30results about How to "Enhanced relaxation properties" patented technology

The invention relates to a high energy density sodium-bismuth titanate based thin dielectric film as well as a preparation method and application thereof. The high energy density sodium-bismuth titanate based thin dielectric film is prepared from Bi0.5(Na0.8K0.2)0.5TiO3-xSiZrO3. The preparation method of the high energy density sodium-bismuth titanate based thin dielectric film is a sol-gel methodand comprises the following steps: preparing a precursor solution according to stoichiometric ratio, and subsequently dropwise adding the precursor solution on a cleaned Pt/Ti/SiO2/Si substrate for rotating and coating; carrying out 150 DEG C heat treatment, 350 DEG C heat treatment and 700 DEG C heat treatment in sequence, and repeating a spin-coating and heat treatment technology until the thickness of the film reaches 500 to 600nm; in addition, a metal top electrode also can be prepared by using a sputtering technology on the thin film. Compared with the prior art, a high energy density thin film capacitor has excellent energy storage performance (energy storage density of the high energy density thin film capacitor is 25J/cm<3> and the energy storage efficiency is 79.16 percent) and good temperature stability.

The invention provides a biodegradable poly-HPMA-Gd magnetic resonance imaging (MRI) probe used for inserting enzyme sensitive polypeptide GFLG into a poly-HPMA backbone structure. The molecular weight of a prepared polymer is basically controllable, the molecular weight is high, and the dispersion coefficient (PDI) is low; and linear HPMA-DOTA-Gd is obtained through coupling with Gd(III). The probe is an efficient nanoscale MRI probe with biocompatibility, and can be used for clinical tumor diagnosis and adjuvant therapy.

The present invention disclose a specific positive magnetic nuclear resonance contrast agent and method of preparing the same, the contrast agent is applying gadopentetate dimeglumine (Gd-DTPA) coating or scion grafting to 1-100 nm hydroxylapatite [Ca [10](PO [4][6](OH)[2], short as HA) particles, to obtain composite granule smaller than 1000 nm, modified by proserum, polyethylene imine (PEI), polyethyleneglycol (PEG) to get dispersion stability colloid solution. Comparing with the present technology the positive magnetic nuclear resonance contrast agent of the invention is provided with low toxicity, high stability, good biocompatibility, high sensibility, high relaxation capability and liver, spleen specificity. The contrast agent colloid solution can be used for enhancing contrast imaging of human body or non-human body liver or spleen.

A method for preparing gadolinium sulfide nanoparticles: using protein molecules as templates, synthesizing gadolinium sulfide nanoparticles through a biomimetic synthesis method. The preparation method of the invention has the advantages of simple process, mild reaction conditions, short preparation cycle, low cost and environmental protection. The gadolinium sulfide nanoparticles obtained in the invention have good stability, aqueous solution dispersibility and high relaxation performance, and can be used as contrast agents for magnetic resonance imaging.

The invention discloses a batch preparation method of a suspended nanowire manipulator. The method comprises the following steps: preparing a nanowire array growing on the edge of a slope step definedby photoetching based on an IPSLS growth mode, then, spin-coating a layer of oxygen resin colloid on the substrate on which the silicon nanowires grow; carrying out photoetching pattern operation, removing an amorphous silicon dielectric layer on the surface of the substrate by wet etching, suspending an epoxy resin colloid thin film adhered to a nanowire array on the surface of a solution, fullyreplacing the epoxy resin colloid thin film with ethanol, and carrying out a drying technology to prepare the self-assembled suspended nanowire manipulator array. According to the invention, the nanowire array is transferred to the photoetched self-supporting substrate by using a transfer technology and a critical point drying technology; the influence of solution surface tension is eliminated, the original appearance of the nanowire manipulator is kept, finally, the operable suspended nanowire manipulator array is obtained, and the method can be widely applied to various fields of nano robots, biomedical cell detection, biosensors and the like.

The invention provides tumor targeting MRI contrast agent and a preparation method thereof. The contrast agent is characterized by comprising a micromolecule gadolinium chelate part and a targeting carrier part, wherein the micromolecule gadolinium chelate part and the targeting carrier part are coupled through a covalent bond, the micromolecule gadolinium chelate part is Gd-DO3A, and the targeting carrier part contains EBP molecules. The contrast agent is good in relaxation enhancement ability, can be combined with EGFR of tumor cells in a targeting mode, has a strong targeting radiography effect and has strong practicability. Furthermore, the imaging time of the contrast agent in a body is prolonged, and the adding amount of the contrast agent is reduced.

