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In this paper, in situ V2C-reinforced Cu composites were successfully fabricated by hot pressing at 750 °C under 25 MPa using Cu and V2SnC powders. Due to decomposition of V2SnC to V2C and Sn during sintering, Sn atoms entered the crystal structure of Cu. Therefore, final compositions of composites consisted of Cu(Sn) and V2C phases. Here, copper composites with 0, 5, 10, 20, and 30 vol.% V2C were designed. Their microstructures and physical and mechanical properties were systematically investigated. It was observed that with increasing V2C content, electrical conductivity decreased from 0.589 × 108 S·m−1 to 0.034 × 108 S·m−1 and thermal conductivity decreased from 384.36 W⋅m−1⋅K−1 to 24.65 W·m−1·K−1, while Vickers hardness increased from 52.6 HV to 334 HV. Furthermore, it was found that composites with 20 vol.% V2C had the highest tensile strength (440 MPa). [ABSTRACT FROM AUTHOR]

In this work, θ-Al2O3 whiskers with twins were successfully fabricated by a hydrothermal method followed by annealing at 1000 °C in argon atmosphere using Al2(SO4)3·18H2O, CO(NH2)2 and PEG2000 as initial materials. It is confirmed that precursor of AlO(OH) whiskers is suitable to be used for preparing alumina whiskers when the molar ratio of Al3+:CO(NH2)2 is selected to be 1:6. The mean length of obtained whiskers is 1.5 μm and the average width is 0.1 μm. Interestingly, it is found that the as-prepared θ-Al2O3 whiskers consist of twins with (100) plane as the twin surface, which is ascribed to the phase transformation from tetragonal phase (δ-Al2O3) to monoclinic phase (θ-Al2O3) during the annealing. Additionally, the specific surface area of θ-Al2O3 whiskers is measured to be 38.2 m2/g. [ABSTRACT FROM AUTHOR]

Carbon‐bonded carbon fiber composites (CBCF) are renowned for their lightweight and thermal insulation properties. However, the brittleness and susceptibility to oxidation hinder the widespread application of CBCF. In this work, the carbon‐bonded carbon/quartz hybrid fiber composites (CBCQF) were prepared by pressure filtration and modified by Cr2AlC ceramics. The microstructure, mechanical properties, thermal insulation, and ablation behaviors were investigated. Cr2AlC ceramics notably enhanced the compressive strength of CBCQF in the XY direction and reduced the room‐temperature thermal conductivity in the Z direction. Most importantly, Cr2AlC ceramics significantly improved the ablation resistance of CBCQF. When 40% Cr2AlC ceramics were added, the linear and mass ablation rates of CBCQF were reduced by 38.0% and 93.2%, respectively, compared to the reference sample. Moreover, the study of ablation mechanisms revealed that the improvement in ablation resistance was primarily derived from the formation of the surface protective oxides as well as the reinforcement of oxidation resistance. Overall, this study presents a promising avenue for the application of Cr2AlC ceramics and the modification of fiber composites. [ABSTRACT FROM AUTHOR]

In this work, two new 312 MAX phases of Zr3PbC2 and Hf3PbC2 were successfully synthesized by spark plasma sintering. It is the first discovery of lead‐containing 312 MAX phases, which together with M2PbC (M = Ti, Zr, Hf) form the lead‐containing MAX phase family. Considering the extremely low electrical conductivity of Hf2PbC, these two new compounds are of great research value. Based on the Rietveld refinement results, their lattice parameters and atomic positions were well determined, as a = 3.3771(5) Å, c = 20.0070(9) Å for Zr3PbC2 and a = 3.3357(1) Å, c = 19.7659(8) Å for Hf3PbC2, where M atoms are located at (0, 0, 0) and (1/3, 2/3, 0.1258(6)[Zr]; 0.1255(2)[Hf]), Pb atoms are located at (0, 0, 1/4), and C atoms are located at (1/3, 2/3, 0.0663(2)[Zr]; 0.0641(3)[Hf]), respectively. Additionally, the typical laminar microstructure of Zr3PbC2 and Hf3PbC2 grains was observed. [ABSTRACT FROM AUTHOR]

In this work, hot forging texture of pre-sintered MoAlB ceramics (relative density, 97.9%) were achieved by spark plasma sintering (SPS). The radial compression and lateral expansion rates reached − 54.8% and 25.8%, respectively. The X-ray diffraction results exhibited a preferred orientation of tailored samples. The b -axis of grains were prone to be parallel to the pressure and the grains grew along the a - and c -axis directions. Therefore, the Lotgering orientation factor of f (0 k 0) on the textured top surface (TTS) get 0.66. The properties of tailored MoAlB exhibited obvious anisotropic characteristics. Remarkably, the electrical conductivity perpendicular to the b -axis reached 4.34 × 106 S/m (25 °C). Compared with untextured MoAlB (5.45 MPa·m1/2), the fracture toughness parallel to the b -axis reached 8.04 MPa·m1/2. Additionally, the tailored surface perpendicular to the b -axis presented better oxidation resistance with thinner oxide layer when exposed at 1400 °C for 20 h in air. [ABSTRACT FROM AUTHOR]

In this work the electronic and optical properties of luminescent materials XSiN 2 (X = Ca, Sr, Ba) were revisited based on density function theory (DFT) calculations with a newly developed DFT-1/2 scheme. It was found that the DFT-1/2 correction on nitrogen can well correct the band gaps to approach the experimental values, showing its advantage comparing to the Perdew–Burke–Ernzerhof (PBE) and the Strongly Constrained and Appropriately Normed (SCAN) functionals. Then the electronic band structures and optical properties of the three compounds were investigated using the DFT-1/2 scheme. Within the three compounds, the band gap shows a monotonic decrease along with the atomic number of alkali earth metal mainly due to the downshift of the conduction band edge, where the electronic conductivity is primarily based on electron since it shows a much smaller effective mass than hole. CaSiN 2 owns more flat valence bands, while SrSiN 2 gives lighter electron. Moreover, the three compounds show high optical absorption, but distinct behavior of light absorption and refractivity in specific energy range, suggesting their applications in optical applications. • A more accurate method was chosen to address the band gap of XSiN 2 (X=Ca,Sr,Ba). • The physical properties were computationally investigated using this approach. • The compounds are predicted to be good candidates for luminescent application. [ABSTRACT FROM AUTHOR]

