Stocking models of Chinese mitten crab (Eriocheir japonica sinensis) in Yangtze lakes

The fanning of Chinese mitten crab, a quality aquatic product in China and neighbouring Asian countries, has been developing rapidly in China since last decade. It reached a total yield of 3.4 X 10(5) tonnes in 2002. Due to the successive over-stocking year after year, many lakes in the mid-lower Yangtze Basin, the main farming area, are under deterioration, leading to a reduction of crab yield and quality, and, subsequently, a loss of fanning profits. Aiming at a normal development of crab culture and the sustainable use of lakes, an annual investigation dealing with lake environmental factors in relation to stocked crab populations was carried out at 20 farms in 4 lakes. The results show that the submersed macrophyte biomass (B-Mac) is the key factor affecting annual crab yield (CY). Using the ratio of Secchi depth to mean depth (Z(SD)/Z(M)), an easily measured parameter closely correlated to BMac, as driving variable, 10 regression models of maximal crab yields were generated (r(2) ranging 0.49-0.81). Based on the theory of MSY (Maximum Sustainable Yield), in combination with body-weight (BW) and recapture rate (RR) of adult crabs, a general optimal stocking model was eventually formulated. All models are simple and easy to operate. Comments on their applications and prospects are given in brief. (c) 2006 Elsevier B.V. All rights reserved.

Local strain rate and curvature dependences of scalar dissipation rate transport in turbulent premixed flames: A direct numerical simulation analysis

The statistical behaviours of the instantaneous scalar dissipation rate Nc of reaction progress variable c in turbulent premixed flames have been analysed based on three-dimensional direct numerical simulation data of freely propagating statistically planar flame and V-flame configurations with different turbulent Reynolds number Ret. The statistical behaviours of N c and different terms of its transport equation for planar and V-flames are found to be qualitatively similar. The mean contribution of the density-variation term T1 is positive, whereas the molecular dissipation term (-D2) acts as a leading order sink. The mean contribution of the strain rate term T2 is predominantly negative for the cases considered here. The mean reaction rate contribution T3 is positive (negative) towards the unburned (burned) gas side of the flame, whereas the mean contribution of the diffusivity gradient term (D) assumes negative (positive) values towards the unburned (burned) gas side. The local statistical behaviours of Nc, T1, T2, T 3, (-D2), and f(D) have been analysed in terms of their marginal probability density functions (pdfs) and their joint pdfs with local tangential strain rate aT and curvature km. Detailed physical explanations have been provided for the observed behaviour. © 2014 Y. Gao et al.

Cognitive models in biomimetic pattern cognition

We describe a new model which is based on the concept of cognizing theory. The method identifies subsets of the data which are embedded in arbitrary oriented lower dimensional space. We definite k-mean covering, and study its property. Covering subsets of points are repeatedly sampled to construct trial geometry space of various dimensions. The sampling corresponding to the feature space having the best cognition ability between a mode near zero and the rest is selected and the data points are partitioned on the basis of the best cognition ability. The repeated sampling then continues recursively on each block of the data. We propose this algorithm based on cognition models. The experimental results for face recognition demonstrate that the correct rejection rate of the test samples excluded in the classes of training samples is very high and effective.

Comparison of cooling rates for hot carriers in GaAs AlAs quantum wells based on macroscopic and microscopic phonon models

By using three analytical phonon models in quantum wells-the slab model, the guided-mode model, and the improved version of the Huang-Zhu model [Phys. Rev. B 38, 13 377 (1998)], -and the phonon modes in bulk, the energy-loss rates of hot carriers due to the Frohlich potential scattering in GaAs/AlAs multiple quantum wells (MQW's) are calculated and compared to those obtained based on a microscopic dipole superlattice model. In the study, a special emphasis is put on the effects of the phonon models on the hot-carrier relaxation process when taking the hot-phonon effect into account. Our numerical results show that, the calculated energy-loss rates based on the slab model and on the improved Huang-Zhu model are almost the same when ignoring the hot-phonon effect; however, with the hot phonon effect considered, the calculated cooling rate as well as the hot phonon occupation number do depend upon the phonon models to be adopted. Out of the four analytical phonon models investigated, the improved Huang-Zhu model gives the results most close to the microscopic calculation, while the guided-mode model presents the poorest results. For hot electrons with a sheet density around 10(12)/cm(2), the slab model has been found to overestimate the hot-phonon effect by more than 40% compared to the Huang-Zhu model, and about 75% compared to the microscopic calculation in which the phonon dispersion is fully included. Our calculation also indicates that Nash's improved version [J. Lumin. 44, 315 (1989)] is necessary for evaluating the energy-loss rates in quantum wells of wider well width, because Huang-Zhu's original analytical formulas an only approximately orthogonal for optical phonons associated with small in-plane wave numbers. [S0163-1829(99)08919-5].

