Abstract: The disclosure relates to the technical filed of organic synthesis, in particular to a method for preparing veratrole. In the disclosure, veratrole is prepared by using lithium hydroxide instead of sodium hydroxide, catechol as raw material, and dimethyl sulfate as methylating agent. Comparing with the existing method of adding sodium hydroxide solution, the method according to the disclosure allows reduced reaction temperature, shortened reaction time, and thereby improves the stability and safety of the reaction and the product yield. The experimental data of the examples in the disclosure shows a veratrole yield up to 95%. Furthermore, the preparation method according to the disclosure does not need to be carried out under a reflux condition, the operation of which is simpler, thereby further improving the safety and stability of the reaction.

Abstract: A diaphragm applied to a sound producing device, a sound producing device, and a method for assembling the same. The diaphragm comprises a film layer prepared by means of a crosslinking reaction of at least one of an ethylene-acrylate copolymer and an ethylene-acrylate-carboxylic acid copolymer. The molecular structure of the diaphragm comprises a vinyl-acrylic group. The group causes the material to have a less symmetrical chemical structure, a reduced tacticity and an increased steric hindrance, such that the diaphragm has a high loss factor, and the sound producing device achieves a good damping effect.

Abstract: A bridge monitoring method, system, a structure state monitoring device and a storage medium, which comprises: obtaining at least one qubit pair in a quantum entangled state; the coupling relationship between the qubit pair state of at least one qubit pair and the physical parameters of the bridge is constructed. The qubit pair state of at least one qubit pair is monitored, and the structural state of the bridge is determined based on the qubit pair state and the coupling relationship. The invention uses the entanglement relation of quantum bits to realize the real-time monitoring of the bridge structure state in the full range of the bridge with high sensitivity and high resolution.

Abstract: An electronic device includes a first graphics processing subsystem, a second graphics processing subsystem, and a screen. The first graphics processing subsystem includes a first application processor, a first graphics processing unit, and a first memory. The second graphics processing subsystem includes a second application processor, a second graphics processing unit, and a second memory. The first graphics processing unit renders a first GUI. The screen displays the first GUI. The second graphics processing unit renders a second GUI, and the second GUI and the first GUI belong to different interface types. The screen displays the second GUI. A display processing method applied to the electronic device is also provided, wherein the first graphics processing subsystem can be switched to the second graphics processing subsystem based on complexity of a to-be-displayed GUI.

Abstract: The present application provides a wireless sensing method, comprising: performing modeling according to a sensing signal received by antennas, determining a reference state of a sensing environment; calculating a difference between a current sensing signal and the reference state; and determining, according to the difference, a position parameter of a changing sensing object in the sensing environment. The present application further provides a wireless sensing apparatus, a communication device, and a computer storage medium.

Abstract: A photography supporting frame comprises a base seat and supporting legs sequentially arranged around the base seat. Connecting bosses are arranged around the base seat; clamping teeth are sequentially arranged on the peripheries of the connecting bosses. The supporting legs each comprise a locating hook, a ball, a spring, an insertion piece, a foot shaft sleeve and a supporting leg rod. The ball and the spring are sequentially arranged in a cavity of the insertion piece from up to down; the locating hook is arranged in the middle of the upper portion of the insertion piece and connected to the ball. The insertion piece is arranged in the foot shaft sleeve. One end of the foot shaft sleeve is connected to one of the connecting bosses, and the other end of the foot shaft sleeve is arranged on the supporting leg rod.

Abstract: A photography supporting frame comprises a base seat and supporting legs sequentially arranged around the base seat. Connecting bosses are arranged around the base seat; clamping teeth are sequentially arranged on the peripheries of the connecting bosses. The supporting legs each comprise a locating hook, a ball, a spring, an insertion piece, a foot shaft sleeve and a supporting leg rod. The ball and the spring are sequentially arranged in a cavity of the insertion piece from up to down; the locating hook is arranged in the middle of the upper portion of the insertion piece and connected to the ball. The insertion piece is arranged in the foot shaft sleeve. One end of the foot shaft sleeve is connected to one of the connecting bosses, and the other end of the foot shaft sleeve is arranged on the supporting leg rod.

Abstract: A tripod head panel device of a tripod head comprises a tripod head panel and a removably mounted snap-fit plate. The tripod head panel comprises a fixed plate, a moveable plate mounted underneath the fixed plate, and a driving plate mounted underneath the moveable plate. The fixed plate comprises a supporting base plate and a first retaining wall protruding upward from the supporting base plate. The moveable plate comprises a supporting base plate and a second retaining wall protruding upward from the supporting base plate, with a driving hole provided in the center of the moveable plate. The driving plate comprises a base mounted underneath the moveable plate and a handle extending from an end of the base, with an offset cam inside the driving hole formed on the seat. The snap-fit plate is mounted on the supporting base plate between the first and the second retaining walls.

Abstract: A tripod head panel device of a tripod head comprises a tripod head panel and a removably mounted snap-fit plate. The tripod head panel comprises a fixed plate, a moveable plate mounted underneath the fixed plate, and a driving plate mounted underneath the moveable plate. The fixed plate comprises a supporting base plate and a first retaining wall protruding upward from the supporting base plate. The moveable plate comprises a supporting base plate and a second retaining wall protruding upward from the supporting base plate, with a driving hole provided in the center of the moveable plate. The driving plate comprises a base mounted underneath the moveable plate and a handle extending from an end of the base, with an offset cam inside the driving hole formed on the seat. The snap-fit plate is mounted on the supporting base plate between the first and the second retaining walls.