593results about How to "React Safe" patented technology

Systems and methods are disclosed for treating teeth to correct for malocclusions. This may be accomplished in one variation by receiving a scanned dental model of a subject's dentition, determining a treatment plan having a plurality of incremental movements for repositioning one or more teeth of the subject's dentition, and fabricating one or more aligners correlating to a first subset of the plurality of incremental movements.

The invention relates to a method for undergoing a chlorobenzene nitration reaction by using a micro-channel reactor, belonging to the technical field of application of organic synthesis. In the method, nitric acid, sulfuric acid, water and chlorobenzene are taken as initial reaction raw materials, and processes such as mixed acid preparation, mixed acid and chlorobenzene preheating, mixed acid and chlorobenzene reacting and the like are completed in a micro-channel reactor system. In the reaction, nitro-sulfuric mixed acid is taken as a nitrating agent, the effective concentration of sulfuric acid in the mixed acid is 50-90 percent, the molar ratio of the nitric acid to the sulfuric acid in the mixed acid is 1:1-1:10, the molar ratio of the chlorobenzene to the nitric acid is 1:1.0-1:2.0, the reaction temperature is 50-100 DEG C, and the reaction time is 30-120 seconds. The chlorobenzene transformation ratio is up to 97 percent, the selectivity of nitrochlorobenzene serving as a product is over 96.5 percent, and the ratio of ortho-para nitrochlorobenzene is over 0.6. A strengthened mixed micro-channel reactor adopted in the invention is particularly suitable for undergoing a continuous nitration reaction, and has the characteristics of stable temperature control and safe process.

A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360° and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

Systems and methods are disclosed for treating teeth to correct for malocclusions. This may be accomplished by applying a series of labels to a digital dental model and applying a rolling ball process to identify tooth boundaries separating one tooth from a neighboring tooth and to also determine the crown/gum margin. The user may further assign regions to the dental model to indicate hard regions and soft regions. With the dental model labeled and defined, the user may then generate a treatment plan for moving the labeled and defined tooth or teeth relative to one another to correct for any malocclusions. Upon approval of the treatment plan, a series of 3D printed dental appliances or aligners to be worn in series by the patient may be fabricated to ultimately move the tooth or teeth to a desired position.

A therapy apparatus for producing thermal neutrons at a tumor site in a patient has a plurality of fast neutron sources surrounding a moderator, a fast neutron reflecting media around the fast neutron sources, a gamma-ray and neutron shielding media surrounding the fast neutron reflecting media, and a patient chamber positioned inside the moderator. The fast neutron sources are positioned around the moderator to maximize and direct the neutron flux to said tumor site.

The invention discloses a preparation method for polymer grafted graphene oxide. The method comprises the following steps: (1) carrying out pre-oxidation on graphite by using phosphorus pentoxide to obtain pre-oxidized graphite; (2) adopting potassium permanganate and concentrated sulfuric acid to oxidize the pre-oxidized graphite, and washing to obtain graphene oxide with hydroxyl on the surface; (3) mixing the graphene oxide with the hydroxyl on the surface and an alkene monomer, heating and introducing nitrogen, adding a tetravalent cerium ion-containing solution in a dropwise manner, carrying out a reaction for 1-6 hours while stirring under the case of nitrogen introducing, and carrying out treatments of filtering, washing and drying to obtain the polymer grafted graphene oxide. According to the present invention, a new method for preparing the polymer grafted graphene oxide is developed; the polymer grafted with the graphene oxide on the surface is obtained with one step through the redox polymerization method based on the graphene oxide, such that the steps are convenient, the reaction is safe, the environmental protection is achieved, and the efficiency is high.

This invention relates to a process for preparing alditol acetals, such as dibenzylidene sorbitols, monobenzylidene sorbitols, and the like, through the reaction of unsubstituted or substituted benzaldehydes with alditols (such as sorbitol, xylitol, and ribitol) in the presence of a mineral acid and at least one surfactant having at least one pendant group of 6 carbon chains in length. Such a reaction provides a cost-effective, relatively safe procedure that provides excellent high yields of alditol acetal product. Furthermore, such a specific reaction is also the best known procedure for the production of certain compounds which can be easily separated from other formed isomers. Additionally, such a procedure facilitates the production of certain asymmetric alditol acetal compounds and compositions in acceptable yields as well. Such alditol acetals are useful as nucleating and clarifying agents for polyolefin formulations and articles, as one example.

The invention provides a phenolic resin/silicon dioxide compositeaerogel material and a preparation method thereof. The phenolic resin/silicon dioxide composite aerogel material has a nano-grid structure in which a silicon dioxide phase and a resin phase are mutually tangled. The phenolic resin/silicon dioxide composite aerogel material is prepared from a material containing an organic silicon precursor, a phenolic compound, an aldehyde compound and chitosan by virtue of a sol-gel method and supercritical carbon dioxide. According to the composite aerogel material, an organic phase and an inorganic phase are respectively continuous nano-scale tangle structures and are integrated with the mechanical property of organic aerogel and the thermal insulation property and fire resistance of silicon dioxide aerogel; and after the composite gel material with a thickness of 1cm is impacted by the 1300-DEG C flame of a blast burner for over 30 minutes, the falling and the separation of the inorganic phase are not caused, and meanwhile, the temperature of a protected side does not exceed 300 DEG C. The preparation method has the beneficial effects that the operation is simple, the reaction is safe and reliable, and the thermal insulation property and the fire resistance of the material can be regulated and controlled by simply changing the material proportion.