森林流域单元水文模型的构建与应用

目前全球缺水、水污染、洪涝灾害以及水土流失仍然非常严重，尤其在我国北方地区。流域水文模型可用来进行不同需水管理的情景分析，为解决我国水问题提供科学依据。分布式水文模型是流域水文模型的发展方向，具有显著特点：1）应用前景广泛，不仅可以模拟流域水文过程，还可以协助模拟泥沙或污染物的运移过程，为水利工程设计、水土保持、环境保护等领域提供技术支持；2）能够预测流域土地利用或气候变化下的流域水文响应过程变化，为管理部门提供决策支持；3）模型所需要的参数全部具有物理意义，可通过实际测量确定，适合模拟实测系列较短或是无观测流域的水文过程；4）对于目前国际水文界的前沿问题—水文尺度转换提供了一种有效的解决途径。 然而分布式水文模型还不完善，如1)真实性问题。对一些水文过程和边界条件还不确定。2)尺度转换问题。目前很少考虑尺度对参数有效性的影响。3)检验问题。还无法判断对有些难以测量的水文状态变量的模拟正确与否。4)计算时间和数据存储的问题。有些分布式水文模型虽然具有很强的水文物理基础和完善的模型结构，但是计算时间过长和(或)数据存储过大，难以应用。上述问题的核心就是对分布式水文模型的核心—单元水文模型的研究不够，需要为进一步完善单元水文模型进行研究。 本文采用饱和入渗理论、Saint-Venant方程、Richards方程、Penman-Monteith方程等等构建了以有限差分法求解的适用于森林流域的单元水文模型，并通过实验室模拟试验和坡地径流场资料进行了验证，主要结论为： 通过不同坡度和不同雨强下的室内坡面产汇流实验模拟，表明：该模型模拟的坡面流和壤中流过程与实测过程基本一致，峰现时间、径流历时、峰值流量、出流总量模拟值与实测值的相对误差均较小，基本小于10%。模型的模拟精度较高，实用性较强，为深入研究壤中流机制和改进流域降雨-径流模型提供了理论依据。 通过坡地径流观测场实测资料的验证，表明：该模型模拟的坡面流过程精度较高，累计流量的精度更高于小时过程的精度，离差系数、效率系数、确定系数均较理想，具有应用价值，有助于改善分布式水文模型在森林流域的模拟效果。

CFD study of a sudden-expanding coal combustor using Euler-Euler and Euler-Lagrange models

In this study, the Euler-Euler (E-E) and Euler-Lagrange (E-L) models designed for the same chemical mechanism of heterogeneous reactions were used to predict the performance of a typical sudden-expanding coal combustor. The results showed that the current E-E model underestimated the coal burnout rate because the particle temperature fluctuation on char combustion is not adequately considered. A comparison of the E-E and E-L simulations showed the underestimation of heterogeneous chemical reaction rates by the E-E model. (C) 2010 Elsevier Ltd. All rights reserved.

