高效液相色谱法测定茶叶中游离糖的含量

1引言 茶叶中的游离糖不仅是构成茶叶滋味的主要成分,给茶汤带来甜醇的味道,而且在茶叶加工过程中可发生非酶促褐变作用,生成相应的醛类和吡咯类、吡嗪类等含氮化合物,因而对于茶叶的色泽和香气的形成有重要影响.     

Hawking Radiation from Topological Kerr Anti-de-Sitter Black Hole with One Rotational Parameter via Covariant Anomalies

Using anomalous viewpoint, we study the Hawking radiation from a kind of topological Kerr Anti-de-Sitter （Kerr-AdS） black hole with one rotational parameter. We employ the covariant gauge and gravitational anomalies. The result supports the Robinson-Wilczek opinion and shows that the Hawking temperature can be correctly determined by cancelling covariant gauge and gravitational anomalies at the horizon.     

Non-equilibrium Landauer transport model for Hawking radiation from a Reissner—Nordstrom black hole

The recent work of Nation et al., in which the Hawking radiation energy and entropy flow from a black hole is considered to be produced in a one-dimensional Landauer transport process, is extended to the case of a Reissner- Nordstrom black hole. The energy flow contains not only the contribution of the thermal flux but also that of the particle flux. It is found that the charge can also be transported via the one-dimensional quantum tunnel. Because of the existence of the electrostatic potential, the entropy production rate is shown to be smaller than that of the Schwarzschild black hole.     

On particles tunneling from the Taub-NUT-AdS black hole

This paper discusses tunneling of scalar particles and Dirac particles from the Taub-NUT-AdS black hole by the Hamilton--Jacobi equation, initially used by Angheben et al, and the Dirac equation, recently proposed by Kerner and Mann. This is performed in the dragging coordinate frame so as to avoid the ergosphere dragging effect. A general form is obtained for the temperature of scalar and Dirac particles tunneling from the Taub-NUT-Ads black hole, which is commensurate with other methods as expected.     

Hawking radiation from Kerr--Newman de Sitter black hole via anomalies

In this paper, Hawking radiation from the Kerr Newman de Sitter black hole is studied via gauge anomaly and gravitational anomaly. The obtained results of Hawking radiation from the event horizon and the cosmological horizon accord with those by other methods.     

微波消解样品-火焰原子吸收光谱法测定花卉中金属元素含量

近年来绿色无污染食品颇受大家欢迎。花卉营养丰富,大量临床和医学试验表明,很多花卉和人类疾病的发生、发展或治疗有着密不可分的联系[1-3]。对于花卉的研究,大多集中在皂苷、黄酮、鞣质、生物碱和挥发油等成分的研究上,少有微量元素含     

Kerr-Newman黑洞的熵修正

基于Majhi等人最近的工作,利用狄拉克方程,在半经典近似外讨论了Kerr-Newman黑洞的熵修正.在单位制G=c=kB=1下,由于普朗克常数与普朗克长度,普朗克质量和普朗克电荷的平方成正比,作用量的量子修正项与半经典项的比例常数被选为(Mrh-Q2/2)-1.结合视界方程的微分形式和黑洞热力学第一定律,本文得到了荷电稳态黑洞的修正熵并发现修正项同样包括Bekenstein-Hawking熵的对数项和倒数项.     

8种海藻中7种金属元素含量的测定

采用火焰原子吸收光谱法测定了谷粒马尾藻、鼠尾藻、海青菜、匍枝马尾藻、裙带菜、大叶藻、矶石鸡冠藻（红、白）这8种藻类植物中钙、镁、铁、锰、铜、锌、钾7种元素的含量。结果表明,这些海藻中含有较丰富的钙、镁、铁、钾元素,而铜、锰、锌元素含量相对较少。钙元素的含量最为丰富,铜的含量最少。该方法的加标回收率在95.7%—101.1%之间,RSD值在0.054%—1.764%之间,具有较好的准确度和精密度。本实验结果为这些藻类植物的食用,药用以及饲养价值提供了依据。     

Hawking radiation from gravity''s rainbow via gravitational anomaly

Based on the anomaly cancellation method, initiated by Robinson and Wilczek, we investigates Hawking radiation from the modified Schwarzschild black hole from gravity＇s rainbow from the anomaly point of view. Unlike the general Schwarzschild space-time, the metric of this black hole depends on the energies of probes. The obtained result shows to restore the underlying general covariance at the quantum level in the effective field, the covariant compensating flux of energy-momentum tensor, which is related to the energies of the probes, should precisely equal to that of a （1 ＋ 1）-dimensional blackbody at the Hawking temperature.