Elemental Composition and Geochemical Characteristics of Iron-Manganese Nodules in Main Soils of China

Elemental composition and geochemical characteristics of iron-manganese nodules from nine main soils in China were studied by chemical and multivariate statistical analyses to better understand the reactions and functions of iron-manganese nodules in soils and sediment. Compared to the corresponding soils, Mn, Ba, Cd, Co and Pb had strong accumulation, Ni had moderate accumulation, while Ca, Cu, Fe, Na, P, Sr and Zn accumulated to a minor degree in the iron-manganese nodules. In contrast, Si, Al, K, Mg and Ti were reduced in the iron-manganese nodules. The contents of Ba, Cd, Co, Cu, Ni, Pb and Zn were positively and significantly correlated with that of MnO2 in the iron-manganese nodules, while the contents of Cr, Cu, Ni, Pb and Zn were positively and significantly correlated with that of Fe2O3 in soils. Based on a principle component analysis, the elements of iron-manganese nodules were divided into four groups: 1) Mn, Ba, Cd, Co, Cu, Li, Ni, Pb and Zn that were associated with Mn oxides, 2) Fe, Cr and P that were associated with Fe oxides, 3) Si, K, and Mg that were included in the elemental composition of phyllosilicate, and 4) Ca, Na, Al and Ti that existed in todorokite, birnessite, lithiophorite and phyllosilicate. It was suggested that accumulation, mineralization and specific adsorption were involved in the formation processes of soil iron-manganese nodules.

Material Composition and Engineering Characteristics of Red Clay in Guigang, Guangxi

There is fine and uniform clay with aluminous and ferrous cementation in the red clay found in Guigang, Guangxi. It has the characteristics of shrinkage outwardly, rigid upper but soft lower and well grown fissure. In addition there are engineering characteristics such as high water content, low compactness and low compressibility, high strength and high contractility but slight expansibility. This paper discusses the red clay's engineering characteristics and its change regulation with depth by analyzing changes in the red clay's grain size composition, mineralogical constitution, and chemical composition.

Species Composition and Gear Characteristics of the Macrobrachium Fishery of the Cross River Estuary,Nigeria

The Cross River Estuary,Nigeria,is an important shrimping area for artisanal fishermen of the coastal communities.The multi-species Macrobrachium fishery is exploited with three main gears,namely beach seine,push net and trap.Studies on species composition of this fishery recorded thirteen shrimp species,one swimming crab (Callinectes amnicola) and two fish species (Eleotris sp.and Pellonula leonensis).The shrimp species identified included Macrobrachium macrobrachion (83.39% and 55.69% by number and weight,respectively),M.vollenhovenii (9.66% and 37.18%),M.equidens (3.8% and 2.87%),juveniles-sub-adults of Penaeus notialis (1.11% and 1.3%),M.dux,M.felicinum,Palaemonetes africanus,Palaemon maculatus,Palaemon elegans,Desmocaris sp.,Leander sp.,Nematopalaemon hastatus and Alpheus pontederiae.While the selectivity index for trap was 0.25,beach seine and push net had a lower index of 0.063.The results present the first comprehensive and representative report for the Estuary shrimp fishery and will assist in the management of the biodiversity of this ecosystem.

Sensory Characteristics, Nutritional Composition, and Quality of Eggs from Different Chickens

The present study evaluated the sensory, composition, and quality of eggs from Cosmopolitan (C), Improved Horro (H), ♂ Improved Horro * Cosmopolitan ♀ (HC), ♂ Cosmopolitan * Improved Horro ♀ (CH), Indigenous(L), and Koekoek (KK) genotypes. A completely randomized design was used in the study. A total of 108 (18/genotype), 180 (30/genotype), and 90 (15/genotype) eggs were used for the sensory, composition, and egg quality tests, respectively. All data were analyzed following the GLM model using SAS software. The boiled and scrambled eggs from L, H, and C were (P ≤ 0.001) preferred followed by CH, HC, and KK. Results showed that KK, HC, CH, and C eggs were higher in moisture, crude fat, crude ash, and crude fiber, but these traits were found lower in H and L genotypes. A significantly highest crude protein was observed in L (21.19 ± 0.19) genotype, with higher in H (20.62 ± 0.26), intermediate in HC (19.96 ± 0.29), C (19.85 ± 0.10), and CH (19.40 ± 0.37), whereas the eggs from KK genotype had the lowest crude protein content (18.69 ± 0.20). The egg quality was (P = 0.001 - 0.01) affected across traits except for eggshell indices (P > 0.05). The genotypes with a negative significant correlation with crude protein had a positive significant correlation with almost all composition and egg external quality traits. The genotypes with positive significant correlations of egg weight had positive significant correlations with most internal egg quality traits except that of yolk weight ratio, yolk albumen ratio, and yolk color. Conclusively: the eggs of L, H, and C genotypes were best favored followed by CH and C, but the KK genotype was the least favored, and these differences were deemed due to genetic variations, and interventions. Furthermore, the eggs laid from genotypes with deep yellow yolk color might be the most nutritious. It could also necessitate future breeding and dietary studies.

