Oviposition Site Preference and Its Effects on Subsequent Development of Variegated Grasshopper (Zonocerus variegatus L.) under Laboratory Conditions

Female grasshoppers can affect the fitness of their offspring through their selection of oviposition site. Knowledge of soil type on oviposition, and its effects on subsequent development can provide guidelines for habitat manipulations that reduce the harmful effects of these pests on farmers fields. The influence of soil types on the oviposition site preference of variegated grasshopper (Zonocerus variegatus L.) reared some cassava (Manihot esculenta Crantz) varieties, was investigated in a cage trial carried out at the Bio factory laboratory, School of Agriculture and Food Sciences, Njala University, Sierra Leone during 2022/2023. The treatments comprised three soil types (Sandy, Loamy and Clay), each with three replications laid out in a randomized complete block design (RCBD) in wooden cages. Data were collected on the following development parameters including, Net reproductive growth ratio (R0), Generation time (Tc), Intrinsic rate of increase (rm), Finite rate of increase (), Doubling time (Dt), and overall survivorship. Findings revealed that, Z. variegatus L. preferred sandy soil in which, on average, most eggs were deposited (338, 6.62 4.40), followed by loamy soil, 286 (5.53 3.96), and then, clayey soil, 200 (3.91 3.85);though, the differences were not significant. This study established that Z. variegatus deposited more eggs in sandy soil > loamy soil > clayey soil, respectively;and subsequent survivorship of the immature unto mature adult insect, revealed a similar order. This indicates that the sandy soil is the most preferred substrate for oviposition and subsequent development into adult insects.

Site preference and thermodynamic properties of R_3Ni_(13-x)Co_xB_2(R=Y,Nd and Sm)

This paper investigates the structural stability of intermetallics R3Ni13-xCoxB2 （R=Y, Nd and Sm） with Nd3Ni13B2-type structure and the site preferences of the transition element Co by using a series of interatomic pair potentials. The space group remains unchanged upon substitution of Co for Ni in R3Ni13-xCoxB2 and the calculated lattice constants are found to agree with reports in literatures. The calculated cohesive energy curves show that Co atoms substitute for Ni with a strong preference for the 3g sites and the order of site preference is 3g, 4h and 6i. Moreover, the total and partial phonon densities of states are first evaluated for the R3Ni13B2 compounds with the hexagonal Nd3Nil3B2-type structure.

Atomistic simulation of site preference,Curie temperature,and lattice vibration of Nd_2Co_(7-x)Fe_x

The effects of Fe substitution for Co on the structural stability and the site preference of intermetallics Nd2CoT-xFex with a hexagonal Ce2NiT-type structure are studied by using a series of interatomic pair potentials. In Nd2CoT-xFex, Fe atoms are substituted for Co atoms with a strong preference for the 6h sites and the order of site preference is 6h, 4e, 4f, 2a, and 12k. Calculated lattice parameters are found to be consistent with the reported results in the literature. The variation behaviour of the Curie temperature of Nd2CoT-xFex is explained qualitatively by the exchange interaction model. The properties related to lattice vibration, such as phonon density of states and Debye temperature, are first evaluated for the Nd2Co7 xFex compounds.

Nest Site Preference and Fidelity of Chinese Alligator (Alligator sinensis)

Oviparous female reptiles select nesting sites with optimal ecological factors that contribute to egg development. Chinese alligator （Alligator sinensis）, an oviparous reptile, is a critically endangered crocodilian with temperature-dependent sex determination. Research on its nesting behavior may facilitate the protection of this species. In this study, we monitored nesting behavior over eight years. We compared selected frequency of nest sites, distance from nest site to water, height from nest site top to the water surface, distance from nest site to human activity region, and canopy density between nest sites on the island and bank. The results showed that 45 nest sites were used by female alligators over eight years and each site was selected from one to 10 times. The selected frequency of nest site occurrence on the island was higher than that on the bank （P 〈 0.001）. We observed that 88% of the individual alligators （15/17） showed different degrees of nest site fidelity. However, Chinese alligators might not always be loyal to only one nest site because of environmental changes or interspecific competition at nest sites. Our findings suggest that female alligators prefer to nest at island, which might be because of the nests on the island had a higher canopy density （P = 0.010） and were further from the human activity region （P 〈 0.001） than those on the bank did. It would be beneficial to reduce human activities during the breeding season and protect the vegetation of Chinese alligator habitats in the future.

Site preferences and lattice vibrations of Nd_6Fe_(13-x)T_xSi(x=Co, Ni)

The site preferences of the rare earth intermetallics Nd6Fe13-xTxSi（T = Co, Ni） are investigated by using interatomic pair potentials which are converted from a lattice-inversion method. Calculation shows that the order of the site preference of Co is 4d, 16 k, 16l1, and 16l2 and that of Ni is 16l2, 16l1, 16 k, and 4d in Nd6Fe13-xTxSi. Calculated lattice and positional parameters are found to agree with those reported in the literature. Furthermore, the phonon density of states for Nd6Fe13-xTxSiis also evaluated, and a qualitative analysis featuring the coordination and the relevant potentials is carried out.

