482 research outputs found

    Consumer Perception of Organic Food in Urumqi

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    The market for organic products in Urumqi is at the beginning of its development. The objective of this paper is to gain knowledge about consumers attitudes toward organic food in Urumqi which is the capital of Xinjiang Uygur Autonomous Region. The consumers attitudes were collected by means of a face-to-face survey. Attitudes, purchasing frequency, supply satisfaction and beliefs about organic food were studied with a sample of 720 consumers. The data obtained from the survey were analyzed with univariate analysis, chi-square test, ANOVA and correlation analysis. About 44.9% of Urumqi consumers had never heard of organic food. Urumqi consumers who know organic food consider organically-grown products as very healthy, of good quality and tasty. Consumers are not very familiar with the supply of organic food in the market. One reason might be that there was very little advertisement about organic products. Some groups of consumers have more positive attitudes towards organic food, and they express an increased willingness to pay higher prices for these food. Therefore, marketing strategies for organic food should be targeted towards such groups. According to the research results, an important task for the producers will be to increase consumers knowledge of what organic food is and how to differentiate it in the marketplace.Urumqi, Consumer behavior, Organic food, Food Consumption/Nutrition/Food Safety,

    Assessment of Severe Accident Depressurization Valve Activation Strategy for Chinese Improved 1000 MWe PWR

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    To prevent HPME and DCH, SADV is proposed to be added to the pressurizer for Chinese improved 1000 MWe PWR NPP with the reference of EPR design. Rapid depressurization capability is assessed using the mechanical analytical code. Three typical severe accident sequences of TMLB’, SBLOCA, and LOFW are selected. It shows that with activation of the SADV the RCS pressure is low enough to prevent HPME and DCH. Natural circulation at upper RPV and hot leg is considered for the rapid depressurization capacity analysis. The result shows that natural circulation phenomenon results in heat transfer from the core to the pipes in RCS which may cause the creep rupture of pipes in RCS and delays the severe accident progression. Different SADV valve areas are investigated to the influence of depressurization of RCS. Analysis shows that the introduction of SADV with right valve area will delay progression of core degradation to RPV failure. Valve area is to be optimized since smaller SADV area will reduce its effect and too large valve area will lead to excessive loss of water inventory in RCS and makes core degradation progression to RPV failure faster without additional core cooling water sources

    Accreted seamounts in North Tianshan, NW China: implications for the evolution of the Central Asian Orogenic Belt

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    The Carboniferous Bayingou ophiolitic mélange is exposed in North Tianshan accretionary complex in the southwestern part of the Central Asian Orogenic Belt (CAOB). The mélange is mainly composed of serpentinised ultramafic rocks (including harzburgite, lherzolite, pyroxenite, dunite and peridotite), pillowed and massive basalts, layered gabbros, radiolarian cherts, pelagic limestones, breccias and tuffs, and displays block-in-matrix structures. The blocks of ultramafic rocks, gabbros, basalts, cherts, and limestones are set in a matrix of serpentinised ultramafic rocks, massive basalts and tuffs. The basaltic rocks in the mélange show significant geochemical heterogeneity, and two compositional groups, one ocean island basalt-like, and the other mid-ocean ridge-like, can be distinguished on the basis of their isotopic compositions and immobile trace element contents (such as light rare earth element enrichment in the former, but depletion in the latter). The more-enriched basaltic rocks are interpreted as remnants/fragments of seamounts, derived from a deep mantle reservoir with low degrees (2–3%) of garnet lherzolite mantle melting. The depleted basalts most likely formed by melting of a shallower spinel lherzolite mantle source with ∼15% partial melting. It is probable that both groups owe their origin to melting of a mixture between plume and depleted MORB mantle. The results from this study, when integrated with previous work, indicate that the Junggar Ocean crust (comprising a significant number of seamounts) was likely to have been subducted southward beneath the Yili-Central Tianshan block in Late Devonian-Early Carboniferous. The seamounts were scraped-off and accreted along with the oceanic crust in an accretionary wedge to form the Bayingou ophiolitic mélange. We present a model for the tectonomagmatic evolution of this portion of the CAOB involving prolonged intra-oceanic subduction with seamount accretion

    Numerical Simulation and Response of Stiffened Plates Subjected to Noncontact Underwater Explosion