The electronic, mechanical, optical and conductive properties of MgPbN 2 and ZnPbN 2 are investigated using hybrid-functional first-principles calculations. Our calculations show that these two compounds preferentially stabilize in the tetragonal chalcopyrite structure. The calculated phonon dispersions show that both compounds are thermodynamically stable. From the calculated elastic constants we infer that the compound are also mechanically stable. As for the electronic properties, MgPbN 2 is computed to be a semiconductor with a direct band gap of 1.071 eV at the Γ point, while ZnPbN 2 is semi-metallic with the valence band and conduction band crossing at the Γ point. Both MgPbN 2 and ZnPbN 2 show an enhanced optical absorption and electric conductivity compared to those of the related semiconductors MgSnN 2 and ZnSnN 2. ZnPbN 2 gives a much stronger electric conductivity and a slightly larger light absorption than MgPbN 2. In addition the influence of alloying is investigated for Mg 1 − x Zn x PbN 2 at different doping amount. When Mg was doped at 25% level, a band gap of 0.22 eV opens up and turns the system to semiconducting. When Sn was doped at Pb site, a similar phenomena was observed. On the other hand, the electric conductivity will increase with a small amount of Zn doping in MgPbN 2. With large amount of doping, a conductivity higher than that of pristine ZnPbN 2 is achieved. Our investigation widens the knowledge of II-IV-N 2 family of ternary nitrides, and may hence help to boost their applications. • The structures of MgPbN 2 and ZnPbN 2 were computationally identified. • The electronic, optical and conductive properties were investigated using hybrid functional. • The alloying effect was explored for Mg x Zn 1 − x PbN 2 and ZnSn x Pb 1 − x N 2. [ABSTRACT FROM AUTHOR]

Transition metal sulfides and their corresponding derivatives, such as MAX phases, have been widely studied because of their unique physical properties. However, due to the low melting/boiling point and volatile characteristics of sulfur, it is difficult to control the element ratio in their in-situ synthesis, and some impurities are introduced. Based on this, we first studied the reaction mechanism of sulfur-containing MAX phase Hf 2 SB. Previous studies generally believed that the mechanism of MAX phase synthesis is that elements M and X first form compounds and then react with elements A. Interestingly, Hf reacts with sulfur to form Hf 2 S firstly, and then boron enters the octahedral gap between the two layers of hafnium to form Hf 2 SB. Based on the reaction mechanism, Hf 2 SB with a purity of 91.99 wt% and its corresponding sulfide Hf 2 S with a purity of 96.75 wt% were successfully and rapidly synthesized by thermal explosion synthesis using a spark plasma sintering furnace. The microstructure of the sample fractured surface was observed by scanning electron microscopy, which confirmed that the Hf 2 SB grains were in lath shape, that is, the typical grain shape of MAX phases. The crystal structure and atomic positions of Hf 2 SB and Hf 2 S were obtained accurately, and the similar structure between them confirms our conclusion on the reaction mechanism. [ABSTRACT FROM AUTHOR]

The out-of-plane ordered structure endows the o -MAX phase with more excellent properties and the derivative o -MXene with more promising applications. However, too few types of o -MAX and o -MXene have been synthesized for studying, significantly limiting their promising applications. In this work, two new high-purity o -MAX phases, Mo 2 VAlC 2 and Mo 2 V 2 AlC 3 , were successfully synthesized using an solid-phase reaction method and their ordered structures were demonstrated. The lattice parameters, X-ray diffraction data, and microstructure of these two o -MAX phases were clearly determined. Meanwhile, two new o -MXene, Mo 2 VC 2 T x and Mo 2 V 2 C 3 T x , were also obtained by etching the o -MAX powders in HF solution, which would expand their further interesting researches. [ABSTRACT FROM AUTHOR]

• Computationally investigated the nanotubes of a new graphene-like phase of MgGeN2. • The band gap and conductivity show strong dependence on the orientation and tube diameter. • The electronic structure hints potential application for energy harvest, optoelectronics and photocatalysis. MgGeN 2 is a type II-IV-V 2 semiconductor with a wide band gap which have previously been studied in bulk, monolayer, and multilayer form. We have investigated single wall MgGeN 2 nanotubes in different orientations and diameters by ab initio calculations. It was found that the band gap is strongly dependent on the type and diameter of the tubes, ranging from 2.1 to 2.6 eV. Moreover, the migration of electrons is favored instead of holes. The obtained results also suggest that the radius- and orientation-dependent single wall MgGeN 2 nano tubes are promising for optoelectronics and photocatalysis. [ABSTRACT FROM AUTHOR]

Present work showed that Ti 3 SiC 2 ceramic has good ablation resistance at 1600 °C. The mass ablation rate and linear ablation rate after exposure to plasma flame for 120 s are −0.23 mg/s and 5.58 μm/s, respectively. After ablation for 120 s, the micro-morphologies of cross section of the ablation fringe show that the ablation layer was divided into four-layers: an oxide outer layer, a porous layer, a decomposition layer, and the matrix layer. The formation of porous layer is mainly related to the Ti vacancies caused by the outward diffusion of Ti ions, and outward diffusion of gaseous SiO and CO. The dense and large grain-sized TiO 2 oxide layer is dismembered by the generated SiO 2 to form a fine-structured TiO 2 and SiO 2 mixture. The solid-liquid mixed oxide layer is quickly blown away under the shearing force of plasma flow, resulting in a significant increase of linear ablation rate. [ABSTRACT FROM AUTHOR]

In this study, a new type of highly porous ceramic was successfully fabricated from α-Al 2 O 3 whiskers and nano-sized Al 2 O 3 particle slurry by vacuum infiltration with the subsequent annealing in air. It was found that with an increase in the alumina slurry amount or sintering temperature, the porosity of the foam ceramic decreased while its compressive strength increased. The optimal alumina slurry content and sintering temperature were equal to 4 g, and 1350 °C, respectively. The as-synthesised porous foam ceramic exhibited a low density of 0.65 g/cm3, high porosity of 83.51%, high compressive strength of 3.84 MPa, and low thermal conductivity of 1.37 W/m⋅K at room temperature, suggesting its potential applications in high-temperature gas filtration and thermal insulation materials. [ABSTRACT FROM AUTHOR]

In this work, MoAlB samples for plasma exposure test were condensed by spark plasma sintering at 1200 °C for 10 min. Ablation resistance of MoAlB ceramic was investigated in a plasma torch facility for about 30 s at high temperature range of ∼1670−2550 °C, which provided a quasi-real hypersonic service environment. The results showed that the linear ablation rate was increased from 0 μm/s at ∼1670 °C to 86.4 μm/s at ∼2550 °C. At ∼1670 °C, the ablated surface of MoAlB ceramic was covered by Al 2 O 3 layer, presenting excellent ablation resistance. At ∼2220 °C, the macroscopic cracks were induced by thermal stress, which opened up channels for the inward diffusion of oxygen and deteriorated the ablation resistance of the substrate. Above ∼2400 °C, the volatile MoO 3 and B 2 O 3 and the erosion of viscous oxides by the high shearing force of plasma stream were the main ablation mechanisms. [ABSTRACT FROM AUTHOR]

