Fracture of colloidal single-crystal films fabricated by controlled vertical drying deposition

Controlled vertical drying deposition method was used to make high-quality single crystal close-packed colloidal films formed of different radii polystyrene latex spheres on glass substrates coming from a low concentration water suspension (0.1% volume fraction). Regardless of the spheres radii the film thickness was about 6.3 microns. However, cracks destroyed the crystalline film structure during the colloidal film growth. The effect of particle radius (85-215 nm range) on film cracking was systematically studied using in situ optical fracture monitoring. Primary parallel cracks run along the vertical growth direction, later followed by secondary branched cracks in-between the primary cracks due to residual water evaporation. Quantitative theoretical relationship between the cracks spacing and particles radius was derived and shows good agreement with experimental observations. Normalized cracks spacing is related to a reciprocal ratio of the dimensionless particle radius.

川西亚高山人工针叶林下11种植物对两种光生境的适应性研究

青藏高原东缘的亚高山针叶林是长江上游重要的生态屏障，经过近六十年的采伐后，取而代之的是大量人工种植的云杉纯林。目前，这些人工林已经表现出树种单一，结构层次简单等生态问题，其物种多样性及生态效益与同地带天然林相比差距较明显。如何丰富该地区物种多样性，完善人工林生态系统的生态功能是一个十分重要的课题。林下植物是人工林群落的重要组成部分，对维持群落的生物多样性及完善生态系统功能具有明显的作用。因此，研究该地区人工针叶林的林下植被对不同生境的适应性对于理解人工林生态系统物种多样性的形成和维持机制都具有重要的意义。 本文以青藏高原东部亚高山针叶林的主要森林类型----云杉人工林为研究对象，选择林下11种具有不同喜光特性的常见植物，分别设置人工林林冠下及成熟林窗为研究样地，通过对各种植物叶片形态与物质分配特征、叶片解剖学特征、叶片光合生理特性、植物自然分布特征等方面的比较分析，研究林下植物对不同光生境的适应策略及其适应能力，揭示不同物种对人工林生境的适应共性，为西南亚高山地区植被恢复及人工林的经营管理提供科学依据。具体研究结果如下： 在叶片形态和物质分配特征方面：在林窗光生境中，11种林下植物叶片比叶重(LMA)显著高于林下光生境的同种植物。同时，林窗下生长的植物叶片叶片厚度及栅栏细胞长度显著增加，这是影响叶片比叶重变化的直接原因。而多数植物叶重比在两种生境中无明显变化。说明在长期适应自然生境之后，植物可能更多地采取调节叶片组织细胞水平（即叶片功能细胞形态）及叶片器官水平（即单个叶片形态）特征的策略来适应各类生境，而非整株水平上的叶片总比重的增减。 在叶片解剖结构特征方面：多数阔叶物种栅栏组织厚度(PT)、栅栏组织厚度/海绵组织厚度(PT/ST)、栅栏细胞层数及近半数种的气孔密度(SD)在林窗生境中更大或更多，而叶片表皮细胞厚度(UET、LET)气孔长径(SL)及海绵组织厚度(ST)受两种生境影响不大。喜光特性相似的物种在生境适应策略上具有一定的趋同性。 在光合生理特征方面：在林窗生境中多数种植物的最大光合速率(Amax)、暗呼吸速率(Rd)及喜光植物光补偿点(LCP)显著或极显著高于林内生境同种植物。且在同一生境条件下，多数深度耐荫植物比喜光及轻度喜光植物有稍低的Rd和LCP。各植物在林内低光生境中具有更大的内禀光能转化效率，并在中午12:00～14:00之间光强最大的时刻发生了的最深程度的光抑制。多数种能通过调节自身某种光合素含量或色素之间的比例来适应不同的光生境，即通过增加叶绿素含量或降低Chla/b值来适应林内弱光生境，通过提高类胡萝卜素含量或单位叶绿素的类胡萝卜素含量降低强光带来的伤害。绝大多数物种并不采取调节叶片C、N含量的策略来适应不同的光生境。总之，植物部分光合参数(Amax、Rd、LCP)受生境的影响与其自身喜光特性有关，但另一些参数（Fv/Fm日变化、色素含量及比例、叶氮相对含量）受生境影响与其自身喜光特性无明显关联。 在表型可塑性方面：在叶片各表型参数中，器官水平及细胞水平的形态特征参数平均可塑性大于整株水平形态和物质分配特征参数可塑性；叶片光合组织的可塑性大于非光合组织可塑性；反映植物光合能力的参数可塑性大于叶片色素含量参数可塑性。植物叶片形态和物质分配、解剖学特征参数平均可塑性大小与其自身喜光特性基本吻合，即喜光种及轻度耐荫种各参数可塑性最高，深度耐荫种可塑性最小，而这种规律并未在光合生理参数的可塑性大小上体现出来。但是叶片形态和物质分配参数、光合生理参数的平均可塑性水平却大于叶片解剖学参数。 在植物自然分布特征方面：喜光物种云杉幼苗及歪头菜在林内生境中分布密度明显降低，深度耐荫种疏花槭却恰恰相反，更多数物种（7种植物）在两种生境中密度变化趋势不明显。从分布格局来看，7种植物在两种生境中均为聚集分布，但聚集强度为林窗>林内；少数物种桦叶荚迷、直穗小檗、冰川茶藨、黄背勾儿茶在林窗中为聚集型，在林内生境中的分布型发生改变而成为随机型，说明光生境的差异能影响到植物种群的分布特征。但这种影响程度与植物自身的喜光特性无关，同时与各物种叶片表型平均可塑性的大小也无明显关联。 The subalpine coniferous forest area in eastern Qinghai-Tibet Plateau is important ecology-barrier of upriver Yangtze. In past sixty years, those forests had been cut down and replaced with a lot of spruce plantations. At now, there are many ecology problems presenting to us such as singleness species, simple configuration, lower species diversity and ecological benefit than natural forests at the same belt. How to restore the species diversity and enhance the eco-function of the plantations is a very important issue. The understory plants are important part of plantation community, which improved the bio-diversity and eco-function distinctly of forests. So, it is very significance to study the adaptation of understory plants to different environment in plantation, and this study would helping us to understand how plantations to develop and remain their biodiversity. This study was conducted in a 60a spruce plantation in Miyaluo located in western Sichuan, China, and spruce plantation is major types of subalpine coniferous forest in eastern Qinghai-Tibet Plateau. In this paper, the leaf morphological and biomass-distributed characteristics, the anatomical characteristics, the photosynthetic characteristics and the distribution patterns characteristics of eleven different light-requirement understory species grown in two different environments (forest gaps and underneath close canopy) were studied and compared. The purpose of this study was to analyze the adaptation of this forest understory plants, to show up the commonness of these different light-requirement understory species in light acclimation, and to provide some scientific reference to manage and restore the vegetation of subalpine plantation of southwest China. The results were as follows: The leaf morphological and biomass-distributed