Bifurcation Analysis of a Nonlinear Vibro-Impact System with an Uncertain Parameter via OPA Method

In this paper,the bifurcation properties of the vibro-impact systems with an uncertain parameter under the impulse and harmonic excitations are investigated.Firstly,by means of the orthogonal polynomial approximation(OPA)method,the nonlinear damping and stiffness are expanded into the linear combination of the state variable.The condition for the appearance of the vibro-impact phenomenon is to be transformed based on the calculation of themean value.Afterwards,the stochastic vibro-impact systemcan be turned into an equivalent high-dimensional deterministic non-smooth system.Two different Poincarésections are chosen to analyze the bifurcation properties and the impact numbers are identified for the periodic response.Consequently,the numerical results verify the effectiveness of the approximation method for analyzing the considered nonlinear system.Furthermore,the bifurcation properties of the system with an uncertain parameter are explored through the high-dimensional deterministic system.It can be found that the excitation frequency can induce period-doubling bifurcation and grazing bifurcation.Increasing the randomintensitymay result in a diffusion-based trajectory and the impact with the constraint plane,which induces the topological behavior of the non-smooth system to change drastically.It is also found that grazing bifurcation appears in advance with increasing of the random intensity.The stronger impulse force can result in the appearance of the diffusion phenomenon.

放置时间对天然乳胶海绵热氧化老化行为的影响机理

研究了5种不同乳胶含量的天然乳胶海绵(80NR,60NR,50NR,40NR和0NR)与老化时间的关系,利用黄度指数、白度指数、交联密度、压陷密度和红外光谱图等指标对乳胶海绵的老化程度和老化特征进行探究。结果表明在老化过程中,乳胶含量越多的海绵,其黄度指数和白度指数上升和下降的速率越快,且黄度指数最后会趋于收敛;交联密度与压陷硬度有着密切关系,反应初期,交联密度上升、压陷硬度下降,反应后期,交联密度和压陷密度都在持续上升;在老化的整个过程中,乳胶海绵发生了氧化反应,碳碳双键消失,同时生成了酯、醚和过氧化物,但是甲基并没有因为反应而消失。

Theoretical Analysis of the Galloping Energy Harvesters under Bounded Random Parameter Excitation

In this paper,the response properties of galloping energy harvesters under bounded random parameter excitation are studied theoretically.The first-order approximate solution of the galloping energy harvester is derived by applying the multi-scales method.The expression for the largest Lyapunov exponent that determines the trivial solution is derived,and the corresponding simulation diagrams,including the largest Lyapunov exponent diagrams and time domain diagrams,verify our results.Then the steady-state response moments of the nontrivial solution are studied using the moment method,and the analytical expressions for the first-order and second-order moments of the voltage amplitude are obtained,respectively.The corresponding results show that wind speed enhances the steady-state response moments of the voltage amplitude.Meanwhile,the voltage output can be controlled by adjusting the cubic coefficient.To further verify the response characteristics of the galloping energy harvester,the stationary probability density functions of the displacement and velocity are obtained by the Monte-Carlo simulation method.The results show that the wind speed enhances the displacement of the bluff and the damping ratios should be reduced asmuch as possible to improve the performance.What’smore,the piezoelectric materials also impact the performance of the energy harvester.

几种水生模式生物在持久性有机污染物毒理学评价中的研究进展

持久性有机污染物对环境及生物体产生的危害已引起全球范围内的持续关注。此类物质能够富集在生物体内,并通过食物链传递产生生物放大效应,进而引发“三致”作用、发育毒性、内分泌干扰效应等。水生模式生物具有饲养成本低、生理周期较短、繁殖量大等优点而被广泛应用于POPs毒理学评价。本文聚焦斑马鱼、青鳉鱼、非洲爪蟾等几种水生模式生物,对其在POPs毒性效应研究中的应用进展进行综述,包括POPs所致骨骼发育畸形、心血管系统病变、性腺发育异常等发育毒性,卵黄蛋白原的诱导、性腺指数、甲状腺激素水平的改变等内分泌干扰效应以及神经行为异常等相关研究内容,希望为POPs污染现状评估以及毒理效应的深入探索、疾病预测模型的建立提供资料参考,并对该领域研究过程中生物模型的筛选具有借鉴意义。

Chromosome-scale genome assembly provides insights into the evolution and flavor synthesis of passion fruit (Passiflora edulis Sims)

