一流专业建设背景下化学实验教学示范中心的改革与实践

本文以山西大学化学实验教学示范中心为例,探讨了一流专业建设背景下化学实验教学示范中心的改革方向与实践措施。中心围绕学生“知识、能力、质素”协调发展的理念,坚持“三全育人”,以“立足化学优势,服务山西煤基产业”为特色发展方向,以创新实验、虚拟仿真实验、课程群建设为抓手,开展了一系列改革措施,取得了显著成效。

Coseismic deformation and fault slip distribution of the 2023 M_(W)7.8 and M_(W)7.6 earthquakes in Türkiye

On February 6,2023,a devastating earthquake with a moment magnitude of M_(W)7.8 struck the town of Pazarcik in south-central Türkiye,followed by another powerful earthquake with a moment magnitude of M_(W)7.6 that struck the nearby city of Elbistan 9 h later.To study the characteristics of surface deformation caused by this event and the influence of fault rupture,this study calculated the static coseismic deformation of 56 stations and dynamic displacement waveforms of 15 stations using data from the Turkish national fixed global navigation satellite system(GNSS)network.A maximum static coseismic displacement of 0.38 m for the M_(W)7.8 Kahramanmaras earthquake was observed at station ANTE,36 km from the epicenter,and a maximum dynamic coseismic displacement of 4.4 m for the M_(W)7.6 Elbistan earthquake was observed at station EKZ1,5 km from the epicenter.The rupture-slip distributions of the two earthquakes were inverted using GNSS coseismic deformation as a constraint.The results showed that the Kahramanmaras earthquake rupture segment was distinct and exposed on the ground,resulting in significant rupture slip along the Amanos and Pazarcik fault segments of the East Anatolian Fault.The maximum slip in the Pazarcik fault segment was 10.7 m,and rupture occurred at depths of 0–15 km.In the Cardak fault region,the Elbistan earthquake caused significant ruptures at depths of 0–12 km,with the largest amount of slip reaching 11.6 m.The Coulomb stress change caused by the Kahramanmaras earthquake rupture along the Cardak fault segment was approximately 2 bars,and the area of increased Coulomb stress corresponded to the subsequent rupture region of the M_(W)7.6 earthquake.Thus,it is likely that the M_(W)7.8 earthquake triggered or promoted the M_(W)7.6 earthquake.Based on the cumulative stress impact of the M_(W)7.8 and M_(W)7.6 events,the southwestern segment of the East Anatolian Fault,specifically the Amanos fault segment,experienced a Coulomb rupture stress change exceeding 2 bars,warranting further attention to assess its future seismic hazard risk.

Mendelian randomization study to investigate the causal relationship between plasma homocysteine and chronic obstructive pulmonary disease

BACKGROUND:Several observational studies have shown an association between homocysteine(Hcy)levels and chronic obstructive pulmonary disease(COPD),but causal relationships are not clear.Our study aimed to explore the causal relationship between plasma Hcy and COPD by two-sample Mendelian randomization(MR).METHODS:A two-sample MR study was performed to infer the causal link.Genetically predicted plasma Hcy was selected as an instrumental variable(Ⅳ)from published genome-wide association study(GWAS)meta-analyses.COPD with different etiologies was extracted as outcome variables from other GWAS meta-analyses.The main MR analysis was performed using the inversevariance weighted(IVW)method.Additional analyses were further performed using Cochran’s Q-test and MR-Egger regression to evaluate the heterogeneity or horizontal pleiotropy of our findings.RESULTS:MR analysis showed no significant association between plasma Hcy and COPD.The results of the groups were consistent with the sensitivity analysis and repeated analysis,without heterogeneity or horizontal pleiotropy.The IVW results showed COPD hospital admissions(odds ratio[OR]1.06,95%confidence interval[CI]0.91-1.24,P=0.42),asthma/COPD(OR 0.97,95%CI0.89-1.06,P=0.55),COPD-related chronic infection(OR 1.50,95%CI 0.57-3.99,P=0.41),COPDI asthma/interstitial lung disease(ILD)-related pneumonia or pneumonia-derived septicemia(OR 0.93,95%CI 0.86-1.02,P=0.13),and COPD-related respiratory insufficiency(OR 1.00,95%CI 0.7-1.44,P=0.99).CONCLUSION:There is no direct causal relationship between plasma Hcy and COPD in our study.As Hcy is known to have deleterious effects on endothelial function and vascular homeostasis,further studies are needed to investigate whether additional factors mediate the association between Hcy and COPD.

