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[Objective] To promote efficient utilization and sustainable development of territorial space, this study identified changes in territorial space functions considering different population shrinking characteristics, aiming to explore territorial space optimization strategies in response to population shrinking challenges. [Methods] By integrating multi-source data from county units in Sichuan Province from 2010 to 2020, this study measured population shrinking and territorial space function changes, and delineated territorial space zones based on population shrinking characteristics using elasticity coefficient. [Results] (1) The relationship between population demand and territorial space supply is the main driver of territorial space function formation and development. Population shrinking affects demand, driving changes in agricultural space management, urban space organization, and ecological space management patterns, thereby reshaping the pattern of territorial space functions. (2) Population shrinking in counties of Sichuan Province exhibited significant spatial differences and agglomeration characteristics, with 69.4% of the counties experiencing population shrinkage. This phenomenon was mainly concentrated in peripheral counties outside the central Chengdu area, as well as in most counties in the southern, northeastern, and southwestern parts of Sichuan. The simultaneous change of population quantity and structure, termed “dual shrinking”, was the main type observed. (3) The overall distribution of territorial space functions in counties of Sichuan showed a high in southeast and low in northwest spatial pattern. From 2010 to 2020, 74.9% of the counties experienced an enhancement in territorial space function. (4) Based on population shrinking characteristics, Sichuan’s county territorial space was divided into growth-oriented, extensive, lagging, intensive, declining, and deteriorating types. Territorial space optimization directions were proposed according to the population challenges and territorial space function changes faced by different types of areas. [Conclusion] Incorporating population aging into the measurement system for population shrinking provides a more comprehensive understanding of regional population shrinking characteristics.Future territorial space optimization at the county level in Sichuan Province should integrate population shrinking characteristics and changes in territorial space functions. This optimization should involve territorial space planning, comprehensive land consolidation, and policy support, optimizing agricultural, urban, and ecological spaces to meet the spatial development needs under varying population shrinking characteristics.

Objective To investigate the protective effect of sevoflurane postconditioning against cerebral ischemia/reperfusion (I/R) injury in rats and its mechanism of action. Methods A total of 80 specific pathogen-free healthy adult male Sprague-Dawley rats were selected and randomly divided into sham-operation group (S group), cerebral I/R group (I/R group), cerebral I/R+sevoflurane postconditioning group (ISP group), and cerebral I/R+sevoflurane postconditioning+nuclear factor ery-throid 2-related factor 2 (Nrf2) inhibitor group (ISPB group), with 20 rats in each group. All rats except those in the S group were used to establish a rat model of cerebral I/R injury using the suture method for occlusion of the middle cerebral artery for 2 h, followed by reperfusion for 24 h, and for the rats in the S group, threading was performed below the middle cerebral artery without ligation. The rats in the ISP group were given inhalation of 3% sevoflurane immediately after reperfusion for 30 min, and those in the ISPB group were given intraperitoneal injection of the Nrf2 inhibitor brusatol (2 mg/kg) at 30 min before ischemia in addition to the treatment in the ISP group. After successful modeling, neurological deficit score was used to eval-uate the degree of neurological impairment. Left ventricular blood samples and pathological sections of brain tissue were obtained, and 2,3,5-triphenyltetrazolium chloride staining was used to determine the percentage of cerebral infarct volume; enzyme-linked immunosorbent assay was used to measure the serum levels of inflammatory factors (interleukin-1β [IL-1β] and tumor necrosis factor-α [TNF-α]) and oxidative stress-related factors (malondialdehyde [MDA] and superoxide dismutase [SOD]); Western blotting was used to mea-sure the expression of apoptosis-related proteins (B-cell lymphoma-2 [Bcl-2], Bcl-2 related x [Bax], and Caspase-3) and Nrf2 signaling pathway-related proteins (Nrf2 and heme oxygenase-1 [HO-1]) in brain tissue; immunofluorescence assay was used to measure the expression of Nrf2 inside and outside the nucleus of brain tissue cells. Results Compared with the I/R group, the ISP group had significant reductions in neurological deficit score, the percentage of cerebral infarct volume, the serum levels of IL-1β, TNF-α, and MDA, and the levels of Bax and Caspase-3 in brain tissue (t=5.76-18.39,P

Objective To investigate the protective effect of remimazolam on cerebral nerves in a rat model of cerebral ischemia/reperfusion injury and its mechanism. Methods A total of 50 male Sprague-Dawley rats were randomly divided into sham-operation group (Sham group), cerebral ischemia/reperfusion group (I/R group), I/R+remimazolam (RE) group, I/R+RE+LY294002 (LY) group, and I/R+LY group. Neurological deficit score was used to evaluate the degree of neurological dysfunction. After arterial blood samples and brain tissue pathological sections were collected from the rats in each group, 2,3,5-trip-henyltetrazolium chloride staining was performed for the brain tissue sections to calculate cerebral infarct volume ratio; ELISA was used to measure the serum levels of interleukin-6 (IL-6), interleukin-1β (IL-1β), and tumor necrosis factor-α (TNF-α); Western blotting was used to measure the relative expression levels of protein kinase B (AKT), phosphorylated AKT (p-AKT), nuclear factor-kappa B p65 (NF-κB p65), and phosphorylated NF-κB p65 (p-NF-κB p65) in brain tissue, and then immunofluorescence assay was used to measure the expression level of p-NF-κB p65 inside and outside the nucleus of cells in brain tissue. Results There were significant differences between these groups in cerebral infarct volume ratio, neurological deficit score, the serum levels of IL-6, IL-1β, and TNF-α, the relative expression levels of p-AKT and p-NF-κB p65, p-AKT/AKT ratio, and p-NF-κB p65/NF-κB p65 ratio (F=72.41-654.90,P

