摘要 :
The ethical integrity and accountability of Information Technology (IT) professionals is important given our reliance on various
forms of IT. We examined the applicability of Lawrence Kohlberg’s theory of Cognitive Moral Develo...
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The ethical integrity and accountability of Information Technology (IT) professionals is important given our reliance on various
forms of IT. We examined the applicability of Lawrence Kohlberg’s theory of Cognitive Moral Development (CMD) in non-Western
contexts by investigating the ethical values of IT professionals in Asia’s two largest economies. Analysis of survey data from Japan
(n=289) and China (n=290) indicates support for the basic six-stage model of CMD. The concept of abiding by universal laws
and rules (termed stage 4 reasoning by Kohlberg) was widely accepted by IT professionals in both Japan and China, despite the
Confucian cultural emphasis on personal relationships with particularistic obligations. However, differences between Japanese
and Chinese IT professionals were found while, in direct contrast with the stage-wise theory of CMD, the respondents from Japan
and especially China exhibited significant volatility, reasoning at different stages simultaneously. The implications of these findings
for research and practice are discussed.
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Arsenic concentrations in shallow groundwaters from the Hetao Basin of Inner Mongolia range between 0.6 and 572 μg/L. High As groundwaters generally occur in the shallow alluvial-lacustrine aquifers, which are mainly composed of ...
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Arsenic concentrations in shallow groundwaters from the Hetao Basin of Inner Mongolia range between 0.6 and 572 μg/L. High As groundwaters generally occur in the shallow alluvial-lacustrine aquifers, which are mainly composed of black (or dark grey) fine sands in a reducing environment. They are characterized by high concentrations of dissolved Fe, Mn, HCO_3~-, P and S~(2-), and low concentrations of NOi and SO_3~-. Low SO_4~(2-) coupled with high S~(2-) suggests that SO_4~(2-) reduction has been an active process. In the reducing groundwaters, inorganic As(Ⅲ) accounts for around 75% of total dissolved As. Total As contents in the sediments from three representative boreholes are observed to be 7.3-73.3 mg/kg (average of 18.9 mg/kg). The total As is mildly-strongly correlated with total Fe and total Mn, while a quite weak correlation exists between total As and total S, suggesting that the As is associated with Fe-Mn oxides, rather than sulfides in the sediments. It is found in the sequential extraction that chemically active As is mainly bound to Fe-Mn oxides, up to 3500 μg/kg. The mobilization of As under reducing conditions is believed to include reductive dissolution of Fe-Mn oxides and reduction of adsorbed As. Although exchangeable As is labile and very vulnerable to hydrogeochemical condition, the contribution is relatively limited due to the low concentrations. The competition between As and other anions (such as HPO_~(2-)) for binding sites on Fe-Mn oxides may also give rise to the release of As into groundwater. Slow groundwater movement helps accumulation of the released As in the groundwaters.
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A coupled system by the 3D rotating Navier-Stokes equations with a mixed boundary condition and a 2D biharmonic problem with two obstacles and the gradient restriction is investigated in this paper. Using the Schauder's fixed poin...
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A coupled system by the 3D rotating Navier-Stokes equations with a mixed boundary condition and a 2D biharmonic problem with two obstacles and the gradient restriction is investigated in this paper. Using the Schauder's fixed point theorem, we show the existence of a strong solution for a sufficiently large viscosity v and sufficiently small data.
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Increasingly complex life forms were found in older biological soil crusts in the Gurbantaunggut Desert in Northwestern China. These crusts may play a critical role in mineral erosion and desert soil formation by modifying the wea...
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Increasingly complex life forms were found in older biological soil crusts in the Gurbantaunggut Desert in Northwestern China. These crusts may play a critical role in mineral erosion and desert soil formation by modifying the weathering environment and ultimately affecting mineralogical variance. To test this hypothesis, variations in the morphological features and mineralogical components of successional biological soil crusts at 1 cm were studied by optical microscopy, SEM and grain size analysis. Concentrations of erosion-resistant minerals decreased with crust succession, while minerals susceptible to weathering increased with crust development. Neogenetic minerals were found in late stage crusts, but not in early stage crusts. Silt and clay concentrations were highest in early formation crusts and soil mean particle size decreased with crust succession. Cyanobacteria, lichen and moss were shown to erode and etch rocks, and secondary minerals produced by
weathering were localized with the living organisms. Thus, more developed crusts appeared to contribute to greater mineral weathering and may be a major cause of mineralogical variance seen in the Gurbantunggut Desert. The greater activity and complexity of older crusts, as well as their improved moisture condition may function to accelerate mineral weathering. Therefore, protection and recovery of biological crusts is vital for desert soil formation.