Site Preferences of Pr and Co in(Nd,Pr)_2(Fe,Co)_(14)B Compounds

The Curie temperature of(Nd_(1-x)Pr_x)_2Fe_(14)Co_yB compounds(x=0,0.2,…,1.0 and y=O,2,4,6,14)has been determined with AC initial susceptibility measurement.It was found that the variations of Curie tempera- ture with x is not linear for y=0 and 14,whereas it is linear for other values of y.The lattice constants of (Nd_(1-x)Pr_x)_2Fet_(14)B were determined by using X-ray diffraction.The lattice expansion was mostly along the c axis,whereas that along the a-axis remained practically zero for the whole series.It is suggested that Pr atoms may show site preference in R_2M_(14)B compounds(M=Fe or Co).Due to the substitution of Co for Fe.the tendency of site preference of Pr becomes less pronounced,which may be attributed to the decrease of differ- ence of crystal electric field(CEF)acting on the two rare earth sites with the introduction of Co or Fe.In con- trast to that of the Pr atoms,the site preference of Co iu(Nd(1-x)Pr_x)_2Fe(14-y)Co_yB compounds does not depend on the composition of the rare earth sublattice(R=N d or Pr).

The origin of the site preference of H adsorption on Pd(100)

Spin-polarized density functional theory （DPT） calculations are carried out to determine the site preference of H adsorption on Pd（100） surface and subsurface, We carefully scrutinize the energy difference between different patterns at θ=0.50 ML and confirm the LEED observation that surface adsorption can form c（2×2） ordering structure. On the contrary, we disclose that p（2×1） structure become more favorable than c（2×2） for subsurface adsorption. These site preferences are rationalized via an analysis of the layer and orbital resolved density of states. Furthermore, we propose that the interstitial charge as a key factor determining the preferred H adsorbed site.

Site occupation and energy transfer in full color emitting phosphor Ba2Ca(BO3)2:Ce3+(K+),Eu^(2+),Mn2+

White light-emitting diodes(WLEDs)fabricated by single-phase full color emitting phosphor are an emerging solution for health lighting.The crystallographic site occupation of activators in a proper host lattice is crucial for sophisticated design of such phosphor.Here,we report a high quality white lightemitting phosphor Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)with spectral distribution covering whole visible region.Blue light emission originates from Ce3+ions occupying preferentially Ba^(2+)site by controlling synthesis conditions.Green and red lights are obtained from Eu^(2+)occupying Ba2+(and Ca)site and Mn2+occupying Casite,respectively.In this triple-doped phosphor,strong red emission with a low concentration of Mn2+is realized by the efficient energy transfer from Ce3+and Euto Mn.Furthermore,high quality white light is accomplished by properly tuning the relative doping amount of Ce^(3+)(K^(+))/Eu^(2+)/Mn^(2+)based on efficient simultaneous energy transfer.The results indicate that Ba_(2)Ca(BO_(3))_(2):Ce^(3+)(K^(+)),Eu^(2+),Mn^(2+)is a promising white light-emitting phosphor in WLEDs application.

Site Occupation of Nb in γ-TiAI:Beyond the Point Defect Gas Approximation

Microalloying is an effective approach to improve the mechanical properties of γ-TiAl intermetallic compound.Knowledge about the site occupancy of the ternary alloying element in the crystal lattice ofγ-TiAl is highly demanded in order to understand the physics underlying the alloying effect.Previous first-principle methods-based thermodynamic models for the determination of the site occupancy were based on the point defect gas approximation with the interaction between the point defects neglected.In the present work,we include the point defect interaction energy in the thermodynamic model,which allows us to predict the site occupancy of the ternary alloying element inγ-TiAl beyond the point defect gas approximation.The model is applied to theγ-TiAl-Nb alloy.We show that,at low temperature,the site occupancy of Nb atoms depends on the composition of the alloy:Nb atoms occupy the A1 sublattice for the Ti-rich alloy but occupy Ti sublattice for the Al-rich alloy.The fraction of Nb atoms occupying A1 sublattice in the Ti-rich alloy decreases drastically,whereas the fraction of Nb atoms on the Ti sublattice in the Al-rich alloy decreases slightly with increasing temperature.At high temperature,Nb atoms occupy dominantly the Ti sublattice for both the Ti-rich and Al-rich alloys.The interaction between the point defects makes the Ti sublattice more favorable for the Nb atoms to occupy.

Structure and Curie temperature of Y_2Fe_(17-x)Cr_x

The structures of Y2Fe17-xCrx are simulated by the ab initio potentials. The site preference of Cr atom in Y2Fe17 is evaluated and the order is determined as 4f, 12j, which is close to the experimental result. Based on the site preference behavior, the calculated parameters and the atom sites of Y-Fe-Cr system are studied. The result corresponds well to observed data. Further, the DOS of the relaxed structures are calculated and the variation in Curie temperature is explained qualitatively by the spin-fluctuation theory.