Passion fruit(Passiflora edulis Sims)is an economically valuable fruit that is cultivated in tropical and subtropical regions of the world.Here,we report an~1341.7Mb chromosome-scale genome assembly of passion fruit,with 98.91%(~1327.18Mb)of the assembly assigned to nine pseudochromosomes.The genome includes 23,171 protein-coding genes,and most of the assembled sequences are repetitive sequences,with long-terminal repeats(LTRs)being the most abundant.Phylogenetic analysis revealed that passion fruit diverged after Brassicaceae and before Euphorbiaceae.Ks analysis showed that two whole-genome duplication events occurred in passion fruit at 65 MYA and 12 MYA,which may have contributed to its large genome size.An integrated analysis of genomic,transcriptomic,and metabolomic data showed that‘alpha-linolenic acid metabolism’,‘metabolic pathways’,and‘secondary metabolic pathways’were the main pathways involved in the synthesis of important volatile organic compounds(VOCs)in passion fruit,and this analysis identified some candidate genes,including GDP-fucose Transporter 1-like,Tetratricopeptide repeat protein 33,protein NETWORKED 4B isoform X1,and Golgin Subfamily A member 6-like protein 22.In addition,we identified 13 important gene families in fatty acid pathways and eight important gene families in terpene pathways.Gene family analysis showed that the ACX,ADH,ALDH,and HPL gene families,especially ACX13/14/15/20,ADH13/26/33,ALDH1/4/21,and HPL4/6,were the key genes for ester synthesis,while the TPS gene family,especially PeTPS2/3/4/24,was the key gene family for terpene synthesis.This work provides insights into genome evolution and flavor trait biology and offers valuable resources for the improved cultivation of passion fruit.

A Weighted Threshold Secret Sharing Scheme for Remote Sensing Images Based on Chinese Remainder Theorem

The recent advances in remote sensing and computer techniques give birth to the explosive growth of remote sensing images.The emergence of cloud storage has brought new opportunities for storage and management of massive remote sensing images with its large storage space,cost savings.However,the openness of cloud brings challenges for image data security.In this paper,we propose a weighted image sharing scheme to ensure the security of remote sensing in cloud environment,which takes the weights of participants(i.e.,cloud service providers)into consideration.An extended Mignotte sequence is constructed according to the weights of participants,and we can generate image shadow shares based on the hash value which can be obtained from gray value of remote sensing images.Then we store the shadows in every cloud service provider,respectively.At last,we restore the remote sensing image based on the Chinese Remainder Theorem.Experimental results show the proposed scheme can effectively realize the secure storage of remote sensing images in the cloud.The experiment also shows that no matter weight values,each service providers only needs to save one share,which simplifies the management and usage,it also reduces the transmission of secret information,strengthens the security and practicality of this scheme.

Effects of Different Processed Products of Radix Codonopsis on Intestinal Flora of Rats with Spleen Deficiency

[Objectives]This study aimed to observe the effects of different processed products of Radix Codonopsis on intestinal flora in rats with spleen deficiency.[Methods]Rat models with spleen deficiency were established by bitter-cold purgation method with Radix et Rhizoma Rhei.Normal group,model group,Radix Codonopsis group,fried Radix Codonopsis group,rice-fried Radix Codonopsis group,honey-fried Radix Codonopsis group and bran-fired Radix Codonopsis group were designed.After subjecting to corresponding treatments,the changes in the quantity of intestinal microorganisms of the rats were detected.[Results]There was no significant change in the quantity of intestinal microorganisms of the rats in the normal group and model group.The rats in the rice-fried Radix Codonopsis group were administered after successful modeling,and the abundance of Bifidobacterium and Lactobacillus in the intestines of the rats increased,and the quantity of Escherichia coli and Staphylococci reduced.The rats in the Radix Codonopsis group,fried Radix Codonopsis groups,honey-fried Radix Codonopsis group and bran-fried Radix Codonopsis group were administered after successful modeling,and the abundance of Bifidobacterium and Lactobacillus in the intestines of the rats increased(the increases were smaller than those in the rice-fried Radix Codonopsis group),and the abundance of E.coli and Staphylococci reduced,close to normal levels.[Conclusions]Different processed products of Radix Codonopsis have obvious regulation effect on intestinal flora of rats with spleen deficiency,and the regulation effect of rice-fried Radix Codonopsis on rats with spleen deficiency is better than that of Radix Codonopsis,fried Radix Codonopsis,honey-fried Radix Codonopsis and bran-fried Radix Codonopsis.

The Research Progress of Endogenous Formaldehyde in Aquatic Products

Endogenous formaldehyde in aquatic products is a hot research topic, as it is an urgent problem to be solved. This paper summarized the advance in background concentration, generation mechanism and detection methods of endogenous formaldehyde in aquatic products, and the work in the future was prospected.