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Novel bioreactor beads for simultaneous saccharification and fermentation (SSF) of lime-pretreated rice straw (RS) into ethanol were prepared. Genetically modified Saccharomyces cerevisiae cells expressing genes encoding xylose re...
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Novel bioreactor beads for simultaneous saccharification and fermentation (SSF) of lime-pretreated rice straw (RS) into ethanol were prepared. Genetically modified Saccharomyces cerevisiae cells expressing genes encoding xylose reductase, xylitol dehydrogenase, and xylulokinase were immobilized in calcium alginate beads containing inorganic lightweight filler particles to reduce specific gravity. For SSF experiments, the beads were floated in slurry composed of lime-pretreated RS and enzymes and incubated under CO_2 atmosphere to reduce the pH for saccharification and fermentation. Following this reaction, beads were readily picked up from the upper part of the slurry and were directly transferred to the next vessel with slurry. After 240 h of incubation, ethanol production by the beads was equivalent to that by free cells, a trend that was repeated in nine additional runs, with slightly improved ethanol yields. Slurry with pre-saccharified lime-pretreated RS was subjected to SSF with floating beads for 168 h. Although higher cell concentrations in beads resulted in more rapid initial ethanol production rates, with negligible diauxic behavior for glucose and xylose utilization, no improvement in the ethanol yield was observed. A fermentor-scale SSF experiment with floating beads was successfully performed twice, with repeated use of the beads, resulting in the production of 40.0 and 39.7 g/L ethanol. There was no decomposition of the beads during agitation at 60 rpm. Thus, this bioreactor enables reuse of yeast cells for efficient ethanol production by SSF of lignocellulosic feedstock, without the need for instruments for centrifugation or filtration of whole slurry.
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We have used density functional theory calculations and mixed quantum/classical dynamics simulations to study the electronic structure and charge-transport properties of three representative mixed-stack charge-transfer crystals, D...
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We have used density functional theory calculations and mixed quantum/classical dynamics simulations to study the electronic structure and charge-transport properties of three representative mixed-stack charge-transfer crystals, DBTTF-TCNQ, DMQtT-F_4TCNQ and STB-F_4TCNQ. The compounds are characterized by very small effective masses and modest electron-phonon couplings for both holes and electrons. The hole and electron transport characteristics are found to be very similar along the stacking directions; for example, in the DMQtT-F_4TCNQcrystal, the hole and electron effective masses are as small as 0.20 and 0.26 m0, respectively. This similarity arises from the fact that the electronic couplings of both hole and electron are controlled by the same superexchange mechanism. Remarkable ambipolar charge-transport properties are predicted for all three crystals. Our calculations thus provide strong indications that mixed-stack donor-acceptor materials represent a class of systems with high potential in organic electronics.
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摘要 :
Purpose - Complex products, such as aircrafts and ships, are assembled from many parts and there are many available assembly sequences. Selecting the best from the available assembly sequences is challenging because of many factor...
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Purpose - Complex products, such as aircrafts and ships, are assembled from many parts and there are many available assembly sequences. Selecting the best from the available assembly sequences is challenging because of many factors, such as assembly performance, assemblability, assembly cost, assembly quality and assembly time. The purpose of this paper is to investigate a new and efficient algorithm aimed at this goal. Design/methodology/approach - A new and efficient algorithm evaluating assembly sequences based on multi-objective harmonious colony-decision method is presented. This algorithm mainly includes three key steps: first, presenting the priority relationship between assembly sequences and the coefficient matrix for these objectives: assembly performance, assemblability, assembly cost, assembly quality, assembly time, and so on by several experts; second, calculating the maximum of harmonious values and harmonious priority value; third, if the maximum of harmonious priority value is not negative, the algorithm ends. Then the priority relationships of assembly sequences are obtained and the optimal assembly sequence can be selected. Findings - This algorithm can efficiently support several experts to evaluate assembly sequences according to plenty of evaluation objectives and then to output a harmonious and recognized priority relationship of assembly sequences.