characteristics: These eleven species in forest gaps had significantly higher dry weight per leaf area (LMA) than those under close canopy. The palisade parenchyma cells of the broad-leaved species in gaps were significantly longer than those grown under the canopy, which been a directed factor for the change of leaf mass per unit area (LMA) in different environment. But the leaf weight ratio (LWR) of most plants species were not evidently changed by the contrasted environments in our study. It was shown the morphological characteristics changing been adopted as a strategy of light acclimation for plants wasn’t on whole plant level (leaf weight ratio) but cellular level (the function cells morphological characteristics) and organic level (the leaf morphological and biomass-distributed characteristics) mostly. The leaf anatomical characteristics: Most broad-leaved plants in gaps increased palisade parenchyma thickness (PT), the palisade parenchyma cell layers and the ratio of palisade to spongy parenchyma (PT/ST). So did as almost about half species in this study in stomatal density (SD). No significant differences in thickness of leaf epidermal cells (UET, LET), stomatal length (SL) and spongy parenchyma (ST) between two environments of most species were observed. The results suggested that species with light-requirement approximately had convergent evolution on adaptation to light condition. The leaf photosynthetic characteristics: The dark respiration rate (Rd) of most plants species, the light compensation point (LCP) of light-demanding plants species in gaps were significantly increased than under close canopy in this study. In a same habitat, most deep-shade-tolerant plants had lower Rd and LCP than those light-demanding plants and slight-shade-tolerant plants. Each species has bigger inherent electron transport rate under close canopy than in gaps, and the greatest photoinhibition happened during 12 to 14 in the daytime. Most species could adapt different light environment by the way of changing their photosynthetic pigments content or the ratio of pigments content. For example, some plants under close canopy increased chlorophyll (Chl) or reduced the values of the ratio Chla/b to adapted the low light condition, some plants in gaps increased carotenoid (Car) or reduced the weight ratio CarChl to avoid been hurt in high light. For most plants, changing the content of C and N in leaf wasn’t a strategy of light acclimation. In conclusion, the variation of some leaf photosynthetic parameters in different light environment such as Fv/Fm, pigments, C and N in leaf related with the light-requirmnet of species, but the others such as Amax, Rd, LCP did not. The leaf plasticity indexes: Among those leaf plasticity indexes, the leaf morphological and biomass-distributed parameters on cellular and organic level were greater than on whole plant level for same species, and the photosynthetic parenchyma parameters were greater than non-photosynthetic parenchyma parameters in same leaf, and photosynthetic capability parameters were greater than photosynthetic pigments content parameters for same species. The average plasticity indexes of leaf morphological and biomass-distributed and anatomical parameters were accordant with plants’ light-requirement approximately: those light-demanding plants and slight-shade-tolerant plants had bigger plasticity indexes than deep-shade-tolerant plants. But this regular wasn’t observed in physiological plasticity indexes for most plants, though the average leaf plasticity indexes of leaf morphological and biomass-distributed, photosynthetic characteristics parameters was greater than the anatomical characteristics parameters. The distribution patterns characteristics: Oppositely to the deep-shade-tolerant specie Acer laxiflorum Pax., the density of light-demanding species Picea asperata Mast. and Vicia unijuga A. Br. in gaps was bigger than under close canopy. Each of the other species has the approximately density in two different environment. The spatial patterns of seven species were aggregated distribution in two environments, but the trend of aggregation of population under close canopy was decrease from in gaps. A few species such as Viburnum betulifoium Batal., Berberis dasystachya Maxim., Ribes glaciale Wall. and Berchemia flavescens Brongn. were aggregated distribution in gaps while random distribution under close canopy. It was shown that the difference between two light environments could affect the distribution pattern of plant population, and the effect didn’t relate with the light-requirement or plasticity indexes of species.

