摘要：Within the domain of homestays,it is imperative to prioritize the augmentation of hosts'pivotal role and the facilitation of pro-environmental behavior among tourists as essential strategies for promoting the sustainability of homestay *** research utilizes homestays in Pingtan Island as a specific example and employs a survey methodology to collect ***,a structural equation model is utilized to analyze the causal relationship between situational factors within homestays and the pro-environmental behavior of tourists,specifically within the context of host-guest *** results of the study indicate that there is a favorable correlation between environmental quality and the interaction between hosts and guests,and visitors'pro-environmental ***,it is worth noting that situational circumstances play a crucial role in shaping the dynamics of host-guest ***,in turn,serves as a mediator for the influence of situational factors on tourists'pro-environmental *** on the aforementioned findings,the present study proceeds to examine the pragmatic ramifications of the research and provides recommendations for prospective areas of investigation.

摘要：Covalent organic frameworks （COFs）, established as an emerging class of crystalline porous polymers with high surface area, structural diversity, and esignability, attract much interest and exhibit potential applications in catalysis. In this review, we summarize the use of COFs as a versatile platform to develop heterogeneous catalysts for a variety of chemical reactions. Catalytic COFs are categorized in accordance with the types of active sites, involving single functional active sites, bifunctional active sites, and metal nanoparticles （NPs） embedded in pores. Special emphasis is placed on the deliberate or incidental synthesis strategies, the stability, the heterogeneity, and the shape/size selectivity for COF catalysis. Moreover, a description of the application of COFs as photocatalysts and electrocatalysts is presented. Finally, the prospects of COFs in catalysis and remaining issues in this field are indicated.

摘要：A field experiment was carried out from 2003 to 2013 in the Wanzhong Farm of the hainan Island, China, to determine the effects of two long-term banana rotations on the abundance and trophic groups of soil nematode communities in the island. The experiment was set out as a randomized complete block design with three replications of three treatments： banana-pineapple rotation （AB）, banana-papaya rotation （BB） and banana monoculture （CK） in a conventional tillage system. Soil samples were taken at depths of 0-10, 10-20 and 20-30 cm, and nematodes were extracted by a modified cotton-wool filter method and identified to the genus level. Nematode ecological indices of Shannon-Weaver diversity （Ht）, dominance index （A）, maturity index （MI）, plant parasite index （PPI）, structure index （SI）, enrichment index （EI）, and channel index （CI） were calculated. A total of 28 nematode genera with relative abundance over 0.1% were identified, among which Tylenchus and Paratylenchus in the AB, Thonus in the BB, Tylenchus and Helicotylenchus in the CK were the dominant genera. The rotation soils favored bacterivores, fungivores and omnivores-predators with high colonizer-persister （c-p） values. Soil food web in the rotation systems was highly structured, mature and enriched as indicated by SI, MI and EI values, respectively. Higher abundance of bacterivores and lower values of CI suggested that the soil food web was dominated by a bacterial decomposition pathway in rotation soils. Nematode diversity was much higher after a decade of rotation. Soil depth had significant effects on the abundance of soil nematodes, but only on two nematode ecological indices （λ and MI）.

摘要：The formation of kitchen greasy dirt was expounded, and the different types of kitchen cleaner and common products were introduced. At last, the development trend for kitchen cleaner was prospected.

摘要：The underwater dry maintenance method based on a dry cabin can achieve the same maintenance quality provided on *** establishment of a reliable seal between the dry cabin and the pipe is a prerequisite for the formation of a dry *** this paper,an airbag is proposed as the means to seal the dry *** finite element software was used to study the influence of the physical characteristics of the airbag on deformation characteristics and sealing *** also studied the adaptive sealing mechanism of the airbag under the time-varying gap *** simulation results show that the peak contact stress of the airbag is close to the gas pressure,so the hardness and thickness of the airbag have little effect on *** time-varying gap conditions,the required inflation pressure increases with the size of the *** simulated relationship between the gap and the inflation pressure can be referred to in order to guide the control of the air pressure of the airbag during actual ***,the similarity between the test results and simulation results demonstrates the accuracy of the simulation results.

摘要：An atomic layer deposition （ALD） method has been employed to synthesize Fe3O4/graphene and Ni/graphene composites. The structure and microwave absorbing properties of the as-prepared composites are investigated. The surfaces of graphene are densely covered by Fe3O4 or Ni nanoparticles with a narrow size distribution, and the magnetic nanoparticles are well distributed on each graphene sheet without significant conglomeration or large vacancies. The coated graphene materials exhibit remarkably improved electromagnetic （EM） absorption properties compared to the pristine graphene. The optimal reflection loss （RL） reaches -46.4 dB at 15.6 GHz with a thickness of only 1.4 mm for the Fe3O4/graphene composites obtained by applying 100 cycles of Fe2O3 deposition followed by a hydrogen reduction. The enhanced absorption ability arises from the effective impedance matching, multiple interfacial polarization and increased magnetic loss from the added magnetic constituents. Moreover, compared with other recently reported materials, the composites have a lower filling ratio and smaller coating thickness resulting in significantly increased EM absorption properties. This demonstrates that nanoscale surface modification of magnetic particles on graphene by ALD is a very promising way to design lightweight and high-efficiency microwave absorbers.