功能菌剂的混合发酵研究

随着化工行业的发展，大量有毒有害难降解有机物随工业废水的排放进入环境，这些物质能够在环境中长期存在、积累和扩散，通过食物链对动植物的生存及人类的健康造成不良影响。本文以苯酚、对氯硝基苯、氯苯和十六烷为模拟污染物，以前期研制的功能菌剂为对象，经过紫外线线诱变筛选出优于出发菌株的功能菌，对诱变后功能菌的理化性能进行了研究，对菌种进行了鉴定，在此基础上，就其相互之间的微生态关系进行研究，为混合发酵提供理论基础，并就其最佳发酵条件及发酵参数进行了研究，最后对发酵产品的性能进行了检测。目前，国内外有关功能菌剂的研究还存在多方面的不足，主要包括：①由于多菌种混合发酵过程较为复杂，各菌之间存在复杂的相互作用，影响因素较多，关于菌种之间的相互关系研究得很少，环境功能菌剂的发酵方法大多采用单独发酵后混合的方式。单独发酵对原材料、设备和能源的利用率较低，对于多菌种制剂发酵，在设备、能源和原材料的方面造成的浪费更大，将会大幅增加菌剂的生产成本，影响多菌种功能菌剂的发展；②功能菌剂生产过程的质量控制方面研究得较少；③功能菌剂产品的稳定性、抗冲击性能研究得较少，对环境微生物制剂的研究主要集中在菌种选育和培养条件优化方面。 通过本论文研究，得到以下主要结论。 （1）在紫外线诱变处理中，用紫外线对发生一定程度退化的出发菌株进行诱变处理后，六株具有高效降解性能的菌株被筛选出来，诱变筛选出的菌株形态和ERIC-PCR指纹图谱与出发菌株相比发生了明显改变；而且诱变后的菌株对目标难降解底物的降解能力均得到改善，其中，FPN、FCB、F14、FEm对目标底物的降解率提高了20%以上；诱变后菌株经过7次连续传代接种后，对目标难降解底物的降解率无显著变化，具有一定的遗传稳定性。并对诱变后的功能菌进行了初步的鉴定，这6株菌都分别是芽孢杆菌。 （2）对诱变后的功能菌相互之间的微生态关系进行了研究，通过抑菌实验、生长量以及基质消耗量的比较，确定它们之间的生长关系是无害共栖关系，可以进行混合发酵。 （3）对该功能菌剂进行发酵培养条件研究，结果表明发酵培养基的最佳成分（g/L）：葡萄糖 31.0g/L、玉米粉10.0g/L、磷酸氢二钾1.0g/L、硫酸铵1.1g/L、硫酸镁0.55g/L。通过研究不同的培养条件对菌体生长和降解性能的影响，确定了最佳培养条件：培养基初始pH7.5；最适温度32℃；培养基装液量125mL（250 mL三角瓶），以及培养时间对降解性能的影响，培养20 h的产物对降解最为有利。通过研究添加不同目标污染物对菌体生长和降解性能的影响，确定了添加目标污染物的最佳量以及最佳时间：苯酚投加量：1.125 g/L，对氯硝基苯投加量：0.1 g/L；最佳投加时间为发酵培养开始后4 h。 （4）以摇瓶分批发酵最优条件为基础，对FPN、F10、FCB、FNa、F14 和 FEm进行了摇瓶分批发酵试验。以摇瓶分批发酵试验数据为依据，对功能菌剂分批发酵动力学进行了研究，建立了菌体生长和基质消耗的动力学模型，拟合模型能较好的反映功能菌剂分批发酵过程。 （5）功能菌剂和活性污泥协同作用，可以提高系统的生物降解能力，功能菌剂投加量为2%，新鲜活性污泥3500 mg/L，降解24 h条件下，功能菌剂和活性污泥的协同作用对COD的去除率和对照组相比，最多的提高了36.8%。功能菌剂和活性污泥协同作用以及活性污泥的单独作用，其生物降解过程均符合一级反应动力学过程，功能菌剂和活性污泥协同作用的生物降解动力学方程为：，相关系数97%。采用SBR运行方式，引入功能菌剂的SBR系统明显能够改善和提高生物降解的效率。与仅有活性污泥的系统相比，系统对COD的平均去除率可以提高27.1%，同时，系统的耐负荷冲击以及耐毒害冲击的性能比仅有活性污泥的SBR系统强，特别是负荷冲击对引入功能菌剂的SBR系统影响很小。仅有活性污泥的SBR系统经过负荷冲击和毒害冲击之后，不能恢复到冲击之前的水平，而且系统有效作用时间的周期比引入功能菌剂的SBR系统相比大大缩短，而引入功能菌剂的SBR系统处理效果较为稳定，恢复能力很强。 Along with the development of industries, many recalcitrant organic chemicals have been discharged into natural environments together with wastewaters and can exist in waters, soil and sediments for a long time without degradation. These haz-ardous substances, their byporducts and metabolizabilities can be highly toxic, mu-tagenic and carcinogenic, thereby threatening animals, plants and human health through food chain. Consequently the removal of these compounds is of significant interest in the area of wastewater treatment. In this dissertation, the phenol, hydro-quinone, chlorobenzene and hexadecane treated as the model pollutants, the func-tional microorganism agent was used as the starting strains, they treated with ultra-violet light, and then the mutant strains with high degradation ability were screened out and identified primarily, the relationship between these stains were studied, the medium composition and fermentation conditions were optimized, the degradation ability of the fermented production was tested. The literature survey indicates that the study of the microorganism agent is far from complete and more information is re-quired on following problems. 1, Because of the complexity of relationship in mixed fermentation and the complicated factors, the study is hardly to process.2, There is a lack of information on the quality control of the producing process .3, And there is a lack of information on the stability about the microorganism agent. In this dissertation, the main results of the present study could be summarized as follows: (1)The degenerate starting strains were treated with the ultraviolet light, and six mutant strains with high biodegradation ability were screened out by using the me-dium with selective pressure of model pollutants. The mutant strains had great changes in colonialmorphology and ERIC-PCR fingerprinting. And the mutant strains got obvious advantages over the starting strains in degradation ability and over 20% improvement of removal rates was achieved for FPN、FCB、F14 and FEm. The de-gradation ability of the mutant strains was stable after seven generations. After that, the mutant strains were primarily identified as bacillus respectively. (2) The relationship between these mutant strains was studied. By the compari-son of antibiosis effect, biomass and consumption of substrate, the relationships were neutralism and they could be mixed fermented. (3) The optimized cultivation conditions were as follows: glucose 31.0 g/L, corn power 10 g/L, K2HPO4 1.0 g/L, (NH4)2SO4 1.1 g/L, MgSO4 0.55 g/L, initial pH7.5, temperature 32℃, working volume 125 mL/250 mL, and cultivation time 20h (con-sidering the time effect on degradation ability), adding pollutants phenol (1.125 g/L) and hydroquinone (0.1 g/L) into the broth at 4 h after cultivation. (4) Based on the above optimum condition, the batch fermentation was per-formed with strains FPN, F10, FCB, FNa, F14 and FEm in shake flask. The batch fermentation kinetics was studied based on the experimental data. Two kinetic models were constructed which could reflect the regularity of growth and substrate consump-tion in the process of batch fermentation. (5) The co-operation of functional microorganism agent and activated sludge could raise biodegradation of system by adding some microorganism agent and 3500 mg/L fresh activated sludge. Bioaugumentation by the addition of high effective deg-radation culture enhanced the treatment effect of SBR system and the COD removal rate was increased by 20%-36.8%. Its biodegradation matched first-order dynamical reaction equation, and the reaction equation was ln0.2327.391ct=−+. The micro-organism agent had the effect of optimization to activated sludge micro-ecosystem. The SBR system adding 2% microorganism agent, the average COD removal rate of that was increased by 27.1% and stronger anti-shock ability to load and toxicant were achieved (compared with SBR system just adding activated sludge). Especially the load-shock has barely effect to the SBR system adding microorganism agent. After the load and toxicant shock, the SBR system just adding activated sludge couldn’t come back to original level and the activated sludge micro-ecosystem was frustrated. The applying of microorganism agent increased biological activity and system’s re-sistance ability to load shock and toxicant shock.