有机碳对混合菌群亚硝酸盐氮氧化的影响

自养硝化过程在自然界氮素循环和污水处理系统脱氮过程中起着关键作用。因此，了解有机碳对硝化的影响和硝化菌与异养菌之间的竞争对微生物生态学和污水处理系统设计都很重要。目前对氨氧化到硝酸盐氮过程的研究文献很多，但对亚硝酸盐氧化过程在异养菌的存在下如何受到有机碳影响的研究甚少。本文从生理生化指标、基因组学、蛋白组学三方面考察了在实验室条件下有机碳（乙酸钠）对硝化细菌和异养菌组成的混合菌群的硝化性能、菌群结构及代谢功能的变化的影响。 全文分为两大部分： 第一部分为乙酸钠对游离态硝化混合菌群的硝化性能和菌群结构的短期影响。混合菌株先在自养条件下进行连续培养，两个月后硝化速率达到20 mg N/(L·d)；而后离心收集菌体进行批式实验。在批式反应器中，初始亚硝氮均为126mg N/ L，乙酸钠-C 与亚硝酸盐-N 的比分别为0，0.44，0.88，4.41，8.82。结果表明：在低C/N 比（0.44 和0.88）时，亚硝酸盐去除速率比C/N=0 下高，细菌呈现一次生长；而在高C/N 比（4.41 和8.82）时，出现连续的硝化反硝化，亚硝酸盐去除率仍比对照下高，细菌呈现二次生长。不同C/N 比下微生物群落明显不同，优势菌群从自养和寡营养细菌体系（包括亚硝酸盐氧化菌，拟杆菌门,α-变形菌纲,浮霉菌门和绿色非硫细菌下的一些菌株）过渡到异养和反硝化菌体系 （γ-变形菌纲的菌株尤其是反硝化菌Pseudomonas stutzeri 和P. nitroreducens 占主导）。 第二部分为乙酸钠对硝化混合菌群生物膜的硝化性能和菌群结构的长期影响。接种富集的硝化混合菌群于装有组合式填料的三角瓶中，于摇床中自养培养；两个月后填料上形成生物膜的硝化速率达到20 mg N/ (L·d)；而后进行长期实验，每12 小时更换混合营养培养基（亚硝氮约200 mg N/ L，C/N 比同上）。结果显示：相较于C/N 比=0 时的亚硝酸盐氧化反应来说，低C/N 比出现了部分的反硝化，而高C/N 比则是几乎完全的反硝化。与对照比，C/N=0.44 时亚硝酸盐氧化速率并未受乙酸钠的影响，反而上升了，但C/N=0.88 时亚硝酸盐氧化速率有所下降。菌群结构分析表明自养对照与混合营养下微生物群落的不同；PCR-DGGE未检测出混合营养下硝化杆菌的存在，而显示异养菌尤其是反硝化菌的大量存 在。荧光定量PCR 结果表明随C/N 比上升，硝化杆菌数量从2.42 × 104 下降到1.34× 103 16S rRNA gene copies/ ng DNA，反硝化菌由0 增加至2.51 × 104 nosZgene copies/ ng DNA。SDS-PAGE 的结果表明不同C/N 比下的蛋白组较为复杂且呈现一定的差异性。 有机碳对亚硝氮氧化及微生物群落的影响很复杂，本文分别讨论了对游离态和生物膜固定态两种状态的混合菌群相应的短期和长期影响研究。研究发现，有机碳并非一定带来硝化的负影响，如果控制在适当的C/N 比范围，有机碳是有利于亚硝氮氧化的。这些发现阐明了有机碳和硝化反硝化的关系，填补了硝化微生物生态学上的空白，对污水处理系统中减少异养菌的影响并提高氮去除率有一定理论指导意义。 Nitrification plays a key role in the biological removal of nitrogen in both nature and wastewater treatment plant (WWTP). So, understanding of the effect of organic carbon on nitrification and the competition between nitrifying bacteria and heterotrophic bacteria is important for both microbial ecology and WWTP design and operation. Despite the fact that the nitrification process of ammonia to nitrate has been extensively investigated, it is not known how the process of nitrite oxidization is affected by organic carbon when heterotrophic bacteria are present. By measuring different physiological and biochemical parameters, as well as using genomic DNA and proteome analysis, we investigated the influence of organic (acetate) on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria under laboratory conditions. The dissertation involves two parts: Part one deals with the effect of organic matter on functional performance and bacterial community shift of nitrite-oxidizing and heterotrophic bacteria under suspended state. The bacteria were prepared in a continuous-flow stirred reactor under autotrophic condition; after two months, the nitrification rate of the culture reached about 20 mg N/ (L·d); then the bacteria were harvested for the next batch experiments. The initial concentrations of nitrite were 126 ± 6 mg N/ L in all flasks, and sodium acetate (C) to nitrite (N) ratios were 0, 0.44, 0.88, 4.41, and 8.82, respectively. The results showed that at low C/N ratios (0.44 or 0.88), the nitrite removal rate was higher than that obtained under autotrophic condition and the bacteria had single growth