48 results about "Turnover number" patented technology

The invention relates to a novel purified isozyme of an autoclavable superoxide dismutase extracted from the plant Potentilla atrosanguinea Lodd. Var. orgyrophylla, said isozyme having the following characteristics, O2- scavenging activity remains same before and after autoclaving; scavenges O2- from sub-zero temperature of -20° C. to high temperature of +80° C.; O2- scavenging activity at 25° C. for 30 days without adding any stabilizing agent such as polyols or sugars; O2- scavenging activity in the presence of saline (0.9% sodium chloride) to 61.8% of the control (without 0.9% sodium chloride), stable at 4° C. for at least 8 months; contamination free and infection free from any living micro- and/or macro-organism after autoclaving; possesses temperature optima at 0° C.; possesses a molecular weight of 33 kD under non-denaturating conditions; possesses a molecular weight of 36 kD under denaturating conditions; has clear peaks in UV range at 268 and 275 nm; has an enzyme turnover number of 19.53x104% per nmol per min at 0° C.; and requires Cu/Zn as a co-factor, method for the preparation of the purified isozyme of autoclavable superoxide dismutase and formulations containing the said autoclavable superoxide dismutase.

The invention discloses a system and a method for controlling the combustion of a mechanical grate incinerator. The system comprises a feed grate control system, an incinerator grate control system, an air volume control system and a temperature control system, wherein the feed grate control system is used for regulating and controlling the feed stroke and the forward-feeding speed of a feed grate in the mechanical grate incinerator by utilizing a proportion integration differentiation (PID) controller; the incinerator grate control system is used for controlling the sliding number of a sliding furnace tile and the turnover number of a turnover furnace tile in an incinerator grate of the mechanical grate incinerator within each control period; the air volume control system is used for regulating and controlling the rotational speeds and the air volume of a primary air blower and a secondary air blower by utilizing the PID controller in the whole combustion process; and the temperature control system is used for regulating and controlling the temperature of the primary air blower and a furnace wall in the whole combustion process. The system can meet the requirements of environment friendliness and power generation, and can reduce the cost.

Described herein are compounds and methods of catalyzing ethenolysis reactions, optionally on an industrial scale. In certain embodiments, the catalysts bear cyclic alkyl amino carbene (CAAC) ligands with an ortho substituent, such as a methyl substituent, on an N-aryl ring. When used to catalyze ethenolysis reactions, certain such compounds produce a turnover number greater than 50,000.

The invention discloses a novel tridentate phosphine ligand and application of the same to linear hydroformylation and similar reactions. The tridentate phosphine ligand is applied to efficient high-selectivity hydroformylation for the first time at present and applicable to efficient high-selectivity isomerized hydroformylation, hydrocarboxylation, hydrocyanation, isomerized formylation, hydroaminomethylation and the similar reactions. During the linear hydroformylation, selectivity of the tridentate phosphine ligand is obviously higher than that of a corresponding bidentate phosphine ligand. Besides, compared with a corresponding quadridentate phosphine ligand, the tridentate phosphine ligand is approximate in selectivity, easier to synthesize and higher in yield and displays higher TON (turnover number). The novel tridentate phosphine ligand selectively converts 1-hexylene and 1-octylene into n-heptaldehyde (used for synthesis of orange essence and rose essence) and n-nonaldehyde (flavoring matter) and is of great significance to hydroformylation-based industrial production.

A hierarchical catalyst composition comprising a continuous or particulate macroporous scaffold in which is incorporated mesoporous aggregates of magnetic nanoparticles, wherein an enzyme is embedded in mesopores of the mesoporous aggregates of magnetic nanoparticles. Methods for synthesizing the hierarchical catalyst composition are also described. Also described are processes that use the recoverable hierarchical catalyst composition for depolymerizing lignin, remediation of water contaminated with aromatic substances, polymerizing monomers by a free-radical mechanism, epoxidation of alkenes, halogenation of phenols, inhibiting growth and function of microorganisms in a solution, and carbon dioxide conversion to methanol. Further described are methods for increasing the space time yield and/or total turnover number of a liquid-phase chemical reaction that includes magnetic particles to facilitate the chemical reaction, the method comprising subjecting the chemical reaction to a plurality of magnetic fields of selected magnetic strength, relative position in the chemical reaction, and relative motion.

