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Additive manufacturing provides a new way to develop high-performance superalloys and components. A γ′- strengthened CoNi-base superalloy suitable for additive manufacturing was developed，and a crack-free block material was prepared by optimizing the parameters of electron beam melting（EBM） technology. The experimental results show that the lowest porosity of the alloy is about 0.14% when the scanning speed is 2000 mm/s. The microstructures of the as-printed CoNi-base alloy are columnar grains growing along the direction，the average grain width is about 235 μm，and the volume fraction of γ′ phase is about 30%. After hot isostatic pressing and solution aging treatment，the porosity of the alloy is further reduced to about 0.09% with unobvious change of columnar grains. The average size of γ′ phases is about （70±18）nm with the volume fraction of about （32±3.6）%. The results of room temperature tensile tests show that the additive manufactured γʹ-strengthened CoNi-base superalloy exhibits excellent strength and ductility，showing a good potential of industrial application.

Ice cream has the characteristic of thermodynamic instability. During processing, storage, transportation, and sales, temperature fluctuations cause recrystallization of ice crystals and then increase the average size of ice crystals, which leads to rough texture and poor taste of ice cream. Therefore, inhibiting the recrystallization of ice crystals in ice cream is the key to ensure the quality of ice cream. This paper reviews the formation mechanism and research progress of supercooling, nucleation, growth and recrystallization of ice crystals during freezing. The inhibitory effects of emulsifiers, stabilizers, sweeteners, and proteins in ice cream raw materials on ice crystal recrystallization are introduced in detail. Meanwhile, it also list the contents of freezing technologies such as ultrasonic assisted freezing, magnetic field assisted freezing, high-pressure assisted freezing, and electric field assisted freezing to inhibit ice cream recrystallization. The development direction of that is prospected, which provides a theoretical reference for adapting to the trend of online sales, developing new ice cream products and solving the problem of its crystal recrystallization.

The combustion of biomass fuel boilers not only produces inorganic pollutants such as carbon oxides, nitrogen oxides, sulfur compounds, but also organic pollutants such as VOCs and PAHs, which directly affect the global biogeochemical cycle and atmospheric changes. Compared with foreign countries, there is relatively less research and related standards on the emission of organic pollutants from biomass fuel boilers in China. Therefore, it is necessary to study the emission characteristics of organic pollutants from biomass boilers, which can provide reference for the establishment of organic pollutant emission standards for biomass fuel boilers in China.The emission characteristics of volatile organic compounds(VOCs) and polycyclic aromatic hydrocarbons(PAHs) organic pollutants in the flue gas of three typical biomass-fired boilers in Chongqing were studied, and the emission concentrations of particulate matter, sulfur dioxides(SO2), and nitrogen oxides(NOX) were measured.The results show that the sulfur dioxide emissions from the three types of biomass-fired boilersrs are lower than the local standards in Chongqing, while nitrogen oxides and particulate matter have a phenomenon of exceeding the emission limits of the local standards in Chongqing. The main components of VOCs emitted from biomass powder and biomass particle combustion are OVOCs and aromatic hydrocarbons, while the main components of VOCs emitted from wood biomass combustion are alkynes. The gas-solid distribution pattern of PAHs during the combustion of three types of biomass is basically consistent. Low ring PAHs are mainly enriched in the gas phase, while medium and high ring PAHs are mainly enriched in particulate matter.

In order to improve air quality and reduce haze, Chongqing has raised the nitrogen oxide emission requirements of gas industrial boilers, reduced the emission limits, and promoted a large number of low-nitrogen transformations of industrial boilers in Chongqing. In this paper, the main generation mechanism of nitrogen oxides and different technical schemes of low nitrogen transformation were introduced. Six representative industrial boilers were selected to carry out low nitrogen transformation based on FGR technology, and nitrogen oxide emission under the reference oxygen content, smoke exhaust temperature, thermal efficiency and actual output of boilers before and after the transformation were compared and tested. The test results show that the actual output of industrial boilers can be reduced and the energy consumption of boilers can be increased by using FGR low nitrogen technology.

In order to screen an optimal thermal protective agent for immunoglobulin G in bovine colostrum, the IgG was extracted from bovine colostrum. Based on single factor experiments, the response value was the retention rate of IgG activity, and the response factors were glycine, maltitol and inulin. Box–Behnken experimental design on three levels and three variables was used for optimization of IgG thermal protectant. The structure of IgG was characterized by Fourier transform infrared Spectroscopy and endogenous fluorescence spectroscopy. The results showed that the best formula of IgG thermal protection agent was: Glycine 0.48%, inulin 14.98%, and maltitol 12.50%. Under these conditions, the IgG activity retention rate at 75 ℃ for 5 min was 36.59%, indicating that the response surface model had high accuracy and the optimized thermal protectant formula had practical application significance. The results of Fourier transform infrared spectrum and endogenous fluorescence spectrum analysis showed that compared with bovine colostrum IgG without compound heat protectant, the β-fold content decreased significantly (P

