The article reviews and summarizes the research works in last decades and recent development of on-chip electron sources including field emission on-chip electron sources, internal field emission on-chip electron sources and new thermionic on-chip electron sources. The article compares the basic principles, fabrication and working performance of such on-chip electron sources, including working voltage, working vacuum, emission current, emission current density and emission efficiency, and analyzes the advantages and disadvantages of various on-chip electron sources. A brief summary of the development status of on-chip electron source is made through these analyses.

How to shorten the pumping time and reduce the cost under the premise of ensuring the vacuum impregnation quality of capacitors is a problem that every capacitor manufacturer pays close attention to. For a long time, because there is no objective measurement data to effectively judge the vacuum impregnation end point, the vacuuming stage time is often prolonged. This paper describes the development results of a water molecular mass spectrometer. From the molecular weight level, the vacuum impregnation endpoint of the capacitor was judged. The number of vapor molecules of the pumped gas can be measured and calculated, and thereby achieving an accurate and effective judgment of the endpoint of the vacuum immersion process.

To meet with the requirement of helium mass spectrometric leak detection for large-scale overlength tanks of the next generation launch vehicle, a new leak test method with the tank in vertical status is proposed in this paper. Theoretic analysis and simulation tests are both used to study the air stratification caused by the gravity along the vertical direction. The results show that there is no significant helium stratification when the leak detection is performed with the large-scale overlength tanks in the vertical status and the error caused by the stratification is negligible, which confirm the engineering feasibility of the leak detection with overlength tanks in vertical status.

The variable filter is designed based on the principle of film thickness and wavelength variable. The fabrication of variable filter based on reactive magnetron sputtering coating machine was introduced, and the correction mask with variable film thickness is designed. The measurement of variable filter is discussed.

This study mainly used RF coupled DC magnetron sputtering technology to prepare N-doped TiO₂ thin films on glass substrates at room temperature with TiO₂ ceramic targets. At the same time, the effects of different RF power ratios on the microstructure and optical properties of the films were investigated by optical profilometry, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy and UV-visible spectrophotometer. The experimental results show that, with the increase of RF power, the deposition rate of the film increases, the crystallinity of the film becomes better, the grain size becomes larger, the proportion of N doping increases, and the valence state of Ti shows incompletely oxidized Ti³⁺. The forbidden band width is also correspondingly reduced, and the absorption edge of the N-doped TiO₂ film is extended to the visible light region.

AZO/Ag/AZO multilayer transparent conductive films were grown on glass substrate by magnetron sputtering at room temperature. The effect of Ag layer thickness on the structure and properties of the multilayer transparent conductive films were mainly studied. The results show that AZO and Ag have preferred orientation to the (002) and (111) planes, respectively, and the resistivity of the multilayer transparent conductive films decrease with the increase of the Ag layer thickness, while the transmittance is reduced first, then increased, and then decreased. The sample with Ag layer thickness of 8nm shows the maximum figure of merit value of 33.1×10^-3 Ω^-1, and the overall performance was the best.

This paper mainly introduces the development history of all-glass vacuum collector coating equipment, and describes the major improvements in the development process of collector coating equipment, as well as the methods of improving production efficiency and saving energy and reducing consumption of coating equipment. It has certain reference significance for the development and improvement of coating machines in other industries.

The counter design of solid rocket engine nozzle profile is directly related to nozzle efficiency and thrust, which is an important research topic in the design of nozzle. In this paper, the research progress on the nozzle profile of solid rocket motor has been reviewed from the aspects of nozzle design method, profile parameter optimization and nozzle fluid-solid coupling analysis. The nozzle design methods such as the direct optimization method, length-shorted nozzle, the six-time Bézier curve, Bi-cubic spline, the B-Spline curve and the method of characteristics are summarized. The applications of computational fluid dynamics and stochastic optimization methods in solid rocket motor design optimization are introduced. The fluid-solid thermal coupling problem of solid rocket engine nozzle has been analyzed. The classical computational fluid dynamics algorithm, characteristic-based split finite element algorithm and a lattice Boltzmann algorithm are used in the study of fluid-solid coupling problems.

In this paper, a helium recovery and purification device for air-conditioning leak detection equipment is studied. The results show that the device can effectively maintain the purity of helium in air-conditioning leak detection equipment above 80%. The helium usage of the process is about 6.7 m³ per day, which is less than the helium emission of the system due to low purity when the process is not used. Considering the actual use of the enterprise, the helium emission from the system is about 7 m³ per day. According to the economic requirement of the device, the direction of the follow-up process optimization of the device is put forward.