Mid‐infrared (MIR) lasers generated by nonlinear optical (NLO) crystals have aroused extensive attention in various military and civilian applications. Among the MIR NLO crystal family, LiInSe2 (LISe) is a promising candidate in the generation of MIR lasers due to its wide transmission range, large bandgap, and high laser‐induced damage threshold. However, the intrinsic defects in LISe induce optical losses, which will induce laser damage and hinder the performance of MIR laser generation. In this work, the mechanism of optical absorption induced by defects is revealed in LISe through transient absorption (TA) spectroscopy. It is verified that the deep‐level defects in LISe give rise to the extra optical absorption, which is owing to the excited state absorption (ESA) and photo‐induced absorption (PIA). Accordingly, for improving the optical properties of LISe crystals, Li2Se vapor‐mediated annealing to reduce defects concentration is rationally designed. The results confirmed that the optical properties of annealed LISe are improved due to the decrease of defects concentration. Ultimately, the performance of MIR laser generation is successfully enhanced by using the annealed LISe crystal. This work provides deep insights into the defect‐induced absorption losses in LISe crystals and promotes the application of LISe crystals in MIR laser generation. [ABSTRACT FROM AUTHOR]

To study the characteristics of nitrogen (N) loss on slopes, different vegetation (bare soil, alfalfa), slopes (5°, 10°, 15°), and rainfall intensities (40, 60, 80 mm/h) were set as variable factors in simulated rainfall experiments. Surface runoff accounts for 60.38–96.16% of total runoff and most N loss (57.69–88.67% of NO3−-N). Alfalfa can reduce average concentrations of N loss in runoff and reduce N loss in surface runoff by more than 48.29%, as well as subsurface runoff by 3.8%. Average N loss in subsurface runoff exceeds that of surface runoff. Rainfall intensity most affects N loss from surface runoff in bare soil conditions, and slope most affects N loss in subsurface runoff. Rainfall intensity in alfalfa treatments most influences runoff volume and N loss. The comprehensive effects of rainfall intensity, slope, and vegetation cover on the total loss of various forms of nitrogen in surface runoff can be described using a linear correlation equation, with a correlation coefficient between 0.84 and 0.91. [ABSTRACT FROM AUTHOR]

Two-dimensional semiconductors, such as MoS2, have demonstrated great potential applications in post-Moore electronic and optoelectronic devices, and organic cations intercalation has been widely utilized to modulate their physical properties. However, the correlation between the conductivity, carrier mobility, carrier density, and structure of organic cations intercalated MoS2 is still unclear. In this Letter, we systematically investigated the structural and electrical transport properties of pristine MoS2 and MoS2 intercalated with various organic cations such as tetradecyltrimethyl-ammonium, tetraheptyl-ammonium, and cetyltrimethyl-ammonium. Semimetal bismuth (Bi) was used as electrodes to make Ohmic contact with MoS2, and four-probe measurements were employed to obtain the intrinsic conductivity of MoS2. The intercalated organic cations greatly expand interlayer spacing and strongly dope MoS2 up to an electron concentration of 6.1 × 1013 cm−2 depending on the size and intercalation amount of organic cations. The severe electron doping constrains the out-of-plane A 1 g vibration mode and screens the Coulomb scattering, such that the intercalated MoS2 has enhanced Hall mobility of >50 cm2 V−1 s−1 at room temperature and even >1700 cm2 V−1 s−1 at 5 K. The intercalated MoS2 responds much faster than pristine MoS2 when functioning as a phototransistor. Our work provides insight for understanding the electrical transport properties of MoS2 and designing more efficient electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

The gas flow temperature signal simulation system (ATSSS) plays a crucial role in the hardware-in-the-loop simulation of hypersonic aircraft. The accuracy of gas flow temperature measurements is of paramount importance for the ATSSS. This system comprises a high-temperature plasma heater, a gas flow mixing chamber, and thermocouples. The ATSSS exhibits specific characteristics such as high temperatures, rapid temperature changes, and fast flow rates. However, due to the large measurement time constant of high-temperature thermocouples, significant dynamic errors are introduced into the measurement results. To address this issue and enhance the dynamic measurement accuracy of gas flow temperature, this study establishes a thermocouple heat transfer model for the ATSSS. It also analyzes the mechanism behind the generation of dynamic errors in the ATSSS and proposes a three-thermocouple coupled temperature measurement dynamic compensation method (TTCTMDC). This method compensates for errors caused by thermal convection, thermal radiation, and thermal conduction under high-temperature conditions. Simulation results demonstrate that the proposed method can reduce errors by 50% to 80%. In addition, an experimental platform for the ATSSS is constructed, and the TTCTMDC method is employed to compensate for measurement errors. The results indicate that the dynamic measurement error can be reduced to 1/4 to 1/2 of the original value using the TTCTMDC method. This research lays a foundation for the successful development of the ATSSS and provides a novel approach to dynamically measuring high-temperature gas flow, thereby advancing scientific research in the field of measurement. [ABSTRACT FROM AUTHOR]