Analysis of the Ideological and Political Concepts and Teaching Strategies for Quality Improvement in Physical Education Courses in Colleges and Universities

In today’s higher education system,the physical education program is not only for teaching sports skills and exercising physical fitness but also an important position for cultivating students’character,emotions,and values.With the in-depth development of the concept of ideological education,the ideology of college physical education courses has become an important direction of educational reform.In this paper,we will discuss the connotation of the concept of ideology and politics in college physical education courses,analyze the methods to effectively integrate the ideology and politics elements while guaranteeing the quality of teaching,and put forward the corresponding strategies to improve the quality,with a view to providing new ideas and methods for the construction of ideology and politics in college physical education courses.

DNA介导荧光铜纳米簇的合成及表征——推荐一个研究型综合化学实验

为达到科研反哺教学、教学创新促进人才培养的目标,有必要对传统化学实验进行改革。在此,基于课题组人员前期科研成果,设计了一个研究型综合化学实验,以DNA分子为模板合成与表征荧光铜纳米簇,并获取稳定合成荧光铜纳米簇的条件。实验内容包括纳米簇的合成、基本光谱分析仪器的使用、光谱数据的处理等。实验交叉融合分析化学、生物化学、纳米科学等多学科前沿知识,实验条件简单温和,实验时长合理,满足实验教学的各项要求,能充分激发学生的科研兴趣、提升综合能力,具有很好的实验教学推广价值。

Partial organic fertilizer substitution promotes soil multifunctionality by increasing microbial community diversity and complexity

Partial substitution of synthetic nitrogen(N)with organic fertilizers(PSOF)is of great significance in improving soil ecosystem functions in systems that have deteriorated due to the excessive application of chemical N fertilizer.However,existing studies typically focus on individual soil functions,neglecting the fact that multiple functions occur simultaneously.It remains unclear how PSOF influences multiple soil functions and whether these impacts are related to soil microbial communities.Here,we examined the impacts of partial substitutions(25%–50%)of chemical N fertilizer with organic form(pig manure or municipal sludge)in a vegetable field on soil multifunctionality,by measuring a range of soil functions involving primary production(vegetable yield and quality),nutrient cycling(soil enzyme activities,ammonia volatilization,N leaching,and N runoff),and climate regulation(soil organic carbon sequestration and nitrous oxide emission).We observed that PSOF improved soil multifunctionality,with a 50%substitution of chemical N fertilizer with pig manure being the best management practice;the result was strongly related to the diversities and network complexities of bacteria and fungi.Random forest analysis further revealed that soil multifunctionality was best explained by the bacterial-fungal network complexity,followed by available phosphorus level and bacterial diversity.The PSOF also shifted the composition of bacterial and fungal communities,with increased relative abundances of dominant bacteria phyla,such as Bacteroidetes,Gemmatimonadetes,and Myxococcota,and fungal phyla,such as Basidiomycota and Olpidiomycota.The observed increases in soil multifunctionality were consistent with significant increases in the relative abundances of keystone taxa such as Blastocladiomycota,Chaetomiaceae,and Nocardiopsaceae.Together,these findings indicate that PSOF can enhance interactions within and among microbial communities and that such practices have the potential to improve soil ecosystem multifunctionality and contribute to the development of sustainable agriculture.

Impacts of laser pulse width and target thickness on laser micro-propulsion performance

In order to optimize the laser ablation performance of a micro-thruster with 1U dimensions,which employs a micro semiconductor laser,the impacts of pulse width and glycidyl azide polymer(GAP)thickness on thrust performance were researched.The results showed that with a GAP thickness of 200μm,the single-pulse impulse(I)increased gradually with the increase in the laser pulse width from 50 to 800μs,while the specific impulse(I_(sp)),impulse coupling coefficient(Cm)and ablation efficiency(η)all reached optimal values with a 200μs pulse width.It is worth noting that the optimal pulse width is identical to the ignition delay time.Both Cmandηpeaked with a pulse width of 200μs,reaching 242.22μN W^(-1)and 35.4%,respectively.With the increase in GAP thickness,I and Cmincreased gradually.GAP of different thicknesses corresponded to different optimal laser pulse widths.Under a certain laser pulse width,the optimal GAP thickness should be the most vertical thickness of the ablation pit,and the various propulsion performance parameters at this time were also optimal.With the current laser parameters,the optimal GAP thickness was approximately 150μm,I_(sp)was approximately 322.22 s,andηwas approximately 34.94%.