The invention discloses a core-shell type cationic/anionic polyacrylamide profile control oil displacing microsphere and a preparation method thereof. The core-shell type cationic/anionic polyacrylamide profile control oil displacing microsphere with a micrometer particle size range is prepared in one pot by adopting a dispersion polymerization method, and the whole preparation process is continuously completed by two steps: firstly synthesizing a core part of a microsphere, and then synthesizing a shell part of the microsphere. The core part of the microsphere consists of water-soluble monomer acrylamide, an ionic monomer I and a crosslinking agent; the shell part of the microsphere consists of water-soluble monomer acrylamide, an ionic monomer II and a crosslinking agent; and the ionic monomer I and the ionic monomer II have opposite charges. The particle size of the core-shell type cationic/anionic polyacrylamide profile control oil displacing microsphere is 1-200mu m. The preparation method is simple in preparation process, the whole preparation process is environmentally friendly and low in cost; and a solvent can be recycled, and the recycling rate is above 80 percent. The core-shell type cationic/anionic polyacrylamide profile control oil displacing microsphere is used as a profile control oil displacing material, and has excellent injectivity and mobility.

A catalyst system for preparing aldehyde and ketone by catalytic oxidization of alcohol is composed of the catalyst consisting of 2,2,6,6-tetramethylpiperidine-free oxygen radical, halogen and nitrite, and the oxidant. The process for preparing said aldehyde and ketone features the high-sensitivity oxidizing reaction between catalyst, alcohol and air or oxygen in pressure reactor.

Method for operating a longitudinal driver assistance system of a motor vehicle (1), especially of an ACC system (2), which is designed to control the speed of a motor vehicle (1) to a desired speed in a free travel mode and/or keeps a controlled distance to a vehicle in front as the control object in a follow mode, at least one control parameter influencing control being adapted depending on at least one item of traffic information that describes traffic conditions on the currently traveled route, especially in the further course of the route, said information being received from an external transmitter (7,9).

The invention discloses a rapid preparation method and application of few layer MXenes. According to the preparation method of the few layer MXenes material, a few layer MXenes solution with good dispersibility is obtained by stripping a multi-layer MXenes liquid phase; the electrostatic balance of the few layer MXenes solution with is destroyed by introducing an electrolyte solution, and the obtained sol, precipitate or filter cake is the few layer MXenes material by means of cation-assisted electrostatic precipitation process (such as NH4 +) through standing or low-speed centrifugation or pumping filtration; and then macro-scale preparation of the few layer MXenes powder can be realized through freeze drying and subsequent annealing treatment. The preparation method has advantages of simple process and thin layers, large sheet diameter, good dispersibility, no agglomeration and agglomeration phenomenon and good electrochemical performance of the prepared few layer MXenes and is suitable for large-scale development and application of lithium ion batteries or sodium ion batteries.

The invention belongs to the technical field of oil-gas-water collecting and transporting and discloses an oil field crude oil pour point depressant and a preparing method of the oil field crude oil pour point depressant. The preparing method includes the steps that acrylic ester or metacrylic acid ester is mixed with perfluor carboxylic ester firstly, an organic solvent is added, the temperature rises, and stirring is conducted; then styrene is added, the temperature rises under the nitrogen protection, an organic solvent solution of an initiator is dripped, and a product A is obtained after a reaction; and finally, a-olefin, a polymer B and the product A are mixed and evenly stirred, and the oil field crude oil pour point depressant is obtained. The oil field crude oil pour point depressant has the paraffin prevention pour point depressing function, does not contain chlorine, is very suitable for transporting of crude oil of an offshore oil field and has the characteristics that the dosage is small, and the pour point depressing amplitude is large. The preparing method of the oil field crude oil pour point depressant is simple, a polar group containing fluorine is directly introduced into a molecular chain through a further reaction, the reaction process is easy to control, safe, reliable and environment-friendly, and high general applicability is achieved.

The invention discloses an epoxidation vegetable oil preparation method. The epoxidation vegetable oil preparation method includes steps of firstly, uniformly mixing mixed acid catalyst containing organic acid and strong acid, uniformly mixing and stirring peroxy acid stabilizer and hydrogen peroxide, dripping the mixed acid catalyst in to mixed solution of the peroxy acid stabilizer and the hydrogen peroxide at the temperature of 25-35 DEG C, and reacting to obtain mixed solution of peroxide intermediates; and secondly, adding the epoxidation stabilizer into vegetable oil, dripping the mixed solution of the peroxide intermediates at the temperature of 65-95 DEG C, reacting for 10-30 minutes with heat preservation; dripping hydrogen peroxide solution, reacting four 1-4 hours with heat preservation, and obtaining epoxidation vegetable oil products after treatment. The vegetable oil is epoxidized by three steps, and suitable catalysts and stabilizers are selected, reaction time is shortened, and thereby reaction selectivity is high, side reaction is reduced, epoxidation time is short, reaction conversion rate is increased, production cost is reduced and production safety is improved.