Insider threat detection approach for tobacco industry based on heterogeneous graph embedding

In the tobacco industry,insider employee attack is a thorny problem that is difficult to detect.To solve this issue,this paper proposes an insider threat detection method based on heterogeneous graph embedding.First,the interrelationships between logs are fully considered,and log entries are converted into heterogeneous graphs based on these relationships.Second,the heterogeneous graph embedding is adopted and each log entry is represented as a low-dimensional feature vector.Then,normal logs and malicious logs are classified into different clusters by clustering algorithm to identify malicious logs.Finally,the effectiveness and superiority of the method is verified through experiments on the CERT dataset.The experimental results show that this method has better performance compared to some baseline methods.

Dynamic Changes of Tobacco-growing Soil Nutrients and Enzymes After Application of Amelioration Materials

[Objectives]This study was conducted to clarify the improvement effects of different soil amelioration materials such as lime,green manure and bio-organic fertilizer on acidic tobacco-planting soil.[Methods]The dynamic changes of soil pH,soil nutrients and enzyme activity were studied by applying lime,lime+green fertilizer,and lime+green fertilizer+biological organic fertilizer.[Results]①After the application of amelioration materials,the soil pH and available phosphorus content of tobacco-growing soil showed a stepwise change of first increasing and then decreasing,and became stable at 60 d after tobacco transplanting;the soil organic matter,alkali-hydrolyzable nitrogen and available potassium content showed a gradual change trend of"high-low-high";and the soil invertase and urease activity showed a gradual change trend of"low-high-low".②To 90 d after tobacco transplanting,the application of amelioration materials increased soil pH by 1.29-1.62 units,and increased organic matter content by 15.21%-20.86%,alkali-hydrolyzable nitrogen content by 6.83%-18.17%,available phosphorus content by 54.15%-217.85%,rapidly available potassium content by 11.42%-30.86%,soil invertase activity by 70.09%-18.93%,and soil urease activity by 64.07%-130.47%.③The combination of lime+green manure+alkaline microbial organic fertilizer had the best effect on the improvement of acidic tobacco-growing soil,and the effect of lime+green manure+acid microbial organic fertilizer on acidic soil was the second.[Conclusions]When applying lime,green fertilizer and alkaline bio-organic fertilizer should be applied to achieve sustainable improvement of strongly acidic soil.

Effects of Different Fertilization Measures on Chemical Composition and Quality of Flue-cured Tobacco

[Objectives]The paper was to obtain fertilizer varieties and fertilization techniques that meet the special nutritional requirements of characteristic tobacco varieties in Mengyin tobacco area.[Methods]With the local main plant variety NC102 as the test material,the effects of combined application,dosage and application methods of different types of organic fertilizers,compound fertilizers and potassium fertilizers on chemical composition and quality of NC102 flue-cured tobacco leaves were studied.[Results]Under the premise of reducing the amount of fertilizer applied,the slow-release integrated fertilizer increased the sugar-alkali ratio and potassium-chloride ratio,and reduced the sulfur content of tobacco leaves,but it did not significantly improve the sensory quality of tobacco leaves.Increasing the application of organic fertilizer made the sugar-alkali ratio and potassium-chloride ratio more coordinated,reduced the sulfur content and improved the sensory quality of tobacco leaves.Microbial agents significantly increased the sugar-alkali ratio in tobacco leaves,and had obvious effects of increasing potassium and reducing chlorine.Different types and application methods of potassium fertilizers had obvious effects on sensory quality of tobacco leaves.Increasing the application amount of potassium fertilizer and later topdressing significantly improved the potassium content and sensory quality of tobacco leaves.[Conclusions]The study provides a basis for balanced fertilization in characteristic flue-cured tobacco production in Mengyin tobacco area.