Preliminary design method for absorber pipe length of tunnel lining ground heat exchangers based on energy efficiency of heat pump

Many ongoing tunnel projects provide a favorable opportunity for the investigation and application of tunnel lining ground heat exchangers(GHEs).Tunnel lining GHEs can be connected to a heat pump to extract geothermal energy for heating and cooling buildings.Numerous studies have focused on the thermal performance of tunnel lining GHEs;however,the studies on the interaction between heat pumps and tunnel lining GHEs are relatively rare.In this study,a coupled heat transfer model of heat pumps and tunnel lining GHEs was proposed and then calibrated based on in situ test results.The model was used to evaluate the energy efficiency of a heat pump with tunnel lining GHEs under different conditions.The results show that the energy efficiency ratio(EER)increases exponentially with the absorber pipe length and thermal conductivity of the surrounding rock.The EER is governed by the convection heat transfer coefficient,which varies exponentially;meanwhile,the EER decreases approximately linearly with the annual average air temperature in the tunnel.Different types of heat pumps affect the EER significantly,and the EER of a Type-3 heat pump is higher than that of a Type-1 heat pump by 27.1%.Based on the aforementioned results,an empirical formula for the EER and absorber pipe length was established.Moreover,a preliminary design method for the absorber pipe length based on this empirical formula was developed.The method was employed to determine the appropriate absorber pipe length for the tunnel lining GHEs in the Shapu tunnel in Shenzhen,China.Finally,groups of absorber pipe layouts with a pipe spacing of 0.5 m,area of 135 m2,and length of 293.5 m were preliminarily determined.

A diffusive Holling-Tanner prey-predator model with free boundary

This paper is concerned with a diffusive Holling-Tanner prey-predator model in a bounded domain with Dirichlet boundary condition and a free boundary. The global existence of the unique solution is proved. Moreover, the criteria governing spreading- vanishing are derived by mainly using the comparison principle. The results show that if the length of the occupying line is bigger than a threshold value （spreading barrier）, then the spreading of predators will make an achievement, and, if the length of the occupying line is smaller than this spreading barrier and the spreading coefficient is relatively small depending on initial size of predators, then the predators will fail in establishing themselves and eventually die out.

Recyclable thermally conductive poly(butylene adipate-co-terephthalate)composites prepared via forced infiltration

With the rapid development of electronic equipment and communication technology,the demand for polymer composites with high thermal conductivity and mechanical properties has increased significantly.However,its nondegradable polymer matrix will inevitably bring more and more serious environmental pollution.Therefore,it is urgent to develop biodegradable thermally conductive polymer composites.In this work,biodegradable poly(butylene adipate-coterephthalate)(PBAT)is used as the matrix material,and vacuum-assisted filtration technology is employed to prepare carbon nanotube(CNT)and cellulose nanocrystal(CNC)networks with high thermal conductivity.Then CNT-CNC/PBAT composites with high thermal conductivity and excellent mechanical properties are prepared by the ultrasonic-assisted forced infiltration method.Both experiment and simulation methods are used to systematically investigate the thermally conductive and dissipation performances of the CNT-CNC/PBAT composites.Above all,a simple alcoholysis reaction is applied to realize the separation of the PBAT matrix and functional fillers without destroying the conductive network skeleton,which makes it possible for the recycling of thermally conductive polymer composites.

Are humic substances soil microbial residues or unique synthesized compounds?A perspective on their distinctiveness

Humic substances(HS),which are defined as a series of highly acidic,relatively high-molecular-weight,and yellow to black colored substances formed during the decay and transformation of plant and microbial remains,ubiquitously occur in nature.Humic substances represent the largest stable organic carbon pool in terrestrial environments and are the central characteristic of the soil.However,the validity of the HS concept and the justification of their extraction procedure have been recently debated.Here,we argue that the traditional humic paradigm is still relevant.Humic substances are distinctive and complex because the extracted HS formed during the humification are chemically distinct from their precursors and are heterogeneous among soils.By reviewing the concept,formation pathways,and stabilization of HS,we propose that the key question facing soil scientists is whether HS are soil microbial residues or unique synthesized compounds.Without revealing the distinctiveness of HS,it is impossible to address this question,as the structure,composition,and reactivity of HS are still poorly known owing to the heterogeneity and geographical variability of HS and the limits of the currently available analytical techniques.In our view,the distinctiveness of HS is fundamental to the soil,and thus further studies should be focused on revealing the distinctiveness of HS and explaining why HS hold this distinctiveness.