Vanadium dioxide (VO 2) is a promising thermally induced phase transition material because of the abrupt changes in electrical and optical properties. However, the high phase transition temperature of VO 2 and its unspecified modulation relationship need to be resolved urgently. Herein, we proposed a simple and precise regulation criterion for VO 2 materials based on size-dependent lattice distortion rate and Born theory. The results indicated that the application of a tensile stress changed the elastic properties of the VO 2 , which promoted VO 2 phase transition, and regulated the phase transition temperature. Moreover, the specific modulation relationship between the stress and phase transition temperature of VO 2 was confirmed experimentally. These results show that our criterion provides theoretical guidance to regulate VO 2 thermally induced phase transition materials. [ABSTRACT FROM AUTHOR]

A novel Mg-8Gd-2Y-1.5Zn-1Mn (GYZ-1Mn, wt.%) alloy with extraordinary high-temperature mechanical properties was developed by introducing RE/Zn segregation on α-Mn nanoparticles. Its ultimate tensile stress (UTS) and yield stress (YS) are 312 MPa and 248 MPa at 300 ℃, which are 87 MPa and 52 MPa higher than the highest strengths of other Mg-Gd-Y-Zn alloys reported in the previous literature. The outstanding performance of GYZ-1Mn alloy was associated with the segregation of RE/Zn atoms on the α-Mn nanoparticles, which facilitated the formation of fine lamellar long period stacking ordered (LPSO) phase and impeded the coarsening of α-Mn. Consequently, retarded dynamic recrystallization behavior occurred in the GYZ-1Mn, resulting in fine grain size, high density of geometrically necessary dislocations and strong fiber texture intensity to strengthen the high-temperature mechanical properties. Hence, this work paved a novel path for the development of heat-resistant Mg alloys by introducing elemental segregation on nanoparticles. [Display omitted] [ABSTRACT FROM AUTHOR]

• Computationally investigated ZnGeN 2 and CdGeN 2 under uniaxial compression. • Phase transition occurs and arrives at layered high pressure phase. • The band gap increases along with compression and decreases due to the formation of new inter-layer bonds. Ternary nitrides ZnGeN 2 and CdGeN 2 were computationally investigated under uniaxial compressions in [100] direction using first principles calculations. Phase transition from Pna 2 1 to Pnma structure occurs for ZnGeN 2 , while CdGeN 2 transforms to a quasi-layered Pna2 1 structure with distorted in-plane hexagons. For both the compounds, the band gap first increase and then decrease along with increasing compression. However, the band gap of ZnGeN 2 monotonically increases until the phase transition occurs at 70 GPa and then decreases, while CdGeN 2 shows a maxima around 30 GPa followed with a reduction. Moreover, for both the compounds, the band gap transforms from direct to indirect under uniaxial compression, and the electron correlation becomes weaker and weaker. It was also confirmed that the compressed structures of ZnGeN 2 and CdGeN 2 will restore their initial structures at ambient conditions when removing the compression, which differs to the cases of MgGeN 2 and MgSnN 2. [ABSTRACT FROM AUTHOR]

• Co@N-doped carbon was prepared for H 2 S selective oxidation for the first time. • Co@N-doped carbon showed a nearly 100% H 2 S conversion at 190 °C for 28 h. • O 2 activation and H 2 S adsorption of the catalyst contributed to the high activity. H 2 S selective catalytic oxidation, regarded as a green purification technology, has attracted much attention due to its ability to convert H 2 S to elemental S directly without thermodynamic limitation. Herein, we report for the first time that Co nanoparticles (NPs) with different Co content were encapsulated by N-doped graphitic carbon (3–5 layers) for H 2 S selective oxidation. The catalytic performance of Co@NC catalysts increases at first and then decreases by increasing the content of Co. It is found that Co@NC-4 with a suitable Co content shows an optimal H 2 S conversion ratio of nearly 100% with the weight hourly space velocity of 18000 mL g−1 h−1 at 190 °C for 28 h. This high performance may be due to optimal mesopore size and abundant pyridinic N. In contrast, NC sample without Co has conversed nearly 95% of H 2 S at 250 °C. The theoretical calculation indicates that N-doped graphene can regulate the electron density around the Co NPs, which promotes the adsorption of H 2 S. We believe that the unique electronic and geometrical configurations improve the activity and stability. Our finding provides a new reference for the study of H 2 S selective oxidation. [ABSTRACT FROM AUTHOR]

Developing green and efficient preparation strategies is a persistent pursuit in the field of 2D transition metal nitrides and/or carbides (MXenes). Traditional etching methods, such as HF-based or high-temperature Lewis-acid-molten-salt etching route, require harsher etching conditions and exhibit lower preparation efficiency with limited scalability, severely constraining their commercial production and practical application. Here, an ultrafast low-temperature molten salt (LTMS) etching method is presented for the large-scale synthesis of diverse MXenes within minutes by employing NH 4 HF 2 as the etchant. The increased thermal motion and improved diffusion of molten NH 4 HF 2 molecules significantly expedite the etching process of MAX phases, thus achieving the preparation of Ti 3 C 2 T x MXene in just 5 minutes. The universality of the LTMS method renders it a valuable approach for the rapid synthesis of various MXenes, including V 4 C 3 T x , Nb 4 C 3 T x , Mo 2 TiC 2 T x , and Mo 2 CT x . The LTMS method is easy to scale up and can yield more than 100 g Ti 3 C 2 T x in a single reaction. The obtained LTMS-MXene exhibits excellent electrochemical performance for supercapacitors, evidently proving the effectiveness of the LTMS method. This work provides an ultrafast, universal, and scalable LTMS etching method for the large-scale commercial production of MXenes., (© 2024 Wiley‐VCH GmbH.)

Herein, we propose a platinization strategy for the preparation of Pt/X catalysts with low Pt content on substrates possessing electron-rich sites (Pt/X: X = Co 3 O 4 , NiO, CeO 2 , Covalent Organic Framework (COF), etc.). In examples with inorganic and organic substrates, respectively, Pt/Co 3 O 4 possesses remarkable catalytic ability toward HER, achieving a current density at an overpotential of 500 mV that is 3.22 times higher than that of commercial Pt/C. It was also confirmed by using operando Raman spectroscopy that the enhancement of catalytic activity was achieved after platinization of the COF, with a reduction of overpotential from 231 to 23 mV at 10 mA cm -2 . Density functional theory (DFT) reveals that the improved catalytic activity of Pt/Co 3 O 4 and Pt/COF originated from the re-modulation of Pt δ+ on the electronic structure and the synergistic effect of the interfacial Pt δ+ /electron-rich sites. This work provides a rapid synthesis strategy for the synthesis of low-content Pt catalysts for electrocatalytic hydrogen production.