The study of fluorescence characteristics and biochemical composition of a marine diatom Thalassiosira pseudonana 3H in light and dark cyclesI. The effects of nutrients

The effects of nutrients on the fluorescence characteristics and biochemical composition of marine diatom Thalassiosira pseudonana 3H in light and dark cycles were investigated with continuous culture. The results show that with the increase of nutrient deficiency, the ratio of enhanced fluorescence to fluorescence (Fd/F), cellular chloropyll-a and protein content of the algae decline, but the fluorescence yield (F/Chl) , DCMU enhanced fluorescence yield (Fd/Chl) , cellular carbohydrate content, carbohydrate/Chl, protein/Chl, carbohydrate/protein increase. The changing amplitude of each parameter is different at different nutrition status, sampling time and different light intensity.

Effect of rock composition microstructure and pore characteristics on its rock mechanics properties

This paper is to study the influence of composition, microstructure and pore characteristics on the rock mechanical properties. Five kinds of sandstone compositions were analyzed by using X-ray diffraction instrument. And the microstructure was observed by using scanning electron microscope. Then the pore distribution characteristic was investigated by using the low field nuclear magnetic resonance equipment. Finally, the uniaxial compression test was carried out to investigate the mechanical characteristics by using RMT150C mechanics experimental system and the uniaxial compressive strength, Poisson's ratio and elastic modulus were obtained. Compared to the analysis of the composition, structure and pore distribution and mechanical properties of the five kinds of sandstones, the relationship among composition,structure, pore distribution and mechanical properties was obtained. The results show that the composition, microstructure, pore distribution and mechanical properties of sandstone are closely related.With the decrease of feldspar and quartz particles, the compressive strength and elastic modulus increase, while the porosity decreases.

National Characteristics and Art Composition Characteristics of Tujia Brocade Art

As one of China's national minorities, Tujia nationality has exerted an important role in the development course of modern national culture. In the development course of national culture of Tujia nationality, its brocade art inherited generation by generation has been extensively applied in art inheritance in modern society. It has also been applied in practical teaching to manifest the unique style and special artistic expression of Tujia brocade art. Under such a context, it is necessary to strengthen analysis on its national characteristics in the art development course and art composition characteristics. For this purpose, this paper makes special analysis on the national characteristics and art composition of Tujia brocade art in the sequence of analysis on the basic components of Tujia brocade art, analysis on its national characteristics and then detailed analysis on its composition characteristics. The author hopes to help people to understand the unique characteristics and results of Tujia brocade art after the analysis in this paper.

Leaf stable carbon isotope composition in Picea schrenkiana var. tianschanica in relation to leaf physiological and morphological characteristics along an altitudinal gradient

To understand the effects of leaf physiological and morphological characteristics on δ13C of alpine trees, we examined leaf δ13C value, LA, SD, LNC, LPC, LKC, Chla+b, LDMC, LMA and Narea in one-year-old needles of Picea schrenkiana var. tianschanica at ten points along an altitudinal gradient from 1420 m to 2300 m a.s.l. on the northern slopes of the Tianshan Mountains in northwest China. Our results indicated that all the leaf traits differed significantly among sampling sites along the altitudinal gradient(P<0.001). LA, SD, LPC, LKC increased linearly with increasing elevation, whereas leaf δ13C, LNC, Chla+b, LDMC, LMA and Narea varied non-linearly with changes in altitude. Stepwise multiple regression analyses showed that four controlled physiological and morphological characteristics influenced the variation of δ13C. Among these four controlled factors, LKC was the most profound physiological factor that affected δ13C values, LA was the secondary morphological factor, SD was the third morphological factor, LNC was the last physiological factor. This suggested that leaf δ13C was directly controlled by physiological and morphological adjustments with changing environmental conditions due to the elevation.