Advanced hydrogels for the repair of cartilage defects and regeneration

Cartilage defects are one of the most common symptoms of osteoarthritis(OA),a degenerative disease that affects millions of people world-wide and places a significant socio-economic burden on society.Hydrogels,which are a class of biomaterials that are elastic,and display smooth surfaces while exhibiting high water content,are promising candidates for cartilage regeneration.In recent years,various kinds of hydrogels have been developed and applied for the repair of cartilage defects in vitro or in vivo,some of which are hopeful to enter clinical trials.In this review,recent research findings and developments of hydrogels for cartilage defects repair are summarized.We discuss the principle of cartilage regeneration,and outline the requirements that have to be fulfilled for the deployment of hydrogels for medical applications.We also highlight the development of advanced hydrogels with tailored properties for different kinds of cartilage defects to meet the requirements of cartilage tissue engineering and precision medicine.

Biochar amendment alters the partitioning of nitrate reduction by significantly enhancing DNRA in a paddy field

Using 15N tracer technique,we investigated the potential rates of denitrification,anaerobic ammonium oxidation,dis-similatory nitrate reduction to ammonium(DNRA),and their partitioning among nitrate reduction,as well as the N_(2)O emission rates in a paddy soil receiving various biochar(0%,0.03%,0.1%,0.5%,and 1.0%;w/w)and straw(0.1%)over six consecutive years.Results showed that except for the 1.0%amendment treatment,biochar significantly(P<0.05)increased denitrification rates by 10.19‒75.96%compared with non-biochar amended treatment,and that biochar significantly(P<0.05)increased DNRA rates by 1.63‒6.84 folds relative to non-biochar amended treatment.Conse-quently,biochar shifted more NO3-partitioning toward DNRA process,as suggested by the increased DNRA/(denitri-fication+DNRA)ratios from 1.60 to 13.18%.On the other hand,biochar significantly(P<0.05)reduced N_(2)O emission rates by 61.86-97.65%accompanied by a significant decrease in N_(2)O/(N_(2)O+N_(2))ratios(65.29-98.39%),indicating bio-char amendment facilitated the reduction of N_(2)O to N_(2).The promoting effects of biochar on DNRA rates and DNRA/(denitrification+DNRA)ratios were attributed to the increased carbon availability and the altered nitrate reducer communities.Collectively,our study suggests that biochar amendment in the paddy soil is helpful for N conservation by favoring nitrate partitioning toward DNRA process,which deepens our understanding of how biochar mediates N cycling in the paddy field.

A long-term retaining molecular coating for corneal regeneration

Corneal injuries will cause corneal surface diseases that may lead to blindness in millions of people worldwide.There is a tremendous need for biomaterials that can promote corneal regeneration with practical feasibility.Here we demonstrate a strategy of a protein coating for corneal injury regeneration.We synthesize an o-nitrosobenzaldehyde group(NB)-modified gelatin(GelNB),which could adhere directly to the corneal surface with covalent bonding to form a thin molecular coating.The molecular coating could avoid rapid clearance and provide a favorable environment for cell migration,thereby effectively accelerating corneal repair and regeneration.The histological structure of the regenerated cornea is more similar to the native cornea.This molecular coating can be used conveniently as an eye drop solution,which makes it a promising strategy for corneal regeneration.

Intrinsically flexible all-carbon-nanotube electronics enabled by a hybrid organic-inorganic gate dielectric

The advancement of Internet of Things has stimulated huge demands on low-voltage flexible electronics.Carbon-nanotube(CNT)-based electronics are of great promise to this end for their intrinsic flexibility,high carrier mobility,and capability to synthesize as semiconducting or metallic to serve as the channels,electrodes,and interconnects of circuits.However,the gate dielectric often has to adopt brittle oxides,which can seriously limit the device flexibility.Herein,we show that a hybrid polyimide-Al2O3 material can serve as a good gate dielectric to realize truly intrinsic flexibility of transistors and circuits based on CNTs.With this hybrid dielectric,high-performance all-CNT transistors and integrated circuits of inverters,ring oscillators,and logic gates are demonstrated.Particularly,the inverters exhibit a remarkably high gain of 342.5 and can be used as an analog amplifier for millivolt small signals.Ultralow voltage(50 mV)operation is also feasible,which highlights the great promise for low-power applications.