Abstract:
The present invention relates to a supported polymetal olefin polymerization catalyst, comprising a porous support, a magnesium-containing support component, a transition metal titanium component supported on the porous support, and further comprising at least one non-magnesium metal component supported on the porous support. Further provided is a preparation method and a use of the supported polymetal olefin polymerization catalyst. An efficient composite support supported polymetal Ziegler-Natta catalyst is provided in the present invention, wherein a porous support, a soluble magnesium compound, and a soluble non-magnesium metal compound are used as raw materials. The supporting of titanium is achieved while a composite support containing magnesium and non-magnesium metal components is formed in situ in the surface of the porous support. The present invention has the advantage of a simple preparation method, a low cost, a controllability of morphology, properties of the catalyst, etc. Comparing the provided catalyst with the same type of magnesium/titanium catalyst free of non-magnesium metal components, the catalytic performance such as polymerzation activity, hydrogen regulation sensitivity and copolymerization performance are significantly improved.
Abstract:
The present invention relates to a method and a device for deep oil removal from wastewater containing a low concentration of wasteoil. Wastewater containing a low concentration of wasteoil enters the device via an inlet and passes through a flow conditioner, causing the fluid to become uniformly distributed. Then, by means of a layer of oleophilic-hydrophobic fibers and hydrophilic-oleophobic fibers woven in a certain manner, a trace of oil droplets are captured and then coalesce and grow on the layer, and a trace of oil-in-water emulsion is demulsified and separated on the layer. Finally, by means of corrugation-enhanced sedimentation and separation, the oil droplets coalesce and grow and are then separated rapidly. The invention also provides a set of devices for implementing the method, having several parts such as a housing, a feed pipe, a flow conditioner, a fiber coalescence layer, a corrugation-enhanced separation layer, and a level gauge. The present technique is highly efficient in separation, consumes little power, and can operate continuously for a long period of time. Thus, this technique can be widely used in processes for treating wastewater containing a low concentration of wasteoil.
Abstract:
The invention relates to a genetically encoded fluorescent sensor for nicotinamide adenine dinucleotide, as well as methods of preparation and uses thereof. In one aspect, this invention relates to a sensor for detecting nicotinamide adenine dinucleotide, particularly, a recombinant fluorescent fusion protein sensor for detecting nicotinamide adenine dinucleotide. In one specific aspect, this invention relates to a recombinant fluorescent fusion protein sensor for detecting reduced nicotinamide adenine dinucleotide (NADH); in another specific aspect, this invention relates to a recombinant fluorescent fusion protein sensor for detecting oxidized nicotinamide adenine dinucleotide (NAD+); in yet another aspect, the invention relates to a recombinant fluorescent fusion protein sensor for detecting the ratio of reduced to oxidized nicotinamide adenine dinucleotide. This invention also relates to the method of preparing the sensors, and uses of the sensors in detecting NADH, NAD+, NADH/NAD+ ratio, screening drugs and measuring NADH metabolism.
Abstract:
Provided herein are Raman active particles and methods for their preparation and use. The particles can include a SERS-active material that is at least partially encased within a spherical porous hollow casing. In some embodiments, this can be especially advantageous when employed for water analysis and/or being employed in combination with silica particles.
Abstract:
A polyester/glyoxalated polyvinyl alcohol semi-interpenetrating polymer network hot-melt adhesive and preparation method therefore, mainly includes the steps of: 1) transesterification of certain amounts of dimethyl terephthalate and another dibasic ester with 1,4-butanediol and other diols in the presence of an organotin catalyst under a nitrogen atmosphere in a reactor, completed upon the amount of distillation of a monohydric alcohol byproduct reaching greater than 95% of the theoretical amount; 2) after the temperature is maintained for a period of time, adding in a stabilizer and a polycondensation catalyst and incrementally increasing the temperature to trigger a polycondensation reaction under a reduced pressure to produce particles of a copolymer, and freezing and pulverizing the copolymer particles to produce a powder of a copolyester; 3) uniformly blending a polyvinyl alcohol/glyoxal mixture with the powder produced in step 2) at ambient temperature to produce the target product. The product is capable of forming an internal semi-interpenetrating network at application temperatures.
