树的点Shelling Structure之minor特征

本文给出了二个 Shelling structure 是树的点 Shelling sture 的充要条件,这个充要条件就是树的点 Shelling structure 的 Minor 特征。

Stable major QTL on chromosomes A07 and A08 increase shelling percentage in peanut(Arachis hypogaea L.)

Peanut is a major oilseed and food legume.Shelling percentage(SP),closely associated with seed yield,is a trait whose improvement is a major goal of peanut breeding.In this study,a mapping population(Xuhua 13×Zhonghua 6)was used to map quantitative trait loci(QTL)controlling SP in four environments.Two stable major QTL for SP were mapped on both SSR-and SNP-based genetic maps.q SPA07.1 on chromosome A07 explained up to 31.7%of phenotypic variation,and q SPA08.2 on chromosome A08 explained up to 10.8%.Favorable alleles of q SPA07.1 and q SPA08.2 were derived from the female and male parents,respectively.Eight recombinant inbred lines(RILs)carrying both favorable alleles showed superiority in SP over the two parents in all environmental trials.A combination of the two favorable alleles using the linked markers was verified to increase SP by~5%in the RIL population and by~3%SP in diverse peanut cultivars.q SPA07.1 and q SPA08.2 were delimited to respectively a 0.73-Mb interval harboring 96 genes and a 3.93-Mb interval harboring 238 genes.Respectively five and eight genes with high expression in pods,including enzymes and transcription factors,were assigned as candidate genes for q SPA07.1 and q SPA08.2.These consistent major QTL provide an opportunity for fine mapping of genes controlling SP,and the linked markers may be useful for genetic improvement of SP in peanut.

Skin Damage and Aesthetic Disadvantage Observed in Women in the Hand Craft Shelling Chain of Cashew Nuts in a Factory to Bobo-Dioulasso, Burkina Faso

Introduction: Occupational dermatitis has long been an unforeseen consequence of industrial progress. Today, most occupational diseases are dermatosis throughout the world. The morbidity and the various prejudices concern different actors, especially those of the cashew industry in Bobo-Dioulasso to Burkina Faso. We considered it appropriate to conduct this study in women who handle cashew nuts in the cashew nut shelling station at a factory. The aim is to contribute to the search for preventive and curative solutions adapted to this health risk. Methods: This was a prospective cross-sectional study with a descriptive purpose in May 2016. The study involved 112 women present in the factory in the shelling unit and having given their approval during our visit. This station is occupied by 118 women. Results: The prevalence of all dermatosis and dermatitis was estimated respectively at 98.21% and 88.39%. The manual shelling station with a shearing machine was exclusively occupied by illiterate women (72.3%) without personal protective equipment, with an average age of 33.74 ± 8.49 years. Among the clinical forms of contact dermatitis, the erythematous contact dermatitis was most observed (86.4%), followed by palmar keratoderma (70.9%), nail disorders (33.6%) and chemical burns (30%). The implication of Cashew Nut Shell Liquid (CNSL) was established with identified promoting factors. Aesthetic damage related to hand injuries had a significant psychosocial impact in 97.32% of cases. Discussion: Few studies exist on dermatitis and the health impacts in the reality of cashew because they reach vulnerable subjects without social welfare and health protection. The cashew nuts shell contains a highly irritating brown oily liquid. Dermatitis occurs during contact with this oily juice. The international literature reports this corrosive effect throughout the history of the chain. Human factors, technical factors and work environment aggravate the situation and compromize workwomen health. Conclusion: Cashew huskers had dermatitis with an impact on daily life. Working conditions and security of employment, hygiene attitudes and anacardic acid were identified as causes of this situation. It is imperious to take measures in collaboration with the occupational physicians to ensure these women’s health at work and improve their quality of life.

