NANJING UNIVERSITY

A method for recycling silver from a waste IC chip include: heating to disassemble an IC chip, and crushing the IC chip into powders; adding the powders to a nitric acid solution, heating, centrifuging and collecting a first filtrate; adding soluble starch to the first filtrate, where a mass concentration ratio of the soluble starch to Fe in the first filtrate is 5.20-7.30; heating a resulting mixture to 130-175° C. for a first hydrothermal reaction, separating a precipitate from the first hydrothermal reaction and collecting a second filtrate; heating the second filtrate to 160-230° C. for a second hydrothermal reaction, separating a solid from the second hydrothermal reaction and collecting a third filtrate; drying, grinding, and sieving the solid to obtain silver powders; and adding alkali to the third filtrate to form a precipitate of Cu, and separating the precipitate to yield copper hydroxide.

A radiative cooling-driven system for automated water collection and seed germination enhancement in desert regions includes a base. A bottom plate is fixedly inserted through a middle part of the base, a water collection cylinder is fixedly connected to an upper part of the bottom plate, a protective assembly is arranged at an upper part of the water collection cylinder, and a filter disc is fixedly connected to an inner wall of a middle part of the water collection cylinder. The present application incorporates the protective assembly. A windmill is driven to rotate during high winds, and a driving wheel and driven wheels drive winding shafts I to rotate via a drive rod. Cables are wound up, pulling protective plates to move toward the middle part of the water collection cylinder. As a result, the water collection cylinder is sealed, effectively blocking wind-blown sand from entering and preventing clogging.

This application provides a single-stage voltage-adjustable rectification system with multi-output full-wave rectification, including a rectifier and a control module. The rectifier includes a producing module, an idling switch component, a first transistor component, a second transistor component, a load, and a third transistor component in electrical connection. The producing module is configured for producing alternating input voltage. The first transistor component and the second transistor component are configured for generating, based on the alternating input voltage, DC output voltage. The load is configured for obtaining the DC output voltage. The control module is configured for: if the DC output voltage is not within a target voltage range, controlling, based on the DC output voltage and a DC output voltage reference level, the idling switch component, the first transistor component, the second transistor component, and the third transistor component to turn on or off, such that the DC output voltage is within the target voltage range, to enable to simultaneously adjust output voltage values at multiple output ports in a rectifier circuit with multiple outputs.

The present disclosure provides a method for directly converting carbon dioxide into solid carbon by a photochemical reaction. The method includes placing a catalyst containing a transition metal element in a reaction device; introducing raw gas containing the carbon dioxide and hydrogen at a predetermined molar ratio into the reaction device; and performing illumination under a predetermined pressure. In this way, the carbon dioxide can be used as a carbon source to form the solid carbon in a hydrogenation reduction manner through the photochemical reaction, which provides a new method for reclaiming the carbon dioxide. Through the above manner, the method provided by the present disclosure has mild reaction conditions, is implemented at a normal temperature, and can realize a high carbon yield. Moreover, overall operation steps are simple and feasible, the applicability is wide, large-scale fixation and reclamation of the carbon dioxide can be realized.

The present invention discloses a negative capacitance transistor with a κ-Ga 2 O 3 /Al 2 O 3 composite ferroelectric dielectric layer. The transistor comprises a substrate, a GaN buffer layer, a UID-GaN channel layer, an Al 0.25 Ga 0.75 N barrier layer arranged sequentially from bottom to top; a source, a drain, and a gate disposed on the Al 0.25 Ga 0.75 N barrier layer; and a κ-Ga 2 O 3 /Al 2 O 3 composite ferroelectric dielectric layer disposed between the gate and the Al 0.25 Ga 0.75 N barrier layer. The negative capacitance transistor of the present invention can improve system stability and data retention reliability after power-off while ensuring high-speed data processing capability.

Disclosed are a training method and device for an analog hardware neural network, the method includes: inputting analog signals into the analog hardware neural network, and measuring output results of the analog hardware neural network after the analog hardware neural network establishes a response to the inputted signals; injecting a perturbation signal into a node while the analog hardware neural network is running; and updating parameters of the analog hardware neural network according to results of two measurements. The present disclosure has a higher recognition rate and generalization capabilities, and is applicable to training all types of analog hardware neural network, thereby solving the problem of reliance on a mathematical model in training of the analog hardware neural network.

A polycationic polysaccharide and an application thereof. Specifically, the polycationic polysaccharide consists of a polysaccharide and a polyamine compound, and is a positively charged polycationic polysaccharide obtained by reacting a polysaccharide with an amine-containing or polyamine compound. The polycationic polysaccharide is applied in a biomedical functional material of an antibacterial biofilm, a biomedical device, and an antibacterial functional material.

The present invention discloses an in-situ detection method for reactive oxygen species, which includes the following steps: attaching a reactive oxygen species composite membrane prepared based on a ratiometric fluorescent probe to a to-be-detected region to react with reactive oxygen species; capturing a green light signal on the reactive oxygen species composite membrane using a digital camera equipped with a 520-540 nm narrow-band filter to obtain an image A; capturing a red light signal on the reactive oxygen species composite membrane using a digital camera equipped with a 640-660 nm filter to obtain an image B; acquiring a numerical value (G) of a green light channel in the image A and a numerical value (R) of a red light channel in the image B respectively, and calculating relative fluorescence intensity (FI) as a reactive oxygen species response value; and obtaining a concentration of the reactive oxygen species in situ.

A nano silk fibroin fibrous membrane with directional water transport and a preparation method thereof are provided. Firstly, renewable pure silk fibroin is extracted from natural silkworm cocoons. A silk fibroin film with a nanofibrous structure is prepared by an electrostatic spinning method, and a methanol treatment method is used to induce a secondary structure transformation of the silk fibroin film. Then, a spraying process is used to spray octadecyltrichlorosilane (OTS) onto the silk fibroin fibrous membrane, and a uniformly and regularly arranged mesh hydrophobic inner layer and mesh water transport channels are deposited on one side.

A method for high-throughput determination of whole water toxicity, including: exposing test organisms in a wastewater sample for pollution, obtaining phenotypic feature data of the test organisms; constructing a toxicity matrix; and building a machine learning model, and in combination with the toxicity matrix, determining a whole toxicity of the wastewater sample.