Objective: To investigate the effect of ultra-early enteral nutrition (UEEN) support on the prognosis of young and middle-aged postoperative patients with cerebral hemorrhage., Methods: The clinical data of young and middle-aged patients (aged 18-59 years) admitted to Tianjin Fifth Central Hospital from January 2020 to June 2023 after surgery for intracerebral hemorrhage were retrospectively analyzed, and the general data, nutritional indexes, gastrointestinal complications, neurological function recovery and long-term prognosis of the patients were recorded. According to the time of initiation of enteral nutrition (EN) support, patients were divided into UEEN group (EN implementation within 12 hour after surgery) and early enteral nutrition (EEN) group (EN implementation within 24 to 48 hour after surgery). The differences of the above indexes between the two groups were analyzed and compared., Results: A total of 64 young and middle-aged postoperative patients with cerebral hemorrhage were enrolled, including 32 cases in the UEEN group and 32 cases in the EEN group. There were no significant differences in gender, age, proportion of hypertension and diabetes, Glasgow coma score (GCS) on admission and surgical methods between the two groups. In terms of nutritional indexes, serum total protein, albumin and hemoglobin levels of patients in both groups on day 7 after admission were lower than those on day 1, and higher than those on day 3, and the above indexes levels in UEEN group were significantly higher than those in EEN group on day 7 [total protein (g/L): 63.05±5.79 vs. 59.02±6.63, albumin (g/L): 40.40±5.26 vs. 37.66±4.63, hemoglobin (g/L): 133.33±12.58 vs. 123.80±22.12, all P < 0.05]. In terms of gastrointestinal complications, the incidence of stress ulcer in the UEEN group within 14 days after admission was significantly lower than that in the EEN group [12.5% (4/32) vs. 31.3% (10/32), P < 0.05], but there was no statistically significant difference in feeding intolerance symptoms between the two groups. In terms of neurological recovery and long-term prognosis, GCS scores and Barthel index scores of 14 days after admission were higher than those of 1 day after admission, but there was no statistical significance between the two groups. Six months after surgery, Glasgow outcome scale (GOS) and Barthel index score of the UEEN group were significantly higher than those of the EEN group (GOS score: 3.81±1.06 vs. 3.18±1.07, Barthel index score: 60.78±7.24 vs. 54.52±5.13, both P < 0.05)., Conclusions: UEEN support can improve the nutritional level of young and middle-aged postoperative patients with cerebral hemorrhage, reduce the occurrence of postoperative gastrointestinal complications, promote the recovery of neurological function, and improve the long-term prognosis.

The unsatisfactory adsorption and activation of CO 2 suppress electrochemical reduction over a wide potential window. Herein, the built-in electric field (BIEF) at the CeO 2 /In 2 O 3 n-n heterostructure realizes the C 1 (CO and HCOO - ) selectivity over 90.0% in a broad range of potentials from -0.7 to -1.1 V with a maximum value of 98.7 ± 0.3% at -0.8 V. In addition, the C 1 current density (-1.1 V) of the CeO 2 /In 2 O 3 heterostructure with a BIEF is about 2.0- and 3.2-fold that of In 2 O 3 and a physically mixed sample, respectively. The experimental and theoretical calculation results indicate that the introduction of CeO 2 triggered the charge redistribution and formed the BIEF at the interfaces, which enhanced the interfacial adsorption and activation of CO 2 at low overpotentials. Furthermore, the promoting effect was also extended to CeO 2 /In 2 S 3 . This work gives a deep understanding of BIEF engineering for highly efficient CO 2 electroreduction over a wide potential window.

MAX phases have great research value and application prospects, but it is challenging to synthesize the MAX phases containing Cd and Sb for the time being. In this paper, we confirmed the existence of the 312 MAX phases of Zr 3 CdC 2 and Zr 3 SbC 2 , both from theoretical calculations and experimental synthesis. The Zr 3 AC 2 (A = Cd, Sb) phase was predicted by the first-principles calculations, and the two MAX phases were confirmed to meet the requests of thermal, thermodynamic, and mechanical stabilities using formation energy, phonon dispersion, and the Born-Huang criteria. Their theoretical mechanical properties were also systematically investigated. It was found that the elastic moduli of Zr 3 CdC 2 and Zr 3 SbC 2 were 162.8 GPa and 164.3 GPa, respectively. Then, differences in the mechanical properties of Zr 3 AC 2 (A = Cd, In, Sn, and Sb) were explained using bond layouts and charge transfers. The low theoretical Vickers hardness of the Zr 3 CdC 2 (5.4 GPa) and Zr 3 SbC 2 (4.3 GPa) phases exhibited excellent machinability. Subsequently, through spark plasma sintering, composites containing Zr 3 CdC 2 and Zr 3 SbC 2 phases were successfully synthesized at the temperatures of 850 °C and 1300 °C, respectively. The optimal molar ratio of Zr:Cd/Sb:C was determined as 3:1.5:1.5. SEM and the EDS results analysis confirmed the typical layered microstructure of Zr 3 CdC 2 and Zr 3 SbC 2 grains.