Reconstructing the interaction between dark matter and holographic dark energy

We reconstruct the interaction rate between dark matter and the holographic dark energy with the parametrized equation of states and the future event horizon as the infrared cutoff length. It is shown that the observational constraints from the 192 type Ia Supernovae (SnIa) and baryon acoustic oscillation (BAO) measurement permit the negative interaction in the wide region. Moreover, the usual phenomenological descriptions cannot describe the reconstructed interaction well for many cases. The other possible interaction is also discussed.

Kinetics of ytterbium(III) extraction with Cyanex 272 using a constant interfacial cell with laminar flow

Studies have been made on the kinetics of ytterbium(III) with bis-(2,4,4-trimethylpentyl) phosphinic acid (Cyanex 272, HA) in n-heptane using a constant interfacial cell with laminar flow. The stiochiometry and the equilibrium constant of the extracted complex formation reaction between Yb3+ and Cyanex 272 are determined. The extraction rate is dependent of the stirring rate. This fact together with the Ea value suggests that the mass transfer process is a mixed chemical reaction-diffusion controlled at lower temperature, whereas it is entirely diffusion controlled at higher temperature. The rate equations for the ytterbium extraction with Cyanex 272 have been obtained. The rate-determining step is also made by predictions derived from interfacial reaction models, and through the approximate solutions of the flux equation, diffusion parameters and thickness of the diffusion film have been calculated.

Interparticle distance-temperature-strain rate equivalence for the brittle-tough transition in polymer blends

From the angle of energy transformation an equation was obtained for the brittle transition in polymer blends. The effects of interparticle distance, temperature and strain rate on the brittle-tough transition in polymer blends were characterized by this equation. The calculations show that, for this transition: (1) increasing temperature and decreasing interparticle distance are equivalent and the shift factor increases with increasing temperature; (2) decreasing strain rate and decreasing interparticle distance have equivalent effects on the transition; (3) the strain rate must be optimum in order to find the brittle-tough transition phenomena for a given temperature region. (C) 1998 Published by Elsevier Science Ltd. All rights reserved.

Analysis on suspended sediment deposition rate for muddy coast of reclaimed land

A new expression for calculating suspended fine-sediment deposition rate is developed based on theoretic analysis and experiments. The resulting equation is applied to simulation of fine sediment deposition in the reclaimed land in the Hangzhou Bay, China. The hydrodynamic environment in this area is solved by use of a long wave model, which gives the 2D-velocity field and considers bathymetric changes due to fine sediment deposition. The expression is proved convenient to use in engineering practice, and the predicted deposition rate agrees with the annual data available from field measurements from the first year to the third year after the construction of the long groin as a reclaiming method.