Rational design of AgGaS/ZnS/ZnS quantum dots with a near-unity photoluminescence quantum yield via double shelling scheme

In this study,a two-step method was used to synthesize highly luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby facilitating the formation of a thick outer shell.After the two-step shelling process,the synthesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum yield(PLQY)of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQY reported thus far for AgGaS QDs.Furthermore,the effect of halogen ions in Zn precursors on the shelling process was investigated.It was proposed that the capacity of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling reaction.Specifically,the ZnS shelling reaction was dominant when ZnCl_(2)was employed,while Zn cation diffusion was the dominant process under the I^(−)-rich environment.This work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored synthesis of core/shell QDs.

Valorization of Camellia oleifera oil processing byproducts to value-added chemicals and biobased materials: A critical review

The C.oleifera oil processing industry generates large amounts of solid wastes,including C.oleifera shell(COS)and C.oleifera cake(COC).Distinct from generally acknowledged lignocellulosic biomass(corn stover,bamboo,birch,etc.),Camellia wastes contain diverse bioactive substances in addition to the abundant lignocellulosic components,and thus,the biorefinery utilization of C.oleifera processing byproducts involves complicated processing technologies.This reviewfirst summarizes various technologies for extracting and converting the main components in C.oleifera oil processing byproducts into value-added chemicals and biobased materials,as well as their potential applications.Microwave,ultrasound,and Soxhlet extractions are compared for the extraction of functional bioactive components(tannin,flavonoid,saponin,etc.),while solvothermal conversion and pyrolysis are discussed for the conversion of lignocellulosic components into value-added chemicals.The application areas of these chemicals according to their properties are introduced in detail,including utilizing antioxidant and anti-in-flammatory properties of the bioactive substances for the specific application,as well as drop-in chemicals for the substitution of unrenewable fossil fuel-derived products.In addition to chemical production,biochar fabricated from COS and its applications in thefields of adsorption,supercapacitor,soil remediation and wood composites are comprehensively reviewed and discussed.Finally,based on the compositions and structural characteristics of C.oleifera byproducts,the development of full-component valorization strategies and the expansion of the appli-cationfields are proposed.

粉煤袋式过滤器内粉煤焖烧的原因分析及处理措施

Shell粉煤气化装置在停车检修期间,发生了粉煤袋式过滤器内粉煤焖烧的事故。分析了事故发生的原因,采取停止粉煤外排、输入一定量氮气惰化粉煤袋内的粉煤、间隔洒水降低粉煤温度等措施,避免了粉煤袋式过滤器滤袋和防爆板的损坏。

Compression and shearing force on kernel rupture in shelling fresh lotus seeds

The mechanical properties of fresh lotus seeds are still poorly understood,which complicates the design of mechanical shelling machinery.Therefore,this work carried out four-factor orthogonal tests to determine the maximum permitted compressive force and minimum necessary shearing force to shell fresh lotus seeds without rupturing the kernel.It was found that the mean compression force that cracked the fresh lotus seed and led to kernel rupture was 213.03 N.Both the compressive force and the seed deformation upon kernel rupture were affected,in descending order of significance,by loading mode,seed grade,loading rate,and seed standing time.On the other hand,the shearing force needed to shell the seeds had a mean value of 7.84 N,far less than the compressive force that cracked the seed shell.The shearing force was affected,in descending order of significance,by seed standing time,tip angle of cutter blade,and loading rate,but not significantly affected by seed grade.The results suggested that mechanical shelling of fresh lotus seeds should ideally be carried out for fresh lotus seeds with a standing time of no more than 6 h using a cutter blade with an angle of about 40°at a loading rate of 30-90 mm/min.

透空结构与半潜式风机集成系统耦合运动响应特性分析

A novel semi-submersible platform is proposed for 5 MW wind turbines.This concept focuses on an integrated system formed by combining porous shells with a semi-submersible platform.A coupled aerodynamic–hydrodynamic–mooring analysis of the new system is performed.The motion responses of the novel platform system and the traditional platform are compared.The differences in hydrodynamic performance between the two platforms are also evaluated.The influence of the geometric parameters(porosity,diameter,and wall thickness)of porous shells on the motion response behavior of the new system is studied.Overall,the new semi-submersible platform exhibits superior stability in terms of pitch and heave degrees of freedom,demonstrating minimal effects on the motion response in the surge degree of freedom.

