Isoprene is a typical physiological marker that can be used to screen for chronic liver disease. This work developed a portable micro-integrated chromatography analysis system based on micro-electromechanical system technology, nanomaterials technology and embedded microcontroller technology. The system integrated components such as graphene oxide quantum dots modified semi-packed microcolumn, In₂O₃ nanoflower (NF) gas-sensitive detector and 3D printed miniature solenoid valve group. The effectiveness of the separation effect of the micro-integrated system was verified by gas mixture test; the laws of the influence of carrier gas pressure and column temperature on the chromatographic separation performance, respectively, were investigated, and the working conditions (column temperature 90 °C and carrier gas pressure 7.5 kPa) for system testing were determined. The percentages of relative standard deviation of the peak areas and retention times obtained for the separated gases were in the range of 0.95%–6.06%, indicating the good reproducibility of the system. Meanwhile, the microintegrated system could detect isoprene down to 50 ppb at small injection volume (1 ml). The system response increased with increasing isoprene concentration and was linearly correlated with isoprene concentration (R ² = 0.986), indicating that the system was expected to be used for trace detection of isoprene, a marker gas for liver disease, in the future.

In this paper, the serpentine-shaped semi-packed chromatographic columns embedded with the micro-post array were developed to separate the characteristic markers of advanced fibrosis. The 3 m long micro separation columns with a rectangular channel cross-sectional dimension of 250 μ m × 200 μ m and the micropost diameter of 30 μ m were prepared by the micro-electromechanical system (MEMS) technology. Based on the static coating process, two kinds of microcolumns (Sp1 and Sp2) with different stationary phase coatings were prepared for comparison. In detail, the Sp1 column was only coated with polydimethylsiloxane (PDMS), and the Sp2 column was coated with PDMS functionalized by graphene oxide quantum dots (GOQDs). GOQDs is a carbon-based nanomaterial that had similar properties to graphene oxide (GO). Moreover, the microcolumns are connected to a conventional gas chromatograph for testing. Alkanes (C ₅ –C ₁₄ ) and benzene series (benzene, toluene, o-xylene, 1,3,5- trimethylbenzene) were used to evaluate the separation characteristics of microcolumns, and the effect of constant column temperature and heating rate on chromatographic performance was studied. The experimental results show that the potential characteristic markers of advanced fibrosis (pentane and benzene) could be effectively separated in alkanes and benzene series, respectively, and the separation effect of Sp2 was better than that of Sp1. In addition, the Sp2 column also showed good repeatability. Therefore, the GOQDs-functionalized PDMS coated column could assist the microdetector of the microsystem under development to rapidly, accurately and effectively distinguish the markers, and is expected to become a candidate for micro gas chromatography ( μ GC) column for micro-system integration.

A serpentine-shaped semi-packed micro gas chromatography (GC) column with mesoporous inner surface and ionic liquid (IL) coating was developed for the separation of various typical volatile organic compounds in exhaled air. The mesoporous surface was prepared by coating silica nanoparticles on the inner surface of the micro GC column through static method and used as stationary phase support to improve the separation performance by its high surface area. The micro GC columns provide efficient separations for analytes including nonpolar (alkanes), weak polar (benzene series) and polar compounds (alcohols), as well as various typical markers of non-alcoholic fatty liver disease. The test results show that the resolution of most analytes is higher than 1.5, the elution peaks are symmetrical. Moreover, due to the chemical stability of IL, the micro GC had good repeatability, thermal stability and oxygen robustness. The maximum relative standard deviation of retention time was 0.44% in four weeks. During the programmed heating, a stable baseline was achieved and the baseline drift value was less than 4.8 mV when the operating temperature increased from 50 °C to 140 °C. The oxygen robustness was verified by a decrease of 7.2% in the peak capacity after exposure to dry air at 140 °C for 48 h. These characteristics showed the micro GC column is suitable for a portable breath analyzer.

A large, fully steerable radio telescope is susceptible to the wind load, leading to structure deformation and pointing deviation of the telescope. To effectively suppress the influence of dynamic wind load, the wind resistance control of the telescope is carried out based on wind speed forecasting. This study developed a wind speed forecasting model to efficiently forecast the wind speed at the telescope position. The proposed model successfully eliminates the random noise of the original wind speed, effectively extracts the wind speed features and solves the automatic optimization of the hyperparameters of the forecasting network. This model significantly improves the accuracy and reliability of wind speed forecasting. To verify the forecasting performance of the proposed model, the wind data from the Qitai Radio Telescope site is examined as a case study. The wind speed forecasting model’s MAE, RMSE and MAPE are 0.0361, 0.0703 and 3.87%, respectively. The performance of the proposed model meets the requirements of wind resistance control and can provide data support for the radio telescope.

With the demand for more powerful functions and miniaturization of electronic equipment, the requirements for complex interconnection design and manufacturing in electronic packaging are increasing. The pros and cons of interconnection configuration have a serious impact on its electrical performance, and have become a key factor affecting the development of complex interconnection in electronic packaging. In order to better study the influence mechanism of the configuration parameters of lead interconnection, a method for predicting the electrical performance of lead interconnection in electronic packaging based on configuration characteristics is presented. First, the configuration parameters of lead interconnection are extracted, then the parameterized characterization of lead interconnection is carried out. Taking the half-envelope rectangular lead interconnection as an example, the road coupling model of lead interconnection based on range analysis, variance analysis and response surface method is built and experimentally verified. Finally, the influence mechanism of the configuration characteristics of lead interconnect on electrical performance is analyzed. The work carried out provides theoretical guidance for the lead interconnection design and fast prediction of electrical signal transmission performance in electronic packaging.

The next-generation communication base station antennas represented by phased array antennas are towards high frequency, high gain, high density, and high pointing accuracy. The influence of mechanical structure factors on communication system channel quality is obviously increasing, and the electromechanical coupling problem is becoming more prominent. To effectively guarantee the realization of 5G/6G communication in complex working environments and accelerate the commercial process of future communication systems, an electromechanical coupling channel capacity model is established in comprehensive consideration of the positional shift, attitude deflection, and temperature change of the communication base station phased array antennas. It can be used to rapidly evaluate the communication index degradation of RF devices within the heating environment. Moreover, a sensitivity model of the electric field strength and array antenna channel capacity to the random position error of each element is constructed. The influence of the random positioning error of each element on the communication indicators is analyzed and compared under different working conditions. The simulation results show that the proposed model can effectively provide a theoretical basis and guiding role for the design and manufacture of high-frequency array base station antennas.