Comparative Study on Effects of Rheum officinale and Wine Prepared Rheum palmatum Dachengqi Decoction on Laxative Effect of Mice

[Objectives] To study the differences in the effects of Rheum officinale and wine prepared Rheum palmatum Dachengqi Decoction(DCQ) on laxative effect of mice.[Methods]First,72 mice were randomly divided into positive control group,blank control group,6 and10 g/kg dose R.officinale DCQ groups,6 and 10 g/kg dose wine prepared R.palmatum DCQ groups.After administration at the dose of20 m L/kg,metabolic cage method and carbon powder propulsion were used to conduct Na+-K+-ATPasc activity experiment,and the comparison was made for the differences in the normal laxative effect of R.officinale and wine prepared R.palmatum on DCQ,the carbon powder propulsion rate,and Na+-K+-ATPasc activit.[Results]There are differences in the laxative effect of R.officinale and wine prepared R.palmatum on DCQ,but their differences in changes are,to some extent,connected with R.officinale and wine prepared R.palmatum.From comparison of R.officinale DCQ group,wine prepared R.palmatum DCQ group,blank control group,and positive control group,it is found that there are differences in the normal laxative effect of normal mice,carbon powder propulsion,and inhibition of Na+-K+-ATPase activity.In addition,the comparison of drug administration groups indicates that the differences in the effects of R.officinale DCQ group are most significant,and there are significant differences in the 6 and 10 g/kg groups.[Conclusions]There are certain differences in the influence of R.officinale and wine prepared R.palmatum Dachengqi Decoction on normal laxative effect of mice,which may be connected with the fact that changes in main chemical components of king drugs R.officinale and wine prepared R.palmatum lead to changes in the dissolution amount of anthraquinones in the compound Dachengqi Decoction.

Preliminary Experimental Study on Anti-inflammatory Effect of Extract from Excoecaria cochinchinensis Lour.as a National Medicine

[Objectives]To study the anti-inflammatory effects of water extract and ethanol extract from Excoecaria cochinchinensis Lour.[Methods]The acute and chronic inflammation models of mouse paw edema induced by cotton ball granuloma and carrageenan were established respectively,and the anti-inflammatory effects of water and ethanol extract from E.cochinchinensis Lour.on acute and chronic inflammation in mice were evaluated.The experimental mice were equally divided into three groups of high,medium and low dose of E.cochinchinensis Lour.(60,40 and 20 g/kg),dexamethasone(0.006 g/kg)group and blank group(distilled water).In the cotton ball granuloma test in mice,the mice were given intragastric administration continuously for 7 d after cotton ball implantation.In the experiment of inflammation induced by carrageenan,the mice in each group were given intragastric administration once a day for 7 d,and the inflammatory model was made after the last administration.[Results]The granuloma inhibition rates of mice in the high,medium and low dose groups of water extract and ethanol extract from E.cochinchinensis Lour were significantly lower than those in the blank group(P<0.05).The degree of paw edema in each dose group of water and ethanol extract from E.cochinchinensis Lour.was significantly lower than that in the blank group(P<0.05).[Conclusions]The water and ethanol extracts from E.cochinchinensis Lour.had significant anti-inflammatory effects.

A TMA-Seq2seq Network for Multi-Factor Time Series Sea Surface Temperature Prediction

Sea surface temperature (SST) is closely related to global climatechange, ocean ecosystem, and ocean disaster. Accurate prediction of SST isan urgent and challenging task. With a vast amount of ocean monitoring dataare continually collected, data-driven methods for SST time-series predictionshow promising results. However, they are limited by neglecting complexinteractions between SST and other ocean environmental factors, such as airtemperature and wind speed. This paper uses multi-factor time series SSTdata to propose a sequence-to-sequence network with two-module attention(TMA-Seq2seq) for long-term time series SST prediction. Specifically, TMASeq2seq is an LSTM-based encoder-decoder architecture facilitated by factorand temporal-attention modules and the input of multi-factor time series. Ittakes six-factor time series as the input, namely air temperature, air pressure,wind speed, wind direction, SST, and SST anomaly (SSTA). A factor attentionmodule is first designed to adaptively learn the effect of different factors onSST, followed by an encoder to extract factor-attention weighted features asfeature representations. And then, a temporal attention module is designedto adaptively select the hidden states of the encoder across all time steps tolearn more robust temporal relationships. The decoder follows the temporalattention module to decode the feature vector concatenated from the weightedfeatures and original input feature. Finally, we use a fully-connect layer tomap the feature into prediction results. With the two attention modules, ourmodel effectively improves the prediction accuracy of SST since it can notonly extract relevant factor features but also boost the long-term dependency.Extensive experiments on the datasets of China Coastal Sites (CCS) demonstrate that our proposed model outperforms other methods, reaching 98.29%in prediction accuracy (PACC) and 0.34 in root mean square error (RMSE).Moreover, SST prediction experiments in China’s East, South, and Yellow Seasite data show that the proposed model has strong robustness and multi-siteapplicability.