Objective: To explore the characteristics of the changes in risk score for intensive care unit (ICU) patients during hospitalization by the intelligent calculation method, and to provide evidence for the risk prevention., Methods: In this retrospective study, ICU patients of the Fifth Central Hospital in Tianjin from November 3, 2021 to March 28, 2022 were enrolled and divided into ≥ 14 days group, 10-13 days group, 7-9 days group, and 3-6 days group according to the ICU length of stay. Risk scores assessed by the intelligent calculation method of the ICU patients were collected, including nutritional risk screening 2002 (NRS 2002), Caprini score and Padua score. NRS 2002 score for all patients, Caprini score for surgical patients and Padua score for internal medicine patients were selected. Trends in change of each score were compared between patients admitted to ICU 1, 3, 7 (if necessary), 10 (if necessary), and 14 days (if necessary)., Results: A total of 138 patients were involved, including 79 males and 59 females, with an average age of (61.71±18.86) years and an average hospital stay of [6.00 (4.00, 9.25)] days. (1) in the group with ICU length of stay ≥ 14 days (21 cases): there was no significant change in the NRS 2002 scores of the patients within 10 days, but the NRS 2002 score was significantly decreased in 14 days as compared with 1 day [3.00 (2.50, 3.50) vs. 4.00 (3.00, 5.00), P < 0.05]; both Caprini and Padua score were increased with prolonged hospital stay and compared with 1 day, the scores at the other time points were significantly increased, especially at 14 days [Caprini score: 5.00 (3.25,7.00) vs. 2.50 (1.25, 5.50), Padua score: 6.00 (6.00, 7.00) vs. 3.00 (1.00, 3.00), both P < 0.05]. (2) in the group with ICU length of stay from 10-13 days (15 cases): with the prolonged hospital stay, there was no significant change in NRS 2002 score, but both Caprini and Padua score were increased at 3, 7, 10 days, especially at 10 days [Caprini score: 3.00 (2.00, 4.75) vs. 2.00 (0.25, 2.75), Padua score: 5.00 (3.50, 6.00) vs. 2.00 (0.50, 4.00), both P < 0.05]. (3) in the group with ICU length of stay from 7-9 days (23 cases): compared with 1 day, the NRS 2002 score at 3 days and7 days were decreased, but the Caprini and Padua score were increased, especially at 7 days [NRS 2002 score: 2.00 (1.00, 4.00) vs. 2.00 (2.00, 4.00), Caprini score: 3.00 (2.00, 5.50) vs. 2.00 (0.25, 3.00), Padua score: 5.00 (4.00, 6.00) vs. 2.00 (0,2.00),all P < 0.05]. (4) in the group with ICU length of stay from 3-6 days (79 cases): compared with 1 day, the NRS 2002 score at 3 days was decreased [NRS 2002 score: 2.00 (1.00, 3.00) vs. 2.00 (1.00, 3.00), P < 0.05], Caprini and Padua score were significantly increased [Caprini score: 3.00 (2.00, 4.00) vs. 2.00 (1.00, 3.00), Padua score: 5.00 (4.00, 5.00) vs. 2.00 (1.00, 3.00), both P < 0.05]., Conclusions: Based on dynamic assessment of intelligent calculation methods, the risk of thrombosis in ICU patients increased with hospital length of stay, and the nutritional risk was generally flat or reducing in different hospitalization periods.

Quasi-solid-state Zn-air batteries are usually limited to relatively low-rate ability (<10 mA cm -2 ), which is caused in part by sluggish oxygen electrocatalysis and unstable electrochemical interfaces. Here we present a high-rate and robust quasi-solid-state Zn-air battery enabled by atomically dispersed cobalt sites anchored on wrinkled nitrogen doped graphene as the air cathode and a polyacrylamide organohydrogel electrolyte with its hydrogen-bond network modified by the addition of dimethyl sulfoxide. This design enables a cycling current density of 100 mA cm -2 over 50 h at 25 °C. A low-temperature cycling stability of over 300 h (at 0.5 mA cm -2 ) with over 90% capacity retention at -60 °C and a broad temperature adaptability (-60 to 60 °C) are also demonstrated., (© 2022. The Author(s).)

This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange-correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear-electronic orbital method, and several different energy decomposition analysis techniques. High-performance capabilities including multithreaded parallelism and support for calculations on graphics processing units are described. Q-Chem boasts a community of well over 100 active academic developers, and the continuing evolution of the software is supported by an "open teamware" model and an increasingly modular design.

We demonstrate a charge transfer boosted hydrogen (H2) evolution of transition metal oxides via a Schottky junction. The FeNi and metallic defect-rich CoFe2O4 (DCF) as well as semiconducting nitrogen-doped carbon (NC), named as FeNi/DCF/NC, possessed only 6.5% charge transfer resistance of DCF. Theoretical calculations indicate that the enhanced electron movement happened from FeNi/DCF to NC. The H2 evolution activity of FeNi/DCF/NC showed 5.8-fold improvement compared to that of DCF at the overpotential of 400 mV in 1.0 M KOH. This work provides an effective way to enhance the electrocatalytic activity of oxides for the H2 evolution reaction and related reactions.

Objective: To compare the therapeutic effect of fluid resuscitation strategy guided by pulse-indicated continuous cardiac output (PiCCO) monitoring and early goal-directed therapy (EGDT) on renal function of acute kidney injury (AKI) patients caused by septic shock., Methods: Septic shock patients with AKI admitted to the intensive care unit (ICU) of Tianjin Fifth Central Hospital and Teda International Cardiovascular Hospital from March 2017 to February 2020 were enrolled. All patients were given fluid resuscitation. Patients were divided into PiCCO-guided fluid resuscitation group [PiCCO group, intrathoracic blood volume index (ITBVI) was maintained between 850-1 000 mL/m 2 ] and EGDT-guided fluid resuscitation group [EGDT group, central venous pressure (CVP) was maintained between 8-12 mmHg (1 mmHg = 0.133 kPa) or CVP ≤ 15 mmHg when patients received mechanical ventilation (MV)] according to both the patient's condition and the informed consent of the patient's family. The changes of heart rate (HR), mean arterial pressure (MAP), CVP, blood lactic acid (Lac), fluid balance, urine volume and serum creatinine (SCr) at 6, 24, and 48 hours after fluid resuscitation in the two groups were observed, and the renal replacement therapy (RRT), duration of MV, length of ICU stay and 28-day mortality between the two group were compared., Results: (1) A total of 94 patients were enrolled, including 51 in the EGDT group and 43 in the PiCCO group. There was no significant difference in gender, age, acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, procalcitonin (PCT), HR, MAP, CVP, Lac or SCr at ICU admission between the two groups. (2) The parameters of hemodynamics, fluid balance, urine volume and SCr were improved with the time of resuscitation in the two groups, and there was no significant difference in HR, MAP or Lac between the two groups. Compared with the EGDT group, the CVP decreased significantly at 24 hours and 48 hours after fluid resuscitation in the PiCCO group (mmHg: 9.1±0.9 vs. 12.0±1.3 at 24 hours, 8.0±1.0 vs. 10.2±1.3 at 48 hours), the fluid balance significantly decreased (mL: 2 929.8±936.3 vs. 3 898.4±923.5 at 24 hours, 3 143.5±1 325.4 vs. 4 843.8±1 326.7 at 48 hours), and the condition of urine volume and SCr were better in the PiCCO group [urine volume (mL×kg -1 ×h -1 ): 1.02±0.21 vs. 0.79±0.14 at 24 hours, 1.28±0.18 vs. 0.94±0.22 at 48 hours; SCr (μmol/L): 145.7±37.6 vs. 164.3±46.4 at 24 hours, 128.4±33.6 vs. 143.5±37.7 at 48 hours), with significant differences (all P < 0.05). (3) Compared with the EGDT group, the rate of RRT in the PiCCO group was lower [11.6% (5/43) vs. 17.6% (9/51)], the duration of MV and the length of ICU stay were shorter [duration of MV (days): 4.64±1.31 vs. 6.50±2.19, length of ICU stay (days): 10.35±3.50 vs. 14.50±5.78), with significant differences (all P < 0.05). There was no significant difference in the 28-day mortality between the PiCCO group and EGDT group [14.0% (6/43) vs. 15.7% (8/51), P > 0.05]., Conclusions: Fluid resuscitation strategy guided by PiCCO in septic shock patients with AKI can reduce the amount of fluid load, improve renal function, shorten the MV duration and length of ICU stay, and shows clinical significance.

