Abstract: A multi-layered micro-channel mixer includes a base plate and a cover plate. Two inlet fluid reservoirs, two inlet channels, two groups of fluid distribution channel networks, two groups of process fluid channels, an impinging stream mixing chamber, a fluid mixing intensification channel and an outlet buffer reservoir are provided on the base plate. Two fluids are fed into the two inlet fluid reservoirs, respectively. The fluids then flow into the process fluid channels via the inlet channels and the multi-stage fluid distribution channel networks, respectively. Then the two fluid streams ejected from the opposing process fluid channels impinges upon each other in the impinging stream mixing chamber. The mixed fluid is subjected to vortex or secondary flow generated by the baffles or the internals in the impinging stream mixing chamber and fluid mixing intensification channel, and finally the mixed fluid is discharged through the outlet buffer reservoir.

Abstract: A micro-zone soil sampling apparatus and method for different contamination situations. The apparatus includes an uncovered cylinder and a plurality of circular separators. The circular separators are vertically arranged in a hollow inner cavity of the uncovered cylinder, and are removably connected to an inner wall of the uncovered cylinder. Each circular separator includes a plurality of inner rings arranged coaxially, an outer ring coaxially arranged outside the inner rings, and a soil-bearing net. Each circular separator is divided into multiple hollow spaces by the inner rings and the outer ring. The inner rings made of a permeable membrane material and the outer ring made of a rigid material both have a certain thickness. The soil-bearing net is fittedly fixed on a bottom of each circular separator. A plurality of spokes passing through a center of the soil-bearing net are fixedly arranged on the soil-bearing net.

Abstract: In a method for extracting microbial DNA from milk, the extracted DNA can be directly used for PCR amplification. The method includes the following steps: treating milk with TE solution, fully disrupting microbial cells by bead milling, immobilizing proteins in the middle layer between the aqueous and organic phases with high-vacuum silicone grease so as to prevent impurities in the middle layer from entering the aqueous phase, etc. The extracted DNA has a high degree of intactness, high concentration and purity.

Abstract: In a method for enriching and separating an anaerobic fiber-degrading bacterium on the basis of cellulosic magnetic nanoparticles, the cellulosic magnetic nanoparticles are prepared by coating cellulose on the surface of a magnetic nanomaterial. Bacteria attach to the cellulosic magnetic nanoparticles. Anaerobic fiber-degrading bacteria degrade the cellulose and then detach from the cellulosic magnetic nanoparticles, and the anaerobic fiber-degrading bacteria are obtained by means of separation using a magnet. The magnetic nano-separation technology can be used as a new technology to efficiently separate anaerobic fiber-degrading bacteria.

Abstract: A database-native Lock-Free Reservation infrastructure is used to provide automatic compensation for the reservable column updates made by successful local transactions (or microservice actions) that are part of a saga that is being aborted. The automatic compensation is achieved by tracking the reservable column updates in a reservations journal, within the database, during the execution of the local transaction and remembering them beyond the commit of the local transaction until the finalization of the saga that the transaction is a part of. If the saga aborts, then the database server automatically uses the information retained in the reservations journal to compensate for the changes made by the committed transactions that were part of the saga.

Abstract: A method for machine learning-based classification may include training a machine learning model with a full training data set, the full training data set comprising a plurality of data points, to generate a first model state of the machine learning model, generating respective embeddings for the data points in the full training data set with the first model state of the machine learning model, applying a clustering algorithm to the respective embeddings to generate one or more clusters of the embeddings, identifying outlier embeddings from the one or more clusters of the embeddings, generating a reduced training data set comprising the full training data set less the data points associated with the outlier embeddings, training the machine learning model with the reduced training data set to a second model state, and applying the second model state to one or more data sets to classify the one or more data sets.

Abstract: An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.

Abstract: A bifunctional catalyst and a preparation method therefor are provided. The bifunctional catalyst is prepared by providing carbon matrix, adding 0.01-10 mol/L platinum containing solution, 0.01-10 mol/L palladium containing solution, 0.01-10 mol/L silver containing solution, and 0.01-15 mol/L sodium citrate trihydrate solution to the carbon matrix for reacting at 20° C. to 80° C. for 0.5 h to 24 h to obtain a mixed solution, and adding reducing agent to the mixed solution for reacting for 0.5 h to 30 h, and centrifuging and drying so as to obtain the bifunctional catalyst.

Abstract: A method for machine learning-based classification may include training a machine learning model with a full training data set, the full training data set comprising a plurality of data points, to generate a first model state of the machine learning model, generating respective embeddings for the data points in the full training data set with the first model state of the machine learning model, applying a clustering algorithm to the respective embeddings to generate one or more clusters of the embeddings, identifying outlier embeddings from the one or more clusters of the embeddings, generating a reduced training data set comprising the full training data set less the data points associated with the outlier embeddings, training the machine learning model with the reduced training data set to a second model state, and applying the second model state to one or more data sets to classify the one or more data sets.

Abstract: The disclosure provides a light-responsive aptamer for regulating the activity of a DNA polymerase. The DNA polymerase includes a G-quadruplex-binding peptide and a polymerase sequence; the polymerase sequence includes an active site; and the light-responsive aptamer includes an aptamer sequence and a photoactive linker connected to the aptamer sequence; the aptamer sequence includes a G-quadruplex-forming sequence and a substrate DNA sequence; the G-quadruplex-forming sequence forms a G-quadruplex, and the substrate DNA sequence folds to form a hairpin structure; the G-quadruplex-forming sequence binds to the G-quadruplex-binding peptide, and the substrate DNA binds to the active site of the DNA polymerase; in the presence of ultraviolet light irradiation (UV irradiation), the photoactive linker is broken, and the substrate DNA is detached from the active site of the DNA polymerase.

