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Abstract  

The thermotropic phase transitions in the perovskite type layer compound (n-C10H21NH3)2MnCl4 and (n-C14H29NH3)2MnCl4 were synthesized and, at the same time, a series of their mixtures C10Mn-C14Mn were prepared. The experimental binary phase diagram of C10Mn-C14Mn was established by differential thermal analysis (DTA), IR and X-ray diffraction. In the phase diagram new material (n-C10H21NH3)(n-C14H29NH3)MnCl4 and two eutectoid invariants were observed, two eutectic points temperatures are about 29.8 and 27.9°C. Contrasting other similar system, there are three noticeable solid solution ranges (α, β, γ) at the left and right boundary and middle of the phase diagram.

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Abstract  

In [10], the notion of homogeneous perfect sets as a generalization of Cantor type sets is introduced and their Hausdorff and lower box-counting dimensions are studied. In this paper, we determine their exact packing and upper box-counting dimensions based on the length of their fundamental intervals and the gaps between them. Some known results concerning the dimensions of Cantor type sets are generalized.

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Abstract  

This paper is concerned with the divergence points with fast growth orders of the partial quotients in continued fractions. Let S be a nonempty interval. We are interested in the size of the set of divergence points

\documentclass{aastex} \usepackage{amsbsy} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{bm} \usepackage{mathrsfs} \usepackage{pifont} \usepackage{stmaryrd} \usepackage{textcomp} \usepackage{upgreek} \usepackage{portland,xspace} \usepackage{amsmath,amsxtra} \usepackage{bbm} \pagestyle{empty} \DeclareMathSizes{10}{9}{7}{6} \begin{document} $$E_\varphi (S) = \left\{ {x \in [0,1):{\rm A}\left( {\frac{1} {{\varphi (n)}}\sum\limits_{k = 1}^n {\log a_k (x)} } \right)_{n = 1}^\infty = S} \right\},$$ \end{document}
where A denotes the collection of accumulation points of a sequence and φ: ℕ → ℕ with φ(n)/n → ∞ as n → ∞. Mainly, it is shown, in the case φ being polynomial or exponential function, that the Hausdorff dimension of E φ(S) is a constant. Examples are also given to indicate that the above results cannot be expected for the general case.

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Drought is a severe abiotic stress that affects wheat production worldwide. In order to identify candidate genes for tolerance to water stress in wheat, sequences of 11 genes that have function of drought tolerance in other plant species were used to identify the wheat ortholog genes via homology searching in the wheat EST database. Atotal of 11 primer pairs were identified and amplified PCR products in wheat. Of them, 10 STS markers were mapped on 11 chromosomes in a set of nulli-tetrasomic lines of ‘Chinese Spring’ wheat; six were mapped on chromosomes 1A, 1B, 4B, 7A, 2B and 5D, respectively, in a spring wheat mapping population (POP1). The marker XTaABH1 mapped on 7A in POP1 was the only one mapped but characterized in a winter wheat mapping population (POP2) for grain yield, kernel weight and diameter, and height in four-field trials applied different water stress or irrigation. The marker XTaABH1 was significantly associated with grain yield under rainfed condition, with kernel weight under terminal stress and non-irrigation conditions, with kernel diameter and height under non-irrigated condition. The STS primers, map information and marker-trait association produced in the currently study would be of interest to researchers working on drought tolerance.

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Garlic is widely used as food flavouring, and China is the world's largest garlic producer and exporter. To develop a convenient technique for evaluation of garlic cultivars would be worthwhile, and it would have wide application in such a huge market. In this research, 3D front-face fluorescence data of 8 garlic cultivars were recorded, and independent component analysis was used to decompose the overall fluorescence spectra into six independent components. The first, second, and fourth independent components showed a big difference among the cultivars, and the chemical fluorophores behind these three components were specified as protein, vitamin B6, and ATP, respectively, as fluorescent markers for evaluation. The result showed that all 8 cultivars cluster separately. The cultivar “YNQJ” have the highest quality in terms of protein and vitamin B6, “NXYC” and “SDHB” have the highest content of ATP, while “SXXA” is the poorest in terms of protein and ATP, and “HNJZ” has the lowest content of vitamin B6. Therefore, rapid evaluation of garlic cultivars can be accomplished successfully by using only the proportion values of three properly selected fluorescent markers.

