6,596 research outputs found

    Effect of interaction with neutrons in matter on flavor conversion of super-light sterile neutrino with active neutrino

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    A super-light sterile neutrino was proposed to explain the absence of the expected upturn of the survival probability of low energy solar boron neutrinos. This is because this super-light sterile neutrino can oscillate efficiently with electron neutrino through a MSW resonance happened in Sun. One may naturally expect that a similar resonance should happen for neutrinos propagating in Earth matter. We study the flavor conversion of this super-light sterile neutrino with active neutrinos in Earth matter. We find that the scenario of the super-light sterile neutrino can easily pass through possible constraints from experiments which can test the Earth matter effect in oscillation of neutrinos. Interestinlgy, we find that this is because the naively expected resonant conversion disappears or is significantly suppressed due to the presence of a potential VnV_n which arises from neutral current interaction of neutrino with neutrons in matter. In contrast, the neutron number density in the Sun is negligible and the effect of VnV_n is effectively switched off. This enables the MSW resonance in Sun needed in oscillation of the super-light sterile neutrino with solar electron neutrinos. It's interesting to note that it is the different situation in the Sun and in the Earth that makes VnV_n effectively turned off and turned on respectively. This observation makes the scenario of the super-light sterile neutrino quite interesting.Comment: 22 pages, 10 figure

    Study on Economic Carrying Capacity of Industries Transfer from the Coastal areas to the Central region in China based on Employment Change Forecast

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    Abstract: Nowadays, industry transfer from the coastal areas to the central region and the west areas has become an essential measure for our national adjusting of industrial layout. Because the central region has a superior location advantage of undertaking east and opening west, it becomes key areas for undertaking industries.Therefore, whether the economic carrying capacity of the central region can adapt to this large-scale industrial transfer will be the key to seize the opportunity. According to the experience of international industrial transfer, large-scale industrial transfer is bound to bring about inevitably rapid increase in employment, so the article tries to use the three industrial employment data of the three central region provinces (Anhui, Jiangxi and Hunan) and the three coastal provinces (Guangdong, Jiangsu, Zhejiang) from 1978 to 2010, and then constructs the ARIMA model to forecast the employment of three industries from 2011 to 2015. Through comparatively analyzing prediction of employment changes of the central and the coastal provinces in the next few years, it will resolve some problems such as the economic carrying capacity of the central region undertaking the coastal industrial transfer, and three conclusions have been pointed out: 1) taking the coastal economic carrying capacity as a benchmark, the economic carrying capacity of the central region has not been saturated; 2)viewing the prediction of employment changes of the coastal and central region, the coastal industrial transfer has not formed in scale trend in the next few years; 3)from the terms of the changes of the future growth of the three industries, the undeveloped secondary industry is the bottleneck factor in restricting the improvement of economic carrying capacity for undertaking the coastal industrial transfer, and the low proportion of the third industry in the coastal areas is the viscosity factor in restricting the transfer of industries to the central region

    Ozone and haze pollution weakens net primary productivity in China

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    Atmospheric pollutants have both beneficial and detrimental effects on carbon uptake by land ecosystems. Surface ozone (O3) damages leaf photosynthesis by oxidizing plant cells, while aerosols promote carbon uptake by increasing diffuse radiation and exert additional influences through concomitant perturbations to meteorology and hydrology. China is currently the world’s largest emitter of both carbon dioxide and short-lived air pollutants. The land ecosystems of China are estimated to provide a carbon sink, but it remains unclear whether air pollution acts to inhibit or promote carbon uptake. Here, we employ Earth system modeling and multiple measurement datasets to assess the separate and combined effects of anthropogenic O3 and aerosol pollution on net primary productivity (NPP) in China. In the present day, O3 reduces annual NPP by 0.6 Pg C (14 %) with a range from 0.4 Pg C (low O3 sensitivity) to 0.8 Pg C (high O3 sensitivity). In contrast, aerosol direct effects increase NPP by 0.2 Pg C (5 %) through the combination of diffuse radiation fertilization, reduced canopy temperatures, and reduced evaporation leading to higher soil moisture. Consequently, the net effects of O3 and aerosols decrease NPP by 0.4 Pg C (9 %) with a range from 0.2 Pg C (low O3 sensitivity) to 0.6 Pg C (high O3 sensitivity). However, precipitation inhibition from combined aerosol direct and indirect effects reduces annual NPP by 0.2 Pg C (4 %), leading to a net air pollution suppression of 0.8 Pg C (16 %) with a range from 0.6 Pg C (low O3 sensitivity) to 1.0 Pg C (high O3 sensitivity). Our results reveal strong dampening effects of air pollution on the land carbon uptake in China today. Following the current legislation emission scenario, this suppression will be further increased by the year 2030, mainly due to a continuing increase in surface O3. However, the maximum technically feasible reduction scenario could drastically relieve the current level of NPP damage by 70 % in 2030, offering protection of this critical ecosystem service and the mitigation of long-term global warming

    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
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