Phytoremediation Potential of Three Species of Macrophytes for Nitrate in Contaminated Water

Three species of aquatic plants (Scirpus validus, Phragmites australis and Acorus calamus) were used as experimental materials to study their capacity to purify contaminated water and their effects on water pH and dissolved oxygen (DO). The water was contaminated with different concentrations of nitrate (5 mg/L, 15 mg/L and 25 mg/L). The results indicated that the concentration of nitrate, species of aquatic plant and their interaction significantly impacted denitrification (P = 0.00). Under the same concentrations, the three species of aquatic plants provided varying degrees of purification. Acorus calamus provided effective purification under all three concentrations of nitrate wastewater, with removal percentages of 87.73%, 83.80% and 86.72% for nitrate concentrations of 5 mg/L, 15 mg/L and 25 mg/L, respectively. In terms of the purification ability by unit fresh weight, Acorus calamus exhibited the worst purification capacity, whereas the capacities of Scirpus validus and Phragmites australis were higher. The purification capacity of Scirpus validus for the three concentrations was as follows: 0.08 mg/(L·g FW), 0.29 mg/(L·g FW), and 0.51 mg/(L·g FW). The capacity of Phragmites australis was 0.07 mg/(L·g FW), 0.25 mg/(L·g FW), and 0.53 mg/(L·g FW). The capacity of Acorus calamus was 0.04 mg/(L·g FW), 0.12 mg/(L·g FW), and 0.21 mg/(L·g FW). Under increased concentrations of nitrate, the three species of aquatic plants exhibited various degrees of increased purification capacity. Under the different concentrations of nitrate, the three species exhibited the same trends with respect to water pH and DO, increasing first and then falling. The pH remained at approximately 7.5, and the DO fell to 4.0 mg/L. A comprehensive analysis reveals that Acorus calamus provides excellent nitrate purification, although by unit fresh weight, both Scirpus validus and Phragmites australis provide superior purification capacity.

Multiplicity of solutions to geophysical inversion reflected by rupture slip distribution of the 2015 Nepal earthquake

The equivalence of geophysical fields, the finiteness of measurements and the measurement errors make the result of geophysical inversion non-unique. For example, the measurements and inversion method used, the priori rupture model determined and the slip distribution smoothing factor selected will have significant influences on the earthquake rupture slip distribution. Using different data and methods, different authors have given different rupture slip distribution models of the 2015 Mw7.9 Nepal earth- quake, with the maximum slip ranging from 3.0 m to 6.8 m. In this paper, geometry parameters of the single rectangular fault model in elastic half-space were inferred constraining with the Global Posi- tioning System （GPS） and Interferometric Synthetic Aperture Radar （InSAR） coseismic deformations and bounding the slip with approximate average value; and then, the single rectangular fault was divided into multiple sub-faults, and the final slip smoothing factor, the final slip distribution and the maximum slip were determined with the misfit-roughness tradeoff curve, the cross-validation sum of squares （CVSS） and the third-party observation data or indexes being comprehensively taken into account. The results show that, the rupture of the Nepal earthquake extended by over 100 km east by south. The maximum slip of the earthquake was about 6.5-6.7 m, and most of the slip is confined at depths of 8 -20 kin, consistent with the depth distribution of aftershocks. The method for reducing the multiplicity of solutions to rupture slip distribution in this paper was ever used in inversion of rupture slip distri- bution for the 2008 Wenchuan and 2013 Lushan earthquakes, and the third-party measurement - surface dislocation has very large effect on reducing the multiplicity of solutions to inversion of the Wenchuan earthquake. Other priori information or indicators, such as fault strike, dip, earthquake magnitude, seismic activity, Coulomb stress, and seismic period, can be used for beneficial validation of and comparison with inversion results.