Cultivation and Management Technologies for New Banana Cultivar ‘Refen 1’(Musa Spp. ABB,Pisang Awak Subgroup)

Banana is one of the most important crops in tropical and subtropical regions of China. Fenjiao( Musa Spp. ABB,Pisang Awak subgroup) has been grown by small scale famers because of its stable market price and better sugar-acid blend. However,the traditional Fenjiao variety is susceptible to banana Fusarium wilt,has a high plant height( over 5. 0 m),and farmers lack large-scale planting techniques.Based on the traditional Fenjiao variety,we selected‘Refen 1’variety through mutagenesis technology,which has low temperature resistance,suitable to marginal soils and relatively low plant height( 3. 2-4. 0 m). This paper mainly introduces the major techniques of propagation,cultivation,and post-harvest stages of‘Refen 1’banana,including the selection of explant materials,treatment,disinfection,initial culture,nursery hardening of in vitro-produced banana plants,and transplant of tissue culture seedlings. The major points of the cultivation technology include banana plantation selection and preparation,planting methods,irrigation and fertilizer management,pruning and retaining,and prevention and control of plant diseases and insect pests.

Effects of Different Drying Methods on Content of Paederosidic Acid in Paederia scandens

[Objectives]To establish a method to simultaneously determine the content of paederosidic acid in Paederia scandens dried by four different methods.[Methods]Reversed-phase high performance liquid chromatography(RP-HPLC)was adopted.The chromatographic column:Thermo SCIENTIFIC Hypersil GOLD Dim.(mm);mobile phase:acetonitrile-0.1%phosphoric acid aqueous solution;gradient elution;column temperature:30℃;flow rate:1 mL/min;detection wavelength:236 nm;injection volume:10μL.[Results]The linear range of the detection injection volume of paederosidic acid was 0.64-9.60μg(R=0.9992);the limit of quantity(LOQ)was 5.10 ng,and the limit of detection(LOD)was 1.36 ng;the RSD of the precision,stability and reproducibility test was all less than 3%;the sample recovery rate was 98.87%,RSD<3.00,n=6.The results show that the content of paederosidic acid in the shade-dried P.scandens is the highest,and the order of the content is P.scandens(dry in shade)>P.scandens(dried at 50℃)>P.scandens(dried at 60℃)>P.scandens(dried at 70℃).[Conclusions]This method is sensitive,reliable and reproducible,and can be used to simultaneously determine the content of paederosidic acid in P.scandens dried by four different methods.

Effects of Dachengqi Decoctions Made from Different Processed Products of Rhubarb on ABP Mice

[Objectives]This study aims to investigate the effects of Dachengqi decoctions made from different processed products of rhubarb on water intake,defecation amount,urination amount,urination volume,dryness of stool,mental state and activity of ABP mice.[Methods]Total 165 mice were randomly divided into Dachengqi decoction groups(made from different processed products of rhubarb,6 and 10 g/kg),positive control group,blank control group and model group.The administration dosage was 20 mL/kg.With the metabolic cage integral method,the effects of Dachengqi decoctions made from different processed products of rhubarb on the water intake,defecation amount,urination volume,dryness of stool,mental state and activity of ABP mice were compared.[Results]Dachengqi decoctions all could soften stool and promote rapid defecation of the mice with fecal peritonitis of excess heat stagnation type except that made from carbonized rhubarb.The water intakes of all the Dachengqi decoction groups were higher than those of the positive control group and the model group,except the carbonized rhubarb-made Dachengqi decoction groups.[Conclusions]Dachengqi decoctions all have obvious purgative effect except those made from carbonized rhubarb.

Potential Preventive and Therapeutic Effects of Traditional Chinese Medicine Compound Prescription and Traditional Chinese Medicine Products on COVID-19

This paper mainly analyzes the traditional Chinese medicine compound prescription and traditional Chinese medicine products with remarkable epidemic prevention effect since the outbreak of COVID-19,and discusses their potential prevention and treatment effects,so as to provide a basis for the further development and application of traditional Chinese medicine compound prescription and traditional Chinese medicine products against COVID-19.

