-earth metal fluoride superionic conductor using a thermal evaporation method. The rare-earth metal fluoride superionic conductor is selected from scandium fluoride, yttrium fluoride, lanthanum fluoride, cerium fluoride, neodymium fluoride, samarium fluoride, europium fluoride, gadolinium fluoride, holmium fluoride, erbium fluoride, ytterbium fluoride, praseodymium fluoride, promethium fluoride, terbium fluoride, dysprosium fluoride, thulium fluoride, and lutetium fluoride. This invention utilizes thermal evaporation to heat and evaporate the rare-earth metal fluoride source material into a gaseous state within an evaporation system. The gaseous fluoride directly adheres to a substrate placed above the source material and recrystallizes. This allows for controllable thickness and defect number of the rare-earth metal fluoride, resulting in high integration. Therefore, rare-earth metal fluoride superionic conductor dielectric materials show great potential in the design and manufacture of novel functional devices.

The present invention relates to an optical amplifier (1) for a fiber laser source (3) for generating laser radiation in the infrared range, in particular over a bandwidth of 2.0-2.2 µm, comprising a preamplifier which is applied to an optical input signal S IN with an input signal wavelength λ IN and a first pump jet with a pump wavelength λ p1 reacts and an amplified input signal S IN2 outputs, and a thulium, thulium:holmium or holmium-doped power amplifier coupled to an output of the preamplifier, which reacts to the amplified input signal S IN2 and a second pump jet with a pump wavelength λ p2 reacts and produces an amplified output signal S OUT outputs, with the preamplifier being Thulium:Holmium-codoped.

Disclosed herein are magnetocaloric materials comprising alloys useful for magnetic refrigeration applications. The disclosed alloys include Dysprosium, Erbium, Holmium, Yttrium, or Terbium, and Cerium, Neodymium, and / or Gadolinium components that are fairly inexpensive. In certain embodiments, the materials exhibit second-order magnetic phase transitions near their Curie temperatures with negligible thermal and structural hysteresis losses, making them attractive for magnetic refrigeration. Surprisingly, the performance of the disclosed materials is comparable to or better than that of other expensive, rare-earth-based magnetocaloric materials.

A core-shell nanoparticle having a cleaned nitrogen-vacancy nanodiamond (NVND) core surrounded by an upconversion nanoparticle (UCNP) shell, wherein the cleaned nitrogen-vacancy nanodiamond (NVND) core comprises a cleaned nitrogen-vacancy nanodiamond, wherein the UCNP shell comprises an upconversion nanoparticle (UCNP), wherein the UCNP comprises lithium yttrium fluoride (LiYF4) doped with a lanthanide ion combination, wherein the lanthanide ion combination comprises a M1 ion and a M2 ion, wherein M1 is ytterbium (Yb) or neodymium (Nd) and M2 is erbium (Er), thulium (Tm) or holmium (Ho), and wherein the core-shell nanoparticle emits a red-emission upon a near-infrared (NIR) excitation is disclosed. Integration of cleaned NVNDs with UNCPs for enhancing optical manipulation and enabling efficient energy transfer for applications in biological imaging, quantum sensing and laser cooling is disclosed.

An alcohol gas concentration remote sensing device based on mode division multiplexing transmission relates to the field of biomedical measurement technology. It aims to solve the problems of low measurement accuracy and high false alarm rate in the process of non-contact measurement of alcohol content in human exhaled breath. The device comprises a semiconductor laser, an erbium-doped fiber amplifier, a wavelength division multiplexer, a thulium-holmium co-doped double-clad fiber, a few-mode optical isolator, a mode selector, a few-mode optical coupler, a polarization controller, a second optical coupler, a first optical coupler, a first optical fiber collimator, a Kepler beam compressor, a two-color beam splitter, a first receiving lens, a first photodetector, a second receiving lens, a few-mode receiving fiber, a mode demultiplexer, a second photodetector, a third photodetector, a fourth photodetector, an analog-to-digital converter, an FPGA, and a microcomputer. According to the different alcohol absorption laws of different mode light beams during the test or analysis of the alcohol content in human exhaled breath, the receiving end performs multi-mode diversity reception, and the alcohol content is deciphered in multiple modes to improve the measurement accuracy.