Effect of Non-Convective Zone Thickness on Thermal Efficiency of Salt Gradient Solar Ponds

An improved radiation transmission and thermal efficiency model for solar ponds has been proposed based on both the Hull Model and Wang/Seyed-Yagoobi Model in this paper.The new model is more accurate to actual measured conditions because multiple reflections and turbidity effects are included.Absorption penetration,thermal conductivity loss and thermal efficiency under different Non-Convective Zone thicknesses are numerically analyzed and thoroughly discussed.The results show thatΔT/I0 plays a critical role for the thermal efficiency of solar pond.Furthermore,it is found through calculation that there is an optimum thickness of the Non-Convective Zone.When the Non-Convective Zone thickness is less than this critical threshold,both temperature and thermal efficiency are decreased with increasing turbidity.However,when the Non-Convective Zone thickness is greater than this critical threshold,the increasing turbidity within a certain range will be beneficial to improve the thermal efficiency of solar pond.In addition,optimum Non-Convective Zone thickness is also related to the temperature,turbidity,salinity variation and bottom reflectivity.

Directional terahertz holography with thermally active Janus metasurface

Dynamic manipulation of electromagnetic(EM)waves with multiple degrees of freedom plays an essential role in enhancing information processing.Currently,an enormous challenge is to realize directional terahertz(THz)holography.Recently,it was demonstrated that Janus metasurfaces could produce distinct responses to EM waves from two opposite incident directions,making multiplexed dynamic manipulation of THz waves possible.Herein,we show that thermally activated THz Janus metasurfaces integrating with phase change materials on the meta-atoms can produce asymmetric transmission with the designed phase delays.Such reconfigurable Janus metasurfaces can achieve asymmetric focusing of THz wave and directional THz holography with free-space image projections,and particularly the information can be manipulated via temperature and incident THz wave direction.This work not only offers a common strategy for realizing the reconfigurability of Janus metasurfaces,but also shows possible applications in THz optical information encryption,data storage,and smart windows.

Inhibitory effect of a Chinese quince seed peptide on protein glycation:A mechanism study

Non-enzymatic glycation can cause the formation and accumulation of advanced glycation end products(AGEs),and it poses great threats to human health.It is urgent to search for safe and efficient inhibitors to prevent reducing sugar induced protein glycation.In this study,we inves-tigated the anti-glycation activity and mechanism of an identified peptide,Asparagine-Tyrosine-Arginine-Arginine-Glutamic acid(NYRRE)from Chinese quince seed protein hydrolysate,by mul-tispectroscopy,confocal imaging,and computational molecular simulation.Firstly,it was found that NYRRE could scavenge hydroxyl radicals and chelate Fe 2+.Besides,the NYRRE was effective in every stage of fructose induced bovine serum albumin(BSA)glycation.The NYRRE could re-duce the formation of fructosamine,carbonyl compounds,glycoxidation products and𝛽-amyloid structure.Meanwhile,NYRRE could protect thiol groups and stabilize the spatial conformation of BSA.The NYRRE presented strong inhibition in fluorescent AGEs,and 68.19%of total AGEs formation was prevented with NYRRE at 15 mmol/L.The results of molecular simulation indi-cated that NYRRE could insert into the hydrophobic pocket of BSA and interact with hot spots,including arginine and lysine residues.The mechanism of NYRRE inhibiting protein glycation could be due to its antioxidant activity,BSA structure stabilizing ability,and specific bond with glycation sites of BSA.These results provided a valuable reference for developing NYRRE as an efficient antiglycation agent in preventing glycation-mediated diseases.