Abstract: A low-damage processing device for complex microstructure by hybrid laser-ultrasonic processing in a steady flow area belongs to the field of precision special processing technology, and the device includes: a base, a workpiece clamping sliding table unit, a laser unit, a jet gun unit and a host computer. The workpiece clamping sliding table unit, the laser unit and the jet gun unit are provided on the base. The laser is applied vertically to the surface of workpiece. The jet gun unit emits a high pressure water jet at an angle of 45 degrees to the surface of the workpiece. The base is provided with a waste liquid collection device. The water jet and the laser act on the workpiece surface at the same time. The present disclosure strips the recast layer of the processed surface in real time, and improves the processed quality and performance of workpiece.

Abstract: A method for determining a user experience for an electronic user interface includes defining a test period for testing two or more versions of an electronic user interface, receiving, from each of a plurality of users during the test period, a respective request for the electronic user interface, determining, for each of the plurality of users, a respective version of the two or more versions of the electronic user interface by maximizing test power during the test period while maintaining higher in-test rewards than an A/B test or maximizing the rewards during the test period while maintaining a test power no worse than an A/B test, and causing, for each of the plurality of users, the determined version of the electronic user interface to be delivered to the user.

Abstract: Disclosed herein relates to organic synthesis, and more particularly to a method for preparing a key intermediate for the synthesis of statins. The key intermediate is 2-[(4R,6S)-6-[(benzo[d]thiazol-2-ylthio)methyl]-2,2-disubstituted-1,3-dioxan-4-yl] acetate of formula (I): where R1 is a C1-C8 alkyl group, a C3-C8 cycloalkyl group, a monosubstituted or polysubstituted aryl group, or monosubstituted or polysubstituted aralkyl group; R2 is hydrogen, or monosubstituted or polysubstituted C1-C3 alkyl group, or halogen; and R3 and R4 are each independently a C1-C5 alkyl group, a C3-C7 cycloalkyl group, a C3-C7 cycloalkenyl group, a C1-C3 alkoxy group, a C6-C10 aryl group, or C7-C12 aralkyl group. In the method, a halomethyl compound and a thiol reagent are subjected to nucleophilic substitution in an organic solvent to synthesize a thioether, which then undergoes ketal exchange reaction with a carbonyl compound (V) in the presence of an organic acid to obtain a target product.

Abstract: A method for machine learning-based classification may include training a machine learning model with a full training data set, the full training data set comprising a plurality of data points, to generate a first model state of the machine learning model, generating respective embeddings for the data points in the full training data set with the first model state of the machine learning model, applying a clustering algorithm to the respective embeddings to generate one or more clusters of the embeddings, identifying outlier embeddings from the one or more clusters of the embeddings, generating a reduced training data set comprising the full training data set less the data points associated with the outlier embeddings, training the machine learning model with the reduced training data set to a second model state, and applying the second model state to one or more data sets to classify the one or more data sets.

Abstract: A full continuous-flow preparation method of (+)-biotin, including: subjecting a cyclic anhydride and a chiral biphenyl propylene glycol to asymmetric ring-opening reaction to produce a first intermediate, which undergoes selective reduction with a borohydride and cyclization with an inorganic mineral acid to produce (3aS, 6aR)-lactone; subjecting the (3aS, 6aR)-lactone and a sulfenylating reagent to sulfenylation to produce (3aS, 6aR)-thiolactone, which undergoes Fukuyama coupling with a zinc reagent in the presence of a palladium catalyst and elimination reaction in the presence of an inorganic mineral acid to produce an alkenyl valerate compound; subjecting the alkenyl valerate compound to reduction in the presence of a Pd/C catalyst to produce a valerate ester, which undergoes hydrolysis to produce a valeric acid salt; and subjecting the valeric acid salt to debenzylation in the presence of an inorganic mineral acid to produce the target product (+)-biotin.

Abstract: A micro-zone soil sampling apparatus and method for different contamination situations. The apparatus includes an uncovered cylinder and a plurality of circular separators. The circular separators are horizontally arranged in a hollow inner cavity of the uncovered cylinder, and are removably connected to an inner wall of the uncovered cylinder. Each circular separator includes a plurality of inner rings arranged coaxially, an outer ring coaxially arranged outside the inner rings, and a soil-bearing net. Each circular separator is divided into multiple hollow spaces by the inner rings and the outer ring. The inner rings made of a permeable membrane material and the outer ring made of a rigid material both have a certain thickness. The soil-bearing net is fittedly fixed on a bottom of each circular separator. A plurality of spokes passing through a center of the soil-bearing net are fixedly arranged on the soil-bearing net. A micro-zone soil sampling apparatus and method for different contamination situations.

Abstract: A method for preparing L-carnitine using a micro-reaction system. (R)-4-halo-3-hydroxybutyrate was subjected to quaternization and hydrolysis in an aqueous trimethylamine solution in the presence of an inorganic base in a micro-channel reactor to produce the L-carnitine.

Abstract: An interferometric demodulation system for a large capacity fiber grating sensing network is provided by the present disclosure, comprising: a continuous light output end of the nanoscale wide-spectrum light source is connected to an input end of the pulse optical modulator, an output end of the reference grating is connected to an input end of the grating array sensing network, and a third communication end of the optical circulator is connected to an input end of the optical amplifier, an output end of the optical amplifier is connected to an input end of the Mach-Zehnder interferometer, three-channel signal output ends of the Mach-Zehnder interferometer are respectively connected to signal input ends corresponding to the embedded signal processor through the photoelectric converter, and the embedded signal processor controls the heating device to control a temperature of an any one of interference arms of the Mach-Zehnder interferometer.