茶叶中锗元素分析

采用高频电感耦合等离子体发射光谱法及催化极谱法，测定了广西部分地区的白毫茶、石龙茶、金花茶、山绿茶、苦丁茶及绞股蓝茶等六种茶叶中铜、锌、铁、锰、钙、镁、钴、铬、锶、钼、硒及锗等１２种无机元素含量，并着重讨论了茶叶中微量元素锗，硒特征，为合理饮茶，增进健康预防疾病提供了参考。     

Tripartite Quantum Operation Sharing with a Six-Qubit Absolutely Maximally Entangled State

International Journal of Theoretical Physics - A three-party scheme for sharing an arbitrary single-qubit operation on a distant target qubit is proposed by utilizing a six-qubit absolutely...     

A maximum principle for fully coupled stochastic control systems of mean-field type

The present paper considers an optimal control problem for fully coupled forward–backward stochastic differential equations (FBSDEs) of mean-field type in the case of controlled diffusion coefficient. Moreover, the control domain is not assumed to be convex. By virtue of a reduction method, we establish the necessary optimality conditions of Pontryagin's type. As an application, a linear–quadratic stochastic control problem is studied.     

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl₂, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35–125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ɛ-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, ¹³C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain–chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk fibroin in aqueous solution. It is possible that the silk protein nanoparticles are potentially useful in biomaterials such as cosmetics, anti-UV skincare products, industrial materials and surface improving materials, especially in enzyme/drug delivery system as vehicle.     

Slow light in photonic crystals waveguide constructed with symmetrically perturbed structure

Symmetrically perturbed photonic crystal waveguide can be constructed by inserting perturbative dielectric rods into photonic crystal waveguide structure with whose rods’ radius distributed according to a certain proportion. Slow light properties in this new structure are studied by using the plane wave expansion method (PWM). In this paper, schemes of adjusting radius of perturbative dielectric rods and adjusting the dielectric constant of perturbative dielectric rods are proposed to optimize slow light properties. The result shows that the scheme for adjusting radius of perturbative rods can realize larger average slow light bandwidth and efficiently control the NDBP value of the waveguide, but it contributes little to obtain smaller group velocity. The scheme for adjusting dielectric constant of perturbative rods can realize smaller group velocity, but can only obtain smaller slow light bandwidth and cannot efficiently enlarge NDBP value of waveguide. Both optimization schemes proposed in this paper realize group velocity that is two magnitudes smaller than the vacuum speed of light meanwhile maintaining large NDBP and low GVD region. Our results provide important theoretical basis for the potential application offered by symmetrically perturbed photonic crystal in future optical networks.     

Handover method in visible light communication between the moving vehicle and multiple LED streetlights

When the moving vehicle is communicating with LED streetlights by visible light, the multiple LED streetlights signals will be selected or signal may be interrupted between adjacent streetlights. The method of receiving signal power (RSP) handover between the moving vehicle and multiple LED streetlights transmitters will be studied. Considering two cases, no power coverage and power overlap between adjacent streetlights. Hard RSP handover used in no power coverage model and soft RSP handover used in power overlap model. Simulation results show both RSP handover methods can protect the communication between the vehicle and LED streetlights and improve the stability of communication.     

Spectrum–effect relationship between HPLC fingerprints and antioxidant activity of Angelica sinensis

Angelica sinensis is one of the most important traditional Chinese medicines and has antioxidant activities that greatly contribute to its pharmacological action. However, the compounds responsible for its antioxidant activity remain unknown. In this study, the fingerprints of 10 batches of A. sinensis collected from different locations in China were established with HPLC to identify the common peaks. The antioxidant activities of these 10 batches were evaluated with 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt, and ferric-reducing antioxidant power assays. The spectrum–effect relationship between HPLC fingerprints and antioxidant effect of A. sinensis was examined by the partial-least-square regression analysis and the variable importance in projection method. Results showed that the antioxidant effect of A. sinensis results from the synergistic effect of various compounds, and peaks X3 and X7–X18 were the main substances responsible for antioxidant efficacy. This study successfully identified the spectrum–effect relationship between HPLC fingerprints and the antioxidant effect of A. sinensis. This relationship can provide methods for establishing the quality standards for A. sinensis and developing new and effective products of A. sinensis based on its antioxidant ingredients.     

浙江萧山、舟山及福建集美臭鼬核型比较研究

对浙江萧山、舟山及福建集美三地臭的进行了染色体组型和带型分析,结果表明,三地臭晌染色体数目均为2n=40,浙江两地常染色体组型为8(m)十2 (sm)十10(st)十18(t),集美组型为8(m)+2(sm)+8(st) }- 20(t),性染色体除萧山标本X染色体为sm外,其余均为m. G带丰富,C带物质普遍缺乏.三地G,C带差异主要表现在性染色体上,尤其是Y染色体变异较大.核型比较初步显示三地臭的种群巳有不同程度的地理分化,尤以福建集美更为明显.     

大山雀领域鸣唱的声谱分析与比较研究

本文通过计算机声谱分析技术, 对浙江省舟山、龙游和杭州等3 个地区大山雀领域鸣声进行了分析比较.3 个地区的大山雀领域鸣唱主要有4 种句型, 但相互没有一种是相同的, 各有其频谱特征.它们都有变化复杂的音调和较宽的频率范围(约在2.6～ 7.8kHz 之间), 鸣声都由2 ～ 3 个音节构成的“ 短语” 重复而成.     

凤阳山自然保护区鸟类调查

本文记录了1980年春夏季和冬季对凤阳山自然保护区鸟调查的74种鸟,隶属于10目24科,其中14种为本省当时的新记录,留鸟占总数的70％;东洋界种类占63.5％。区系组成上具有华南区的特色。 以大田坪(1220米)和夏边(650米)两地为调查点。两地春夏季鸟类的群体密度无显著性差异,大田坪的多样性指数(H′)高而群落的优势度指数(C)小;冬季两地的群体密度具极显著差异,夏边的H′值高而C值小。 此外,在春夏季观察了鸟类的繁殖活动并记述了采到的五种鸟巢及内容。