The present invention discloses L-alanine dehydrogenase mutant zymoprotein and a preparation method thereof. According to a homologous sequence secondary structure comparison result, site-specific mutagenesis of 73th lysine near an L-alanine dehydrogenase activity center of Bacilluspseudofirmus into alanine through PCR is performed to construct a mutant expression vector, and prokaryotic expression and Ni-NTA affinity chromatography purification are performed to obtain a mutant enzyme K73A, wherein specific activity of the obtained mutant enzyme K73A is 202% of specific activity the wild type, and other enzymatic properties are not changed. In addition, a turnover number Kcat on a substrate L-alanine by the mutant zymoprotein is 376.7 min<-1> and is 2.0 times the turnover number Kcat of the wild type, a turnover number Kcat on beta-NAD<+> by the mutant zymoprotein is 290.1 min<-1> and is 2.1 times the turnover number Kcat of the wild type, and the mutant zymoprotein can be applicable for production processes of production of pyruvic acid, L/D-alanine, and the like through improvement biology methods.

The invention is related to a safe energy saving intelligent fuel gas meter having unmanned automatic switching fuel gas function. A main frame uses a single machine chip as a main control unit composed of an instruction signal coding transceiving module unit, a study pair code and state display or turnover number of people display unit, a voice recording and playing unit, an infrared ray human body detection sensor unit; a branch machine also uses a single machine chip as a main control unit composed of an instruction signal coding transceiving module unit, a fuel gas leakage alarming module unit, an instruction output control gas valve unit and a study pair code and state display unit. The invention applies coding remote control technology, infrared ray human body detection technology to overcome defections of various intelligent fuel gas furnaces not capable of automatically switching fuel gas when there is nobody in the room in prior art thoroughly, to use various intelligent fuel gas meters and fuel gas furnaces safer, more reliable and energy saving, which greatly improves safe and energy saving value and practical range of the various intelligent fuel gas meters and fuel gas furnaces having great market foreground.

The invention relates to a hot-metal bottle combined cover and a cover adding and uncovering method thereof, and belongs to the technical field of hot metal transportation. The hot-metal bottle combined cover consists of a positioning ring (1), a hot-metal bottle cover (2), a suspension ring (3), a hinge (4), a hot metal receiving opening cover (5) and a swinging shifting ring (6), wherein the hot-metal bottle cover (2) is connected with the hot metal receiving opening cover (5) through the hinge (4); and the whole combined cover is positioned on a fixed pin shaft on a hot-metal bottle through the positioning ring (1). The adding and uncovering method for the hot metal receiving opening cover (5) of a casting house is to arrange a special mechanism in a hot metal outlet opening position of the casting house to complete cover adding and uncovering operations; and the adding and uncovering method for the hot-metal bottle cover (2) of the casting house is to realize cover adding and uncovering operations by a special hanger and a gantry trolley (15). The cover adding and uncovering method has the advantages that a hot-metal bottle is provided with the cover for shielding during transmission and shelving, so that the cover adding and uncovering method greatly saves energy resources, reduces consumption of resistant materials and a heat-insulated covering agent and environmental pollution, prolongs the service life of the resistant materials of the hot-metal bottle, and obviously reduces the turnover number of the hot-metal bottle.

