Vowel normalisation: Time-domain processing of the internal dynamics of speech

Human listeners can identify vowels regardless of speaker size, although the sound waves for an adult and a child speaking the ’same’ vowel would differ enormously. The differences are mainly due to the differences in vocal tract length (VTL) and glottal pulse rate (GPR) which are both related to body size. Automatic speech recognition machines are notoriously bad at understanding children if they have been trained on the speech of an adult. In this paper, we propose that the auditory system adapts its analysis of speech sounds, dynamically and automatically to the GPR and VTL of the speaker on a syllable-to-syllable basis. We illustrate how this rapid adaptation might be performed with the aid of a computational version of the auditory image model, and we propose that an auditory preprocessor of this form would improve the robustness of speech recognisers.

沉水植物分布格局对湖泊水环境N、P因子影响

利用实地调查数据模拟保安湖沉水植物分布及水环境生态因子场。应用GIS空间分析功能 ,分别空间选取四种优势沉水植物 (金鱼藻CeratophyllumdemersumL .,穗状狐尾藻MyriophyllumspicatumL .,微齿眼子菜PotamogetonmaackianusA .Benn .,及苦草VallisneriaspiralisL .)的分布水域及无沉水植物分布水域的局部生态因子场。根据得到的局部因子场特征 ,比较分析不同水生植物分布格局对水环境中N、P因子的影响。结果显示四种沉水植物的分

湖北汉族人大肠癌HLA-DRB1等位基因遗传易感性研究

目的　探讨湖北汉族人 HL A- DRB1等位基因与大肠癌遗传相关性。方法　针对 HL A- DRB1等位基因第 2外显子多态性 ,设计 2 3对引物的序列特异性引物聚合酶链反应 ,结合等位基因序列分析 ,检测了无亲缘关系的湖北籍汉族健康人 136名及大肠癌患者 72例的 HL A- DRB1基因。 SAS软件进行数据处理。结果　湖北地区汉族人大肠癌患者与正常人比较 ,HL A- DRB1* 0 90 1等位基因分布频率 0 .2 2 92 vs0 .1397(P<0 .0 0 5 ,OR=2 .182

通江湖泊的渔业意义及其资源管理对策

长江中、下游的江湖复合生态系统包含有河流和湖泊两个环境单元。其中的鱼类群落由河海洄游鱼类、江湖洄游鱼类、河流鱼类和定居性鱼类等４个生态类群组成，尤以江湖徊游鱼类对这一特殊的生态环境形成了良好的适应，因而种群数量繁盛。从渔业的角度看，水利工程造成的江湖阻隔削弱了通江湖泊的生态功能，成为导致鱼类资源下降和种类结构改变的主要原因之一。当前应从控制捕捞、人工增殖和恢复生态环境结构等方面着手进行资源管理，确保鱼类资源的永续利用。

The smallest thermal nuclear reactor

There is a growing need for very small nuclear reactors for space applications and as portable high-intensity neutron sources. This technical note investigates the question of what is the smallest possible thermal reactor. It was found that the smallest reactor is a spherically shaped solution of 242mAm(NO3)3 in water. The weight of such a reactor is 4.95 kg with 0.7 kg of 242mAm nuclear fuel. The radius of the reactor in this case is 9.6 cm.

Recycle of transuranium elements in light water reactors for reduction of geological storage requirements

This paper presents results of a feasibility study aimed at developing a zero-transuranic-discharge fuel cycle based on the U-Th-TRU ternary cycle. The design objective is to find a fuel composition (mixture of thorium, enriched uranium, and recycled transuranic components) and fuel management strategy resulting in an equilibrium charge-discharge mass flow. In such a fuel cycle scheme, the quantity and isotopic vector of the transuranium (TRU) component is identical at the charge and discharge time points, thus allowing the whole amount of the TRU at the end of the fuel irradiation period to be separated and reloaded into the following cycle. The TRU reprocessing activity losses are the only waste stream that will require permanent geological storage, virtually eliminating the long-term radiological waste of the commercial nuclear fuel cycle. A detailed three-dimensional full pressurized water reactor (PWR) core model was used to analyze the proposed fuel composition and management strategy. The results demonstrate the neutronic feasibility of the fuel cycle with zero-TRU discharge. The amount of TRU and enriched uranium loaded reach equilibrium after about four TRU recycles. The reactivity coefficients were found to be within a range typical for a reference PWR core. The soluble boron worth is reduced by a factor of ∼2 from a typical PWR value. Nevertheless, the results indicate the feasibility of an 18-month fuel cycle design with an acceptable beginning-of-cycle soluble boron concentration even without application of burnable poisons.

稀有鮈鲫临界温度的研究

稀有鮈鲫临界温度的研究王剑伟中国科学院水生生物研究所武汉４３００７２稀有钢鲫（ｆｆｏｂｍｐｎｉｒａｎＹｅｅｔＦｕ）是一种小型鲤科鱼类，在作为一种新的实验鱼。灭蚊鱼等方面具有广阔的应用前景［’，’）。从１９９０年开始，我们就积累了有关稀有铜鲫越冬、度夏...

