Abstract: A lipid delivery system, a virus-like structure (VLS) vaccine constructed therefrom, and a lipid particle capable of encapsulating an mRNA molecule encoding a SARS-CoV-2-specific antigen are provided. After the lipid particle encapsulates an mRNA molecule encoding a SARS-CoV-2 antigen, a SARS-CoV-2 S1 antigen protein can be embedded on a surface of an envelope structure of the lipid under specific buffer conditions to produce a VLS vaccine with an antigen-encoding mRNA molecule encapsulated inside and an outer membrane presenting a required viral antigen protein. The vaccine has a superior specific antibody-inducing ability to a SARS-CoV-2 mRNA vaccine and a polypeptide vaccine, can maintain a long-lasting high antibody level, and can also exhibit excellent immune binding abilities for the emerging different variants.

Abstract: A method of preparing a dye-functionalized flexible upconversion-luminescence solid-phase sensor, including: preparation of upconversion-luminescence nanoparticles, preparation of an upconversion nanoparticle-doped solid-phase sensor, and preparation of a dye-functionalized flexible upconversion-luminescence solid-phase sensor. A method for detecting a gaseous pollutant is also provided, including: preparing a dye-functionalized flexible upconversion-luminescence solid-phase sensor through the above method; establishing a prediction model; and substituting a fluorescence intensity of a sample into the prediction model to calculate the gaseous pollutant concentration in the sample.

Abstract: A method of preparing a dye-functionalized flexible upconversion-luminescence solid-phase sensor, including: preparation of upconversion-luminescence nanoparticles, preparation of an upconversion nanoparticle-doped solid-phase sensor, and preparation of a dye-functionalized flexible upconversion-luminescence solid-phase sensor. A method for detecting a gaseous pollutant is also provided, including: preparing a dye-functionalized flexible upconversion-luminescence solid-phase sensor through the above method; establishing a prediction model; and substituting a fluorescence intensity of a sample into the prediction model to calculate the gaseous pollutant concentration in the sample.

Abstract: An apparatus and method for determining a volume stability of well cement including a reaction kettle, a radial contraction, an expansion ring, a heater, a pressurizer, and a volume change parameter tester. The radial contraction and expansion ring include a first casing and a second casing, the first casing is a casing made of elastic material, the second casing is a steel casing, and the first casing sheathes the second casing. The heater and the pressurizer are used to provide a preset temperature and a preset pressure respectively and the volume change parameter tester is used to detect a radial volume change parameter of the well cement. The apparatus is provided with the radial contraction and expansion ring to acquire the radial volume change parameter of the well cement, and comprehensively evaluates the volume stability of the well cement using the radial volume change parameter of the well cement.

Abstract: The invention provides a method and device for measuring the elasticity of hardened cement for cementing of oil-gas wells. The measurement method comprises: determining the loading and unloading rates of the hardened cement; determining the maximum loading on the hardened cement; determining the experimental temperature and the experimental pressure of the hardened cement; establishing a stress-strain curve for the hardened cement; and describing the elasticity of the hardened cement with the degree of strain recovery of the hardened cement in different cycles, and describing the mechanic integrity of the hardened cement with the degree of damage to the hardened cement in different cycles. The invention further provides a device for measuring the elasticity of hardened cement for cementing of oil-gas wells.

Abstract: An apparatus and method for determining a volume stability of well cement including a reaction kettle, a radial contraction, an expansion ring, a heater, a pressurizer, and a volume change parameter tester. The radial contraction and expansion ring include a first casing and a second casing, the first casing is a casing made of elastic material, the second casing is a steel casing, and the first casing sheathes the second casing. The heater and the pressurizer are used to provide a preset temperature and a preset pressure respectively and the volume change parameter tester is used to detect a radial volume change parameter of the well cement. The apparatus is provided with the radial contraction and expansion ring to acquire the radial volume change parameter of the well cement, and comprehensively evaluates the volume stability of the well cement using the radial volume change parameter of the well cement.

Abstract: The invention provides a method and device for measuring the elasticity of hardened cement for cementing of oil-gas wells. The measurement method comprises: determining the loading and unloading rates of the hardened cement; determining the maximum loading on the hardened cement; determining the experimental temperature and the experimental pressure of the hardened cement; establishing a stress-strain curve for the hardened cement; and describing the elasticity of the hardened cement with the degree of strain recovery of the hardened cement in different cycles, and describing the mechanic integrity of the hardened cement with the degree of damage to the hardened cement in different cycles. The invention further provides a device for measuring the elasticity of hardened cement for cementing of oil-gas wells.