Asymptotic periodicity of the Volterra equation with infinite delay

For some species, hereditary factors have great effects on their population evolution, which can be described by the well-known Volterra model. A model developed is investigated in this article, considering the seasonal variation of the environment, where the diffusive effect of the population is also considered. The main approaches employed here are the upper-lower solution method and the monotone iteration technique. The results show that whether the species dies out or not depends on the relations among the birth rate, the death rate, the competition rate, the diffusivity and the hereditary effects. The evolution of the population may show asymptotic periodicity, provided a certain condition is satisfied for the above factors. (c) 2006 Elsevier Ltd. All rights reserved.

Learning World Models in Environments with Manifest Causal Structure

This thesis examines the problem of an autonomous agent learning a causal world model of its environment. Previous approaches to learning causal world models have concentrated on environments that are too "easy" (deterministic finite state machines) or too "hard" (containing much hidden state). We describe a new domain --- environments with manifest causal structure --- for learning. In such environments the agent has an abundance of perceptions of its environment. Specifically, it perceives almost all the relevant information it needs to understand the environment. Many environments of interest have manifest causal structure and we show that an agent can learn the manifest aspects of these environments quickly using straightforward learning techniques. We present a new algorithm to learn a rule-based causal world model from observations in the environment. The learning algorithm includes (1) a low level rule-learning algorithm that converges on a good set of specific rules, (2) a concept learning algorithm that learns concepts by finding completely correlated perceptions, and (3) an algorithm that learns general rules. In addition this thesis examines the problem of finding a good expert from a sequence of experts. Each expert has an "error rate"; we wish to find an expert with a low error rate. However, each expert's error rate and the distribution of error rates are unknown. A new expert-finding algorithm is presented and an upper bound on the expected error rate of the expert is derived.

Modifying weighted fuzzy subsethood-based rule models with fuzzy quantifiers

K. Rasmani and Q. Shen. Modifying weighted fuzzy subsethood-based rule models with fuzzy quantifiers. Proceedings of the 13th International Conference on Fuzzy Systems, pages 1679-1684, 2004

Genetic correlates of longevity and selected age-related phenotypes: a genome-wide association study in the Framingham Study

BACKGROUND: Family studies and heritability estimates provide evidence for a genetic contribution to variation in the human life span. METHODS:We conducted a genome wide association study (Affymetrix 100K SNP GeneChip) for longevity-related traits in a community-based sample. We report on 5 longevity and aging traits in up to 1345 Framingham Study participants from 330 families. Multivariable-adjusted residuals were computed using appropriate models (Cox proportional hazards, logistic, or linear regression) and the residuals from these models were used to test for association with qualifying SNPs (70, 987 autosomal SNPs with genotypic call rate [greater than or equal to]80%, minor allele frequency [greater than or equal to]10%, Hardy-Weinberg test p [greater than or equal to] 0.001).RESULTS:In family-based association test (FBAT) models, 8 SNPs in two regions approximately 500 kb apart on chromosome 1 (physical positions 73,091,610 and 73, 527,652) were associated with age at death (p-value < 10-5). The two sets of SNPs were in high linkage disequilibrium (minimum r2 = 0.58). The top 30 SNPs for generalized estimating equation (GEE) tests of association with age at death included rs10507486 (p = 0.0001) and rs4943794 (p = 0.0002), SNPs intronic to FOXO1A, a gene implicated in lifespan extension in animal models. FBAT models identified 7 SNPs and GEE models identified 9 SNPs associated with both age at death and morbidity-free survival at age 65 including rs2374983 near PON1. In the analysis of selected candidate genes, SNP associations (FBAT or GEE p-value < 0.01) were identified for age at death in or near the following genes: FOXO1A, GAPDH, KL, LEPR, PON1, PSEN1, SOD2, and WRN. Top ranked SNP associations in the GEE model for age at natural menopause included rs6910534 (p = 0.00003) near FOXO3a and rs3751591 (p = 0.00006) in CYP19A1. Results of all longevity phenotype-genotype associations for all autosomal SNPs are web posted at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007. CONCLUSION: Longevity and aging traits are associated with SNPs on the Affymetrix 100K GeneChip. None of the associations achieved genome-wide significance. These data generate hypotheses and serve as a resource for replication as more genes and biologic pathways are proposed as contributing to longevity and healthy aging.