Nitrogen Metabolism and Curing Characteristics of Flue-cured Tobacco Variety NC71

[Objectives]To explore the growth characteristics,nitrogen metabolism and curing characteristics of the new variety NC71 in strongly aromatic tobacco leaves production area.[Methods]With Yunyan 87 as the control and NC71 as the experimental material,the experiment was carried out in Nanyang tobacco area for two consecutive years to study the growth characteristics of tobacco plants,the activity of key enzymes in nitrogen metabolism,the content of secondary metabolites,and the differences of tobacco-related water content,PPO enzyme activity and total phenol content.[Results]NC71 plants had lower height,better appearance quality and lower nicotine,total sugar and chlorine content.NC71 high nitrogen treatment and Yunyan 87 medium nitrogen treatment had similar key enzyme activity of nitrogen metabolism,content of secondary metabolites;Yunyan 87 and NC71 were easy to cure and resistant to curing.[Conclusions]This study provides a reference for measuring the appropriate nitrogen application rate and optimizing the curing process from the activities of the key enzymes NR and GS in nitrogen metabolism at the mature stage of the variety.

Comparative Study on the Efficacies of 11 Chemical Agents against Taro Soft Rot Caused by Pectobacterium aroidearum

[Objective]The paper was to screen the effective agents for effectively controlling the occurrence and prevalence of taro soft rot.[Method]The fungicidal effects of 11 fungicides on taro soft rot were determined by inhibition zone method.[Result]0.3%Tetramycin,25%bromothalonil,3%Zhongshengmycin and 30%zinc thiazole had better antifungal effect on Pectobacterium aroidearum at recommended concentration.The indoor toxicity of four fungicides showed that the EC50 of 0.3%tetramycin AS was the smallest of 0.6μg/mL,indicating that tetramycin had the largest toxicity and the best inhibitory effect against P.aroidearum;followed by 25%bromothalonil EC and 3%Zhongshengmycin WP,with the EC_(50) of 2.57 and 97.72μg/mL,respectively;the inhibitory effect of 30%zinc thiazole SC against P.aroidearum was the poorest.[Conclusion]The study provides a reference for screening out new and efficient chemical agents against taro soft rot.

Tuning interaction strength between CeO_(2) and iridium to promote CO oxidation over Ir/TiO_(2)

The interaction between support and noble metal plays a crucial role in heterogeneous catalysis design.However,how to tune metal support interactions to optimize the activity still needs further exploration.CeO_(2) was introduced to promote CO oxidation ove r Ir/TiO_(2) by adjusting the interaction strength between iridium(Ir)and CeO_(2).The strong interaction between Ir and CeO_(2) blocks CO adsorption and causes low CO oxidation activity.However,introducing CeO_(2) on Ir/TiO_(2) produces localized interaction between Ir and CeO_(2),which can tune the surface electronic state of Ir,so a"volcano curve"relationship between CO oxidation activity and electronic state is built.Limited amount of CeO_(2) on Ir/TiO_(2)(Ir/Ce_(0.2)Ti)leads to CO complete oxidization at 22℃,and a new pathway for CO oxidation was explored.The study demonstrates that the utilization of tuning interaction strength between active metal and support is a potential method to increase the catalytic activity.

Gas flow and filter ventilation of an unlit cigarette: model building,numerical solution and experimental validation

Understanding the fundamcntal relationship betwecn gas dilution rate of a cigarette and key cigarette design parameters is important in the overall control of smoke yield.In this work,an equation was derived to express the total gas dilution with the cigarette rod length,cigarette paper air permeability,and the filter ventilation level.The relationship was validated using experimental results.The accuracy of the developed model was dependent on the regression method used,i.e.,linear or a nonlinear.The expression provides a quantitative description of the interactions between filter ventilation level,cigarette length,cigarette circumference and cigarette paper air permeability and the total air dilution at the cigarette's mouth end.

Incorporating organic-modified nano SiO_(2) for the comprehensive improvement of recycled PET

1.Introduction Polyethylene terephthalate(PET)is a thermoplastic resin with excellent optical transparency,gas barrier and mechanical properties,widely used in fibers,plastics and film[1-3].However,PET has a long degradation half-life in the natural environment,and greenhouse gases such as carbon dioxide will be produced after incineration,indicating that recycling is an effective way to reduce plastic pollution and save energy,and how to correctly use recycled PET(rPET)has become a global concern[4-7].It was reported that each 0.45 kg recycled PET sheet used can reduce energy consumption by 84%and greenhouse gas emissions by 71%compared with the original PET production[8,9].

