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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.

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.

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%.

The tensile creep behavior of a Co-Al-W-base single crystal alloy containing Ta and Ti was investigated at 982 ∘C and 248 MPa. The lattice misfit of experimental alloy was measured to be positive by synchrotron X-ray diffraction at high temperature, and long term heat treatment at 1000 ∘C for 1000 h revealed a γ′ volume fraction of 75% without secondary phases. The creep test indicated that the creep properties of experimental alloy exceeded commercial 1st generation Ni-base single crystal superalloy CMSX-3 with respect to the rupture life. The initial cuboidal γ′ precipitates directionally coarsened parallel to the applied stress axis during the creep process. The stacking faults in {111} planes within γ′ rafts were the primary creep deformation mode by TEM investigation.

[001] tilt artificial grain boundaries of Ni-based single crystal superalloys CMSX-4 and DD10 have been prepared by self-diffusion bonding. The microstructural stability of 0 ∼ 30∘ artificial grain boundaries have been investigated after heat treatment at 1100 ∘C for 0 ∼ 300 h. TCP phases and cellular colony developed on boundaries are related to misorientation angle of the bonded boundaries of DD10 and DD10 alloys as well as the bonded boundaries of CMSX-4 and DD10 alloys. The heterogeneous nucleation of TCP phase, enveloped by γ′ film, occurred along 15∘ and 20∘ boundaries. Discontinuous Precipitation (DP) reaction occurred along high misorientation angle (20∘∼ 30∘) boundaries. However, no TCP phase formation existed along grain boundaries with different misorientation angles in CMSX-4/CMSX-4 bonded alloys as well as for a 0∘ boundary in DD10/DD10 and CMSX-4/DD10 bonded alloys. The current study clearly suggests that grain boundary precipitation and its morphology were influenced by the misorientation angle of grain boundary and the content of refractory elements in alloy.

Microstructural instability involving the formation of topologically close-packed (TCP) phases is restricted during the alloy development of Ni-based single crystal superalloys. In this study, the effects of alloying elements including Co, Cr, Mo and Ru on the formation of different TCP phases were investigated in a series of single crystal superalloys. Experimental results showed that more additions of Cr and Mo promoted the TCP phase formation, while Co and Ru played a positive role in improving microstructural stability. It is indicated that σ, P and R phases existed with various morphology and compositions in different experimental alloys during thermal exposure at 1100 ∘C. The content of Co, Cr and Mo in those alloys affected the types of TCP phases significantly, while Ru additions showed a negligible effect. R phase was prone to form in alloys containing high level of Co addition. Meanwhile, the ratio of Cr and Mo content had strong influence on the formation of σ and P phases in alloys containing low level of Co addition. The effects of alloying additions on the elemental partitioning ratios between γ and γ′ phases contributed to their corresponding influence on TCP phase formation.