The pressure simulation test simulates the airflow condition of the specimen in the practical working processes by precisely controlling the surrounding pressure, for the purpose of testing the ventilation efficiency and structural reliability of the specimen. In this study, to meet the demand that the pressure at a specific position can be measured during the test, a calibration method of pressure measurement via the pressure pipeline is proposed. In the calibration test, the primary pressure value that using the pressure pipeline is measured by the measuring gauge and the standard pressure value could be measured by the standard gauge. The proper fitting function could be chosen in MATLAB and a set of correction formula could be fitted by the pressure value. The as-measured value could be corrected by the formula to obtain an accurate pressure value in the subsequent test. It is verified by experiments that the calibration method can effectively eliminate the influence of the pressure piping on the pressure measurement and ensure the implementation of the pressure simulation test.

The method of filling simulated gases into the vacuum interlayer of insulated cylinder is successively put forward to evaluate the vacuum life of insulated cylinder for leakage and material outgassing. The test result shows that the static evaporation rate of cryogenic insulated cylinder rises rapidly after the interlayer pressure is greater than 5×10^-2Pa at low temperature, that is to say, 5×10^-2Pa can be regarded as the inflection point (or threshold) of the interlayer vacuum life termination. 5A molecular sieve has great adsorption potential for nitrogen at liquid nitrogen temperature, however, with weak adsorption capacity for hydrogen. The effect of material outgassing on vacuum life of vacuum insulating sandwich is far greater than that of leakage. The technical way to improve vacuum life of insulating cylinder is to reduce the outgassing rate of sandwich material and improve the adsorption capacity of built-in adsorbent for hydrogen. This test can directly, practically and accurately study the influence of leakage and outgassing on vacuum life, provides reference data for determining practical design parameters and process, and then promotes the application and evaluation of vacuum life of various vacuum insulated cryogenic vessels.

In order to further improve the application of the vacuum insulation panel, the development trend of special-shaped vacuum insulation panel were analyzed, and the key high barrier composite film was studied in the influence of the special-shaped vacuum insulation panel, through comparing several high barrier composite film of the mainstream on the market, analyse the special-shaped vacuum insulation panel with a groove on the feasibility of using, and through comparative experiments such as coefficient of thermal conductivity to further verification. It is concluded that the best film material options provide a reference basis for mass production of vacuum insulation panel with grooves.

Ceramic materials have excellent thermal and mechanical properties with important application prospects in many fields. Its inherent high strength and high hardness bring many difficulties to the forming of ceramic parts. The introduction of material-adding manufacturing technology into ceramic forming will effectively overcome such difficulties and provide a new possibility for the complex forming processes of ceramic materials. In this paper, from the point of view of raw material status, the research status and progress of several common ceramic augmentation manufacturing technologies are reviewed in detail. The advantages and disadvantages of each technology in the field of ceramics are systematically compared. The development of ceramic augmentation manufacturing technology in the future is prospected.

The forming part quality is mainly affected by the drastic changing of the temperature field during the additive manufacturing process. The molten pool temperature can be predicted by empirical equation to optimize the building process parameters, which will improve the forming quality and ensure the dimensional accuracy of the building parts. In order to build the empirical equation of molten pool temperature, an infrared measuring system was built to measure the molten temperature. The measurement data is used to establish mathematical models by multiple linear regression analysis method in Matlab. According to the comparison of the testing result by infrared measuring system and the calculation results by empirical equation, the mean error is 8.18℃ and the accuracy error is 0.12, which means the empirical equation has a certain accuracy in the appropriate range.

The service life of soil-engaging components for agricultural machinery was seriously shortened by the wear failure, which greatly affected the cost of agricultural production and restricted the development of agricultural mechanization. With its excellent performance, cladding technology has become an important means to improve the wear resistance of soil-engaging components of agricultural machinery. This paper briefly discussed the wear failure of soil-engaging components, the working principle and characteristics of cladding technology, and the application status of cladding technology on soil-engaging components for agricultural machinery. Finally, it provides relevant prospect.

In order to investigate the effect of process parameters on the surface microhardness of plasma cladding coatings of high chromium iron-based alloy, a single hard coating of high chromium iron-based alloy coated on Q235 steel was studied, and the quadratic regression orthogonal rotation combination test was carried out. Variance and response surface analysis of test data were performed by using the Design-Expert 8.0.6 analysis software. The mathematical model of various factors and microhardness of coating surface were established, and the influence of working current, powder feeding speed and scanning speed on microhardness of coating surface was explored. According to the extremum theory of multivariate functions, the optimal parameter combination was determined and verified by experiment. The optimal parameter combination obtained by the test were working current of 105A, power feeding speed of 14r/min, scanning speed of 80mm/min, under the conditions, the surface microhardness of the coating reached 1075.03HV, which is about 7. 49 times that of the substrate material. The results may provide a theoretical basis for improving the surface properties of high chromium iron-based hard coatings.