Effects of Functional Organic Materials on Morphological Indexes,Quality and Yield of Watermelon

[Objectives]This study was conducted to explore suitable organic compound application models for watermelon growth.[Methods]With watermelon hybrid material"M22×P18"as the test material,the effects of four functional organic materials,namely garlic straw treatment(T_(1)),onion straw treatment(T_(2)),garlic straw+sheep manure treatment(T_(3))and onion straw+chicken manure treatment(T_(4)),on the morphological indexes,yield and quality of watermelon were investigated.[Results]Different functional organic materials had different effects on morphological indexes,yield and quality of watermelon.The morphological indexes,nutritional quality indexes and yield of watermelon treated with garlic straw and sheep manure compound(T_(3))and onion straw and chicken manure compound(T_(4))were significantly higher than those treated simply with garlic straw(T_(1))and onion straw(T_(2)),and T_(3)performed relatively better.Compared with treatment T_(2),T_(3)showed a stem diameter,vine length and leaf number increasing by 43.05%,46.69%and 40.77%respectively,central sugar and side sugar contents increasing by 11.72%and 21.90%respectively,and a yield increasing by 42.91%,with significant differences from T_(2).[Conclusions]This study provides technical support for high-quality and high-yielding cultivation of watermelon.

A New Approach to the Calculation of Work Index and the Potential Energy of a Particulate Material

The work index Wi was defined by F. Bond as the specific energy (kWh/ton) required to reduce a particulate material from infinite grain size to 100 microns. The calculation is based on the size-energy relationship e1,2=C.(1/x2n–1/x1n ) , which for n = 0.5, x1 = ∞ and x2 =100, by definition gives e∞, 100 = Wi and consequently C=10Wi. In theory, for a given material the value found for Wi.should be constant regardless of the measured sizes x1 and x2 used to calculate the constant C by measuring the energy e. In practice this is not so due to the fact that n ≠ 0.5 and many correction factors have been proposed to overcome this inadequacy experienced by accepting n= 0.5. The present paper proposes a simple way to calculate the appropriate exponent n using conventional grinding procedures. The same calculation can be used to calculate the true value of Wi and attribute a potential energy state to a material at any size.

NUMERICAL SIMULATION METHODS AND THEIR APPLICATION IN MATERIAL HOT-WORKING

With the development of modern science and technology, especially computer science, the numerical simulation method has been widely used in material hot-working. Mary achievements have been made in this field by using the numerical simulation method. The numerical simulation method, especially finite element method fully described in this paper.Applications of the numerical simulation method in material hot-working are also discussed. Finally, the future of the numerical simulation method is outlined.

Work Ability Index and Work Ability Score: A Comparation between both Scores in a Persistent COVID-19 Cohort

Aims: The present study aims to compare the assessment of work ability based on the use of the Work Ability Index (WAI) with another questionnaire base only on the use of WAI’s first item, termed as the “Work Ability Score” (WAS). Study design: A cohort of 384 Spanish workers included in a Post COVID-19 condition or persistent COVID-19 multicenter research was utilized. Place and Duration of Study: This cohort was enlisted in four hospitals (Hospital Universitario 12 de Octubre, Madrid;Hospital Universitario Virgen Macarena, Sevilla, Andalucía;Hospital Universitario Gregorio Marañón, Madrid and Complejo Asistencial Universitario de Salamanca, Castilla y León), since 2021 until 2022. Methodology: 384 Spanish workers (176 men and 208 women;aged 20 to 70 years) with Post COVID-19 condition or persistent COVID-19 were included. Descriptive analysis of primary scores was conducted. Given the non-normal distribution of data, the Mann-Whitney and Kruskal-Wallis tests were employed. Spearman and Kendall correlations were employed to assess the relationship between WAI and WAS, also used weighted Kappa to estimate the degree agreement between WAI and WAS. Logistic regression models were utilized to study determinants influencing WAI and WAS, categorized as poor or moderate. Results: WAI had an average score of 32.98 (SD = 10.28), whereas WAS had an average of 5.95 (SD = 2.77). Significant differences were observed in both WAI and WAS across the same variables. Strong and statistically significant correlations were evident between WAI and WAS (rs = 0.83, p < 0.001). All the variables used in the logistic regression model (gender, the sector employment, and previous chronic diseases) were statistically significant in both questionnaires. Conclusion: WAS questionnaire could be used as a tool for reliable assessment of work ability among Spanish workers with Post COVID-19 condition or Persistent CO-VID-19.