EXPERT SYSTEM FOR SINTER CHEMICAL COMPOSITION CONTROL BASED ON ADAPTIVE PREDICTION

In order to stabilize the sinter chemical composition,the expert system for composition control based on adaptive prediction has been developed on the basis of modern control theory and artificial intelligence.It has been verified by using real data at No.3 Sintering Plant of Anshan Iron and Steel Co.,and satisfactory results have been obtained.

Dynamic Characteristics of Long -Span Steel -Concrete CompositeBeam Bridge Based on Vehicle -Bridge Coupling Effect

In order to investigate the effect of vehicle-bridge coupling on the dynamic characteristics of the bridge,a steel-concrete composite beam suspension bridge is taken as the research object,and a three-dimensional spatial model of the bridge and a biaxial vehicle model of the vehicle are established,and then a vehicle-bridge coupling vibration system is constructed on the basis of the Nemak-βmethod,and the impact coefficients of each part of the bridge are obtained under different bridge deck unevenness and vehicle speed.The simulation results show that the bridge deck unevenness has the greatest influence on the vibration response of the bridge,and the bridge impact coefficient increases along with the increase in the level of bridge deck unevenness,and the impact coefficient of the main longitudinal girder and the secondary longitudinal girder achieves the maximum value when the level 4 unevenness is 0.328 and 0.314,respectively;when the vehicle speed is increased,the vibration response of the bridge increases and then decreases,and the impact coefficient of the bridge in the middle of the bridge at a speed of 60 km/h achieves the maximum value of 0.192.

Effect of High Temperature Annealing on Characteristics of 4H Silicon Carbide MESFET

For very high temperature annealing (1620℃) after ion implantation for 4H silicon carbide (4H SiC),the residual components of Al and O in the alundum furnace impact seriously on the surface of material,which yields the derivation of SiOC.This causes a significant degradation of the 4H SiC surface characteristics according to the results of surface composition analysis.As validity,Ni/SiC ohmic contact measurement illustrates a higher specific contact resistance than the normal value by a factor of 2～3.Consequently the MESFET fabricated with this kind of 4H SiC material results in a degraded I V output performance compared with that of normal 4H SiC MESFET.

Research on Nourishing Compositions of Fagopyrum tataricum

[Objective] The aim was to identify the nourishing compositions of Fagopyrum tataricum and screen high-quality buckwheat materials.[Method]A total of 10 species of buckwheat including T32,T31,T30,T14,T28,T23,T24,Jiujiang Buckwheat,Weiku 2 and WK-1 were employed as experimental materials,and the contents of the nutritional components（including total sugar,reducing sugar,starch,amylose,amylopectin and protein）,flavonoids content,physical and chemical characteristics（such as expansive force,water holding capacity）of them were respectively measured.[Result]There were significant differences in contents of soluble protein,total sugar,reduced sugar,amylase and expansive force among the cultivars,but the differences in contents of total starch,amylopectin,flavonoids content and water holding capacity were not significant.[Conclusion]The starch content in seeds of buckwheat was relatively high,and amylopectin was the main composition.

To Be an Expert Learner: New Characteristics of a Good Teacher in the New Era

The past decades have seen much plethora of publications about what makes a good teacher. Many of these have fallen into content of educational tips and advice on such guides as organizing and assessing students' learning and behaviour and ignored such matters as that a teacher should be an expert learner in this dramatically changing society. This paper suggests that to keep exploring good teaching and to be an expert learner as two essential strategies of getting charismatic characteristics of a good teacher in the new era.