Objective: To investigate the changes and clinical significance of blood coagulation function and von Willebrand factor antigen (vWF:Ag) in patients with HELLP syndrome (hemolysis, elevated liver function, low platelet count)., Methods: The clotting data of patients with severe preeclampsia and HELLP syndrome (observation group) admitted to the department of critical care medicine of the Fifth Center Hospital in Tianjin from May 2015 to December 2019 were retrospectively analyzed, and normal late pregnancy women with the same period were enrolled as the control group. The coagulation indexes such as prothrombin time (PT), activated partial thrombin time (APTT), antithrombin (AT), fibrinogen (Fib), D-dimer and plasma vWF:Ag level were compared between the two groups, and among patients with HELLP syndrome with different disease degree., Results: (1) Sixty-five patients with HELLP syndrome and 65 normal pregnant women with third trimester were included. Both groups were women of childbearing age, and there were no significant difference in the baseline data. (2) The levels of Fib, D-dimer in both groups increased, but they were significantly higher in the observation group than those in the control group [Fib (g/L): 4.94 (4.76, 5.85) vs. 3.58 (2.97, 4.14), D-dimer (mg/L): 3.34 (2.55, 4.32) vs. 1.72 (1.29, 2.08), both P < 0.05], the AT was obviously reduced [62.00 (49.00, 73.00)% vs. 97.50 (90.75, 107.00)%, P < 0.01], and both PT and APTT were in the normal reference range in the two groups. In addition, the plasma vWF:Ag level in the observation group was significantly higher than that in the control group [516.50 (467.20, 563.00)% vs. 246.45 (189.95, 274.10)%, P < 0.01]. (3) According to thrombocytopenia, among the 65 patients with HELLP syndrome, 26 cases were mild [platelet count (PLT) > 100×10 9 /L], 22 cases were moderate [PLT (50-100)×10 9 /L], and 17 cases were severe (PLT < 50×10 9 /L). With the aggravation of the disease, the D-dimer, Fib, vWF:Ag levels in the mild, moderate, severe patients significantly increased, while the AT level significantly decreased, and there was statistically significant difference between the two groups [D-dimer (mg/L): 2.63 (2.60, 2.73), 3.15 (2.55, 3.73), 3.84 (3.52, 4.23); Fib (g/L): 4.23 (4.06, 4.47), 4.72 (4.34, 5.04), 5.43 (5.14, 5.76); vWF:Ag: 465.20 (437.20, 495.40)%, 500.10 (472.40, 534.50)%, 543.50 (521.30, 563.00)%; AT: 67.50 (61.60, 78.00)%, 63.70 (53.30, 70.40)%, 54.40 (44.00, 61.20)%; all P < 0.05]., Conclusions: Patients with HELLP syndrome may show hypercoagulability and excessive expression of peripheral blood vWF:Ag level, which can induce platelet aggregation, leading to thrombocytopenia and thrombotic microangiopathy, and the clinicians should pay attention to that.

The graphitic carbon nitride (g-C 3 N 4 ) is a promising layered two-dimension material with an opened bandgap. It is of interest to explore the tunability of the bandgap together with the magnetism by doping transition metal atoms. In this work, we investigated the transition metals (Mn, Fe, Co, Ni) and their hydroxides doped g-C 3 N 4 monolayers. The electron correlations between the 3 d electrons of the doped transition metal atoms are self-consistently calculated and analyzed based on the density functional theory. The magnetism, electronic band structures and optical properties are systematically investigated. It reveals that the transition metal doped g-C 3 N 4 is ferromagnetic (FM) state at small doping concentration, where the two spins show different bandgaps. When the doping is high enough, it turns to metallic antiferromagnetic (AFM) state except that Mn doped g-C 3 N 4 is metallic FM state. On another hand, the system shows variable absorption spectra at different doping level. When the vacancy sites are fully occupied, a large absorption peak appears around 1.5 eV suitable for visible light. Moreover, within the transition metal hydroxides doped g-C 3 N 4 , the global ground state shows as AFM, and the absorption spectra within low energy range is distinct due to the presence of hydroxyl group. Therefore, doping with transition metal atoms and hydroxides can effectively tune the bandgap, magnetism and optical properties of g-C 3 N 4 so as to promote its applications., (© 2020 IOP Publishing Ltd.)

Objective: To compare the effects of freshwater and seawater drowning on sheep's pulmonary circulation hemodynamics and respiratory mechanics., Methods: According to the random number table method, healthy crossbred sheep were divided into freshwater drowning group (n = 12) and seawater drowning group (n = 12). 30 mL/kg of freshwater or seawater was infused respectively through trachea for approximately 5 minutes. Before the drowning, immediately after drowning, and 30, 60, 120 minutes after drowning, the systemic circulation hemodynamic parameters [heart rate (HR), mean arterial pressure (MAP), cardiac output (CO)] were monitored by pulse indicator continuous cardiac output (PiCCO); the respiratory parameters were obtained through the ventilator, including tidal volume (VT), lung compliance (Cdyn), oxygenation index (PaO 2 /FiO 2 ), peak airway pressure (Ppeak)]; PiCCO and the right heart floating catheter (Swan-Ganz catheter) was used to measure pulmonary hemodynamic parameters [pulmonary systolic pressure (PAS), pulmonary diastolic pressure (PAD), pulmonary artery wedge pressure (PAWP), and extravascular lung water (EVLW)]. The animals were sacrificed at the end of the experiment, and the amount of residual water in the respiratory tract was measured; the pathological changes in the lung tissue were observed by hematoxylin-eosin (HE) staining., Results: (1) Systemic circulation hemodynamics: compared with the values before drowning, HR, MAP, and CO at the time of immediately after drowning in both freshwater and seawater were significantly increased and peaked. In addition, all indicators in the freshwater drowning group were significantly higher than those in the seawater drowning group [HR (bpm): 170.75±1.87 vs. 168.67±2.27, MAP (mmHg, 1 mmHg = 0.133 kPa): 172.92±1.62 vs. 159.42±3.18, CO (L/min): 13.27±0.71 vs. 10.33±0.73, all P < 0.05]. (2) Respiratory parameters: compared with values before drowning, PaO 2 /FiO 2 , VT, and Cdyn decreased immediately in both freshwater and seawater drowning groups, Ppeak was significantly increased; in addition, the values in the seawater drowning group were decreased or increased more significantly than freshwater drowning group [PaO 2 /FiO 2 (mmHg): 37.83±1.99 vs. 60.42±5.23, VT (mL): 86.25±7.66 vs. 278.75±9.67, Cdyn (mL/cmH 2 O): 8.86±0.33 vs. 23.02±0.69, Ppeak (cmH 2 O, 1 cmH 2 O = 0.098 kPa): 42.17±2.69 vs. 17.67±1.15, all P < 0.01]. In addition, PaO 2 /FiO 2 in the freshwater drowning group was gradually increased over time, while the seawater group continued to decline. (3) Pulmonary circulation hemodynamic parameters: PAS, PAD, PAWP at the time of immediately after drowning in both freshwater and seawater groups were significantly higher than before drowning; in addition, the freshwater drowning group was significantly higher than the seawater drowning group [PAS (mmHg): 34.58±2.87 vs. 26.75±1.66, PAD (mmHg): 27.25±1.22 vs. 16.75±0.87, PAWP (mmHg): 27.83±1.85 vs. 11.75±1.82, all P < 0.01]. Thereafter, PAS and PAD in the freshwater drowning group gradually decreased, while the parameters in the seawater drown group continued to increase. PAWP gradually decreased after freshwater or seawater drowning, and recovered to pre-drowning levels 120 minutes after drowning and 30 minutes after drowning, respectively. EVLW continued to increase after freshwater drowning, reaching a peak at 30 minutes, and then decreased, until 120 minutes after drowning was still significantly higher than that before drowning (mL/kg: 10.73±1.27 vs. 7.67±0.69, P < 0.01); EVLW could not be measured. (4) Residual water in the respiratory tract: residual water in the freshwater drowning group was significantly less than that in the seawater drowning group (mL: 164.33±25.21 vs. 557.33±45.23, P < 0.01). (5) HE staining: partial alveolar atrophied in the freshwater drowning group, some alveolar spaces were broken, alveolar spaces and alveolar cavity showed a little powdery substance deposition; it was noted that alveolar expanded in the seawater drowning group, alveolar spaces were broken and bleeding and edema were obvious in the interstitial space., Conclusions: The effect of seawater drowning on the respiratory mechanics and pulmonary circulation of animals is more obvious than that of freshwater drowned animals, and the amount of residual water in the respiratory tract is also significantly more than that of freshwater drowned animals.

