Smoldering charcoal detection in forest soil by multiple CO sensors

Cleaning up residual fires is an important part of forest fire management to avoid the loss of forest resources caused by the recurrence of a residual fire.Existing residual fire detection equipment is mainly infrared temperature detection and smoke identification.Due to the isolation of ground,temperature and smoke characteristics of medium and large smoldering charcoal in some forest soils are not obvious,making it difficult to identify by detection equipment.CO gas is an important detection index for indoor smoldering fire detection,and an important identification feature of hidden smoldering ground fires.However,there is no research on locating smoldering fires through CO detection.We studied the diffusion law of CO gas directly above covered smoldering charcoal as a criterion to design a detection device equipped with multiple CO sensors.According to the motion decomposition search algorithm,the detection device realizes the function of automatically searching for smoldering charcoal.Experimental data shows that the average CO concentration over the covered smoldering charcoal decreases exponentially with increasing height.The size of the search step is related to the reliability of the search algorithm.The detection success corresponding to the small step length is high but the search time is lengthy which can lead to search failure.The introduction of step and rotation factors in search algorithm improves the search efficiency.This study reveals that the average ground CO concentration directly above smoldering charcoal in forests changes with height.Based on this law,a CO gas sensor detection device for hidden smoldering fires has been designed,which enriches the technique of residual fire detection.

Identification of Antarctic minke and killer whales with passive acoustic monitoring in Prydz Bay, Antarctica

Although four species of odontocete and four species of baleen whale have been recorded in Prydz Bay,their vocalizations have been rarely investigated.Underwater vocalizations were recorded during March 2017 in Prydz Bay,Antarctica.Bio-duck sounds,downsweeps,inverted“u”shape signals,whistles,pulsed sounds,and broadband clicks were recorded.Bio-duck sounds and downsweeps were associated with Antarctic minke whales(Balaenoptera bonaerensis)based on visual observations.Similarities between inverted“u”shape signals,biphonic calls,and clicks with vocalizations previously described for killer whales(Orcinus orca)lead us believe the presence of Antarctic killer whales.According to sound structures,signal characteristics,and recording location,Antarctic type C killer whales were the most probable candidates to produce these detected calls.These represent the fi rst detection of inverted“u”shape signals in Antarctic waters,and the fi rst report of Antarctic killer whale in Prydz Bay based on passive acoustic monitoring.The co-existence of Antarctic minke and killer whales may imply that minke whales can detect diff erences between the sounds of mammal-eating and fi sh-eating killer whales.Our descriptions of these underwater vocalizations contribute to the limited body of information regarding the distribution and acoustic behavior of cetaceans in Prydz Bay.

Prediction and Analysis of Surface Quality of Northeast China Ash Wood during Water-Jet Assisted CO_(2) Laser Cutting

As a natural and environmentally friendly renewable material,Northeast China ash wood(NCAW)(Fraxinus mandshurica Rupr.)was cut by water-jet assisted CO_(2) laser(WACL),the surface quality was evaluated by surface roughness of cut section.The surface roughness was measured by three-dimensional(3D)profilometry.Furthermore,the micromorphology of machined surface was observed by scanning electronic microscopy(SEM).Carbon content changes of machined surface were measured by energy dispersive spectrometer(EDS).A relationship between surface roughness and cutting parameters was established using response surface methodology(RSM).It is concluded that the cutting speed,laser power and water pressure played an important role in surface roughness of cut section.The surface roughness increased as an increase in laser power.It decreased caused by increasing of cutting speed and water pressure.Measurements revealed that the surface quality of NCAW part was improved using the optimized combination of cutting parameters.The established quadratic mathematical model of a good prediction is helpful for matching suitable cutting parameters to obtain expected surface quality.