Development of the Internet of smart orchard Things based on multi-sensors and LoRa technology

With the rapid growth of science and technology,the Internet of Things(IoT)technology has matured and attracted the attention of many researchers.The development of agricultural modernization leads to the gradual emergence of intelligent management gradually taking root in agricultural production.Among many technologies in the IoT technologies,low-power Wide Area Network(WAN)technology has the characteristics of reliable and stable transmission with long distance and low power consumption.This is very useful for data transmission in special environments,especially for orchards in mountainous areas.This paper proposed a new agricultural Internet of Things in orchard management based on multi-sensors,such as DHT11 for temperature/humidity and GY-30 for illumination,the Long Range(LoRa)technology for transmitting the collected data or control command between the terminal and data cloud center,etc.Setting a low-power IoT sensor network in the orchard can remotely measure the parameters in the orchard.LoRa WAN is used to transmit data to the central node.In order to reduce power consumption and cost,a single monitoring node selects two power supplies,a solar power supply and a power supply,and the power supply can be turned on remotely by users in special circumstances.Experiments in different environments in the peach orchard show that the monitoring system has enough reliability and accuracy,and is suitable for environmental monitoring in orchards in remote areas or areas with complex terrain.

Litter mixing significantly affects decomposition in the Hulun Buir meadow steppe of Inner Mongolia, China

Aims We explored the decomposition rates of single-and mixed-species litter,the litter-mixing effect and the effect of component litters in a mixture on decomposition.Methods In a litter bag experiment,shoot litters from two dominant grasses(Leymus chinensis and Stipa baicalensis)and one legume(Melissitus ruthenica)were decomposed separately and as a mixture from May 2010 to September 2011 in the Hulun Buir meadow steppe of Inner Mongolia,China.We separated the litter mixture into its individual component litters(i.e.the different single-species litters)and analyzed the changes in litter mass remaining and litter nitrogen(N)remaining during single-and mixed-species litter decomposition.Important Findings(i)Litter mixing had significant positive effects on litter decomposition.The litter-mixing effect was strongest for the mixture of S.baicalensis and L.chinensis litters,followed by the mixture of S.baicalensis and M.ruthenica litters.(ii)Single-species component litters decomposed faster in the mixtures than separately(positive effect),but these effects were not significant for legume species M.ruthenica litter.Relative to single-species litter decomposition,the decomposition rates of the two grass(S.baicalensis and L.chinensis)litters significantly increased when they were mixed with each other or with M.ruthenica litter.(iii)For each species litter type,the percentage of litter N remaining during decomposition(NR)differed between the single-species litter and mixed litter treatments.The NR of S.baicalensis litter was higher when it was decomposed in the mixture than in isolation.However,the NR of L.chinensis litter was lowest in its mixture with M.ruthenica among the treatments.Regardless of its decomposition in the mixture or in isolation,the NR of M.ruthenica litter varied little among treatments.There was a significant positive relationship between the NR and percentage of initial litter mass remaining in both the single litter and mixed litter treatments.These results suggest that N transfer may happen among component litters in mixture and further affect the decomposition.

Dual-color terahertz spatial light modulator for single-pixel imaging

Spatial light modulators(SLM),capable of dynamically and spatially manipulating electromagnetic waves,have reshaped modern life in projection display and remote sensing.The progress of SLM will expedite next-generation communication and biomedical imaging in the terahertz(THz)range.However,most current THz SLMs are adapted from optical alternatives that still need improvement in terms of uniformity,speed,and bandwidth.Here,we designed,fabricated,and characterized an 8×8THz SLM based on tunable liquid crystal metamaterial absorbers for THz single-pixel compressive imaging.We demonstrated dual-color compressive sensing(CS)imaging for dispersive objects utilizing the large frequency shift controlled by an external electric field.We developed auto-calibrated compressive sensing(ACS)algorithm to mitigate the impact of the spatially nonuniform THz incident beam and pixel modulation,which significantly improves the fidelity of reconstructed images.Furthermore,the complementary modulation at two absorption frequencies enables Hadamard masks with negative element values to be realized by frequency-switching,thereby halving the imaging time.The demonstrated imaging system paves a new route for THz single-pixel multispectral imaging with high reliability and low cost.

