Characterization of the key aroma compounds in four varieties of pomegranate juice by gas chromatography-mass spectrometry(GC-MS),gas chromatography-olfactometry(GC-O),odor activity value(OAV),aroma recombination,and omission tests

P omegranate(Punica granatum L.)has attracted considerable attention in world markets due to its valuable nutrients and highly appreciated sensory properties.The aroma profiles of 4 varieties of pomegranate juice,including Dahongtian(DP),Jingpitian(JP),Luyudan(LP),and Tianhonngdan(TP),were investigated via gas chromatography-mass spectrometry(GC-MS)and gas chromatography-olfactometry(GC-O)analyses.A total of 43 volatile compounds were identified by using GC-MS.Among these compounds,16 were considered as potential aroma-active compounds as detected by GC-O.These compounds belonged to the classes of terpinenes,alcohols,and aldehydes.Eleven volatile compounds were defined as the main contributors to the overall aroma of pomegranate juice due to their high odor activity values(OAVs≥1).Aroma recombination and omission tests confirmed thatβ-myrcene,1-hexanol,and(Z)-3-hexen-1-ol were the key aroma compounds,and limonene,1-octen-3-ol,linalool,and hexanal were important aroma-active compounds in DP samples.

Basic leucine zipper gene VvbZIP61 is expressed at a quantitative trait locus for high monoterpene content in grape berries

The widely appreciated muscat flavor of grapes and wine is mainly attributable to the monoterpenes that accumulate in ripe grape berries.To identify quantitative trait loci(QTL)for grape berry monoterpene content,an F1 mapping population was constructed by a cross between two grapevine genotypes,one with neutral aroma berries(cv.‘Beifeng’)and the other with a pronounced muscat aroma(elite Vitis vinifera line‘3–34’).A high-density genetic linkage map spanning 1563.7 cM was constructed using 3332 SNP markers that were assigned to 19 linkage groups.Monoterpenes were extracted from the berry of the F1 progeny,then identified and quantified by gas chromatography–mass spectrometry.Twelve stable QTLs associated with the amounts of 11 monoterpenes in berries were thus identified.In parallel,the levels of RNA in berries from 34 diverse cultivars were estimated by RNA sequencing and compared to the monoterpene content of the berries.The expression of five genes mapping to stable QTLs correlated well with the monoterpene content of berries.These genes,including the basic leucine zipper VvbZIP61 gene on chromosome 12,are therefore considered as potentially being involved in monoterpene metabolism.Overexpression of VvbZIP61 in Vitis amurensis callus through Agrobacterium-mediated transformation significantly increased the accumulation of several monoterpenes in the callus,including nerol,linalool,geranial,geraniol,β-myrcene,and D-limonene.It is hypothesized that VvbZIP61 expression acts to increase muscat flavor in grapes.These results advance our understanding of the genetic control of monoterpene biosynthesis in grapes and provide important information for the marker-assisted selection of aroma compounds in grape breeding.

Assessment of Heavy Metal Pollution in the Water, Sediment and Fish during a Complete Breeding Cycle in the Pond of the Pearl River Delta, China

The paper aimed to investigate the concentration variations and evaluate the bioaccumulation as well as the health risk of Cr, Ni, Cu, Zn, As, Cd and Pb in the aquaculture pond ecosystem during a complete breeding cycle. The samples of water, sediment and aquatic organisms were collected from the pond of gull island in the Pearl River Delta, China. In the breeding cycle, the results revealed the metal concentration in the water increased, while the sediment metal concentration showed no significant difference. The heavy metal concentrations in the water were higher than the background values (December 2017) which related to the input of feeds. Sediment metal concentrations (Cr, Ni, Cu, Zn, As and Cd) in the sediment were higher than the background values of Guangdong Province, China, indicating these metal pollutions came from anthropogenic activities. While the concentration of Pb was comparable to the background value, implying that the Pb was mainly from the earth crust. In addition, various metals showed different affinity to fish organs (muscle, skin, bladder, gill, heart, kidney and liver). Zinc was abundant in skin, while As and Cd concentrations were highest in kidneys;Cu was accumulated highest in liver;Cr concentrations was highest in hearts;and Ni was mainly found in bladders, and the Pb was most commonly found in gills. The distribution of heavy metals in the tissues organs was in the sequence of: Zn > Cu > Cr > Ni > Pb > As > Cd. As the fish ages, the Cu and Zn concentration in tissue organs declined, while the Cr, Ni, As, Cd and Pb increased slightly. Estimations of health risks showed no evidence of potential threats to consumers.

The Enlightenment on Urban Ecological Construction by Research Progress of Sponge City in China Based on Literature Analysis

To quantitatively analyze main figure,field,agency and level of sponge city research in China,and clear research focus and hot spot in each year,by using the Full Text Database of Chinese Sci-tech Periodicals and other retrieval tools,the statistics and analysis of 3152 research literatures on sponge city published in domestic academic journals of 2004-2016 are conducted based on bibliometrics. It is found that since the concept of " sponge city" was firstly proposed in 2012,development research of sponge city involves 40 subject fields and is mainly published in 32 kinds of journals,which is dominated by natural science research( 1427 literatures). Researchers are mainly from each college and university,some design institutes and Chinese Academy of Sciences. The research could play certain guidance significance for further research and construction of ecological city construction in China.

