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Improper layout of drainage structures and inadequate insulation measures in high-altitude cold areas have resulted in varying degrees of frost damage in numerous tunnels during operation. To address this issue and propose a viable drainage structure layout scheme, this paper analyzes and studies the temperature field distribution characteristics of the lower surrounding rock and drainage structure around high-altitude cold tunnels, as well as the layout of the central drainage ditch and anti-cold water leakage hole. Based on physical model test results of cold area tunnels, the distribution characteristics of the temperature field around the tunnel drainage structure under different insulation conditions are obtained, and a control equation of temperature change along the depth direction is proposed. By comparing and analyzing the differences in temperature field and water flow characteristics of drainage structures under different insulation methods, the setting conditions of different drainage structures are determined. Furthermore, the function relationship between the freezing depth of the lower surrounding rock of the tunnel arch and the air temperature inside the tunnel is established, and the curve of the on-site tunnel freezing depth change is predicted. This study provides valuable insights into the design and construction of drainage structures and insulation measures for high-altitude cold tunnels, ultimately contributing to the prevention of frost damage and ensuring safe and efficient tunnel operation.

The purpose of this study was to investigate differences in the pharmacodynamic, pharmacokinetic, and kidney distribution between Ligustri Lucidi Fructus (LLF) and wine-steamed Ligustri Lucidi Fructus (WLL) extracts in diabetic nephropathy (DN) rats. The DN rats were induced by high-fat-sugar diet (HFSD)/streptozotocin (STZ) regimen. For pharmacodynamics, the DN rats were treated with LLF and WLL extracts to assess the anti-diabetic nephropathy effects. For pharmacokinetics and kidney distribution, the concentrations of drugs (hydroxytyrosol, salidroside, nuezhenidic acid, oleoside-11-methyl ester, specnuezhenide, 1‴-O-β-d-glucosylformoside, G13, and oleonuezhenide) were determined. Regarding the pharmacodynamics, LLF and WLL extracts decreased the levels of blood glucose, serum creatinine (SCr), blood urea nitrogen (BUN), and 24-h urinary protein (24-h Upro) in DN rats. Furthermore, LLF and WLL extracts increased the level of high-density lipoprotein cholesterol (HDL-C); decreased the levels of total cholesterol (TC), triglycerides (TG), low-density lipoprotein cholesterol (LDL-C); and reduced levels of pro-inflammatory cytokines (IL-1β, TNF-α, and IL-6) in DN rats. The anti-diabetic nephropathy effect of the WLL extract was better than that of the LLF extract. Regarding the pharmacokinetic and kidney tissue distribution, there were obvious differences in the eight ingredients between LLF and WLL extracts in DN rats. LLF and WLL extracts had protective effects on DN rats, while the WLL extract was better than the LLF extract regarding anti-diabetic nephropathy effects. The pharmacokinetic parameters and kidney distribution showed that wine-steaming could affect the absorption and distribution of the eight ingredients. The results provided a reasonable basis for the study of the clinical application and processing mechanism of LLF.

The use of a flow discharge measuring device in irrigated areas is the key to utilizing water in a planned and scientific manner and to developing water-saving irrigation techniques. In this study, a new type of flow discharge measuring device for a U-channel&mdash, a plate flowmeter&mdash, was designed, and then the hydraulic characteristics of the flow discharge measurement process using the plate flowmeter were simulated and experimentally verified by adopting an RNG (Renormalization Group) k-&epsilon, turbulence model based on Flow-3D software. The results showed that in the process of measuring flow discharge with the plate flowmeter, the transverse flow velocity, the vertical flow velocity, and the relationship between the measured flow discharge and the deflection angle of the angle-measuring plate were basically consistent with the experimental results. The maximum relative errors were 5.3%, 6.2%, and 6.8% respectively, proving that it was feasible to use Flow-3D software to simulate the hydraulic characteristics of the flow discharge measurement process using the plate flowmeter. The vertical flow velocities at the center of the upstream section of the channel increased gradually from the bottom of the channel to the free water surface. The vertical flow velocities at the center of the downstream section of the channel first increased and then decreased from the bottom of the channel to the free water surface, and the maximum vertical flow velocity was located at a position below the free water surface. The maximum range of influence of the plate flowmeter on the flow disturbance in the channel was from 0.75 m upstream to 1.24 m downstream of the plate flowmeter. These results can provide a theoretical basis for optimizing the structural parameters of a plate flowmeter.