Investigation of interface materials for enhancing stability in nonfullerene solar cells

Organic solar cells(OSCs)have attracted attention due to their lightweight nature,flexibility,and facile preparation using solution-based methods.Their efficiency has been further elevated by the rapid advancement of nonfullerene materials,achieving individual cell efficiencies that surpass 19%.Hence,the stability of nonfullerene solar cell production must be scrutinized.The stability of the cathode interface layer significantly impacts the overall stability of OSC devices.PFN-Br,a commonly employed cathode interface material,is susceptible to degradation due to its sensitivity to environmental humidity,consequently compromising the device stability.In this study,we introduce fluorescent dye molecules,rhodamine 101,as cathode interface layers in OSCs to establish device stability and assess their universality.A comparative investigation of rhodamine 101 and PFN-Br devices demonstrates the former’s distinct advantages in terms of thermal stability,photostability,and storage stability even without encapsulation,particularly in an inert environment.By employing the Kelvin probe,we compare the work function of different cathode interface films and reveal that the work function of the rhodamine 101 interface material remains relatively unaffected by environmental factors.As a consequence,the device performance stability is significantly enhanced.The application of such fluorescent dye molecules extends the scope of cathode interface layers,amplifies device stability,and propels industrialization.

Qualitative Analysis of Relationship between Refractive Index and Atomic Parameters of Solid Materials

The refractive index is one of the important parameters describing the optical properties of solid materials. However, it is difficult to obtain a quantitative relation between the refractive index and the structure and composition of materials. A qualitative relation between the refractive index and some atomic parameters of materials was proposed and demonstrated by some oxide optical crystals. A parameter P=r~-/F=r~-/(r~+ΔxD) is defined, in which Δx is the difference of the electronegativities between cations and anions in the materials and r~+ and r~- are the radii of cations and anions respectively. On the other hand, the factor D was introduced to describe the effect of mass difference of the ions. It is demonstrated by both theoretical discussion and experimental data that refractive index is a decreasing function of parameter P. The relation may be useful for the investigation of optical materials.

Aberration-free two-thin-lens systems based on negative-index materials

Since the complete correction of all five monochromatic Seidel aberrations for a singlet lens with random shape or a two-thin-lens system is unprocurable merely by using the conventional positive-index materials both in theory and practice, this paper proposes that when one or both of the two lenses is/are made from negative-index materials, an imaging system composed of a pair of spherical thin lenses is possible to form a real image, in air, free from all five monochromatic Seidel aberrations. The calculated numerical solutions to the structural parameters of such lens systems possessing superior performance are provided and examples of them are illustrated for the given combinations of the two lenses＇ refractive indices, including an ultimately-remote imaging system.

Exploration of Work Manual Teaching Materials in Higher Vocational Education

In order to thoroughly implement the national vocational education reform plan,vocational colleges and universities have vigorously promoted the reform of teaching materials.As a new form of teaching material,work manual teaching materials highlight the characteristics of vocational education,provide the direction of vocational education textbook reform,and act as the foundation of the“three education”reform in vocational colleges.Based on the analysis of the current situation of the construction of teaching materials for higher vocational education,we explore the ideas for the development of work manual teaching materials,aiming to provide some reference for the development of teaching materials for vocational education in the new era.

新型电介质:Metamaterials(特异材料)与光子晶体材料

作者对目前国际研究热点的Metamaterials(有特异材料,奇异材料,超常材料,左手性材料,负折射率材料,异向材料,元材料等多种中文译名)与光子晶体材料(即光子带隙材料、电磁波带隙材料)的原理与构成方法作了基本的介绍.作者还讨论了这两类新型电介质的共性问题与个性问题.并且讨论与介绍了这两类新型电介质材料的实现方法与应用前景,同时就这两类材料在微波频段的应用与制备技术作了专门的讨论.

Recent Advances in Design Strategies and Multifunctionality of Flexible Electromagnetic Interference Shielding Materials

With rapid development of 5G communication technologies,electromagnetic interference(EMI)shielding for electronic devices has become an urgent demand in recent years,where the development of corresponding EMI shielding materials against detrimental electromagnetic radiation plays an essential role.Meanwhile,the EMI shielding materials with high flexibility and functional integrity are highly demanded for emerging shielding applications.Hitherto,a variety of flexible EMI shielding materials with lightweight and multifunctionalities have been developed.In this review,we not only introduce the recent development of flexible EMI shielding materials,but also elaborate the EMI shielding mechanisms and the index for"green EMI shielding"performance.In addition,the construction strategies for sophisticated multifunctionalities of flexible shielding materials are summarized.Finally,we propose several possible research directions for flexible EMI shielding materials in near future,which could be inspirational to the fast-growing next-generation flexible electronic devices with reliable and multipurpose protections as offered by EMI shielding materials.