The invention discloses a ruthenium catalyst capable of efficiently catalyzing decomposing of formic acid for preparing hydrogen, and belongs to the technical field of energy source catalysis materials and hydrogen preparation. The invention mainly relates to preparation of the efficient catalyst and the process of catalyzing decomposition of formic acid by applying the catalyst. An optimum catalyst turnover number (TON) is obtained by reasonably controlling the reaction temperature, catalyst solvents, additives and other factors in the decomposition process of formic acid. The catalyst has the TON value larger than 1.8 million under an optimum reaction condition. The catalyst is capable of catalyzing formic acid for preparing hydrogen under a normal-temperature condition, and obtained hydrogen is directly applicable to chemical synthesis, fuel cells, engines and the like.

New metal persulfido compositions of matter are described. :In one embodiment the metal is molybdenum and the metal persulfido complex mimics the structure and function of the triangular active edge site fragments of MoS₂, a material that is the current industry standard for petroleum hydro desulfurization, as well as a promising low-cost alternative to platinum for electrocatalytic hydrogen production. This molecular [(PY5W₂)MoS₂]^x+ containing catalyst is capable of generating hydrogen from acidic-buffered water or even seawater at very low overpotentials at a turnover frequency rate in excess of 500 moles H₂ per mole catalyst per second, with a turnover number (over a 20 hour period) of at least 19,000,000 moles H₂ per mole of catalyst.

The invention discloses a high-speed optical cable SZ stranding binding machine with a low turnover number, which comprises a stranding binding part. The stranding binding part comprises a first rack, and a stranding device, a winding and binding device and a passive anti-back twisting belt are sequentially arranged on the first rack along an optical fiber sleeve conveying direction; the stranding device comprises a stranding pipe and a positive and negative rotation motor, the stranding pipe is arranged horizontally along the stranding axis of the optical cable, the stranding pipe is connected with the positive and negative rotation motor, the output shaft of the positive and negative rotation motor is also connected with one end of an elastic energy storage device, the other end of the elastic energy storage device is connected with the first rack, and the positive and negative rotation motor drives the stranding pipe to rotate in a positive and negative alternative mode through a stranding synchronous belt. Continuous and automatic SZ stranding and binding for the optical fiber sleeve can be realized, the rotation speed is improved and the SZ stranding turnover number in a unit time is reduced, the stranding quality is improved, the cabling speed is improved, energy is saved, consumption is reduced, and the operation noise is reduced.

The invention belongs to the field of urban railway system construction, and in particular relates to mobile framework equipment, which comprises a main beam, a framework arranged on the lower part of the main beam. The front end of the main beam is provided with a front leg, while the rear end is provided with a rear leg; the main beam at the rear end of the rear leg is provided with a longitudinal auxiliary leg; two sides of the main beam are hinged with overhanging beams; the end parts of the overhanging beams are all hinged with suspension arms; lower ends of the suspension arms on the two sides are hinged with side frameworks; an inner framework is hinged between the side frameworks on the two sides; and the bottoms of the side frameworks on the two sides are in rolling connection with bottom frameworks. The upstroke mobile framework has the advantages of large turnover number, short construction period, safe and reliable construction and civilized and concise field; most importantly, when the equipment is used for construction, the traffic under bridges is not needed to be interrupted, and great convenience is provided for activities of citizens.

A process for the synthesis of an unsaturated product by cross metathesis between a first unsaturated compound having at least 8 carbon atoms and a second unsaturated compound having less than 8 carbon atoms, the first unsaturated compound being capable of producing an unsaturated coproduct comprising more than 14 carbon atoms, by homometathesis, said process including at least one production phase which includes: feeding a reactor with the first unsaturated compound; feeding the reactor with the second unsaturated compound; feeding the reactor with at least a first metathesis catalysts, then feeding the reactor with at least a second metathesis catalyst; withdrawing a product stream arising from the reactor; the turnover number of the first catalyst being higher than the turnover number of the second catalyst so as to achieve the same target degree of conversion of the first unsaturated compound.

The present invention relates to a catalyst L-M-L'(in which L and L' represent chiral diphenol ligand and M represents central metal) formed from metal M and several kinds of chiral diphenol. Said catalyst can high-effectively catalyze asymmetric hetero-Diels-Alder reaction, its enantiomeric selectivity is up to 99.8% ee. TON(Turnover Number) is up to 12.720, so that it is a high-effective chiral Lewis acid catalysis system.