PtSe 2 is an emerging layered two-dimensional material of applied interest. Its monolayer shows promising properties for applications in electronic devices, while the bandgap of a multilayer PtSe 2 film can be tuned via changing its thickness. In this work the bilayer PtSe 2 thin films are investigated as an example of structural engineering with first-principles calculations. Various van der Waals corrections schemes are firstly discussed, and the optB86b scheme shows a better description of the semiconductor-metal transition for PtSe 2 films. Six bilayer PtSe 2 thin films in different stacking modes are constructed in order to structurally tune the electronic and transport properties. The bandgap can be effectively broadened with the structural engineering for wider potential applications. The carrier mobility, dynamical stability and Raman spectra are also calculated and discussed.

The construction of van der Waals heterostructures is deemed to be a novel scheme to circumvent the shortcomings of their components and bear potentials for applications in electronic devices. Here we systematically investigate the structural and electronic properties of a monolayer MnPSe 3 /MoTe 2 heterostructure with the first principles calculations. The heterostructure stablizes in the antiferromagnetic state and possesses a typical type-II band alignment, with which the photoexcited electrons and holes can be effectively separated and their fast recombination can hence be suppressed. Meanwhile, an inherent electric field is observed at the interface between MnPSe 3 and MoTe 2 . Interestingly, the band gap of the heterostructure shows a quasi-linear dependence on the external electric field applied, and is tunable within the semiconductor to semimetal range. The tunability with applied strain is also investigated and discussed.

The surface hydroxyls on SiC nanosheets provide local protons, stabilize intermediates and localize photogenerated electrons in the deep photoreduction of CO2, significantly promoting the efficiency and selectivity of CH4 yield. This study describes the surface reaction for selective CO2 reduction based on both thermodynamic and kinetic requirements.

Objective: To compare the systemic pathologic physiology parameter changes in sheep drowning in freshwater and seawater., Methods: The experimental animals were healthy crossbred sheep. According to the envelope method, 24 sheep were randomly divided into two groups, with 12 animals in each group. The animals in both groups were subjected to mechanical ventilation and analgesia and sedation, the drowning models were reproduced by injecting 10-25 mL/kg of seawater or freshwater into the endotracheal tube of animals. The changes in hemodynamics before drowning, immediately after drowning (immediately after water injection) and 30, 60, and 120 minutes after drowning in both groups were recorded. The urine color changes after drowning and occurrence time were recorded. The animals were sacrificed at 120 minutes after drowning, and heart, kidney, liver, spleen and intestine were harvested for pathological observation under light microscope using hematoxylin and eosin (HE) staining., Results: (1) The changes in systemic hemodynamic: there was no significant difference in hemodynamics before drowning between the two groups. Compared with before drowning, heart rate (HR), mean arterial pressure (MAP), cardiac output (CO), left ventricular maximum systolic force index (dPmax), and pulmonary wedge pressure (PAWP) immediately after drowning in both seawater and freshwater groups were significantly increased, which showed a decrease tendency with drowning time prolongation. Compared with drowning immediately, dPmax at 30 minutes after freshwater drowning was significantly decreased (mmHg/s: 919.83±14.51 vs. 2 628.42±59.75, P < 0.01), which was below the level before drowning till 120 minutes. CO at 30 minutes after freshwater drowning was retreated as compared with drowning immediately, but it was still higher than that before drowning (L/min: 8.25±0.66 vs. 5.75±0.73, P < 0.01). Global end-diastolic volume (GEDV) and PAWP at 120 minutes after freshwater drowning were decreased to the level before drowning [GEDV (mL): 642.92±7.29 vs. 638.25±7.00, PAWP (mmHg, 1 mmHg = 0.133 kPa): 5.83±1.19 vs. 5.42±1.08, both P > 0.05]. Compared with immediately after drowning, MAP, CO and PAWP at 30 minutes after seawater drowning were significantly lowered [MAP (mmHg): 90.50±3.58 vs. 159.42±3.18, CO (L/min): 2.37±0.45 vs. 10.33±0.73, PAWP (mmHg): 4.17±0.72 vs. 11.75±1.82, all P < 0.01], which were lower than those before drowning till 120 minutes. After drowning for 30 minutes, MAP, CO and PAWP in seawater group were significantly lower than those in freshwater group [MAP (mmHg): 90.50±3.58 vs. 117.42±1.78, CO (L/min): 2.37±0.45 vs. 8.25±0.66, PAWP (mmHg): 4.17±0.72 vs. 24.83±1.27], dPmax was significantly increased (mmHg/s: 1 251.42±62.50 vs. 919.83±14.51, all P < 0.01), and the tendency continued till 120 minutes. There was no significant difference in HR at all the time points between the two groups. (2) The changes in urine: after freshwater drowning, the animals had hemoglobinuria and lasted until the end of the experiment, and the time of hemoglobinuria occurrence was at 20-35 minutes after drowning with an average of (25.30±5.15) minutes. After seawater drowning, the change in urine was not found until the end of the experiment. (3) The variations of each organ tissue in pathology and hematology at 120 minutes after drowning: after freshwater drowning, the systemic tissue edema was found in organs such as heart, kidney, liver, spleen, and small intestine. After seawater drowning, there were different degrees of edema in the systemic organs, and some of them shrank., Conclusions: After freshwater drowning, the animals showed decreased dPmax, increased CO and blood volume, edema and hemolysis of the tissue cells. After seawater drowning, CO and blood volume decreased, and some tissue cells were in atrophy.