Comparative Transcriptome Analysis of Shell-Matrix-Protein Genes and Observation of the Shell Microstructure in the Deep-Sea Clam Calyptogena marissinica

The deep-sea clam Calyptogena marissinica is widely distributed in the Haima cold seep ecosystem on the northwes-tern slope of the South China Sea with low pH values,low temperature and high pressure.Limited information is available on the biomineralization of this species.In this research,we generated a comprehensive transcript dataset of C.marissinica’s mantle tissue,and a total of 19821 unigenes were assembled.Fourteen shell matrix proteins(SMP)-related genes were identified.The qPCR results showed that four out of six prismatic matrix genes(MSP2,MSP5,prisilkin-39,and shematrin),four out of the six nacreous matrix genes(perlucin,pif,pif97,and papilin),and two extrapallial fluid proteins(SPARC and calmodulin)were significantly expressed in the mantle.Both the nacreous and the prismatic layers are chrysanthemum-shaped,which are stacked on the top of each other to form a laminated nacreous structure.The alignment and phylogenetic analysis of MSP-5,Prisilkin-39,Perlucin,and Pif homologues showed that some amino acids of C.marissinica that differed from those detected in other molluscs may cause the different shape of the nacreous and prismatic layers,but do not lead to a change in the species’evolutionary status.These results indicated the conservation of the functions of SMP-related genes in C.marissinica,and the specific shape of the prismatic and nacreous layers of this deep-sea mollusc,which will contribute to the research on the molecular regulation mechanisms of biomineralization in C.marissinica and provide a new perspective to investigate biomineralization in deep-sea clams in general.

Mechanical Performance of Bio-inspired Bidirectional Corrugated Sandwich Pressure Shell Under External Hydrostatic Pressure

This paper aims to enhance the compression capacity of underwater cylindrical shells by adopting the corrugated sandwich structure of cuttlebone.The cuttlebone suffers uniaxial external compression,while underwater cylindrical shells are in a biaxial compressive stress state.To suit the biaxial compressive stress state,a novel bidirectional corrugated sandwich structure is proposed to improve the bearing capacity of cylindrical shells.The static and buckling analysis for the sandwich shell and the unstiffened cylindrical shell with the same volume-weight ratio are studied by numerical simulation.It is indicated that the proposed sandwich shell can effectively reduce the ratio between circumferential and axial stress from 2 to 1.25 and improve the critical buckling load by about 1.63 times.Numerical simulation shows that optimizing and adjusting the structural parameters could significantly improve the advantage of the sandwich shell.Then,the hydrostatic pressure tests for shell models fabricated by 3D printing are carried out.According to the experimental results,the overall failure position of the sandwich shell is at the center part of the sandwich shell.It has been found the average critical load of the proposed sandwich shell models exceeds two times that of the unstiffened shell models.Hence,the proposed bio-inspired bidirectional corrugated sandwich structure can significantly enhance the pressure resistance capability of cylindrical shells.

Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) prefer shells for nesting:A field experiment

Shorebird populations are declining worldwide,mainly due to human disturbances and loss of coastal wetlands.However,supratidal habitats as saltpans could play a role in buffering human impact.Saltpans have shown to be important as feeding or breeding sites of some shorebird species.A potential conservation strategy to increase shorebird populations in saltpans is to manipulate the cues that birds use to select optimal breeding habitat.Here it is hypothesized that shorebirds are attracted to bivalve shells due to the advantages they offer.Following this hypothesis,we supplemented a restored saltpan in 2019 and 2021 with bivalve shells,expecting an increase in the number of breeding birds’ nests.More than 75% of Kentish Plover(Charadrius alexandrinus) and Little Tern(Sternula albifrons) nests were found in patches with shells in both years.The best model for both species indicates that the presence of shells is the factor that most correlates with the location of nests.The probability of choosing one place over another to settle their nest increases in areas with an abundance of shells,double in the case of the Kentish Plover and triple in the case of the Little Tern.The result of this study may constitute a valuable tool for attracting birds to restored saltpans and could contribute to the success of expensive restoration projects where time is usually a constraint.