Mineralogical Characteristics of Exsolved Spinel in the Panzhihua V-Ti Magnetite Deposit, Sichuan: Implications for the Mineralization Process

Spinel exsolution is widespread in titanomagnetite from the Fe-Ti oxide gabbro of the Panzhihua intrusion, Emeishan Large Igneous Province, SW China. However, little research has been conducted into the implications of patterns in the mineralogical characteristics of the spinel for spatial variation in the controls on the exsolution mechanism and, hence, the formation process of the ore deposit. This study selected the Lanjiahuoshan Ore Block in the Panzhihua V-Ti magnetite deposit to explore this issue, systematically studying exsolution textures in the titanomagnetite through petrographic observation and the integrated use of in-situ microanalysis. The results show that the exsolved spinel gradually becomes finer-grained and less abundant from the center to edge and the bottom to top of the ore bodies. Compositionally, there is an inverse correlation between the size of exsolved spinel grains and their Mg# value. In addition, there is compositional zonation in the spinel interiors, with a gradual increase in the Mg content and decrease in Fe content from the core to the rim. The analysis suggests that fractional crystallization of ferrotitanium magma with a high oxygen fugacity in a shallow magma chamber caused compositional differences in the primary magnetite solid solution in different parts of the Panzhihua intrusion. Additionally, the thermal evolution of the magnetite solid solution differed in different parts of orebody, bringing about variations in spinel development. Together, these effects resulted in spatial variation in the abundance, grain size, and morphology of spinel in different parts of the orebody and intrusion that follows an identifiable distribution law. Furthermore, the compositional zonation of exsolved spinels reflects the rapid growth of exsolution features in a high-temperature environment. Thus, the size, morphology, abundance, and composition of spinel exsolution features in titanomagnetite provide a valuable petrogenetic tool for estimating the maturity and formational environment of the deposit.

Science Letters:Nutritional composition of Pakistani wheat varieties

Pakistani wheat varieties are grown over a wide agro-climatic range and as such are anticipated to exhibit yield and quality differences. It is therefore necessary to investigate the nutritional status of wheat varieties in terms of biochemical and physiochemical characteristics available for food and nutritional purposes in Pakistan. The result shows that wheat grains of different varieties contain a net protein level of 9.15%～10.27%, 2.15%～2.55% total fats, 1.72%～1.85% dietary fibers, 77.65×10-6～84.25×10-6 of potassium and 7.70×10-6～35.90×10-6 of sodium ions concentration, 0.24×10-6～0.84×10-6 of phosphorus, 1.44%～2.10% ash, 31.108～43.602 g of thousand grain mass (TGM) and 8.38%～9.67% moisture contents. This study is significant in providing an opportunity to explore the available wheat varieties and to further improve their nutritional excellence and also essential for setting nutritional regulations for domestic and export purposes.

Study on Chemical Characteristics of Rainfall in Tobacco-Growing Regions of Chenzhou, Hunan Province

In order to clarify the chemical properties of rainfall in typical tobacco areas in Chenzhou City, Hunan Province, and analyze its potential for soil and flue-cured tobacco planting, rainfall samples in 2020 were collected by rainfall instruments in Fangyuan Town and Aoquan Town of Guiyang County, and the chemical properties that are closely related to the quality of flue-cured tobacco were determined, such as pH, EC, total nitrogen (TN), nitrate nitrogen (), ammonium nitrogen () and ion concentrations (K+, Na+, Ca2+, Mg2+, , Al3+, , Cl−,). The results show that the pH values of rainfall samples at Fangyuan and Aoquan monitoring sites are in the range of 4.92 - 6.17 and 4.93 - 5.69 respectively, with an average of 5.27 and 5.27 respectively. The acid rain characteristic is very obvious, which is mainly dominated by . The variation of rainfall EC has seasonal characteristics. EC is low from January to September, in the range of 6.09 - 56.72 and 11.83 - 30.93 μS/cm respectively, besides, it is high from October to December, in the range of 102.63 - 174.60 and 25.05 - 86.37 μS/cm respectively. The annual deposition of TN was 22.19 and 20.76 kg/hm2/yr respectively, which were higher than that in the western regions with less human disturbance, but lower than or equal to that in the developed agricultural regions in eastern China. The proportion of in the annual deposition of TN was higher than that of at two monitoring sites, with an average of 56.51% and 38.86% respectively. Ammonia volatilization from agricultural activities contributed more to rainfall nitrogen content. The ratios of ammonium nitrogen to nitrate nitrogen deposition at two monitoring points were 1.84, 1.81, 1.86 and 1.34, 1.46, and 1.29 during the whole year, summer and autumn, winter and spring respectively. The ratio is higher in summer and autumn than in winter and spring. The weighted average equivalent concentrations of the main ions at two monitoring sites were 238.88 μeq/L and 211.21 μeq/L respectively, and the orders of the ion concentrations were slightly different. Both the concentrations of and are higher, while Mg2+, and Al3+ are lower. , and are mainly from human activities with a contribution rate between 91.90% and 99.35%. Ca2+ mainly comes from soil and ground dust, besides, Cl− and Mg2+ mainly come from marine sources and K+ mainly comes from terrestrial sources. In general, the acidic rainfall and higher concentration are beneficial to reducing the high pH value of soil in Aoquan tobacco area and improving the quality of flue-cured tobacco. Higher concentrations of and in rainfall are not conducive to the improvement of flue-cured tobacco quality, because of the high content of soil available sulfur in Chenzhou tobacco area and the characteristics of flue-cured tobacco’s preference for ammonium.