Practical implications - The algorithm is applied successfully to evaluate assembly sequences and select the optimal assembly sequence for component of aircraft's wing with fixtures. Originality/value - This algorithm provides a new method to synthetically evaluate assembly sequences for complex product according to multi-objectives.
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The compound HgBa_2CuO_(4+δ) (Hg1201) exhibits a simple tetragonal crystal structure and the highest superconducting transition temperature (T_c) among all single Cu-O layer cuprates, with T_c=97 K (onset) at optimal doping. Due ...
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The compound HgBa_2CuO_(4+δ) (Hg1201) exhibits a simple tetragonal crystal structure and the highest superconducting transition temperature (T_c) among all single Cu-O layer cuprates, with T_c=97 K (onset) at optimal doping. Due to a lack of sizable single crystals, experimental work on this very attractive system has been significantly limited. Thanks to a recent breakthrough in crystal growth, such crystals have now become available. Here we demonstrate that it is possible to identify suitable heat treatment conditions to systematically and uniformly tune the hole concentration of Hg 1201 crystals over a wide range, from very underdoped (T_c=47 K, hole concentration p ≈ 0.08) to overdoped (T_c=64 K, p ≈ 0.22). We then present quantitative magnetic susceptibility and dc charge transport results that reveal the very high-quality nature of the studied crystals. Using x-ray photoemission spectroscopy on cleaved samples, we furthermore demonstrate that it is possible to obtain large surfaces of good quality. These characterization measurements demonstrate that Hg1201 should be viewed as a model high-temperature superconductor.
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Staphylococcus aureus has not been used to remove Cr(VI) ions from aqueous solutions. In the present study, biosorption experiments for Cr(VI) were investigated using S. aureus biomass isolated from activated sludge, Lianyungang D...
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Staphylococcus aureus has not been used to remove Cr(VI) ions from aqueous solutions. In the present study, biosorption experiments for Cr(VI) were investigated using S. aureus biomass isolated from activated sludge, Lianyungang Dapu sewage treatment plant, China. The effects of solution pH, contact time reaction temperature and ionic strength on Cr(VI) uptake were studied. The biomass was characterized by energy dispersive X-ray spectroscopy and Fourier transform infrared spectrometer. The applicability of the Langmuir and Freundlich models was tested. The correlation coefficients (R) of both models were higher than 0.9. The maximum adsorption capacity was found to be 27.36 mg/g for Cr(VI) at 20℃. The adsorption process was quick and found to follow the pseudo-second-order equation. The optimum adsorption was achieved at pH 2. The adsorption was strongly dependent on NaCl concentrations as well as on reaction temperature. The S. aureus biomass could serve as adsorbent to remove Cr(VI) from industrial effluents.
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摘要 :
Spun carbon nanotube (CNT) fibers have great potential for conducting and sensing applications owing to their unique, tunable electrical properties. Here we report the electron transport properties of neat, well-aligned CNT fibers...
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Spun carbon nanotube (CNT) fibers have great potential for conducting and sensing applications owing to their unique, tunable electrical properties. Here we report the electron transport properties of neat, well-aligned CNT fibers spun from arrays of millimeter-long CNTs. The conductivity of as-spun CNT fibers is around 595.2 S cm~(-1) at room temperature, and its variation with temperature shows a semiconductive behavior from 300 to 75.4 K. The electron transport was found to follow a three-dimensional (3D) hopping mechanism. Importantly, it was found that chemical treatments may significantly affect the conductivities of as-spun fibers. Oxidizing the CNT fibers in air or HNO_3 increased the conductivities, while covalent bonding of Au nanoparticles to the CNT fibers remarkably improved conductivity and changed conduction behavior. Conversely, annealing CNT fibers in Ar + 6 % H_2 at 800 °C or under the CNT array growth conditions at 750 °C led to a dramatic decrease in conductivity.
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