University of Electronic Science and Technology of China

Shineon Environments Technology Services Co., Ltd.

Jing Luo

Hua Fan

Quanyuan Feng

Panfeng Zhao

Tao Zhang

Wei Zhang

Yilin Liu

Huichao Yue

Yiming Hu

Guo Li

Sheng Zhou

Xiongying He

Guanjun Wang

Weisheng Zhao

Fuyou Huang

Disclosed are a flocculant for treating fracturing flowback fluid and a preparation method therefor, which relate to oilfield sewage treatment. The method includes: in parts by weight, dissolving gelatinized starch in water, adding unsaturated polyethylene glycol, unsaturated short-chain carboxylic acid, hydroxyethyl methacrylate phosphate and an initiator under a nitrogen atmosphere for reaction for 3-8 h, and after the reaction is completed, separating and purifying to obtain a product. The flocculant for treating fracturing flowback fluid is prepared by a one-pot method, and the solvent is water, so that the preparation method is simple and has better environmental protection performance; meanwhile, the flocculant not only can reduce turbidity, color and suspended matters of the flowback fluid, but also can effectively reduce COD and total iron of the flowback fluid, and also can reduce the mineralization to a certain degree. The flocculant has good biodegradability and has less impact on the environment.

Flocculant for treating fracturing flowback fluid and preparation method therefor

Disclosed is a three-axis Hall angle sensor with an accuracy of 0.3°. The sensor is mainly designed by means of finite element software and COMSOL Multiphysics. The present specification will be mainly performed in three steps. In the first step, a cross-shape horizontal Hall element for measuring the magnetic field in the vertical direction, that is, the direction z, is studied. The second section mainly studies a three-contact four-Hall vertical element for measuring the magnetic field in the directions x, y. The third part is to design the angle sensor. Compared with the horizontal Hall element, the vertical Hall element has a relatively large offset, therefore, four vertical Hall elements are used to measure the magnetic field in the horizontal direction, and two complementary vertical structures are used to eliminate the error when the magnetic field in the same horizontal direction is measured.

Three-axis Hall angle sensor with accuracy of 0.3°

The present disclosure relates to the field of microelectronics and solid-state electronics, and in particular to a calibration system and method for weighting errors brought about by parasitic capacitance in split capacitor-based successive approximation analog-to-digital converters. The method uses an MSB array that does not add additional capacitors, only a switch Sto reduce the comparator design difficulty. Meanwhile, an LSB array may add a calibration DAC array Cincluding a binary array of P-bit unit capacitors, a calibration structure C, and a ground switch S. The calibration structure Cincludes four unit capacitors and two switches Sand S. By controlling the switches Sand Sdifferent capacitance values can be generated to reduce the chip area consumption. This structure can reduce the error to LSB/4 and the weighting error of the ADC, and increases the effective number of bits of the ADC without excessively increasing comparator gain.

System and method for calibrating weighting errors in split capacitance successive approximation analog-to-digital converters

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Chengdu, China

Jing Luo