α-氨基酸各官能团对其Co(Ⅱ)配合物可逆氧合性能的影响

选择氧合性能良好的组氨酸(His)-Co(Ⅱ)作为研究对象,分别掩蔽—NH2、取代—O-和去除—COO-,得到短肽、伪肽和多胺等类组氨酸结构.采用UV-Vis光谱法研究了α-氨基酸中的3个官能团对其Co(Ⅱ)配合物氧合性能的影响.对比研究表明:α-氨基酸中—NH2对其Co(Ⅱ)配合物的吸氧性具有决定作用;—COO-对其Co(Ⅱ)配合物氧合作用的可逆性起关键作用;而—O-对其Co(Ⅱ)配合物的吸氧性影响不大.在前期研究结果的基础上,对α-氨基酸-Co(Ⅱ)配合物可逆吸收和释放O2的机理进行了探讨.     

薄膜材料横向热扩散率的热辐射检测

利用薄膜材料横向尺寸远大于其厚度的特点，通过测量横向传播热波的幅值和相位来确定薄膜的热扩散率是可行的．本文介绍带有背树的薄膜的横向热扩散率的检测理论，以及利用非接触的热辐射技术对金刚石一硅复合膜的检测结果．     

WIND SPEED DISTRIBUTION REGULARITY AND WIND REDUCTION EFFECT OF SHELTER NET

Wind speed distribution regularities in a shelter mesh (S. M.) have been deduced from the wind speed distribution in the sheltered area of a single shelter beh (S. B.).The components of a wind vector in a mesh follow the error function distribution model or the logarithmic model of 2-variable power function.The wind vector itself follows the vector composition model of these models.We can calculate the wind speed distribution and wind reduction effect of a mesh under the conditions of any shelter-belt characteristics, any size and shape of a mesh and any wind inclination angle with this model. The results of our field model experiment are in better agreement with the theoretically calculated results.     

碳水化合物的气相色谱分析——甲基糖苷形成的前处理

近两年来我们已将气相色谱技术应用于碳水化合物的研究中,参考文献中常用的方法,结合我们实验室条件进行了一些探索和总结。在多糖、寡糖的组成分析中,我们常采用甲醇解后以三甲基硅烷(TMS)化甲基糖苷的形式进行气相色谱分析。本文针对甲醇解过程中所用的甲醇-HCl易转化成氯甲烷的现象及甲醇解后如何选用适宜的中和剂等问题进行了研究,系统地测定了不同浓度的甲醇-HCl在甲醇解过程中酸浓度的变化,为甲醇解条件的选择及中和剂的用量提供了依据。最后选用了甲醇-NaOH溶液为中和剂并与其他中和方法进行了比较。同时在80℃用0.5—2.0N甲醇-HCl测定了肝糖原的甲醇解速度。所得结果已满意地应用于有关多糖结构的测定中。     

High Coupling Efficiency Generation in Water Confined Laser Plasma Propulsion

High coupling efficiency generation in water confined laser plasma propulsion is investigated. It is found that the coupling efficiency is enhanced over thirty times in water confined ablation compared to that of direct ablation. From calculation of the ablation pressure induced by the plasma on the target surface, it is realized that high coupling efficiency is attributed to the confinement of the water layer on the plasma expansion.     

原子吸收法测定牛黄降压丸中11种金属元素的含量

本文提出一种悬浮液进样－火焰原子吸收光谱法测定玉米面中锌、铁的新方法。将玉米面悬浮于琼脂胶体中,直接喷入空气－乙炔火焰中,用标准加入法测定,测定结果与灰化法一致。方法简便、快速。     

蒸气开采过程中金属盐对稠油粘度及平均分子量的影响

探讨了在注蒸气条件下，稠油的粘度和平均分子量随蒸气温度、反应时间的变化规律，研究了金属盐、油层矿物对稠油水热裂解反应的影响。实验结果表明，在注蒸气的条件下，辽河稠油可以发生水热裂解反应。金属盐的存在，可以加速稠油的水热裂解反应，从而导致粘度和平均分子量的进一步降低，使稠油的粘度由原始的124.5 Pa·s下降到32.4 Pa·s，下降了74.0%，平均分子量由反应前的654下降到398。高温下油层矿物对水热裂解反应有促进作用，在反应体系中，在有水时加入质量分数为10%的油层矿物时，稠油的粘度由原始的124.5 Pa·s下降到82.5 Pa·s，下降了33.7%。在蒸气条件下，在金属盐和油层矿物共存时，稠油粘度由124.5 Pa·s下降到26.8 Pa·s，下降了78.5%。这为实现井下催化降粘开采稠油提供了理论依据。     

拓扑绝缘体薄膜和有限尺寸效应

拓扑绝缘体是近年来发现的一类新的量子材料,已成为凝聚态物理的研究热点领域.厚度仅几纳米的拓扑绝缘体薄膜不但具有奇特的物理性质,而且还是拓扑绝缘体应用于平面器件的基础.文章以Bi2Se3为例,介绍了Bi2Se3家族拓扑绝缘体薄膜的分子束外延生长以及其能带、自旋结构和拓扑性质随层厚的演化.这些结果为人工调控拓扑绝缘体的电子结构和物理性质提供了指导.     

Observation of multiple charge density wave phases in epitaxial monolayer 1T-VSe2 film

As a special order of electronic correlation induced by spatial modulation, the charge density wave (CDW) phenomena in condensed matters attract enormous research interests. Here, using scanning—tunneling microscopy in various temperatures, we discover a hidden incommensurate stripe-like CDW order besides the ($sqrt{7}$ × $sqrt{3}$) CDW phase at low-temperature of 4 K in the epitaxial monolayer 1T-VSe₂} film. Combining the variable-temperature angle-resolved photoemission spectroscopic (ARPES) measurements, we discover a two-step transition of an anisotropic CDW gap structure that consists of two parts Δ₁ and Δ₂. The gap part Δ₁ that closes around ～ 150 K is accompanied with the vanish of the ($sqrt{7}$ × $sqrt{3}$) CDW phase. While another momentum-dependent gap part Δ₂ can survive up to ～ 340 K, and is suggested to the result of the incommensurate CDW phase. This two-step transition with anisotropic gap opening and the resulted evolution in ARPES spectra are corroborated by our theoretical calculation based on a phenomenological form for the self-energy containing a two-gap structure Δ₁ + Δ₂, which suggests different forming mechanisms between the ($sqrt{7}$ × $sqrt{3}$) and the incommensurate CDW phases. Our findings provide significant information and deep understandings on the CDW phases in monolayer 1T-VSe₂} film as a two-dimensional (2D) material.     

电感耦合等离子体质谱测定不同酒类中铬、砷、镉、汞、铅含量

应用微波消解处理酒样,不经富集直接用ICP—MS测定Cr、As、Cd、Hg、Pb含量,方法快速,干扰少．测定的33种不同酒样中Cr、As、Cd、Hg、Pb的含量均值分别为45．84、19．53、2．22、1．92μg·kg^-1和115．06μg·kg^-1,其中白酒中含量最高,葡萄酒和啤酒居次,黄酒含量最低．Cr、As、Cd、Hg、Pb的检出限分别为0．063、0．082、0．007、0．001μg·L^-1和0．080μg·L^-1,各元素的加标回收率基本在90%～110％,RSD（n=10）在0．25％～6．76％．