Abstract:
The present invention relates to a device for liquid degassing by means of the swirling or the centrifugal field coupled with the pressure gradient field. This device comprises a cavity. The cavity is furnished with an inlet for liquid gas, an outlet for gas phase and an outlet for gas liquid phase. The outlet for gas phase is inserted into the cavity through the upper surface of the cavity, wherein the depth of the insertion is around 0.1-3 times of the maximum diameter of the cavity. Specifically, the outlet for gas phase is realized through an overflow pipe with the diameter gradually increasing from the bottom to the top. The end of the overflow pipe is further furnished with a bell mouth. The advantages of the present invention are: The present invention designs the structure of an inverted cone shaped outlet for gas phase which is inserted into the cavity of the swirling device. The present invention makes full use of the impact of pressure gradient in the cavity on the solubility of gas in liquid and combines the centrifugal field and the pressure gradient field to remove the gas entrained with liquid while the dissolved gas is removed under the inlet partial pressure.
Abstract:
Provided is an optically controlled gene expression system of prokaryotic bacterium, comprising: a) a photosensitive recombinant transcription factor encoding gene, the photosensitive recombinant transcription factor is one fusion protein comprising a first polypeptide as the DNA bonding domain and a second polypeptide as the photosensitive domain; b) a target transcription unit comprising promoter or promoter-reaction element or reaction element-promoter containing at least one reaction element recognized/bound by the first polypeptide and the nucleic acid sequence to be transcribed. Also provided is a prokaryotic expression vector comprising said optically controlled gene expression system, and a method for regulating gene expression in a prokaryotic host cell by using the optically controlled gene expression system. Also provided is a reagent kit containing different components of the optically controlled gene expression system. The optically controlled gene expression system of prokaryotic bacterium has a quick, effective and powerful induction, is safer than other inducers, is of little or no toxicity, and can control gene expression both spatially and temporally, and can regulate many life processes of prokaryotic bacterium.
Abstract:
Provided is a method of eliminating the dependence of methanol induced promoter on a single methanol carbon source for expressing foreign polypeptide. The method comprises activating the expression of the promoter requiring methanol induction by increasing the expression quantity of Mit1 polypeptide in cells of methylotrophic yeast, so that the promoter originally depending on methanol induction no longer depends on single methanol and can also express foreign polypeptide.
Abstract:
The present invention relates to a novel method for producing astaxanthin by using microalgae. The method comprises: heterotrophic cultivation of microalgae, dilution, photo-induction, collection of microalgal cells, and extraction of astaxanthin. The method according to the present invention takes full advantages of rapid growth rate in the heterotrophic stage and fast accumulation of astaxanthin in the photo-induction stage by using a large amount of microalgal cells obtained in the heterotrophic cultivation stage, so as to greatly improve the astaxanthin production rate and thereby achieve low cost, high efficiency, large scale production of astaxanthin by using microalgae. The method not only provides an important technical means to address the large scale industrial production of astaxanthin through microalgae but also ensures an ample source of raw material for the widespread utilization of astaxanthin.
Abstract:
A hot oxygen nozzle and uses thereof in a gasifier, the hot oxygen nozzle comprising an outer-ring spout, a middle-ring spout, an inner-ring spout, and a central spout all sequentially and coaxially disposed, and a cooling system; the gasifier is an entrained-flow gasifier provided with one or more nozzles on a certain plane or a plurality of planes at the top or on the periphery of the gasifier body. The nozzle has a simple structure and is easy to make and maintain. A fuel gas passage is disposed inside the nozzle. Oxygen can be heated by the combustion of fuel gas; and high-temperature and high-speed oxygen can directly ignite carbonaceous materials such as coal water slurry and coke oven gas. The present invention can be applied in a gasifier and then in the final process of synthesis gas preparation.
Abstract:
A calibration method for brittle fracture assessment parameters for pressure vessel materials based on the Beremin model includes selecting at least two types of specimens of different constraints, and calculating the fracture toughness values K0 corresponding to 63.2% failure probability for each type of specimens at a same calibration temperature by using the respective fracture toughness data. The method proceeds by obtaining the stress-strain curve of the material at the calibration temperature, generating finite element models for each type of specimens, and calculating the maximum principal stress and element volume of every element at K=K0 in each model. A series of values of m are assumed to compute a group of σu values for each type of specimens, and then m˜σu curves are plotted for each type of specimens. Brittle fracture assessment parameters are then determined for the material according to the coordinates of the intersection of the m˜σu curves.
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:
A method of preparing an amorphous, low-melting-point polyester hot-melt adhesive is disclosed. The method includes the steps of: 1) esterifying terephthalic acid, isophthalic acid and an aliphatic dicarboxylic acid with ethylene glycol and a C3-C6 dial in a presence of an esterification catalyst; 2) adding a stabilizer, a polycondensation catalyst and an antioxidant to a product from step 1) and lowering the pressure to perform a polycondensation reaction which results in a polyester having a melting point of lower than 120° C. The polyester hot-melt adhesive of the invention assumes a transparent state with no crystallization both in normal-temperature and high-temperature conditions and has a high flowability and an excellent wettability in low-temperature applications.
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 hydrogel composition is formed by conveying separate first and second liquid components subject to a selectively applied application pressure P(A) into an outlet path for mixing and discharge. A liquid flushing agent is automatically conveyed into the outlet path subject to a substantially constantly applied purge pressure P(P) when the application of P(A) is interrupted, to continuously flush residual hydrogel composition from the outlet path.