Abstract: An instrument calibration apparatus and a calibration method using same. The apparatus comprises a physical quantity input/output unit, a physical quantity measurement unit, a physical quantity configuration unit, a display unit, a man-machine interaction unit, a storage unit, and a control unit. The apparatus can be widely applied to automatic calibration of multivariable instruments.

Abstract: A method for preparing a large-area structural chromogenic pattern by ink-jet printing, a structural chromogenic pattern obtained by the method, and an anti-counterfeiting method based on a structural color change. A dispersion liquid containing mono-disperse colloidal microspheres with high index of refraction is printed onto a piece of paper by using an ink-jet printer, and nano-microspheres are arranged and assembled on the paper to obtain a micro-structure having the features of being ordered from a short distance and disordered from a long distance. A pretty structural color can be observed by means of the interaction of the structure with light, thus displaying a pattern, changing the angle of observation, changing the brightness of the structural color, and hiding and displaying the pattern. The method is simple and convenient, is widely applicable, and can achieve the preparation and anti-counterfeiting of a large-area structural color without external stimulation.

Abstract: An instrument calibration apparatus and a calibration method using same. The apparatus comprises a physical quantity input/output unit, a physical quantity measurement unit, a physical quantity configuration unit, a display unit, a man-machine interaction unit, a storage unit, and a control unit. The apparatus can be widely applied to automatic calibration of multivariable instruments.

Abstract: A device for protecting a direct current source and method are provided. Electric energy outputted from the direct current source is stored and an enable signal is received by the hiccup drive circuit. In a case that the enable signal is an OFF-ENABLE signal, the driving signal is generated based on the electric energy stored internally. By periodically switching on the switching device based on the driving signal, the output voltage of the direct current source is periodically short-circuited. Therefore, the issue of a large conduction loss in the conventional art is avoided, which is caused by the fact that a minimum required voltage for driving the electronic switch is required to be continuously provided by the output voltage of the direct current source.

Abstract: A method for preparing a large-area structural chromogenic pattern by ink-jet printing, a structural chromogenic pattern obtained by the method, and an anti-counterfeiting method based on a structural color change. A dispersion liquid containing mono-disperse colloidal microspheres with high index of refraction is is printed onto a piece of paper by using an ink-jet printer, and nano-microspheres are arranged and assembled on the paper to obtain a micro-structure having the features of being ordered from a short distance and disordered from a long distance. A pretty structural color can be observed by means of the interaction of the structure with light, thus displaying a pattern, changing the angle of observation, changing the brightness of the structural color, and hiding and displaying the pattern. The method is simple and convenient, is widely applicable, and can achieve the preparation and anti-counterfeiting of a large-area structural color without external stimulation.

Abstract: A cascaded multilevel converter self-test system and a self-test method for the cascaded multilevel converter self-test system are provided. The self-test system includes a cascaded multilevel converter and a self-test device. The cascaded multilevel converter includes at least two converting circuits which are cascaded. The self-test device includes at least one current detecting circuit, a voltage acquiring module and a calculating module. The current detecting circuit is configured to detect a first detected current and a second detected current. The voltage acquiring module is configured to acquire first bus voltages and second bus voltages. The calculating module is configured to calculate an insulation resistance value of the cascaded multilevel converter based on the first detected current, the second detected current, the first bus voltages and the second bus voltages.

Abstract: A device for protecting a direct current source and method are provided. Electric energy outputted from the direct current source is stored and an enable signal is received by the hiccup drive circuit. In a case that the enable signal is an OFF-ENABLE signal, the driving signal is generated based on the electric energy stored internally. By periodically switching on the switching device based on the driving signal, the output voltage of the direct current source is periodically short-circuited. Therefore, the issue of a large conduction loss in the conventional art is avoided, which is caused by the fact that a minimum required voltage for driving the electronic switch is required to be continuously provided by the output voltage of the direct current source.

Abstract: A cascaded multilevel converter self-test system and a self-test method for the cascaded multilevel converter self-test system are provided. The self-test system includes a cascaded multilevel converter and a self-test device. The cascaded multilevel converter includes at least two converting circuits which are cascaded. The self-test device includes at least one current detecting circuit, a voltage acquiring module and a calculating module. The current detecting circuit is configured to detect a first detected current and a second detected current. The voltage acquiring module is configured to acquire first bus voltages and second bus voltages. The calculating module is configured to calculate an insulation resistance value of the cascaded multilevel converter based on the first detected current, the second detected current, the first bus voltages and the second bus voltages.