phase, while at high C/N ratios (4.41 or 8.82), continuous aerobic nitrification and denitrification occurred besides higher nitrite removal rates, and the bacteria had double growth phases. The community structure of total bacteria strikingly varied with the different C/N ratios; the dominant populations shifted from autotrophic and oligotrophic bacteria (NOB, and some strains of Bacteroidetes, Alphaproteobacteria, Actinobacteria, and green nonsulfur bacteria) to heterotrophic and denitrifying bacteria (strains of Gammaproteobacteria, especially Pseudomonas stutzeri and P. nitroreducens). Part two describes the influence of acetate on nitrite oxidizing performance, community structure and metabolic function of nitrite-oxidizing and heterotrophic bacteria in biofilms. Bacterial enrichments was transferred into flasks with polypropylene carriers and cultured under agitated and autotrophic condition. After two month, the biofilms grown on the carriers had a nitrification rate of about 20 mg N/ (L·h); then the biofilms were refreshed with mixotrophic medium (nitrite were 200 mg N/ L in all flasks, and C/N ratios was the same as above) every 12 h. the results show: normal nitrite oxidization reactions were performed when C/N = 0, but nitrite oxidization and partial denitrification occurred with low C/N ratios (0.44 or 0.88). At high C/N ratios (4.41 or 8.82), we mainly observed denitrification. In contrast to C/N = 0, the nitrite oxidization rate was unaffected when C/N = 0.44, but decreased with C/N = 0.88. The structure of bacterial communities varied significantly between autotrophic and mixotrophic conditions. Nitrobacter was hard to detect by PCR-DGGE while heterotrophs and especially denitrifiers were in the majority under mixotrophic conditions. Real-time PCR indicated that the Nitrobacter population decreased from 2.42 × 104 to 1.34 × 103 16S rRNA gene copies/ ng DNA, while the quantity of denitrifiers obviously increased from 0 to 2.51×104 nosZ gene copies/ ng DNA with an increasing C/N ratio. SDS-PAGE indicated the complexity of and a certain difference between the proteome of nitrite-oxidizing and heterotrophic bacteria at different C/N ratios. We conclude that the influence of organic matter on nitrite oxidation and the community structure of NOB and heterotrophic bacteria is complex. In this dissertation, we focused on how sodium acetate influenced the system both under suspended state and in biofilms. We observed that acetate did not necessarily have a negative impact on nitrification. Instead, an appropriate amount of acetate benefited both nitrite oxidization and denitrification. These findings provide a greater understanding about the relationship between organics and nitrification; they fill the gaps in the field of microbial ecology of nitrifying bacteria; they also provide insight into how to minimize the negative impact of heterotrophic bacteria and maximize the benefit of nitrogen removal in biological treatment systems.