Influences and mechanisms of nanofullerene on the horizontal transfer of plasmid-encoded antibiotic resistance genes between E.coli strains

The spread and development of antibiotic resistance globally have led to severe public health problems.It has been shown that some non-antibiotic substances can also promote the diffusion and spread of antibiotic resistance genes(ARGs).Nanofullerene(nC60)is a type of nanomaterial widely used around the world,and some studies have discovered both the biological toxicity and environmental toxicity of nC6O .In this study,cellular and molecular biology techniques were employed to investigate the influences of nC6O at sub-minimum inhibitory concentrations(sub-MICs)on the conjugation of ARGs between the E.coli strains.Compared with the control group,nC6O significantly increased the conjugation rates of ARGs by 1.32-10.82 folds within the concentration range of 7.03-1800μg/L.This study further explored the mechanism of this phenomenon,finding that sub-MICs of nC6O could induce the production of reactive oxygen species(ROS),trigger SOSresponse and oxidative stress,affect the expression of outer membrane proteins(OMPs)genes,increase membrane permeability,and thus promote the occurrence of conjugation.This research enriches our understanding of the environmental toxicity of nC6O,raises our risk awareness toward nC6O ,and may promote the more rational employment of nC6O materials.

Photo-responsive Behaviors of Hydrogen-Bonded Polymer Complex Fibers Containing Azobenzene Functional Groups

Two azobenzene compounds,Disperse Red 1(DR1)and 4-aminoazobenzene(Aazo),were separately linked to poly(acrylic acid)(PAA)side chains to form PAA-DR1 and PAA-Aazo,which were then associated with poly(ethylene oxide)(PEO)to produce hydrogen-bonded polymer complex fibers.After UV irradiation,the initial modulus and yielding strength of PAA-Aazo/PEO fiber were both increased tremendously,while the mechanical properties of PAA-DR1/PEO fiber only slightly changed.After drawn and dried in vacuum,PAA-DR1/PEO and PAA-Aazo/PEO fibers with an extended length exhibited a contraction of 20%and 25%under UV irradiation,showing potential for photo-actuation.

Broadband terahertz rotator with an all-dielectric metasurface

Polarization manipulation is essential in developing cutting-edge photonic devices ranging from optical communication displays to solar energy harvesting. Most previous works for efficient polarization control cannot avoid utilizing metallic components that inevitably suffer from large ohmic loss and thus low operational efficiency.Replacing metallic components with Mie resonance-based dielectric resonators will largely suppress the ohmic loss toward high-efficiency metamaterial devices. Here, we propose an efficient approach for broadband, highquality polarization rotation operating in transmission mode with all-dielectric metamaterials in the terahertz regime. By separating the orthogonal polarization components in space, we obtain rotated output waves with a conversion efficiency of 67.5%. The proposed polarization manipulation strategy shows impressive robustness and flexibility in designing metadevices of both linear-and circular-polarization incidences.

Physicochemical and Functional Properties of Water Soluble Gum from Wrinkle Floweringquince(Chaenomeles Speciosa)Seeds

Wrinkle Floweringquince(Chaenomeles speciose(Sweet)Nakai)seed,as an unexploited forestry residue,contains considerable amount of bioactive carbohydrates with potential functionality,which was not widely concerned.The aim of this study is to determine the basic characterizations(molecular weight and functional group),specificcomponents(carbohydrate,protein and uronic acid contents),and functional properties of Chaenomeles speciosa seedgum(CSG).Results indicated that carbohydrate(63.80%),protein(13.69%)and uronic acid(10.30%)contents wereachieved.The CSG(average molecular weight,9.85×106 u)consists rhamnose,arabinose,xylose and glucose in a molarpercentage of 29.77꞉10.54꞉18.55꞉15.84,respectively.The Fourier transform infrared(FT-IR)analysis revealed hydroxyl,carboxyl and methyl groups andα-glycosidic linkages are founded in the CSG.The CSG was surface active and its abilityto decrease surface tension was comparable to commercial gums.Moreover,the CSG solutions showed pseudoplasticflow behavior under dynamic shear rate at high concentrations.The GSC also presented good emulsifying and foamingproperties,indicating the potential of the GSC as bioresource stabilizer and thickener in industry.