Effect of microbial fermentation on the sensory characteristics and chemical compositions of Chinese sweet tea(Lithocarpus litseifolius(Hance)Chun)

Sweet tea,which has hundreds of years of use among in Chinese folk,is a traditional herbal tea with pleasant sweetness,bitterness and astringency.In the current study,we used traditional microbial fermentation to improve sensory characteristics of sweet tea,especially for the reduction of bitterness and astringency.The dynamic changes of non-volatile,volatile compounds and microbial community were investigated during microbial fermentation.The contents of polyphenols,flavonoids,soluble sugar,soluble protein,catechins and dihydrochalcones decreased significantly while the tea pigments,free amino acids and gallic acid content inversely increased during microbial fermentation.A total of 61 volatile compounds were identified and quantified in sweet tea,of which 20 key compounds were identified as odor active compounds(OAV),including 3 aldehydes,1 ketone,4 alcohols,9 esters,4 alkenes and 3 other compounds.In addition,eight fungi and four bacteria were considered as core microorganisms,such as Aspergillus,Alternaria,Cladosporium,Epicoccum,Itersonilia,Penicillium,Periconia,Wallemia,Aureimonas,Enterobacter,Klebsiella and Stenotrophomonas,which were significantly correlated with non-volatile compounds and flavor compounds.These results provided theoretical guidance for processing of fermented sweet tea.

Discharge characteristics of different lightning air terminals under composite voltages

Different types of lightning air terminals have been designed over the years.Concern regarding the effect of different types of air terminals,especially the early streamer emission(ESE)-type,remains controversial.This paper describes the discharge characteristics of different types of air terminals,two of which are quite similar to the ESE-type dynasphere,and concludes that the tested non-standard air terminals have discharge characteristics similar to those of Franklin rods and that their lightning protection performance should be similar.

Microstructure characteristics of Ni/WC composite cladding coatings

A multilayer tungsten carbide particle（WCp）-reinforced Ni-based alloy coating was fabricated on a steel substrate using vacuum cladding technology.The morphology,microstructure,and formation mechanism of the coating were studied and discussed in different zones.The microstructure morphology and phase composition were investigated by scanning electron microscopy,optical microscopy,X-ray diffraction,and energy-dispersive X-ray spectroscopy.In the results,the coating presents a dense and homogeneous microstructure with few pores and is free from cracks.The whole coating shows a multilayer structure,including composite,transition,fusion,and diffusion-affected layers.Metallurgical bonding was achieved between the coating and substrate because of the formation of the fusion and diffusion-affected layers.The Ni-based alloy is mainly composed of y-Ni solid solution with finely dispersed Cr7C3/Cr（23）C6,CrB,and Ni＋Ni3Si.WC particles in the composite layer distribute evenly in areas among initial Ni-based alloying particles,forming a special three-dimensional reticular microstructure.The macrohardness of the coating is HRC 55,which is remarkably improved compared to that of the substrate.The microhardness increases gradually from the substrate to the composite zone,whereas the microhardness remains almost unchanged in the transition and composite zones.

Relationship between Environmental Pollution of Coal Mine and Spectral Characteristics of Nearby Plants

Remote sensing technology, as the most advanced method for collecting data, along with the common ways often used in the past on research of environmental science, was integrated to study the relationship between environmental pollution of coal mine and spectral characteristics of nearby plants. With compositive index and mean reflectivity at near infrared, a regression equation was established, and a conclusion was made that spectral reflectivity can be used to distinguish regions with different pollution degree. Through testing with real status of the research region, it is verified that this kind of integration and conclusion not only are helpful for human being in controlling the movement law of pollutants and the corresponding change of coal mine environmental quality but also bring a new way for the research of environment problems of coal mine.