Theoretical and experimental investigation of the resonance responses and chaotic dynamics of a bistable laminated composite shell in the dynamic snap-through mode

The dynamic model of a bistable laminated composite shell simply supported by four corners is further developed to investigate the resonance responses and chaotic behaviors.The existence of the 1:1 resonance relationship between two order vibration modes of the system is verified.The resonance response of this class of bistable structures in the dynamic snap-through mode is investigated,and the four-dimensional(4D)nonlinear modulation equations are derived based on the 1:1 internal resonance relationship by means of the multiple scales method.The Hopf bifurcation and instability interval of the amplitude frequency and force amplitude curves are analyzed.The discussion focuses on investigating the effects of key parameters,e.g.,excitation amplitude,damping coefficient,and detuning parameters,on the resonance responses.The numerical simulations show that the foundation excitation and the degree of coupling between the vibration modes exert a substantial effect on the chaotic dynamics of the system.Furthermore,the significant motions under particular excitation conditions are visualized by bifurcation diagrams,time histories,phase portraits,three-dimensional(3D)phase portraits,and Poincare maps.Finally,the vibration experiment is carried out to study the amplitude frequency responses and bifurcation characteristics for the bistable laminated composite shell,yielding results that are qualitatively consistent with the theoretical results.

Mechanical property of cylindrical sandwich shell with gradient core of entangled wire mesh

To explore the wide-frequency damping and vibration-attenuation performances in the application of aerospace components,the cylindrical sandwich shell structure with a gradient core of entangled wire mesh was proposed in this paper.Firstly,the gradient cores of entangled wire mesh in the axial and radial directions were prepared by using an in-house Numerical Control weaving machine,and the metallurgical connection between skin sheets and the gradient core was performed using vacuum brazing.Secondly,to investigate the mechanical properties of cylindrical sandwich shells with axial or radial gradient cores,quasi-static and dynamic mechanical experiments were carried out.The primary evaluations of mechanical properties include secant stiffness,natural frequency,Specific Energy Absorption(SEA),vibration acceleration level,and so on.The results suggest that the vibration-attenuation performance of the sandwich shell is remarkable when the high-density core layer is at the end of the shell or abuts the inner skin.The axial gradient material has almost no influence on the vibration frequencies of the shell,whereas the vibration frequencies increase dramatically when the high-density core layer approaches the skin.Moreover,compared to the conventional sandwich shells,the proposed functional grading cylindrical sandwich shell exhibits more potential in mass reduction,stiffness designing,and energy dissipation.

Mechanistic investigation on Ag-Cu_(2)O in electrocatalytic CO_(2) to CH_(4) by in situ/operando spectroscopic and theoretical analysis

Silver-copper electrocatalysts have demonstrated effectively catalytic performance in electroreduction CO_(2) toward CH_(4),yet a revealing insight into the reaction pathway and mechanism has remained elusive.Herein,we construct chemically bonded Ag-Cu_(2)O boundaries,in which the complete reduction of Cu_(2)O to Cu has been strongly impeded owing to the presence of surface Ag shell.The interfacial confinement effect helps to maintain Cu^(+)sites at the Ag-Cu_(2)O boundaries.Using in situ/operando spectroscopy and theoretical simulations,it is revealed that CO_(2) is enriched at the Ag-Cu_(2)O boundaries due to the enhanced physisorption and chemisorption to CO_(2),activating CO_(2) to form the stable intermediate^(*)CO.The boundaries between Ag shell and the Cu_(2)O mediate local^(*)CO coverage and promote^(*)CHO intermediate formation,consequently facilitating CO_(2)-to-CH_(4) conversion.This work not only reveals the structure-activity relationships but also offers insights into the reaction mechanism on Ag-Cu catalysts for efficient electrocatalytic CO_(2) reduction.

