Process envelopes for stabilisation/solidification of contaminated soil using lime-slag blend.

PURPOSE: Stabilisation/solidification (S/S) has emerged as an efficient and cost-effective technology for the treatment of contaminated soils. However, the performance of S/S-treated soils is governed by several intercorrelated variables, which complicates the optimisation of the treatment process design. Therefore, it is desirable to develop process envelopes, which define the range of operating variables that result in acceptable performance. METHODS: In this work, process envelopes were developed for S/S treatment of contaminated soil with a blend of hydrated lime (hlime) and ground granulated blast furnace slag (GGBS) as the binder (hlime/GGBS = 1:4). A sand contaminated with a mixture of heavy metals and petroleum hydrocarbons was treated with 5%, 10% and 20% binder dosages, at different water contents. The effectiveness of the treatment was assessed using unconfined compressive strength (UCS), permeability, acid neutralisation capacity and contaminant leachability with pH, at set periods. RESULTS: The UCS values obtained after 28 days of treatment were up to ∼800 kPa, which is quite low, and permeability was ∼10(-8) m/s, which is higher than might be required. However, these values might be acceptable in some scenarios. The binder significantly reduced the leachability of cadmium and nickel. With the 20% dosage, both metals met the waste acceptance criteria for inert waste landfill and relevant environmental quality standards. CONCLUSIONS: The results show that greater than 20% dosage would be required to achieve a balance of acceptable mechanical and leaching properties. Overall, the process envelopes for different performance criteria depend on the end-use of the treated material.

The Hudson-Raritan Estuary as a crossroads for distribution of blue (Callinectes sapidus), lady (Ovalipes ocellatus), and Atlantic rock (Cancer irroratus) crabs

Blue (Callinectes sapidus)(Portunidae),lady (Ovalipes ocellatus)(Portunidae), and Atlantic rock (Cancer irroratus) (Cancridae) crabs inhabit estuaries on the northeast United States coast for parts or all of their life cycles. Their distributions overlap or cross during certain seasons. During a 1991–1994 monthly otter trawl survey in the Hudson-Raritan Estuary between New York and New Jersey, blue and lady crabs were collected in warmer months and Atlantic rock crabs in colder months. Sex ratios, male:female, of mature crabs were 1:2.0 for blue crabs, 1:3.1 for lady crabs, and 21.4:1 for Atlantic rock crabs. Crabs, 1286 in total, were subsampled for dietary analysis, and the dominant prey taxa for all crabs, by volume of foregut contents, were mollusks and crustaceans. The proportion of amphipods and shrimp in diets decreased as crab size increased. Trophic niche breadth was widest for blue crabs, narrower for lady crabs, and narrowest for Atlantic rock crabs. Trophic overlap was lowest between lady crabs and Atlantic rock crabs, mainly because of frequent consumption of the dwarf surfclam (Mulinia lateralis) by the former and the blue mussel (Mytilus edulis) by the latter. The result of cluster analysis showed that size class and location of capture of predators in the estuary were more influential on diet than the species or sex of the predators.

倒刺鲃属鱼类系统分类的研究（鲤形目：鲤科）

倒刺鲃属（Ｓｐｉｎｉｂａｒｂｕｓ）鱼类分布于我国秦岭以南和元江以东诸水系以及台湾和海南岛。其属级和种级分类，历来意见不一。对采自６个省区的１０４尾标本进行形态性状测量和对骨骼标本进行观察的结果表明，倒刺鲃属鱼类以其最末一枚前躯椎上方无上髓棘、第４椎骨的髓棘发达、背鳍前方具一卧伏于皮下的倒刺等特征与亚科（Ｂａｒｂｉｎａｅ）其余属种明显相区别，进一步肯定了把它们作为亚科的一个属是合适的。该属鱼类共有５个有效种，而且首次提出长身刺鲃（Ｓ．ｅｔｏｎｇａｔｕｓ）是光倒刺鲃（Ｓ．ｈｏｌｌａｎｄｉ）的同物异名。光倒刺鲃和倒刺鲃（Ｓ．ｄｅｎｔｉｃｕｌａｔｕｓ）的种内地理变异呈现出独特的相关性，提示海南岛的倒刺　属鱼类可能是源自珠江水系，而不是源自元江水系。

