The Impact of Phenotypic Characteristics on Thermoregulation in a Cold-Climate Agamid lizard,Phrynocephalus guinanensis

Physiological and metabolic processes of ectotherms are markedly influenced by ambient temperature. Previous studies have shown that the abdominal black-speckled area becomes larger with increased elevation in plateau Phrynocephalus, however, no studies have verified the hypothesis that this variation is correlated with the lizard＇s thermoregulation. In this study, infrared thermal imaging technology was first used to study the skin temperature variation of torsos, heads, limbs and tails of a cold-climate agamid lizard, Phrynocephalus guinanensis. The heating rates of the central abdominal black-speckled skin area and peripheral non-black-speckled skin area under solar radiation were compared. Our results showed that the heating rates of limbs and tails were relatively faster than the torsos, as heating time was extended, rates gradually slowed before stabilizing under solar radiation. Under the environment without solar radiation, the cooling rates of limbs and tails were also relatively faster than the torsos of lizards, the rates slowed down and finally became stable as the cooling time was extended. We also found that the heating rate of the abdominal black-speckled skin area was faster than the nearby non-black-speckled skin area. These results increased our insights into the functional significance of these phenotypic traits and help explain their covariation with the thermal environment in these cold-climate agamid lizards.

Sex Ratio and Sexual Size Dimorphism in a Toad-headed Lizard, Phrynocephalus guinanensis

Phrynocephalus guinanensis has sexual dimorphism in abdominal coloration, but its ontogenetic development of sexual size dimorphism （SSD） is unknown. Using mark-recapture data during four days each year from August from 2014 to 2016, we investigated the development of sex ratios, SSD, sex-specific survivorship and growth rates in a population of P guinanensis. Our results indicated that the sex ratio of males to females was 1：2.8. Males had a lower survival rate （6%） than females （14%） across the age range from hatchling to adult, which supported the discovered female-biased sex ratio potentially associated with the low survival rate of males between hatchlings and juveniles. Male-biased SSD in tail length and head width existed in adults rather than in hatchling or juvenile lizards. The growth rates in body dimensions were undistinguishable between the sexes during the age from hatchling to juvenile, but the growth rate in head length from juvenile to adult was significantly larger in males than females. Average growth rate of all morphological measurements from hatchling to juvenile were larger compared with corresponding measurements from juvenile to adult, but only being significant in tail length, head width, abdomen length in females and snout-vent length in males. We provided a case study to strengthen our understanding of the important life history traits on how a viviparous lizard population can survive and develop their morphology in cold climates.

Chloride molten salt derived attapulgite with ground-breaking electrochemical performance

The existence of adsorbed water and structural water in the crystal structure of attapulgite(ATP)endows it with poor capability to store lithium ions.Herein,the chloride molten salt method was developed to function ATP materials based on theoretical calculations,which exhibit ground-breaking electrochemical performance.After the modification process,the metal ions in chloride molten salt occupy the vertices of the Mg-O octahedral structure from the liberation of structural water and hydroxyl groups in ATP,forming MaMgbAlcSixOy(M=Li,Na,or K).Using Li Cl molten salt-modified ATP(Li-ATP)as a proof-of-concept,the detailed phase transition,physicochemical properties,and lithium storage capacity were investigated.Compared to the original ATP,Li-ATP achieves a nearly 7-fold increase in lithium storage capacity(498mAh/g),featuring a promising low-cost polyanionic type anode material.

重载机车车轮不圆演变规律及动态影响

针对六轴重载机车存在的车轮不圆顺伤损问题,开展了一个镟轮周期内的不圆顺现场跟踪测试,分析了车轮不圆顺随运行里程的演变规律及谐波分布特征.建立了重载机车-轨道纵垂耦合动力学模型,以不圆顺作为激扰输入,研究了不圆顺演变对机车轮轨动态相互作用的影响.结果表明,三轴转向架端部轮对不圆顺发展速率比中间轮对更快,运营至17×10^4km时,车轮径向偏差幅值最大接近0.9 mm, 1~3, 6~8阶谐波是车轮不圆顺的主要构成.不圆顺极易引起较大的轮轨垂向冲击振动和轮重减载现象,诱发轮轨高应力接触状态,不利于机车牵引性能的稳定发挥,尤以7阶谐波影响最为显著.运营里程超过10×10^4km时,建议进行车轮不圆检修.