Transient responses of double-curved sandwich two-layer shells resting on Kerr's foundations with laminated three-phase polymer/GNP/fiber surface and auxetic honeycomb core subjected to the blast load

This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fiber surface subjected to the blast load.Each of the two layers that make up the double-curved shell structure is made up of an auxetic honeycomb core and two laminated sheets of three-phase polymer/GNP/fiber.The exterior is supported by a Kerr elastic foundation with three characteristics.The key innovation of the proposed theory is that the transverse shear stresses are zero at two free surfaces of each layer.In contrast to previous first-order shear deformation theories,no shear correction factor is required.Navier's exact solution was used to treat the double-curved shell problem with a single title boundary,while the finite element technique and an eight-node quadrilateral were used to address the other boundary requirements.To ensure the accuracy of these results,a thorough comparison technique is employed in conjunction with credible statements.The problem model's edge cases allow for this kind of analysis.The study's findings may be used in the post-construction evaluation of military and civil works structures for their ability to sustain explosive loads.In addition,this is also an important basis for the calculation and design of shell structures made of smart materials when subjected to shock waves or explosive loads.

Full-Scale Isogeometric Topology Optimization of Cellular Structures Based on Kirchhoff-Love Shells

Cellular thin-shell structures are widely applied in ultralightweight designs due to their high bearing capacity and strength-to-weight ratio.In this paper,a full-scale isogeometric topology optimization(ITO)method based on Kirchhoff-Love shells for designing cellular tshin-shell structures with excellent damage tolerance ability is proposed.This method utilizes high-order continuous nonuniform rational B-splines(NURBS)as basis functions for Kirchhoff-Love shell elements.The geometric and analysis models of thin shells are unified by isogeometric analysis(IGA)to avoid geometric approximation error and improve computational accuracy.The topological configurations of thin-shell structures are described by constructing the effective density field on the controlmesh.Local volume constraints are imposed in the proximity of each control point to obtain bone-like cellular structures.To facilitate numerical implementation,the p-norm function is used to aggregate local volume constraints into an equivalent global constraint.Several numerical examples are provided to demonstrate the effectiveness of the proposed method.After simulation and comparative analysis,the results indicate that the cellular thin-shell structures optimized by the proposed method exhibit great load-carrying behavior and high damage robustness.

Snap-through behaviors and nonlinear vibrations of a bistable composite laminated cantilever shell:an experimental and numerical study

The snap-through behaviors and nonlinear vibrations are investigated for a bistable composite laminated cantilever shell subjected to transversal foundation excitation based on experimental and theoretical approaches.An improved experimental specimen is designed in order to satisfy the cantilever support boundary condition,which is composed of an asymmetric region and a symmetric region.The symmetric region of the experimental specimen is entirely clamped,which is rigidly connected to an electromagnetic shaker,while the asymmetric region remains free of constraint.Different motion paths are realized for the bistable cantilever shell by changing the input signal levels of the electromagnetic shaker,and the displacement responses of the shell are collected by the laser displacement sensors.The numerical simulation is conducted based on the established theoretical model of the bistable composite laminated cantilever shell,and an off-axis three-dimensional dynamic snap-through domain is obtained.The numerical solutions are in good agreement with the experimental results.The nonlinear stiffness characteristics,dynamic snap-through domain,and chaos and bifurcation behaviors of the shell are quantitatively analyzed.Due to the asymmetry of the boundary condition and the shell,the upper stable-state of the shell exhibits an obvious soft spring stiffness characteristic,and the lower stable-state shows a linear stiffness characteristic of the shell.