The invention relates to a breeding method for beef cattle. The method comprises the following steps: 1) selecting fattening cattle; 2) performing one-time fattening; and 3) performing management in the fattening period. According to the method provided by the invention, the specific fattening cattle are selected, and feed without any poor additive is adopted for artificial feeding, so that feed consumption is less, the costs are low, and a turnover number can be increased; concentrated feed contains rich crude proteins, a content of crude fibers is up to 35% or more, and the crude fibers haveimportant nutritional effects on the cattle and are indispensable nutrient substances; coarse feed contains an ammoniated main ingredient, so that digestibility, nutritional value and palatability ofa straw material are improved; and supplementary feed mainly supplements calcium, phosphorus and vitamins in daily ration, so that needs of the fattening cattle are met, nutrient ingredients of the daily ration are perfected, a digestion and utilization rate of the feed is improved, weight gain of the cattle is promoted, and diseases are prevented. The method disclosed by the invention concentrates on fattening, and shortens marketing time of the beef cattle, beef on the market has excellent quality and delicious taste, and the method ensures market demand of the high-quality beef.

The invention discloses a gas-liquid heat exchange type refrigeration device. Refrigeration capability variations caused by the variations of the turnover number of a compressor can be suppressed, and the rise of discharge temperature at an outlet of the compressor can be suppressed to prevent refrigerator oil from being degraded. The liquid-gas heat exchange type refrigeration device consists of the compressor 1, a condenser 2, a heat exchange control valve 3, a gas-liquid heat exchanger 4, an expansion valve 5 and an evaporator 6, which are connected in series through a coolant pipeline to form a closed coolant circulation pipeline. A discharge temperature sensor 7 is arranged between the compressor 1 and the condenser 2 of the coolant circulation loop. A pressure sensor 8 is arranged between the heat exchange control valve 3 and the gas-liquid heat exchanger 4. A controller (control device) 10 is also arranged to control the opening of the heat exchange control valve 3 on the basis of coolant temperature detected by the discharge temperature sensor 7 at the outlet of the compressor 1 and coolant pressure detected by the pressure sensor 8 at an outlet of the heat exchange control valve 3.

A chiral hydrogenated H₈-BINOL bisphosphine compound is provided, with the structure shown as the following formula (I), wherein both R¹ and R² are halogen, H or C₁-C₁₀ aliphatic group; R³ is H or C₁-C₁₀ aliphatic group; R⁴ is halogen, amino, nitro, H, C₁-C₁₀ aliphatic group or C₁-C₁₀ aromatic group; and X is phenyl, substituted phenyl, cyclohexyl, substituted cyclohexyl, C₆-C₃₀ aromatic group, or C₆-C₃₀ heterocyclic aromatic group containing one or more heteroatoms selected from N, S, O. The present invention further provides a catalyst for an asymmetric catalytic hydrogenation reaction which contains the compound, wherein the catalyst can produce more than 90% of enantiomers and efficiency with the turnover number of greater than 100,000 in the asymmetric hydrogenation reaction of imines.

A method of increasing the amount of diphenylcarbonate produced per amount of catalyst consumed in a phenol carbonylation process is described. Phenolic carbonylation produces water as a reaction product which reduces the turnover number (TON) of the catalyst. A mixture of a phenolic precursor, a base containing catalyst and co-catalyst components and at least one chemical additive comprising a halide or hydroxide of alkali metal or alkaline earth metal when carbonylated together under specific conditions increases the turnover number (TON) and water resistivity of a palladium catalyst. The metal halide likely makes the catalyst less susceptible to degradation by water hence increasing the reaction yield per weight of catalyst consumed.

