First-principles study of plasmons in doped graphene nanostructures

The operating frequencies of surface plasmons in pristine graphene lie in the terahertz and infrared spectral range,which limits their utilization.Here,the high-frequency plasmons in doped graphene nanostructures are studied by the time-dependent density functional theory.The doping atoms include boron,nitrogen,aluminum,silicon,phosphorus,and sulfur atoms.The influences of the position and concentration of nitrogen dopants on the collective stimulation are investigated,and the effects of different types of doping atoms on the plasmonic stimulation are discussed.For different positions of nitrogen dopants,it is found that a higher degree of symmetry destruction is correlated with weaker optical absorption.In contrast,a higher concentration of nitrogen dopants is not correlated with a stronger absorption.Regarding different doping atoms,atoms similar to carbon atom in size,such as boron atom and nitrogen atom,result in less spectral attenuation.In systems with other doping atoms,the absorption is significantly weakened compared with the absorption of the pristine graphene nanostructure.Plasmon energy resonance dots of doped graphene lie in the visible and ultraviolet spectral range.The doped graphene nanostructure presents a promising material for nanoscaled plasmonic devices with effective absorption in the visible and ultraviolet range.

Learning Vector Quantization Neural Network Method for Network Intrusion Detection

A new intrusion detection method based on learning vector quantization （LVQ） with low overhead and high efficiency is presented. The computer vision system employs LVQ neural networks as classifier to recognize intrusion. The recognition process includes three stages： （1） feature selection and data normalization processing;（2） learning the training data selected from the feature data set; （3） identifying the intrusion and generating the result report of machine condition classification. Experimental results show that the proposed method is promising in terms of detection accuracy, computational expense and implementation for intrusion detection.

Effect of Boron Fertilizer on the Root Growth Characteristics and Nutrient Contents of the Tuberous Root of Yacon

[Objectives]This study was conducted to investigate the effects of boron fertilizer on the root system and nutrient contents of yacon.[Methods]By the field test method,high-and low-dose of boron fertilizer(Na2B8O13,9000 and 3000 g/hm2)and equal amount of clean water(CK)were sprayed 3 times in the soil area where plants were grown in the early,middle and late stages of yacon growth,and the effects of applying boron fertilizer on the growth and fruit quality of yacon were analyzed.[Results]The indexes of the root system of yacon treated with boron fertilizer were significantly higher than those of the CK.The yield and total sugar,vitamin C,ash,Ca,Fe,Zn and other nutrients of the boron fertilizer treatments increased significantly compared with the CK.The yields of the low-and high-dose treatments increased by 77.2%and 211.2%,respectively,compared with the CK;and the contents of total sugar,vitamin C,ash,Ca,Fe and Zn in the high-dose treatment increased by 28.4%,163.6%,33.2%,73.3%,41.2%and 56.2%,respectively,compared with the CK.The nutrients in yacon treated with the low dose of boron fertilizer were lower than those with the high dose.The application of boron fertilizer could increase the yield of yacon,improve its quality and increase the contents of nutrients such as Ca,Fe,Zn and total sugar.[Conclusions]This study provides a reference for the reasonable application of boron fertilizer in the production of yacon and the improvement of the quality of yacon.

Existence and Algorithm of Solutions for Generalized Mixed Implicit Quasi-Variational-Like Inequalities

By applying the auxiliary variational principle technique, the existence of solutions for a new class of generalized mixed implicit quasi-variational-like inequalities and the convergence criteria of a new iterative algorithm to compute approximate solutions are proved in Hilbert spaces. The obtained result is a improvement over and generalization of the main theorem proposed by Ding.

Effect of C/N ratio,aeration rate and moisture content on ammonia and greenhouse gas emission during the composting

Gaseous emission （N2O, CH4 and NH3） from composting can be an important source of anthropogenic greenhouse gas and air pollution. A laboratory scale orthogonal experiment was conducted to estimate the effects of C/N ratio, aeration rate and initial moisture content on gaseous emission during the composting of pig faeces from Chinese Ganqinfen system. The results showed that about 23.9% to 45.6% of total organic carbon （TOC） was lost in the form of CO2 and 0.8% to 7.5% of TOC emitted as CH4. Most of the nitrogen was lost in the form of NH3, which account for 9.6% to 32.4% of initial nitrogen. N20 was also an important way of nitrogen losses and 1.5% to 7.3% of initial total nitrogen was lost as it. Statistic analysis showed that the aeration rate is the most important factor which could affect the NH3 （p = 0.0189）, CH4 （p = 0.0113） and N20 （p = 0.0493） emissions significantly. Higher aeration rates reduce the CH4 emission but increase the NH3 and N20 losses. C/N ratio could affect the NH3 （p = 0.0442） and CH4 （p = 0.0246） emissions significantly, but not the N20. Lower C/N ratio caused higher NH3 and CH4 emissions. The initial moisture content can not influence the gaseous emission significantly. Most treatments were matured after 37 days, except a trial with high moisture content and a low C/N ratio.

Effects of aeration method and aeration rate on greenhouse gas emissions during composting of pig feces in pilot scale

The aim of this study was to uncover ways to mitigate greenhouse gas（GHG） emissions and reduce energy consumption during the composting process. We assessed the effects of different aeration rates（0, 0.18, 0.36, and 0.54 L/（kg dry matter（dm）·min）） and methods（continuous and intermittent） on GHG emissions. Pig feces and corn stalks were mixed at a ratio of 7：1. The composting process lasted for 10 weeks, and the compost was turned approximately every 2 weeks. Results showed that both aeration rate and method significantly affected GHG emissions. Higher aeration rates increased NH3 and N2O losses,but reduced CH4 emissions. The exception is that the CH4 emission of the passive aeration treatment was lower than that of the low aeration rate treatment. Without forced aeration,the CH4 diffusion rates in the center of the piles were very low and part of the CH4 was oxidized in the surface layer. Intermittent aeration reduced NH3 and CH4 losses, but significantly increased N2 O production during the maturing periods. Intermittent aeration increased the nitrification/denitrification alternation and thus enhanced the N2 O production. Forced aeration treatments had higher GHG emission rates than the passive aeration treatment. Forced aeration accelerated the maturing process, but could not improve the quality of the end product. Compared with continuous aeration, intermittent aeration could increase the O2 supply efficiency and reduced the total GHG emission by 17.8%, and this reduction increased to 47.4% when composting was ended after 36 days.