Abstract Background Side effects in psychotherapy are common and have a negative impact on patients or clients. However, effective evaluation tools are still lacking and have not been fully studied. The present study aims to develop a scale with good reliability and validity to measure the side effects of psychotherapy. Methods The 25 items in the Psychotherapy Side Effects Scale (PSES) were condensed and distributed to 420 subjects online to test its psychometric properties. Results The internal consistency of the PSES was satisfactory to excellent (Cronbach's ɑ coefficient was .95, and the Guttman split‐half coefficient was 0.88). A statistically significant negative correlation between the satisfaction score and the total score of the PSES was shown (r = −0.51, p

Turbine blades of aircraft engines may suffer serious degradation caused by overheating service exposures. In this paper, microstructure characteristics and tensile properties of K465 alloy, which is an equiaxed cast superalloy and widely used in turbine blades and vanes, were investigated after overheating treatment at 1180~1270℃. The microstructure before and after overheating was also examined and quantitatively characterized using SEM, XRD and physicochemical phase analysis. The relationship between microstructural degradation after overheating and tensile properties was investigated. The results indicate that primary γ' phase, carbides and grain boundaries are gradually dissolved in K465 alloy with increasing the overheating temperature; γ' phase distributed in the interdendritic region has a higher dissolution temperature than that in the dendrite core region due to a higher content of γ' phase forming elements. Incipient melting mainly occurs at the residual eutectic region and grain boundaries at 1270℃. The tensile properties are decreased significantly with increasing the overheating temperature, the yield strength was 439MPa at 1000℃ and dramatically decreased to 85MPa and 26MPa at 1180℃ and 1240℃, respectively. The tensile properties are mainly influenced by the dissolution behaviors of primary γ' phase and γ' film along grain boundaries as well as the influence of incipient melting.

With the increasing intensity of oil and gas field exploration and development, oil and gas wells are also drilling into deeper and more complex formations. Conventional steel drilling tools can no longer meet the requirements of ultra-deep, high-temperature and high-pressure wells. The paper first analyzes the advantages of titanium alloy drill pipe based on basic performance of titanium alloy drill pipe. The experimental results show that the basic properties of titanium alloy drill pipes meet the operating standards of the petroleum industry. Then the buckling performance of titanium alloy drill pipe and steel drill pipe is compared, the calculation results show that the buckling performance of titanium alloy drill tools is slightly lower than that of steel drill tools. Secondly, the maximum allowable buildup rate of titanium alloy drill pipe and steel drill tool is studied. The research shows that under the same condition of the drill pipe outer diameter, titanium alloy drill pipe can be used for a smaller curvature radius and greater buildup rate. This advantage of titanium alloy drill pipe makes it more suitable for short radius and ultra-short radius wells. Finally, taking a shale gas horizontal well as an example, with the goal of reducing drill string friction and ensuring drill string stability, a comparative study on the application of titanium alloy drill pipe and steel drill pipe is carried out. The results show that titanium alloy drill pipe has a wider application in the field, and is suitable for operations under various complex working conditions.

The microstructure and property degradation of turbine blades in aircraft engines during service would finally pose threat to service safety. But report on systematic research work about microstructure and property degradation of serviced turbine blades is limited. In this paper, the 2nd stage turbine blade made of wrought Ni-based superalloy GH4033 was taken from an aircraft engine and investigated by metallographic analysis and physical and chemical phase analysis after service exposure for about 1600 engine operating hours (EOH). Microstructural features including grain microstructure, γ+γ' matrix and grain boundary (GB) carbides in different locations of the serviced blade were observed and quantitatively characterized. Vickers hardness and stress rupture tests were also conducted. The microstructure characterization indicates that the degradation in grain size, γ' precipitates and GB carbides is rarely observed in the airfoil. The service temperature is estimated to be lower than 700℃ based on the coarsen of γ' phase. The Vickers hardness and rupture lives of different locations in this blade are similar to those in the shank and met the requirement of Chinese Aeronautical Industry Standard HB/Z 91-1985. Therefore, it is suggested that the service exposure of this blade can be continuously prolonged. This study would be helpful for the evaluation of turbine blade made of wrought superalloys containing low volume fraction of γ' precipitates.

Relying on the experimental data, by using the theory of error control and function approximation to establish new wet and dry bulb coefficientÂ(v, ta). Through searching method and Iterative approximation, it finds an approximation function whose figure is closer to "experimental data" than previous one did. Hence, it increases the measurement accuracy of relative humidity by the wet and dry bulb method under the condition of the relative humidity in the range of 10℃≤t≤70℃, air flow rate 0.1m/s≤v≤4m/s, and relative humidity 30%≤U≤90%.