Abstract:
A method of preparing a polyester/polyolefin hot-melt adhesive for use in a solar cell bus bar is disclosed, in which 2,6-naphthalenedicarboxylic acid and ethylene glycol are first sequentially subjected in a predetermined ratio to esterification and polycondensation in the presence of a certain amount of a titanium-based catalyst to result in a polyethylene naphthalate (PNT) with a weight-average molecular weight of 16,000˜20,000. The PNT is then melt-blended with a low-density polyethylene (LDPE) in the presence of a compatibilizer to produce the hot-melt adhesive that can be shaped into films having a high light transmittance, good mechanical properties, high heat and yellowing resistance and thus particularly suitable for use in solar cell bus bars.
Abstract:
The present invention relates to a carriered hybrid vanadium-chromium-based catalyst, characterized in the catalyst is carriered on a porous inorganic carrier and a V active site and an organic Cr active site are present on the porous inorganic carrier at the same time. The present invention further relates to a process for producing a carriered hybrid vanadium-chromium-based catalyst. The catalyst of the present invention can be used for producing ethylene homopolymers and ethylene/α-olefin copolymers. The hybrid vanadium-chromium-based catalyst can have high activity and produce polyethylene polymers having the properties of broad molecular weight distribution (Part of the products are bimodal distribution) and excellent α-olefin copolymerization characteristic.
Abstract:
A method of preparing a composite catalyst for polyester synthesis includes the steps of: 1) sequentially dissolving a titanium compound, a silicon compound and a tin compound in an organic solvent; 2) adding a water solution of an acidic compound or of an alkaline compound in the compound from step 1) to cause hydrolysis thereof and collecting a precipitate, and washing the hydrolysis precipitate with a deionized water to obtain the composite catalyst. The catalyst is not only effective in polyester production polycondensation, but also has significant catalytic activity in esterification. The produced polyester chips all have a desirable hue.
Abstract:
A polyester/glyoxalated polyvinyl alcohol semi-interpenetrating polymer network hot-melt adhesive and preparation method therefore, mainly inlcudes the steps of: 1) transesterification of certain amounts of dimethyl terephthalate and another dibasic ester with 1,4-butanediol and other diols in the presence of an organotin catalyst under a nitrogen atmosphere in a reactor, completed upon the amount of distillation of a monohydric alcohol byproduct reaching greater than 95% of the theoretical amount; 2) after the temperature is maintained for a period of time, adding in a stabilizer and a polycondensation catalyst and incrementally increasing the temperature to trigger a polycondensation reaction under a reduced pressure to produce particles of a copolymer, and freezing and pulverizing the copolymer particles to produce a powder of a copolyester; 3) uniformly blending a polyvinyl alcohol/glyoxal mixture with the powder produced in step 2) at ambient temperature to produce the target product. The product is capable of forming an internal semi-interpenetrating network at application temperatures.
Abstract:
A luminescent probe and its preparation method and application are provided. The luminescent probe has a steric hindrance group R1 of aliphatic hydrocarbon structure such as adamantane or norborneol, a detection group R2 of nitrobenzyl and its derivative structure, an electron-withdrawing group R3 containing cyano group and an electron-donating group methoxy group. In the presence of HSA or BSA, the detection group is cut off to form a parent structure that exposes atomic oxygen anions and is activated under external light irradiation, the luminescent probe can be used in solution or cells, when detecting HSA or BSA, the luminescent probe has obvious chemiluminescence characteristics, which can sensitively distinguish HSA and BSA, quantitatively analyze HSA and BSA, and determine the mixing ratio of HSA and BSA at the same time, and the luminescent probe has been successfully used for cell fluorescence imaging.