摘要：Covalent organic frameworks(COFs),with two dimensional(2D-)or three dimensional(3D-)structures,have accessible open channels or nanopores,with uniform sizes ranging from angstroms to nanometers and have emerged as an excellent and promising platform for designing catalysts or catalyst ***,a 2 D-COF grafted with a 1-alkyl-3-methylimidazolium-based ionic liquid(AMIMBr@H2 P-DHPh COF)on the channel walls was synthesized and utilized as a highly efficient heterogeneous catalyst for the chemical fixation of CO2 via a reaction with epoxides under solvent-free and co-catalyst-free *** as-synthesized AMIMBr@H2 P-DHPh COF shows excellent catalytic activity in promoting the cycloaddition reactions between epoxide and CO2;the excellent catalytic activity was maintained for up to five *** like high porosity,functional versatility,easy modification of COFs,and high catalytic activity of ionic liquids,have been realized in a single material.

摘要：Photocatalytic hydrogen(H_(2))evolution using covalent organic frameworks(COFs)is an attractive and promising avenue for exploration,but one of its big challenges is low photo-induced charge *** this study,we present a straightforward and facile dipole polarization engineering strategy to enhance charge separation efficiency,achieved through atomic modulation(O,S,and Se)of the COF *** findings demonstrate that incorporating atoms with varying electronegativities into the COF matrix significantly influences the local dipole moment,thereby affecting charge separation efficiency and photostability,which in turn affects the rates of photocatalytic H_(2) *** a result,the newly developed TMT-BO-COF,which contains highly electronegative O atoms,exhibits the lowest exciton binding energy,the highest efficiency in charge separation and transportation,and the longest lifetime of the active *** leads to an impressive average H_(2) production rate of 23.7 mmol g^(−1) h^(−1),which is 2.5 and 24.5 times higher than that of TMT-BS-COF(containing S atoms)and TMT-BSe-COF(containing Se atoms),respectively.A novel photocatalytic hydrogen evolution mechanism based on proton-coupled electron transfer on N in the structure of triazine rings in vinylene-linked COFs is proposed by theoretical *** findings provide new insights into the design of highly photoactive organic framework materials for H_(2) evolution and beyond.

摘要：Robotic subsea stratum drilling robot is a method for new subsea stratigraphic geological investigation and resource *** at the front end is the main source of resistance to the robot’s motion in the *** there is no continuous and strong downward drilling force as in conventional drilling rigs,robot movement relies heavily on the drill bit to reduce the drilling *** this study we propose a self-propelling drill bit that can discharge soil debris to provide propulsive force and reduce the *** key parameter of the drill bit design,the spiral blade lead angle,was determined by theoretical analysis of the drill bit’s soil discharging *** verify the structural advantages of the self-propelling drill bit in reducing resistance,a comparative analysis with a conventional conical drill bit was *** drilling process of both bits was simulated using finite element simulation at various rotation speeds,the penetration force and torque data of both drill bits were obtained,and tests prepared accordingly in subsea soil were *** simulations and tests verified that the penetration force of the self-propelling drill bit was lower than that of the conventional conical drill *** self-propelling drill bit can reduce the resistance effectively,and may play an important role in the stratum movement of drilling robots.

摘要：The secretion of melatonin(MT)is obviously different in the younger and the senior sectors of the population,and the maximum plasma concentration of seniors is only half of that in the younger population *** exogenous MT can be supplied to senior citizens based on the secretion rate and amount of endogenous MT in the younger population by a bio-mimetic drug delivery system(DDS),an improved therapeutic effect and reduced side effects can be *** upon this hypothesis,the pharmacokinetic parameters of MT,namely,the absorption rate constant(ka),the elimination rate constant(ke),and the ratio of absorption rate(F)to the apparent volume of distribution(V)were obtained by a residual method depending on the plasma concentration curve of immediate release preparations in the healthy younger *** dose-division method was applied to calculate the cumulative release profiles of MT achieved by oral administration of a controlled release drug delivery system(DDS)to generate plasma MT profiles similar to the physiological level-time *** in vivo release of MT deduced from the healthy younger population physiological MT profiles as the pharmacokinetic output of the bio-mimetic DDS showed a two-phase profile with two different zero order release rates,namely,4.919μg/h during 0-4 h(r=0.9992),and 11.097μg/h during 4-12 h(r=0.9886),*** the osmotic pump type of DDS generally exhibits a good correlation between in vivo and in vitro release behaviors,an osmotic pump controlled delivery system was designed in combination with dry coating technology targeting on the cumulative release characteristics to mimic the physiological MT profiles in the healthy younger *** high similarity between the experimental drug release profiles and the theoretical profiles(similarity factor f_(2)>50)and the high correlation between the predicted plasma concentration profiles and the theoretical plasma concentration profiles(r=0.9366,0.9163,0.9264)ind