Tuning performance of Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for methane combustion by optimizing calcination temperature of support

A series of 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2 catalysts were prepared by impregnation method based on the presynthesis of Sn_(0.9)Ce_(0.1)O_2 support prepared by co-precipitation method, and then characterized by Brunauer–Emmett–Teller(BET), X-ray diffraction(XRD), X-ray photoelectron spectroscopy(XPS), Raman, CO chemical adsorption and hydrogen temperature-programmed reduction(H_2-TPR) techniques. The effect of calcination temperature of the composite oxide support on the catalytic performances of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst for the CH_4 total oxidation was studied. It is found that the catalytic activity of the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst increases with the increase in calcination temperature of the Pd/Sn_(0.9)Ce_(0.1)O_2 support. The 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst(the Pd/Sn_(0.9)Ce_(0.1)O_2 support was calcined at 1100 ℃) exhibits the best reactive activity(T_(10)= 255 ℃). The excellent activity of the 0.2 wt% Pd/Sn_(0.9)Ce_(0.1)O_2/1100 catalyst should be attributed to the high reducibility of PdO, the excellent oxygen mobility of the support and the high content of active Pd^(2+) species on the Pd/Sn_(0.9)Ce_(0.1)O_2 catalyst.

Surface tuning of LaCoO_(3) perovskite by acid etching to enhance its catalytic performance

The stoichiometric LaCoO_(3) and nonstoichiometric LaCo_(1.2)O_(3) perovskite catalysts were prepared by citric acid sol-gel method,and then,LaCoO_(3) perovskite was etched with nitric acid.The structure,surface composition and reducibility of the catalyst were studied by X-ray diffraction(XRD),nitrogen desorption,transmission electron microscope(TEM),temperature program reduction of H_(2)(H_(2)-TPR) and X-ray photoelectron spectroscopy(XPS).It was found that nitric acid etching did not change the crystal structure and the overall morphology of the LaCoO_(3) catalyst,but it can cause the exposure of B-site Co metal to the surface of the catalyst.As a result,after acid etching,the reducibility of the LaCoO_(3) catalyst was improved,leading to the improvement in the catalytic activity of the LaCoO_(3) catalyst for CO oxidation and C_(3)H_(8) combustion.Moreover,the catalytic activity of the LaCoO_(3) catalyst after acid etching was higher than that of LaCo_(1.2)O_(3) and CoOx/LaCoO_(3) catalyst.

Genetic variation in alkaloid accumulation in leaves of Nicotiana

Alkaloids are plant secondary metabolites that are widely distributed in Nicotiana species and contribute greatly to the quality of tobacco leaves. Some alkaloids, such as nornicotine and myosmine, have adverse effects on human health. To reduce the content of harmful alkaloids in tobacco leaves through conventional breeding, a genetic study of the alkaloid variation among different genotypes is required. In this study, alkaloid profiles in leaves of five Nicotiana tabacum cultivars and Nicotiana tomentosiformis were investigated. Six alkaloids were identified from all six genotypes via gas chromatograph-mass spectrometry(GC-MS). Significant differences in alkaloid content were observed both among different leaf positions and among cultivars. The contents of nornicotine and myosmine were positively and significantly correlated(R2=0.881), and were also separated from those of other alkaloids by clustering. Thus, the genotype plays a major role in alkaloid accumulation, indicating a high potential for manipulation of alkaloid content through traditional breeding.

Pressure control as an effective method to modulate aggregative growth of nanoparticles

Recent studies suggested that the interactions between particles can induce aggregative nucleation and growth processes beyond those predicted by the traditional LaMer model of nanoparticle formation,but their nucleation and growth processes are still unclear.Here,we report a simple way to control the interaction between nanoparticles by manipulating the oleylamine(OAm)adsorbed on the surface of the nanoparticles.The size distributions of Ag nanoparticles produced at different reaction pressures were monitored as evidence for aggregative growth.From these kinetic data,the aggregative nucleation rate(C)of primary Ag nanoparticles under a 0.01 MPa was demonstrated to be faster than that under atmospheric pressure.This leads to a higher uniformity of Ag nanoparticles in a shorter time(10 min)than that achievable with previous methods.Furthermore,Ag nanoparticles supported on TiO2 exhibited a remarkable performance in the catalytic reduction of 4-nitrophenol(4-NP).After 4 min,4-NP was completely reduced into4-aminophenol(4-AP).