The invention discloses a fluorine-doped iron oxide nanoparticle contrast agent and a preparation method thereof, wherein the nanoparticles form a magnetic aggregate with a cubic structure, and the magnetic aggregate is prepared by reacting an iron precursor such as carbonyl iron or ferric oleate with sodium fluoride in the presence of oleic acid and octadecene. Compared with a traditional spherical iron oxide nanoparticle contrast agent, the contrast agent has larger effective radius and local magnetic field non-uniformity, the transverse relaxation rate r2 is obviously higher than that of conventional spherical nanoparticles and T2 magnetic resonance imaging performance is very high, so that the more accurate and reliable basis can be provided for clinical research and disease diagnosis of magnetic resonance imaging.

The invention provides barium titanate-based relaxor ferroelectric ceramic powder, ceramic and a preparation method and application thereof, the chemical general formula of the ceramic powder is (1-z) (Ba1-xCax) (Ti1-ySny) O3-zBi (Zn2/3 (Nb0.85Ta0.15) 1/3) O3, 0 < = x < = 0.05, 0 < = y < = 0.09, and 0.1 < = z < = 0.15. The ceramic powder is obtained by adopting a traditional solid-phase ceramic preparation technology and industrial raw materials, the sintering temperature of the ceramic can be reduced to 1150 DEG C, the discharging speed t0.9 of the material is 24 ns, the charging and discharging speed is extremely high, and the ceramic powder belongs to a novel lead-free energy storage ceramic capacitor material. The barium titanate-based relaxor ferroelectric ceramic has ultra-fast charging and discharging capacity and high power density, and has wide application prospects in the fields of pulse power equipment, high-power capacitors, directional energy weapons and the like.

The invention provides a lead-free ceramic material with high energy storage and charge-discharge performance and a preparation method thereof, the chemical formula of the ceramic material is (1-x) (Na0.5Bi0.5) 0.7 Sr0.3TiO3-xSr (Ti0.85Zr0.15) O3, and x is more than or equal to 0.10 and less than or equal to 0.40. The preparation method comprises the following steps: (1) uniformly mixing SrCO3, Na2CO3, TiO2, ZrO2 and Bi2O3 to obtain raw material powder, briquetting, presintering, crushing and sieving to obtain presintered powder; (2) carrying out ball milling on the presintered powder to obtain raw material powder; and (3) tabletting and molding the raw material powder, and sintering into porcelain to obtain the lead-free high-energy-storage and charge-discharge-performance ceramic material. The ceramic material has high energy storage performance and excellent charging and discharging performance, is a promising high-performance dielectric candidate material, and has the characteristics of environmental friendliness, high practicability and the like.

The invention discloses a lead-free thin film with high energy storage density and wide working temperature, a capacitor and a preparation method thereof, the lead-free thin film with high energy storage density and wide working temperature comprises an Nb: SrTiO3 substrate and a thin film, and the thin film is arranged on the surface of the Nb: SrTiO3 substrate; the thin film is a BaHf < x > Ti < 1-x > O < 3 > thin film, wherein x is larger than or equal to 0.05 and smaller than or equal to 0.32. The preparation method comprises the following steps: preparing the BaHf < x > Ti < 1-x > O3 thin film on the surface of the Nb: SrTiO3 substrate by utilizing a ceramic target material of the BaHf < x > Ti < 1-x > O3 thin film in a magnetron sputtering manner, and then annealing to obtain the lead-free thin film with high energy storage density and wide working temperature. The lead-free film with high energy storage density and wide working temperature has the characteristics of high energy storage density and wide temperature range.

The invention discloses an MRI contrast agent, which is prepared from gadolinium oxide nanoparticles and mesoporous carbon nanoparticles. The gadolinium oxide nanoparticles are loaded into holes of the mesoporous carbon nanoparticles, and the surfaces of the mesoporous carbon nanoparticles are modified with biological affinity substances such as PEG. The invention further discloses a preparation method and application of the MRI contrast agent. Compared with the prior art, the MRI contrast agent is simple in preparation method, has the high relaxation rate, and good hydrophilicity and biocompatibility, and has the longer blood circulation time and excellent tumor target performance.