广西河池地区鱼类动物地理学特征

据调查鉴定,流经广西河池地区的红水河、龙江和四堡河的鱼类资源有156种,分隶7目19科97属。其中有91种为本区第一次记录,有土著鱼类153种,并发现金线鲃属鱼类有4个新种。

谷皮菱形藻的耐盐适应性

本文报道了在水产养殖上有较大经济价值的硅藻代表种类——谷皮菱形藻对盐度的适应性。该藻有较强的耐盐适应性,在含≤1.0mol/L NaCl的培养基中均能生长,其最适生长盐度约为18‰(含0.25 mol/L NaCl的培养基)。在不同盐度下生长的细胞中其主要生化组分含量有不同程度的改变。类胡萝卜素/叶绿素的比值随盐度的增加略有升高,这主要是由于叶绿素含量随盐度增高而降低所致;细胞蛋白质含量与盐度改变无明显关系;但糖类却随盐度提高而成倍增加,表明糖类是谷皮菱形藻适应盐度改变的主要渗透调节物。同时,在较高盐度时

盐泽螺旋藻藻胆蛋白的分离和特性研究

盐泽螺旋藻(Spirulina subsalsa)的水溶性色素粗提物经过硫酸铵沉淀和羟基磷灰石(HA)柱层析后可以分出两种藻胆蛋白,即藻蓝蛋白(c-PC)和别藻蓝蛋白(APC)。它们的纯度(指其在可见光部分的最大吸收与280nm处吸收之比)可分别达到7.27(c-PC)和6.55(APC)。而一般认可的纯度标准,PC为5,APC为6。纯化后的c-PC和APC在聚丙烯酰胺凝胶电泳(PAGE)中仅见一条色带,其最大吸收峰分别在620_(nm)和650_(nm),其室温荧光发射峰分别为642_(nm)和657_

Computational analysis of liquid crystalline elastomer membranes: Changing Gaussian curvature without stretch energy

Liquid crystalline elastomers (LCEs) can undergo extremely large reversible shape changes when exposed to external stimuli, such as mechanical deformations, heating or illumination. The deformation of LCEs result from a combination of directional reorientation of the nematic director and entropic elasticity. In this paper, we study the energetics of initially flat, thin LCE membranes by stress driven reorientation of the nematic director. The energy functional used in the variational formulation includes contributions depending on the deformation gradient and the second gradient of the deformation. The deformation gradient models the in-plane stretching of the membrane. The second gradient regularises the non-convex membrane energy functional so that infinitely fine in-plane microstructures and infinitely fine out-of-plane membrane wrinkling are penalised. For a specific example, our computational results show that a non-developable surface can be generated from an initially flat sheet at cost of only energy terms resulting from the second gradients. That is, Gaussian curvature can be generated in LCE membranes without the cost of stretch energy in contrast to conventional materials. © 2013 Elsevier Ltd. All rights reserved.

用浮游植物的生产量估算武昌东湖鲢鳙生产潜力与鱼种放养量的探讨

本文根据浮游植物生产量求得对鲢、鳙的供饵能力,并通过浮游植物对鲢、鳙转化效率的计算,估算出武昌东湖鲢、鳙的生产潜力,进而求得武昌东湖鲢、鳙的合理投放量。作者求得东湖浮游植物全年对鲢、鳙的供饵能力是61,153吨(鲜重);由此估算出东湖鲢、鳙的生产潜力是789公斤/公顷以上,每年鱼种(四寸以上)的合理投放量,鲢是 209万尾,鳙是 110万尾。

Foundations for offshore wind turbines

Offshore wind turbines impose unique combinations of loads on their foundations. They impose large lateral loads in relation to vertical loading which must be resisted, but are also subject to approximately a million cycles of loading through their design life. As the performance of these systems is dominated by their dynamic response, the stiffness of the foundations becomes critical in design. Conventional design codes which are conservative by virtue of predicting a lower stiffness than might be observed in practice may not be conservative for these problems. By utilizing centrifuge modeling the behaviour of monopile foundations in both sands and clays under cyclic loading can be investigated in order to predict the dynamic behaviour of these systems. © 2010 Taylor & Francis Group, London.

Determination of PAH, PCB, and OCP in water from the Three Gorges Reservoir accumulated by semipermeable membrane devices (SPMD)

Bioavailable water concentrations of polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticides (OCP) were measured in the water column from Three Gorges Reservoir (TGR) collected in May 2008 using semipermeable membrane devices (SPMDs). The sampling sites spanned the whole reservoir from the upstream Chongqing to the great dam covering more than 600 km long distance with water flow velocities ranging from <0.05 to 1.5 m s(-1). This is the first experience of SPMD application in the biggest reservoir in the world. The results of water sampling rates based on performance reference compounds (PRC) were tested to be significantly correlated with water flow velocities in the big river. Results of back-calculated aqueous concentrations based on PRC showed obvious regional variations of PAH, PCB and OCP levels in the reservoir. Total PAH ranged from 13.8 to 97.2 ng L-1, with the higher concentrations occurring in the region of upstream and near the dam. Phenanthrene, fluoranthene, pyrene and chrysene were the predominant PAH compounds in TGR water. Total PCB ranged from 0.08 to 0.51 ng L-1, with the highest one occurring in the region near the dam. PCB 28, 52, 101, 138, 153, 180, 118 were the most abundant PCB congeners in the water. The total OCP ranged from 2.33 to 3.60 ng L-1 and the levels showed homogenous distribution in the whole reservoir. HCH, DDT and HCB, PeCB were the major compounds of OCP fingerprints. Based on water quality criteria, the TGR water could be designated as being polluted by HCB and PAH. Data on PAH, PCB and OCP concentrations found in this survey can be used as reference levels for future POP monitoring programmes in TGR. (C) 2009 Elsevier Ltd. All rights reserved.