Problems in Transplanting Large Trees to Cities and Recommendations

This paper first elaborated the purpose of accelerating the greening process,improving the landscape effect,and improving the ecological environment for transplanting large trees to cities. Then,it introduced main problems: destroying the ecological environment of the producing area,damaging the entire ecosystem,increasing the cost of social greening,and seriously wasting forest resources. It analyzed the reasons for these problems,including the imperfect laws and regulations,blind and not scientific transplanting,and eagerness for quick success.Finally,it came up with recommendations including improving policies and regulations,reinforcing technical specifications,and first pseudo planting then field planting,and setting up the overall point of view.

Establishment of the Determination Methods of Total Anthraquinone Content in Different Processed Products of Rhubarb

[Objectives]Ultraviolet spectrophotometry was established for the determination of total content of anthraquinone in different processed products of rhubarb.[Methods]Emodin was used as the control substance,and its color was developed by magnesium acetate methanol solution with the concentration of 1%,the absorbance was determined at the wavelength of 516 nm,the content of total anthraquinone in different processed products of rhubarb was determined to compare the content differences.[Results]The regression equation was y=0.0452 x+0.0015,R 2=0.9991.Emodin had a good linear range in the concentration of 0.98-23.52μg/mL,with high accuracy,good repeatability and stable detection results.This method revealed the content changes of total anthraquinone in rhubarb before and after processing.[Conclusions]This method could be used as the quality control method of different processed products of rhubarb,and provided reference for the comprehensive development and utilization of rhubarb resources in the future.

Determination of Sedative Component in Chinese Medicines by High Resolution Chromatography-Electron Impact-Mass Spectrometry

The sedative compounds in two traditional Chinese medicines were studied. These compounds are present in the medicinal herbs “Zao Ren” and “Lu Lu Tong”. The samples were first extracted by ethanol and pre-treated by ultrasonic wave, and then they were separated and qualitatively analyzed by high-resolution GC-EI-MS and High Performance Liquid Chromatography (HPLC) systems. We have found that the Chinese herb medicines “Zao Ren” contained clonazepam (120 ppm), whereas “Lu Lu Tong” Chinese drug contained estazolam (270 ppm). The Analytical measurements were done by using three different diagnostic indices using the GC-retention time of the GC-EI-MS total –ion–chromatogram;single stage EI-MS analysis identification and from the measurements of the retention time in the HPLC.

Determination of 7 Indictor Polychlorinated Biphenyls (PCBs) Residues in Porphyra by Ultrasonic Extraction and Gas Chromatography (GC)

A method was developed for determination of 7 indictors the polychlorinated biphenyls (PCBs) residues in porphyra by gas chromatography (GC) with electron capture detector (ECD). The PCBs were extracted with hexane/methylene chloride (1:1, v/v) by ultrasonic extraction and the samples were cleaned up by concentrated sulfuric acid and Alumina-N solid phase extraction cartridge. The analytes were quantified by an internal standard method. Under optimal experimental conditions, good linearity was observed in the range of 5 - 200 ng/mL and the correlation coefficients were 0.9994 - 0.9998. The limit of quantitation (LOQ) for target analytes ranged from 6.0 to 10.0 μg/kg. At the spiked levels of 10, 50, 100 μg/kg, the average recoveries ranged from 90.9% to 102% with the relative standard deviations 2.12% - 6.32%. The result showed that the proposed method was rapid, and could be used for the determination of the PCBs in porphyra.

Research progress on the MYB transcription factors in tropical fruit

Tropical fruits,such as bananas,passion fruit,mangoes,and lychees,are rich in vitamins,flavonoids and non-flavonoid phenols,and are the healthiest way to intake bioactive compounds in one's daily diet.Coupled with their unique taste,tropical fruits are becoming more increasingly popular.The production of bananas is second only after grapes,while other tropical fruit are limited by the planting environment,resulting in a relatively low planting area and yield.With the improvement in breeding technology and planting technology,the development of tropical fruit crops will have broad prospects.MYB plays a major regulatory role in several biological processes,including growth and development of plants,quality formation,and stress resistance.There is a comparatively junior level of research on tropical fruit crops compared to grain fruit and model plants.Despite the progress that has been made in the development of molecular biology methods that can transform the genetic makeup of tropical fruit crops,the functional understanding of the multiple MYB genes is still in its initial stages.This paper aims to review the current status of the research on the development of these genes and their prospects.It is expected to provide a reference for the study of MYB transcription factors in tropical fruit crops and to provide new ideas for the functional resolution of MYB transcription factors in different biological processes.