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    A numerical simulation has been carried out to examine the response of steel plates with different arrangement of stiffeners and subjected to noncontact underwater explosion (UNDEX) with different shock loads. Numerical analysis of the underwater explosion phenomena is implemented in the nonlinear finite element code ABAQUS/Explicit. The aim of this work is to enhance the dynamic response to resist UNDEX. Special emphasis is focused on the evolution of mid-point displacements. Further investigations have been performed to study the effects of including material damping and the rate-dependant material properties at different shock loads. The results indicate that stiffeners configurations and shock loads affect greatly the overall performance of steel plates and sensitive to the materials data. Also, the numerical results can be used to obtain design guidelines of floating structures to enhance resistance of underwater shock damage, since explosive tests are costly and dangerous

    Herb-resistant UPEC strains have different biofilm formation abilities and different expression of certain biofilm related genes

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    Background: The mechanisms and patterns of drug resistances of E. coli strains that cause uncomplicated urinary tract infections (UTIs) vary considerably. The emerging herbresistance of uropathogenic Escherichia coli (UPEC) has been a serious health problem, yet with unknown underlying mechanisms.Methods: To explore the potential herb-resistance mechanisms of E. coli strains that cause uncomplicated UTIs, three clinically isolated herb-resistant UPEC strains (1351, 4996, 5028) were analyzed for their abilities to form biofilms and the expressions of the pga ABCD and luxS genes.Results: We found that the expression of pgaA and pgaB are very different between 1351 and 5028, and the loss-offunction of luxS in 4996 has impact on biofilm formation.Conclusions: 1. Herb-resistance of the strains is related to their abilities of biofilm formation. 2. Biofilm formation capabilities of herb-resistant strains show different responses to the presence of glucose. 3. luxS encoded AI-2 is not essential for biofilm formation in this strain but may help with more biofilm formation.Keywords: Herb-resistance; Biofilm formation; Uropathogenic Escherichia coli (UPEC); pga ABCD; lux

    A Pseudo DNA Cryptography Method

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    The DNA cryptography is a new and very promising direction in cryptography research. DNA can be used in cryptography for storing and transmitting the information, as well as for computation. Although in its primitive stage, DNA cryptography is shown to be very effective. Currently, several DNA computing algorithms are proposed for quite some cryptography, cryptanalysis and steganography problems, and they are very powerful in these areas. However, the use of the DNA as a means of cryptography has high tech lab requirements and computational limitations, as well as the labor intensive extrapolation means so far. These make the efficient use of DNA cryptography difficult in the security world now. Therefore, more theoretical analysis should be performed before its real applications. In this project, We do not intended to utilize real DNA to perform the cryptography process; rather, We will introduce a new cryptography method based on central dogma of molecular biology. Since this method simulates some critical processes in central dogma, it is a pseudo DNA cryptography method. The theoretical analysis and experiments show this method to be efficient in computation, storage and transmission; and it is very powerful against certain attacks. Thus, this method can be of many uses in cryptography, such as an enhancement insecurity and speed to the other cryptography methods. There are also extensions and variations to this method, which have enhanced security, effectiveness and applicability.Comment: A small work that quite some people asked abou

    Prescribed Performance Fuzzy Adaptive Output-Feedback Control for Nonlinear Stochastic Systems

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    A prescribed performance fuzzy adaptive output-feedback control approach is proposed for a class of single-input and single-output nonlinear stochastic systems with unmeasured states. Fuzzy logic systems are used to identify the unknown nonlinear system, and a fuzzy state observer is designed for estimating the unmeasured states. Based on the backstepping recursive design technique and the predefined performance technique, a new fuzzy adaptive output-feedback control method is developed. It is shown that all the signals of the resulting closed-loop system are bounded in probability and the tracking error remains an adjustable neighborhood of the origin with the prescribed performance bounds. A simulation example is provided to show the effectiveness of the proposed approach

    Can the digital economy promote the development of the energy economy? Evidence from China

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    In this paper, 22 indexes are selected at three levels, including the informatization development level, the Internet development level, and the digital transaction development level, based on China’s provincial panel data from 2011 to 2020, so as to build a digital economy development index system. Moreover, 28 basic indexes are selected from three aspects, including energy construction, energy production and energy consumption, so as to develop an energy economy development evaluation index system. The development index of China’s digital economy and energy economy are measured by using the entropy weight method. The effect of the digital economy on the energy economy and its mechanism are tested by the static panel, the dynamic panel, and the mediating effect and regulating effect models. The results indicate that the digital economy has pronouncedly promoted the development of China’s energy economy, and the development of the digital economy can have an effect on the rationalization of the industrial structure and then affect the development of the energy economy, and there is an intermediary effect. Moreover, the upgrading of the industrial structure is conducive to regulating the digital economy and facilitates the development of the energy economy. The development of the energy economy can be better promoted by focusing on the coordinated regional layout of the digital economy development, building a reliable energy commodity trading platform, and expediting the optimization and upgrading of the industrial structure
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