Technical note for intraoperative determination of proper acetabular cup size in primary total hip arthroplasty

BACKGROUND Selecting the optimal size of components is crucial when performing a primary total hip arthroplasty.Implanting the accurate size of the acetabular component can occasionally be exacting,chiefly for surgeons with little experience,whilst the complications of imprecise acetabular sizing or over-reaming can be potentially devastating.AIM To assist clinicians intraoperatively with a simple and repeatable tip in elucidating the ambivalence when determining the proper acetabular component size is not straightforwardly achieved,specifically when surgeons are inexperienced or preoperative templating is unavailable.METHODS This method was employed in 263 operations in our department from June 2021 to December 2022.All operations were performed by the same team of joint reconstruction surgeons,employing a typical posterior hip approach technique.The types of acetabular shells implanted were:The Dynasty®acetabular cup system(MicroPort Orthopedics,Shanghai,China)and the R3®acetabular system(Smith&Nephew,Watford,United Kingdom),which both feature cementless press-fit design.RESULTS The mean value of all cases was calculated and collated with each other.We distinguished as oversized an implanted acetabular shell when its size was>2 mm larger than the size of the acetabular size indicator reamer(ASIR)or when the implanted shell was larger than 4 mm compared to the preoperative planned cup.The median size of the implanted acetabular shell was 52(48–54)mm,while the median size of the preoperatively planned cup was 50(48–56)mm,and the median size of the ASIR was 52(50–54)mm.The correlation coefficient between ASIR size and implanted acetabular component size exhibited a high positive correlation with r=0.719(P<0.001).Contrariwise,intraoperative ASIR measurements precisely predicted the implanted cups’size or differed by only one size(2 mm)in 245 cases.CONCLUSION In our study,we demonstrated that the size of the first acetabular reamer not entering freely in the acetabular rim corroborates the final acetabular component size to implant.This was also corresponding in the majority of the cases with conventional preoperative templating.It can be featured as a valid tool for avoiding the potentially pernicious complications of acetabular cup over-reaming and over-sizing in primary total hip arthroplasty.It is a simple and reproducible technical note useful for confirming the predicted acetabular cup size preoperatively;thus,its application could be considered routinely,even in cases where preoperative templating is unavailable.

Study on Adsorption Removal of Polycyclic Aromatic Hydrocarbons by Modified Mussel Shells

Polycyclic aromatic hydrocarbons(PAHs)are typical persistent organic pollutants(POPs)that are commonly found in the environment.They are carcinogenic,teratogenic,mutagenic and biodegradable obviously.In this paper,the modified mussel shells were used to adsorb and remove anthracene.The results show that the adsorption removal rate of the mussel shells was higher after calcination at 600℃.5%H_(3)PO_(4) solution was more suitable for shell treatment than 3 mol/L ZnCl_(2) solution.As the dosage of the modified shells was 0.5 g/L,the adsorption reached a stable state,and the removal rate of PAHs was about 69.44%;the adsorption efficiency rose with the increase of time.It can be seen that as a new and cheap biological adsorbent,the modified shells can be used to remove PAHs from wastewater.

Gravitation, Density Upper Limit and Quantization of Space

The singularity at distance r → 0 at the center of a spherically symmetric non-rotating, uncharged mass of radius R, is considered here. Under inverse square law force, the Schwarzschild metric, needs to be modified, to include Newton’s Shell Theorem (NST). By including NST for r, both Schwarzschild singularity at r = 2GM/c2 and at r → 0 singularities are removed from the metric. Near R → 0, the question of maximal density is considered based on Schwarzschild’s modified metric, and compared to the quantum limit of maximal mass density put by Planck’s quantum-based universal units. It is asserted, that General relativity, when combined with Planck’s universal units, inevitably leads to quantization of gravity.