Nucleon 3PF2 Superfluid Pairing Gap in Asymmetry Nuclear Matter

The 3PF2 superfluidity of neutron and proton is investigated in isospin-asymmetric nuclear matter within the Brueckner–Hartree–Fock approach and the BCS theory by adopting the Argonne V14 and the Argonne V18 nucleon-nucleon interactions. We find that pairing gaps in the 3PF2 channel predicted by adopting the AV14 interaction are much larger than those by the AV18 interaction. As the isospin-asymmetry increases, the neutron 3PF2 superfluidity is found to increase rapidly, whereas the proton one turns out to decrease and may even vanish at high enough asymmetries.As a consequence, the neutron 3PF2 superfluidity is much stronger than the proton one at high asymmetries and it predominates over the proton one in dense neutron-rich matter.

Gound State Properties of Nuclei in (295)118 alpha-Decay Chain

The properties of nuclei belonging to the alpha-decay chain of superheavy element (295)118 have been studied in the framework of axially deformed relativistic mean field (RMF) theory with the parameter set of NL-Z2 in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, and alpha-decay energies Q(alpha) have been obtained and agree well with those from finite-range droplet model (FRDM). The single-particle spectra of nuclei in (295)118 alpha-decay chain show that the shell gaps present obviously nucleon number dependence. The root-mean-square (rms) radii of proton, neutron and matter distributions change slowly from (283)112 to (295)118 but dramatically from (279)110 to (283)112, which may be due to the subshell closure at Z = 110 in (279)110. The alpha-decay half-lives in (295)118 decay chain are evaluated by employing the cluster model and the generalized liquid drop model (GLDM), and the overall agreement is found when they are compared with the known experimental data. The alpha-decay lifetimes obtained from the cluster model are slightly larger than those of GLDM ones. Finally, we predict the alpha-decay half-lives of Z = 118, 116, 114, 112 isotopes using the cluster model and GLDM, which also indicate these two models can corroborate each other in studies on superheavy nuclei. The results from GLDM are always lower than those obtained from the cluster model.