The invention provides a preparation method of optically active citronellal, which can obviously enhance the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation for homogeneous catalysis, thereby implementing higher turnover number. In the preparation method of the optically active citronellal, a substrate is subjected to an asymmetric hydrogenation reaction in the presence of the transition metal catalyst to generate the optically active citronellal, and the transition metal catalyst is obtained by reacting a transition metal compound with an optically active ligand containing two phosphorus atoms, wherein the substrate raw material is one or a combination of two of neral and geranial, and the hydroxyl value in the substrate raw material for the asymmetric hydrogenation reaction is controlled to be less than or equal to 6mgKOH/g and/or the iron content is controlled to be less than or equal to 50ppm.

The invention provides a speed reducer structure, which comprises a box body and a box cover arranged on the top of the box body, wherein a lower support plate is installed in the lower part of the box body; the upper part in the box body is provided with a transparent cover; the transparent cover is provided with a blank cover; the lower support plate is provided with a plurality of lower support plate sliding bearings; a cone roller bearing is installed between the transparent cover and the blank cover; a coupler is installed on the cone roller bearing; a gear speed reduction motor is connected to one end of the coupler; the other end of the coupler is connected with a worm; one ends of worm wheel shafts are installed on lower support plate sliding bearings on the lower support plate; the other ends of the worm wheel shafts are connected to the worm; the end parts of a lengthened worm wheel shaft and the worm wheel shafts are provided with worm wheels. According to the speed reducer structure disclosed by the invention, the worm wheels and the worm are meshed by insection, the worm is effectively driven by the speed reducer, so that the turnover number of the speed reducer is effectively lowered to the required turnover number so as to guarantee power transmission accuracy and high efficiency, the energy waste is reduced, and the energy use ratio is improved.

The invention relates to a preparation method of a woven mesoporous polymer silver-loaded catalyst and application of the silver-loaded catalyst in synthesis of acetylenic acid from CO2. The catalysttakes a woven mesoporous polymer as a carrier and nano-scale Ag as an active component, wherein the mass content of woven mesoporous polymer to nano-scale Ag is 0.01%-1.0%. The catalyst can efficiently catalyze the reaction of the CO2 and alkyne under mild conditions for converting the CO2 into the acetylenic acid. The catalyst has the characteristics of easy preparation, high activity and high stability, wherein the yield of phenylpropiolic acid is up to 92%, and the initial Turnover Number (TON) of the phenylpropiolic acid is 9936. The method provided by the invention provides a method for preparing the catalyst for efficiently synthesizing the acetylenic acid, and has a good application prospect.

The invention provides an austenitic stainless steel part machining method. A 06Cr18Ni11Ti austenitic stainless steel material is selected and used, a part with a revolution-solid shape and paraboliccurve appearance is machined, and mold cavities are formed in the two ends of a parabolic curve. By means of the austenitic stainless steel part machining method, the cutting machinability of the 06Cr18Ni11Ti austenitic stainless steel part is improved by reasonably arranging process routes and optimizing tool materials, the best tool sharpening angle, reasonable cutting parameters and a cutting lubrication fluid; the machining process is made to be compact, the turnover number is less, the production efficiency is improved, the production cost is reduced, tool wear is reduced, and the tool service life is prolonged; and meanwhile, the surface machining quality of the 06Cr18Ni11Ti austenitic stainless steel part is improved, the machining cycle of the part is shortened, the production costis reduced, and the austenitic stainless steel part machining method has great economic and practicability in production practice.

The invention provides a method for preparing optically active citronellal, and a catalyst for the method. The method comprises: in the presence of a catalyst, asymmetrically hydrogenating citral represented by a formula (I) and/or geranial represented by a formula (II) to prepare optically active R-citronellal represented by a formula (III), wherein the catalyst comprises rhodium as a catalytically active transition metal, a chiral bidentate diphosphine ligand, and basic alumina. According to the present invention, the catalytic stability of an optically active transition metal catalyst for asymmetric hydrogenation of homogeneous catalysis can be significantly improved without introducing of carbon monoxide so as to achieve high turnover number.