Uv 1780

Nitrogen adsorption–desorption isotherms were collected by using a physisorption analyzer (Autosorb iQ Station 1, Quantachrome Co.) at 77 K held using a liquid nitrogen bath. The multipoint BET method and the slit-pore model-based nonlocal density functional theory method were applied to calculate the specific surface area and the pore width distribution, respectively. Water vapor isotherms were collected using the physisorption analyzer at 298 K. A field-emission scanning electron microscope (SEM, Ultra-55, Zeiss Co.) with an accelerating voltage of 5 kV was used to observe the morphology of samples. An ultrathin gold layer was coated on the prepared sample by using an ion sputter coater to minimize the recharging effect. An atomic force microscope (AFM, Bioscope Catalyst Nanoscope-V, Bruker, USA) was employed to measure the surface roughness of membranes. An ultraviolet absorption experiment was carried out by using an ultraviolet-visible (UV-vis) spectrophotometer (UV-1780, SHIMADZU). An optical contact angle and interface tension meter (ST200KB, USA KINO Industry Co.) was used to investigate the water and blood contact angles of samples. The zeta potential of membranes was measured by using a streaming potential analyzer (SurPASS, Anton Paar, Austria) with the background electrolyte of 1 mmol l⁻¹ KCl solution.

The UV-Vis transmittance was measured using a spectrophotometer (UV-1780, Shimadzu, Japan) with a wavelength from 200–900 nm. The UVA and UVB blocking rates of the composite films were calculated by Equations (1) and (2): $$\mathrm{UVA} \mathrm{blocking}=1-\frac{{{\displaystyle \int }}_{320}^{400}{\mathrm{T}}_{\mathsf{\lambda }}\times \mathrm{d}\mathsf{\lambda }}{{{\displaystyle \int }}_{320}^{400}\mathrm{d}\mathsf{\lambda }}$$
$$\mathrm{UVB} \mathrm{blocking}=1-\frac{{{\displaystyle \int }}_{280}^{320}{\mathrm{T}}_{\mathsf{\lambda }}\times \mathrm{d}\mathsf{\lambda }}{{{\displaystyle \int }}_{280}^{320}\mathrm{d}\mathsf{\lambda }}$$
where T_λ is the average spectral transmittance, d(λ) is the bandwidth, and λ is the wavelength.

Chlorophyll (chl) was extracted using 80% (v/v) acetone, ground into homogenate, and then stored in darkness for 10 min. The samples were centrifuged at 12,500× g for 10 min, and the absorbance of supernatant was measured at 470, 646, and 663 nm with a spectrophotometer (UV-1780, Shimadzu, Japan). The calculation of chlorophyll was as described by Liu [87 (link)]. MDA contents were measured using 5% thiobarbituric acid, as described by the method of Saher [88 (link)].

The fully expanded, mature leaves (n = 10 per population) of two dominant species were randomly collected and stored at 4°C in a refrigerator to measure the physiological parameters (Supplementary Table S1). All absorbance values below are read by a UV–VIS spectrophotometer (SHIMADZU UV-1780).

A series of standard curves of the proline solution were drawn. We accurately weighed 0.2 g of a mixed blade sample, added liquid nitrogen to grind into powder, and then quickly transferred the sample to a test tube. We added 2 cm³ 30 g/dm³ sulfosalicylic acid solution to each test tube, and the homogenate was extracted in a boiling water bath for 10 min after cooling. The sample was centrifuged at 3000× g for 10 min, and the supernatant was the extraction solution of proline.
We took 2 cm³ of supernatant into the tube with a plug, added 1 mL distilled water, 1 mL glacial acetic acid, and 2 cm³ acid ninhydrin reagent, and colored them in a boiling water bath for 1 h. After cooling, 2 cm³ toluene was added to each tube, and the tube was fully shaken for 30 s, and then placed for stratification. The upper toluene solution was absorbed into the colorimetric cup. Toluene was used as a blank control. The absorbance value was determined at 520 nm wavelength of the spectrophotometer (SHIMADZU, UV-1780, Tokyo, Japan). We determined the content of proline in the determination solution from the standard curve, and then calculated the percentage of the proline content in the sample.

Chlorophyll was extracted and quantified by following the method of He and Gan, (2002) (link). Chlorophyll was extracted by using 95% ethanol. The supernatant was measured at 649 and 665 nm using a spectrophotometer (UV-1780, Shimadzu, Japan). Chlorophyll contents were calculated, and mean values were obtained based on three biological replicates.

Soil pH was measured at a water/soil ratio of 2.5:1 using a pH meter (Mettler Toledo FE28-Standard, Switzerland). The total SOC content was determined by the H₂SO₄–K₂Cr₂O₇ external heating method. Available N was determined by the alkali diffusion method. Soil available P was determined by spectrophotometry (Shimadzu UV-1780, Japan) (Shao et al., 2019 (link)). Available K was determined by flame photometry (Chen et al., 2021 (link)). Soil moisture content was measured by the drying method. Soil total C and total N was determined by an elemental analyzer (Euro EA3000, Italy).