Experimental Study on Inert Gas-assisted Laser Cut Veneer Based on LOM

Based on the LOM(Laminated Object Manufacturing)process,an inert gas-assisted laser method for wood cutting was proposed.The carbonization degree of wood surface was improved by the introduction of helium(He)gas,and the influence of process parameters on the carbonization layer of wood surface was solved,it was significance to reduce the post-processing of LOM and improve the quality of forming workpiece.The cherry wood veneer was used as the experimental material,under the condition of the same process parameters,the wood was cut with or without inert gas-assisted,and the influence factors of kerf quality were studied by variance analysis.The results showed that under the same condition,compared with traditional laser processing,the kerf width was obviously reduced in the inert gas-assisted cutting.Because the He gas had oxygen-isolation and flame retardant effect,which prevented heat accumulation and conduction.The micro morphology of the kerf surface showed that the flatness was better in the inert gas-assisted cutting.As the excess heat was blown out by the cooling and purging of the gas,the phenomenon of oxidation and burning was reduced,the range of HAZ(heat affected zone)was reduced,and the carbonization phenomenon was obviously improved.The surface quality of kerf was improved effectively.According to the analysis of variance,in addition to the effect of laser power,cutting speed and inert gas flow on the cutting width,the interaction between inert gas flow and laser power,laser power and cutting speed were also the main factors which affected the cutting width.The feasibility of the combined inert gas and laser processing to improve wood cutting quality has been verified through experimental research,which provided a certain reference for the followup research on improving the wood processing quality.

Current Situations of Development and Use of Wild Vegetables in Yichun Area and Recommendations

Based on the survey on wild plants in 21 counties( cities) in Yichun Area,89 species of 32 families of wild vegetables were collected. The species,parts,edible parts,distribution and current development and use of wild vegetables in Yichun Area were expounded. Then,existing problems of wild vegetables in Yichun Area were discussed. Finally,pertinent recommendations were put forward.

A Comparison of Fractal Dimensions of EEG Time Series of Partial Epilepsy

In order to develop a new diagnostic method for partial epilepsy using fractaldimension measurement of theory of nonlinear dynamics, two kinds of EEG fractaldimensions (correlation dimension Dc and wave form dimension Dw) were calculatedand compared. It was observed that most of the EEG fractal dimension values of Dcand Dw at the epileptic electrodes were smaller than those at the non-epilepticelectrodes. The results showed that the fractal dimension could be a special parameterto diagnose epilepsy diseases and are worthy to study further.

Alantolactone inhibits proliferation,metastasis and promotes apoptosis of human osteosarcoma cells by suppressing Wnt/β-catenin and MAPKs signaling pathways

Although there are many therapeutic strategies such as surgery and chemotherapy,the prognosis of osteosarcoma(OS)is still far from being satisfactory.It is urgent to develop more effective,tolerable and safe drugs for the treatment of OS.In the present study,we investigated the anti-OS activity of Alantolactone(ALT),a natural eucalyptone sesquiterpene lactone mainly exists in Inula helenium,and probed the possible mechanism involved.We demonstrated that ALT significantly inhibited cell proliferation of various human OS cell lines while had relative lower cytotoxicity against normal cells.Then,we validated that ALT reduced migration,decreased invasion possibly through reversing epithelial mesenchymal transition(EMT)process and suppressing Matrix metalloproteinases(MMPs).Moreover,we confirmed that ALT promoted apoptosis and arrested cell cycle at G2/M phase of human OS cells in vitro.In addition,we confirmed that ALT restrained tumor growth and metastasis of OS 143 cells in a xenograft model in vivo.Mechanistically,ALT inhibited the activity of Wnt/β-catenin and p38,ERK1/2 and JNK Mitogen Activated Protein Kinases(MAPKs)signal pathway.Notably,the combination of ALT and Wnt/β-catenin inhibitor,as well as the combination of ALT and MAPKs inhibitors resulted in a synergistically effect on inhibiting the proliferation,migration and invasion of OS cells.Collectively,our results validate the ALT may inhibit proliferation,metastasis and promotes apoptosis of human OS cells possibly through suppressing Wnt/β-Catenin and MAPKs signaling pathways.