香溪河鱼类群落组成及资源评价

采用定置刺网的捕捞方法,于2005年3—4月在香溪河官庄坪库湾连续捕捞20次,共调查到21种鱼类。对采集的渔获物数据,分析了多样性和种群优势度。确定上层、中上层、中下层和底层的优势类群分别是贝氏、蒙古、翘嘴、鲫、鲤、蛇、鲇。三峡水库蓄水对官庄坪鱼类群落构成影响显著:鲤科鱼类种类组成比例占总种数76.2%,其中亚科有7种,占鲤科总数的43.8%。静水性生活的鱼类所占比重较大,已经形成优势种群。经济鱼类在生物量上占有举足轻重地位,上层肉食性鱼类以蒙古、翘嘴为主。鳅科鱼类基本绝迹。

Dynamics of spread of Salmonella enterica in the systemic compartment

Traditional microbiological and immunological tools, combined with modern imaging, and molecular and mathematical approaches, have revealed the dispersive nature of Salmonella infections. Bacterial escape from infected cells, spread in the tissues and attempts to restrain this process by the host give rise to fascinating scenarios that underpin the pathogenesis of salmonelloses. © 2013 Institut Pasteur.

Low temperature annealing effects on the structure and optical properties of ZnO films grown by pulsed laser deposition

ZnO thin films were deposited on glass substrates at room temperature (RT) similar to 500 degrees C by pulsed laser deposition (PLD) technique and then were annealed at 150-450 degrees C in air. The effects of annealing temperature on the microstructure and optical properties of the thin films deposited at each substrate temperature were investigated by XRD, SEM, transmittance spectra, and photoluminescence (PL). The results showed that the c-axis orientation of ZnO thin films was not destroyed by annealing treatments: the grain size increased and stress relaxed for the films deposited at 200-500 degrees C, and thin films densified for the films deposited at RT with increasing annealing temperature. The transmittance spectra indicated that E-g of thin films showed a decreased trend with annealing temperature. From the PL measurements, there was a general trend, that is UV emission enhanced with lower annealing temperature and disappeared at higher annealing temperature for the films deposited at 200-500 degrees C; no UV emission was observed for the films deposited at RT regardless of annealing treatment. Improvement of grain size and stoichiometric ratio with annealing temperature can be attributed to the enhancement of UV emission, but the adsorbed oxygen species on the surface and grain boundary of films are thought to contribute the annihilation of UV emission. It seems that annealing at lower temperature in air is an effective method to improve the UV emission for thin films deposited on glass substrate at substrate temperature above RT.

一维量子波导中的Rashba电子输运

主要研究了平面一维波导系统中的Rashba电子波函数的输运性质,得到了如下的结果.根据Rashba效应,能量为E的平面电子波,将分裂成波矢分别为k_1=k_0+k_δ与k_2=k_0-k_δ的两种波函数,其自旋取向与波导的夹角分别为+π/2(自旋向上态)与-π/2(自旋向下态).若在支路的终端是栅极或者铁磁接触,则相应的波函数成为驻波形式:exp(±ik_δl)sin[k_0(l-L)],其中L是支路的长度,l是支路内的坐标.与不考虑自旋的情况不同的是,Rashba电子波函数的相位与支路的取向角度θ有关.此外,两种自旋取向的波传播的群速度相同,都是hk_0/m*.在各支路结点处,由波函数的连续性和流密度守恒条件,得到了Rashba电子波函数所必须满足的边界条件.利用这些边界条件,我们研究了Rashba电子在一些结构中的透射和反射性质,发现自旋向上和向下的Rashba电子波函数的干涉效应将受到铁磁接触或栅极的调制.最后得到了多分支结构中,Rashba电子输运的一般性理论.我们提出的Rashba电子的一维量子波导理论可以被用来设计各种自旋极化器件.

Applicatioo of Pade Approximation in Simulating Photonic Crystals

To save finite-difference time-domain(FDTD) computing time, several methods are proposed to convert the time domain FDTD output into frequency domain. The Padé approximation with Baker's algorithm and the program are introduced to simulate photonic crystal structures. For a simple pole system with frequency 160THz and quality factor of 5000,the intensity spectrum obtained by the Padé approximation from a 28-item sequence output is more exact than that obtained by fast Fourier transformation from a 220-item sequence output. The mode frequencies and quality factors are calculated at different wave vectors for the photonic crystal slab from a much shorter FDTD output than that required by the FFT method,and then the band diagrams are obatined. In addition,mode frequencies and Q-factors are calculated for photonic crystal microcavity.