Aim: To investigate the effects of differential sites for cold saline injection on transpulmonary thermodilution parameter values., Methods: This was a prospective study. Twelve patients were recruited for the following examinations: control condition (injection site at proximal injection end of the Swan-Ganz catheter), proximal end condition (injection site at sheath of the Swan-Ganz catheter), and distal end condition (injection site at PA end of the Swan-Ganz catheter). Sixty measurements were performed for each condition. The cardiac index, global end diastolic volume index (GEDI), and extravascular lung water index for the three different injection sites were recorded from each patient. In addition, the mean transmission time (MTt), downslope time, and area under the curve obtained from PiCCO-VoLEF-Win software were compared among different groups., Results: There were no differences in cardiac index and extravascular lung water index values among the three conditions (P>0.05). There were no differences in GEDI between the proximal end condition and control condition (P>0.05), while the GEDI was significantly lower for the distal end condition (493.33±254.65 mL/m(2)) than for the control condition (645.53±234.46 mL/m(2)) (P<0.05) and proximal end condition (717.96±321.63 mL/m(2)) (P<0.01). There were no differences in downslope time and area under the curve among the three conditions (P>0.05). There were no differences in MTt between the proximal end condition and control condition (P>0.05), while the MTt was significantly lower for distal end condition (40.22±16.37 seconds) than for the control condition (42.91±17.93 seconds) (P<0.05) and proximal end condition (47.16±16.64 seconds) (P<0.01)., Conclusion: The differential sites for cold saline injection impacted transpulmonary thermodilution parameter values.

Objective: To compare unilateral lung and traditional lung recruitment maneuver (RM) in animals with unilateral acute respiratory distress syndrome (ARDS) by implementing independent lung ventilation, and to explore the rational mechanical ventilation strategy for unilateral lung lesions., Methods: Healthy hybrid pigs were used as experimental animals, and they were divided into two groups according to random number table method (sealed concealed envelope). There were 20 pigs in each group. According to different methods of lung RM, the conventional mechanical ventilation (i.e. implementing ventilation for both lung by using a ventilator) was performed as control group; the individual lung ventilation (that was, implementing ventilation for both lung individually by using two ventilators) as independent lung ventilation group. The model of left lung ARDS was reproduced, and the respective RM was implemented according to respective method of the two groups. The differences in hemodynamic parameters and dead space ratio (VD/VT) between two groups under the RM pressure of 20, 40, 60 cmH₂O (1 cmH₂O=0.098 kPa) were observed., Results: (1) Hemodynamics parameters changes: with the increase in RM pressure, the heart rate (HR) in control group showed a tendency of gradual increase, and the level at 60 cmH₂O was significantly higher than that at 20 cmH₂O (192.65 ± 22.99 bpm vs. 178.20 ± 18.25 bpm, P<0.05). Mean arterial pressure (MAP) showed a tendency of gradual decrease, and that at 60 cmH₂O was lower significantly than that at 20 cmH₂O and 40 cmH₂O (78.55±25.77 mmHg (1 mmHg=0.133 kPa) vs. 112.40 ± 10.84 mmHg, 106.15 ± 13.54 mmHg, both P<0.01). Cardiac output (CO) gradually lowered, and the differences at 20, 40, 60 cmH₂O were logistically significant (11.14 ± 2.65 L/min, 9.56 ± 2.17 L/min, 6.01 ± 1.39 L/min, P<0.05 or P<0.01). With an increase in RM pressure, the difference in HR, MAP, CO in independent lung ventilation group were not significant, and the HR at 60 cmH₂O was significantly lower than that of the control group (178.20 ± 18.26 bpm vs. 192.65 ± 22.99 bpm, P<0.05), and MAP and CO were significantly higher than those of the control group (MAP: 110.80 ± 11.60 mmHg vs. 78.55 ± 25.77 mmHg, CO: 9.68 ± 2.08 L/min vs. 6.01 ± 1.39 L/min, both P<0.01). (2) VD/VT changes: with an increase in RM pressure, the oxygenation index (PaO₂/FiO₂) in control group showed a tendency of gradual decrease, and the level at 60 cmH₂O was significantly lower than that at 20 cmH₂O and 40 cmH₂O (126.40 ± 37.55 mmHg vs. 187.40 ± 21.66 mmHg, 175.20 ± 23.00 mmHg, both P<0.01). On the right side, VD/VT showed a tendency of gradual increase, and there was statistical significance in paired comparison among 20, 40, 60 cmH₂O (0.52 ± 0.12, 0.60 ± 0.15, 0.72 ± 0.12, P<0.05 or P<0.01). There was no obvious change on the left side. Along with the increase in RM pressure, the PaO₂/FiO₂ of independent lung ventilation group showed a tendency of gradual increase, and that at 40 cmH₂O and 60 cmH₂O were significantly higher than that at 20 cmH₂O (244.45 ± 53.93 mmHg, 270.05 ± 53.42 mmHg vs. 205.65 ± 31.33 mmHg, P<0.05 and P<0.01), and the level at 20, 40, 60 cmH₂O was higher than that of the control group (205.65±31.33 vs. 187.40 ± 21.66, P<0.05; 244.45 ± 53.93 vs. 175.20 ± 23.00, P<0.01; 270.05 ± 53.42 vs. 126.40 ± 37.55, P<0.01). There were no changes in VD/VT on both sides, and VD/VT on the right side was significantly lower than that of the control group when the inflation pressure was 20, 40, 60 cmH₂O (0.38 ± 0.14 vs. 0.52 ± 0.12, 0.43 ± 0.11 vs. 0.60 ± 0.15, 0.50 ± 0.13 vs. 0.72 ± 0.12, all P<0.01)., Conclusions: For severe ARDS caused by single lung injury, implementation of independent lung RM on the basis of independent lung mechanical ventilation for individual lung was significantly superior to the traditional lung RM for the improvement of hemodynamic parameters and VD/VT.