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Abstract  

Flammable chemicals are frequently encountered in industrial processes. Under the safe operation basis and for fire/explosion danger prevention, it is imperative to recognize the flammability characteristics of these processes, especially under the working scenarios for elevated pressure and temperature. This study was conducted to investigate fire and explosion properties, including the explosion limits (LEL and UEL), maximum explosion overpressure (P max), maximum rate of explosion pressure rise (dP/dt)max, gas or vapor deflagration index (K g) and explosion class (St) of various acetone/water solutions (100, 75, 50 and 25 vol.%) at higher initial pressure/temperature up to 2 atm and 200°C via a 20-L-Apparatus. We further discussed the safety-related parameters and fire/explosion damage degree variations in the above aqueous acetone within 1 atm and 150°C. The results offered a successful solution for evaluating the flammability hazard effect in such a relevant crucial process with elevated pressure and temperature.

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The study site is the Honghe National Nature Reserve, a Ramsar designated site on the Sanjiang Plain in Northeast China. We present results regarding the spatial pattern and structure of plant communities in these most important natural but continually diminishing freshwater wetlands of China to help promote both protection and restoration. By investigating three ecological levels (landscape, ecosystem and community), this paper quantifies the characteristics of spatial pattern with the aim to identify specific ecological correlations with different hydrogeomorphic features. Specifically, the research involves hierarchical mapping of vegetation types by use of remote sensed data, and the coupling of landscape indices with fluvial topographic zones that have been deduced by GIS from DEM. Statistics from historical survey data are also used to measure the degradation of marshes as well as the historical change of the hydrological regime. We found that dominant is the Calamagrostis angustifolia — Carex spp. community type, a wet meadow and marsh complex within the prevailing landscape mosaic of shrubland and meadow. The results suggest that the sites’ hydro-geomorphic character has decisive influence on plant community structure and composition. There is only limited direct human interference in the sites and, as a consequence, the spatial pattern of vegetation distribution is natural. However, changes to the hydrological regime as the result of extensive irrigation activity in the surrounding area has led to rapid degradation of marsh wetlands within the sites, which threatens the ecological status in this storehouse of “Natural Genes” in the reserve.

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Nuclear Techniques in National Security Studies on Contraband Detection

IEC-based neutron generator for security inspection system

Journal of Radioanalytical and Nuclear Chemistry
Authors: G. H. Miley, L. Wu, and H. J. Kim

Summary  

The Federal Radiological Monitoring and Assessment Center (FRMAC) is authorized by the Federal Radiological Emergency Response Plan to coordinate all off-site radiological response assistance to state and local governments, in the event of a major radiological emergency in the United States. The FRMAC is established by the U.S. Department of Energy, National Nuclear Security Administration, to coordinate all Federal assets involved in conducting a comprehensive program of radiological environmental monitoring, sampling, radioanalysis, quality assurance, and dose assessment. During an emergency response, the initial analytical data is provided by portable field instrumentation. As incident responders scale up their response based on the seriousness of the incident, local analytical assets and mobile laboratories add additional capability and capacity. During the intermediate phase of the response, data quality objectives and measurement quality objectives are more rigorous. These higher objectives will require the use of larger laboratories, with greater capacity and enhanced capabilities. These labs may be geographically distant from the incident, which will increase sample management challenges. This paper addresses emergency radioanalytical capability and capacity and its utilization during FRMAC operations.

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Abstract  

Styrene is an important chemical in the petrochemical industry. In recent years, there have been sporadic releases, runaway reactions, fires, and thermal explosion accidents incurred by styrene and its derivatives worldwide. The purpose of this study was to estimate the impact of styrene and its derivatives of α-methylstyrene (AMS) and trans-β-methylstyrene (TBMS) contacting with benzaldehyde. Experiments were carried out to evaluate the thermokinetic parameters estimated by differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III). TAM III was used to determine the fundamental thermokinetics under various isothermal temperatures, 80, 90 and 100°C. This autocatalytic reaction was demonstrated in thermal curves. After styrene was contacted with benzaldehyde, the exothermic onset temperature (T 0) and the total heat of reaction (Q total) were altered by DSC tests. When benzaldehyde is mixed with AMS and TBMS, the reaction time will be shorter but the enthalpy reduced, as revealed by TAM III tests. As AMS and TBMS, respectively, were contacted with benzaldehyde, both exothermic phenomena were changed during the reaction excursion. According to the results of this research, an operator should dictate the oxygen concentration in order to avoid any potential hazards during handling and transportation.

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