Isospin dependence of nucleon (PF2)-P-3 superfluidity in asymmetric nuclear matter

We have investigated the isospin dependence of the neutron and proton (PF2)-P-3 superfluidity in isospin-asymmetric nuclear matter within the framework of the Brueckner-Hartree-Fock approach and the BCS theory. We show that the (PF2)-P-3 neutron and proton pairing gaps depend sensitively on isospin asymmetry of asymmetric nuclear matter. As the isospin asymmetry increases, the neutron (PF2)-P-3 superfluidity becomes stronger and the peak value of the neutron (PF2)-P-3 pairing gap increases rapidly. The isospin dependence of the proton (PF2)-P-3 superfluidity is shown to be opposite to the neutron one. The proton (PF2)-P-3 superfluidity becomes weaker at a higher asymmetry and it even vanishes at high enough asymmetries. At high asymmetries, the neutron (PF2)-P-3 superfluidity turns out to be much stronger than the proton one, implying that the neutron (PF2)-P-3 superfluidity is dominated in the highly asymmetric dense interior of neutron stars.

The level and distribution of chromosomal aberration of tomato seeds at different penetration depths of carbon ions

The relationship between the penetration depth and the level and distribution of chromosomal aberration of the root tip cells were investigated by exposure of the superposed tomato seeds to 80 MeV/u carbon ions. The results showed that on the entrance of the beam the chromosomal aberration level was low. Damage such as breaks and gaps were dominant. At the Bragg peak, the chromosomal aberration level was high. The yields of dicentrics, rings and disintegrated small chromosomes increased but the yields of breaks and gaps decreased. These results are consistent with the distribution of the physical depth dose pro. le of carbon ions. It is effective to deposit the Bragg peak on the seeds to induce hereditary aberration in the mutation breeding with heavy ions.

Proton and neutron S-1(0) superfluidity in asymmetric nuclear matter

The proton and neutron S-1(0), pairing gaps and their isospin dependence in isospin asymmetric nuclear matter have been studied by the isospin dependent Brueckner-Hartree-Fock approach and the BCS theory. We have focused on investigating and discussing the effect of three-body force. The calculated results indicate that as the isospin asymmetry increases, the density range of the S-1(0) neutron superfluidity is narrowed slightly and the maximum value of the neutron pairing gap increases 9 while the density domain for the proton superfluidity enlarges rapidly and the peak value of the proton gap decreases remarkably. The three-body force turns out to affect only weakly the neutron S-1(0) superfluidity and its isospin dependence, i. e., it leads to a small reduction of the neutron S-1(0) paring gap. However, the three-body force not only reduces largely the strength of the proton S-1(0) gaps at high densities in highly asymmetric nuclear matter but also suppresses strongly the density domain for the proton S-1(0) superfluidity phase.

Isospin dependence of S-1(0) proton and neutron superfluidity in asymmetric nuclear matter

We investigate the S-1(0) neutron and proton superfluidity in isospin-asymmetric nuclear matter. We have concentrated on the isospin dependence of the pairing gaps and the effect of a microscopic three-body force. It is found that as the isospin asymmetry goes higher, the neutron S-1(0) superfluid phase shrinks gradually to a smaller density domain, whereas the proton one extends rapidly to a much wider density domain. The three-body force turns out to weaken the neutron S-1(0) superfluidity slightly, but it suppresses strongly the proton S-1(0) superfluidity at high densities in nuclear matter with large isospin asymmetry.

Theoretical study on properties of new isotope (265)Bh

The properties of nuclei belonging to the newly observed a-decay chain starting from (265)Bh have been studied. The axially deformed relativistic mean-field calculation with the force NL-Z2 has been performed in the blocked BCS approximation. Some ground state properties such as binding energies, deformations, spins, and parities, as well as Q-values of the alpha-decay for this decay chain have been calculated and compared with known experimental data. Good agreement is found. The single-particle spectrum of the nucleus (265)Bh is studied and some new magic numbers are found, while the magnitudes of the shell gaps in superheavy nuclei are much smaller than those of nuclei before the actinium region, and the Fermi surfaces are close to the continuum. Thus the superheavy nuclei are usually not stable. The alpha-decay lifetimes in the (265)Bh decay chain are evaluated by different formulae, and compared with experimental data. The methods which give good agreement with the data are selected.