Weathering and soils formation on different parent materials in Golestan Province,Northern Iran

Geochemical, mineralogical, and micromorphologieal characteristics of soils and their relevant parent rocks including loess, ignimbrite, sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province, northern Iran. Highly developed Caleixerolls and moderately developed Haploxerepts were formed on loess and limestone, respectively. In contrast, the soils formed on ignimbrite and sandstone were non- developed Entisols. Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material. In loess derived soils however, smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation. In limestone, illite and vermiculite were dominant both in the A and C horizons. Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically. Chemical index of alteration （CIA）, micromorphological index of soil development （MISECA）, smectite/illite＋chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development. Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively. Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.

Analysis of optical properties of bio-smoke materials in the 0.25–14 μm band

At present, research into optical properties of bio-smoke materials mostly concentrates on single band or single germplasm. Herein, we measured the spectral reflectance of three eukaryotic bio-smoke materials and three prokaryotic bio-smoke materials in the waveband from 0.25 μm to 14μm. Based on the Kramers-Kroning algorithm, the complex refractive index m(λ) was calculated and the Fourier-transform infrared(FTIR) spectra of materials were analyzed. The results show that n(λ) of bio-smoke materials varies between 1.1-2, and n(λ) values in the visible light to near-infrared wavebands are significantly larger than those in other wavebands. The k(λ) of bio-smoke materials varies between 0-0.4.At 6-6.5 μm, k(λ) of prokaryotic materials is 3 times that of eukaryotic materials, which is caused by C=O stretching vibration of amide I and C-N stretching vibration of amide Ⅱ in proteins. At 2.5-3 μm and 9.75 μm, k(λ) values of eukaryotic bio-smoke materials are nearly 2 times that of prokaryotic ones. The absorption peak at 2.5-3 μm is mainly triggered by C-H stretching vibration in lipid and O-H stretching vibration in bound water. The absorption peak at 9.75 μm is mainly caused by symmetric stretching vibration of PO2-in nucleic acids.

Stopband Phenomena in the Passband of Left-Handed Metamaterials

Stopband phenomena are reported in the passband of left-handed metamaterials. The samples with linear defect are designed by removing one layer of split ring resonators （SRRs）. It is shown that the left-handed transmission peaks have a distinct transform with the relative deviation of the SRRs centre from the wire centre 8, from a single left-handed peak, double left-handed peaks with different magnitude to no transmission peak, i.e. left-handed properties of metamaterials disappear. Numerical simulation shows that the change of 8 makes the effective permeability shift at a frequency range, where stopband occurs. It is thought that the stopband in left-handed passband is due to the symmetry breaking between SRRs and wires in the metamaterials.

THEORETICAL MODEL OF EFFECTIVE STRESS COEFFICIENT FOR ROCK/SOIL-LIKE POROUS MATERIALS

Physical mechanisms and influencing factors on the effective stress coefficient for rock/soil-like porous materials are investigated, based on which equivalent connectivity index is proposed. The equivalent connectivity index, relying on the meso-scale structure of porous material and the property of liquid, denotes the connectivity of pores in Representative Element Area （REA）. If the conductivity of the porous material is anisotropic, the equivalent connectivity index is a second order tensor. Based on the basic theories of continuous mechanics and tensor analysis, relationship between area porosity and volumetric porosity of porous materials is deduced. Then a generalized expression, describing the relation between effective stress coefficient tensor and equivalent connectivity tensor of pores, is proposed, and the expression can be applied to isotropic media and also to anisotropic materials. Furthermore, evolution of porosity and equivalent connectivity index of the pore are studied in the strain space, and the method to determine the corresponding functions in expressions above is proposed using genetic algorithm and genetic programming. Two applications show that the results obtained by the method in this paper perfectly agree with the test data. This paper provides an important theoretical support to the coupled hydro-mechanical research.

ON SOME BASIC PRINCIPLES IN DYNAMIC THEORY OF ELASTIC MATERIALS WITH VOIDS

According to the basic idea of dual-complementarity,in a simple and unified way proposed by the author,some basic principles in dynamic theory of elastic materials with voids can be established sys- tematically.In this paper, an important integral relation in terms of convolutions is given,which can be con- sidered as the generalized principle of virtual work in mechanics.Based on this relation,it is possible not on- ly to obtain the principle of virtual work and the reciprocal theorem in dynamic theory of elastic materials with voids,but also to derive systematically the complementary functionals for the eight-field,six-field, four-field and two-field simplified Gurtin-type variational principles.Furthermore,with this approach,the in- trinsic relationship among various principles can be explained clearly.