Properties and structure of N = Z nuclei within relativistic mean field theory

The axially deformed relativistic mean field theory with the force NLSH has been performed in the blocked BCS approximation to investigate the proper-ties and structure of N=Z nuclei from Z=20 to Z=48. Some ground state quantities such as binding energies, quadrupole deformations, one/two-nucleon separation energies, root-mean-squaxe (rms) radii of charge and neutron, and shell gaps have been calculated. The results suggest that large deformations can be found in medium-heavy nuclei with N=Z=38-42. The charge and neutron rms radii increase rapidly beyond the magic number N=Z=28 until Z=42 with increasing nucleon number, which is similar to isotope shift, yet beyond Z=42, they decrease dramatically as the structure changes greatly from Z=42 to Z=43. The evolution of shell gaps with proton number Z can be clearly observed. Besides the appearance of possible new shell closures, some conventional shell closures have been found to disappear in some region. In addition, we found that the Coulomb interaction is not strong enough to breakdown the shell structure of protons in the current region.

Isospin-dependent pairing interaction from nuclear matter calculations

The isospin dependence of the effective pairing interaction is discussed on the basis of the Bardeen, Cooper, and Schrieffer theory of superfluid asymmetric nuclear matter. It is shown that the energy gap, calculated within the mean field approximation in the range from symmetric nuclear matter to pure neutron matter, is not linearly dependent on the symmetry parameter owing to the nonlinear structure of the gap equation. Moreover, the construction of a zero-range effective pairing interaction compatible with the neutron and proton gaps in homogeneous matter is investigated, along with some recent proposals of isospin dependence tested on the nuclear data table.

Biopotentials of marine sponges from China oceans: past and future

An extensive literature survey of over 17 Journals was carried out on Chinese sponges and their natural products in the period from 1980 to 2001. This review is thus intended to provide the first thorough overview of research on marine sponges from China Ocean territories. Information is provided about the rather-limited taxonomic study of Chinese marine sponges, with an analysis on their distribution and diversity. Research findings on the natural products and their bioactivity screening from Chinese sponges are summarized. The weaknesses, gaps and problems in the past R&D program of Chinese sponges are identified, which point to the future opportunities in exploiting these huge untapped sponge resources. The report is expected to serve as an entry point for understanding Chinese sponges and for furthering R&D on their bioactive compounds for new drug development. (C) 2003 Elsevier Science B.V. All rights reserved.

Band Gap Tunable, Donor-Acceptor-Donor Charge-Transfer Heteroquinoid-Based Chromophores: Near Infrared Photoluminescence and Electroluminescence

A series of D-pi-A-pi-D type of near-infrared (NIR) fluorescent compounds based on benzobis(thia diazole) and its selenium analogues were synthesized and fully characterized by H-1 and C-13 NMR, high-resolution mass spectrometry, and elemental analysis. The absorption fluorescence, and electrochemical properties were also studied. Photoluminescence of these chromophores ranges from 900 to 1600 nm and their band gaps are between 1.19 and 0.56 eV.

Different electronic structures and spectroscopic properties of cationic [M(ppy)2(N--N)]+ (M = Rh, Ir; N--N = Hcmbpy, H2dcbpy), a DFT study.

We report a comparative quantum-chemical study of the electronic structures and optical properties of a series of cationic complexes [M(ppy)(2)(N--N)](+) (N--N = Hcmbpy = 4-carboxy-4'-methylbpy, M = Rh (Rh1), Ir(Ir2); N--N = H(2)dcbpy = 4,4'-dicarboxy-bpy, M = Rh (Rh3) and Ir (Ir4)). The theoretical calculation reveals that the increased number of -COOH groups on the bpy ligand can decrease the energy levels of LUMO more than HOMO and narrow down the HOMO-LUMO energy gaps, which results in the red-shifted of the lowest-lying absorption and phosphorescent spectra. The lowest-lying singlet absorptions were categorized as d(M,M = Rh or Ir) + pi(ppy) -->pi*(bpy) with MLCT and LLCT characters.