Continuum Constitutive Modeling for Isotropic Hyperelastic Materials

The partial differential equation for isotropic hyperelastic constitutive models has been postulated and derived from the balance between stored energy and stress work done. The partial differential equation as a function of three invariants has then been solved by Lie group methods. With geometric meanings of deformations, the general solution boils down to a particular three-term solution. The particular solution has been applied for several isotropic hyperelastic materials. For incompressible materials, vulcanized rubber containing 8% sulfur and Entec Enflex S4035A thermoplastic elastomer, three coefficients have been determined from uniaxial tension data and applied to predict the pure shear and equibiaxial tension modes. For a slightly compressible rubber material, the coefficients have also been extracted from the confined volumetric test data.

Performance of n-type silicon/silver composite anode material in lithium ion batteries: A study on effect of work function matching degree

In this paper, two types of silicon（Si） particles ball-milled from n-type Si wafers, respectively, with resistivity values of 1 Ω·cm and 0.001 Ω·cm are deposited with silver（Ag）. The Ag-deposited n-type 1-Ω·cm Si particles（nl-Ag） and Ag-deposited n-type 0.001-Ω·cm Si particles（n0.001-Ag） are separately used as an anode material to assemble coin cells,of which the electrochemical performances are investigated. For the matching of work function between n-type 1-Ω·cm Si（nl） and Ag, nl-Ag shows discharge specific capacity of up to 683 mAh·g^-1 at a current density of 8.4 A·g^-1, which is40% higher than that of n0.001-Ag. Furthermore, the resistivity of nl-Ag is lower than half that of n0.001-Ag. Due to the mismatch of work function between n-type 0.001-Ω·cm Si（n0.001） and Ag, the discharge specific capacity of n0.001-Ag is 250.2 mAh·g^-1 lower than that of nl-Ag after 100 cycles.

Determination of Work Index of Gyel-Bukuru Columbite Ore in Plateau State, Nigeria

Determination of the work index of Gyel-Buruku columbite ore sample in Plateau state, Nigeria, was investigated. The sample of the columbite ore was sourced from Gyel village in Jos East Local Government Area of Plateau state, Nigeria. The “reference ores (granites)” samples were sourced from Jiche and Gurum villages of Plateau state respectively. The reference ores and columbite ore of known weights were ground and pulverized. 80% passing size for the columbite ore, Jiche and Gurum granites samples was obtained at 100 μm sieve size for the feeds and products respectively. The work indexes of reference ores i.e. Jiche and Gurum granites were used to calculate the work index of the Gyel columbite ore sample. The values of 3.42 kWh/ton and 2.72 kWh/ton were obtained respectively for the two different reference granites ores samples used and 3.07 kWh/ton was calculated as their average and determined as the value of the work index of the Gyel-Bukuru columbite ore sample. This work index value obtained for the Gyel-Buruku columbite ore sample lies favourably within the work indexes of 3.94 - 10.81 kWh/ton for columbite minerals sighted in the literatures.

Heat Transfer Characteristics of Work Fluid Including Phase Change Material That Flow into Heating Surface from Narrow Path

Use of the low temperature (less than 100°C) energy contributes to effective use of heat resources. The cost recovery by power generation is difficult by using an existing system (the binary cycle or the thermoelectric conversion element), because the initial investment is large. The final purpose of this research is development of the low temperature difference drive engine supposing use in a hot-springs resort as a power source for electric power generation. In order that a traveler may look at and delight a motion of an engine, it is made to drive at low-speed number of rotations. An engine cycle of this study is aimed at the development of Stirling cycle engine which can maintain high efficiency in small size. This kind of engine has simple structure;it brings low cost, and it is easy to perform maintenance. However, it is difficult to obtain enough output by this type of engine, because of its low temperature difference. This paper deals with the heat transfer characteristic that the working fluid including a phase change material flows into the heating surface from the narrow path. In order to increase the amount of the heat transmission, Diethylether is added to the working fluid. Diethylether is selected as a phase change material (PCM) that has the boiling point which exists between the heat source of high temperature and low temperature. The parameters of the experiment are additive amount of PCM, rotational speed of the displacer piston and temperature of heat transfer surface. It is shown that it is possible to make exchange of heat amount increase by adding phase change material. The result of this research shows the optimal condition of the difference in temperature in heat processing, number of revolutions, and addition concentration of PCM.