Systematic Analysis of Gene Expression in Western Flower Thrip( Frankliniella occidentalis Pergande ) before and after Infection with Impatiens Necrotic Spot Virus(INSV)

Impatiens necrotic spot virus( INSV) is an important plant virus identified in recent years. Western flower thrip( Frankliniella occidentalis) has been confirmed to be the most efficient vector for INSV. In the present study,Illumina's second-generation sequencing technique was used to determine the variation in gene expression at the transcriptome level in western flower thrip before and after infection with INSV. By aligning 168 188 unigenes of western flower thrip to the NCBI protein database,47 558 unigenes were annotated,accounting for 28. 27% of the total. Species classification revealed that 58. 7% of the annotated unigenes of western flower thrip did not match any other species,and 15. 4% of had a match in Zootermopsis navadensis,12. 4% in Mus musculus,7. 3% in Mustela putorius,3. 4% in Theileria parva,and 2. 7% in Tribolium castaneum. By analyzing DEGs between INSV-free and INSV-carrying western flower thrips,we found that 11 genes were upregulated,and 9 genes were downregulated in western flower thrip after INSV infection. In addition,cell cycle and ubiquitin-proteasome pathway in western flower thrip were significantly infected by INSV infection.

Leisure Agriculture Based on Cultural Resources of Sani People in Yunnan

Through exploring the material and nonmaterial cultural resources in leisure agriculture of Sani People in Shilin of Yunnan Province,this paper introduced festivals,marriage,traditional clothing,and food culture of Sani People,and present the long history and brilliant culture of Sani People. These culture resources could be used to expand the cultural aspects of leisure agriculture,to solve the problems of low participation and less distinct characteristics. This study can provide a reference for building the high-end leisure agriculture with distinct characteristics of Yunnan Province,to form a new growth point for regional growth.

Study on Antifungal Activity of Some Medicinal Plants against Gray Mold(Botrytis cinerea)

In order to investigate antifungnl effect of medicinal plant extracts on Botrytis cinerea, the antifungal activity of ethanol extracts of 8 medicinal plants in- eluding Ginkgo biloba against Botrytis cinerea was determined by growth rate method. The results showed that Ginkgo biloba and Ginnamomum cassia extracts had significant inhibition effects on B. cinema mycelium growth （P 〈 0.05）, with inhibition rates over 70% and ECho values of 0.027 mg/ml and 0.039 mg/ml, re- spectively, significantly different from the antifungal effects of other kinds of medicinal plants ; and P. ternata and A. tsaoko extracts showed the second highest in- hibition effects, with ECho values of 0. 011 9 and 0. 039 3 mg/ml, respectively. Further experimental application could be carried out.

A Study on the Operating Model of Internet + QQ Farm

The'Internet+QQ farm'creative agriculture presented in this paper is the innovation based on the currently booming reality QQ farm,aimed at reducing cost,improving efficiency and optimizing human and material resource elements.It can make Internet provide technical support for intelligence-based life,leisure,entertainment,with good prospects for development.

Construction Strategy of Sponge City in the Old Urban Area of Kunming Based on LID Concept

Sponge city construction,as an important measure of ecological construction in China,can effectively solve a series of problems such as large annual runoff,serious non-point source pollution,regional water shortage,low utilization rate of rain and flood resources,unsustainable ecological benefits of water landscape and poor landscape functions in urbanization construction. This paper uses LID concept to construct sponge city in the old urban area of Kunming,to reduce the total runoff and promote the utilization of rainfall and flood resources so as to rebuild,upgrade and optimize the regional environment and provide some reference for the regional construction of small-scale sponge city.

Teaching Reform and Practice of Plant Growth Environment Course in the Context of Application Transformation Development

Through the personnel training program,revising the syllabus,optimizing teaching contents,reforming teaching methods,strengthening practical teaching links and reforming examination methods,this paper explored the teaching reform and practice of Plant Growth Environment Course,in order to improve the teaching effect,stimulate learning interests of students,and cultivate application type talents meeting social demands.

Oxygen-assisted spinodal structure achieves 1.5 GPa yield strength in a ductile refractory high-entropy alloy

Refractory high-entropy alloys(RHEAs)with room-temperature ductility are drawing growing attention for potential high-temperature applications.However,the most widely used metallurgical mechanisms appear weak in optimizing their strength and ductility.Here,we report that the nanoscale spinodal struc-ture in Ti_(41)V_(27)Hf_(15)Nb_(15)O_(2)leads to the highest tensile yield strength(∼1.5 GPa)among the existing RHEAs and good elongation of∼12%.With the aid of thermodynamic calculations,we show that oxygen plays a dominant role in controlling the formation of the spinodal structure by influencing the spinodal gap of the Ti-V-Hf-Nb system.Exploring the atomic structure of the spinodal structure(β+β^(∗)),we showed that the large lattice misfit of the spinodal phases is mainly responsible for the excellent strengthen-ing effect while the planar to wavy dislocation glide mode transition accounts for the retained ductility.This work provides a novel strategy to improve the mechanical properties of the RHEAs and deepens the understanding of their phase stabilities.

Characterization of squash polysaccharide and the anti-diabetic effect on type 2 diabetic rat revealed by urine metabolomics analysis

The present study reports the structural characteristics of 3 polysaccharide fractions(SPS-F1,SPS-F2 and SPS-F3)isolated and purified from squash.SPS-F1(molecular weight(Mw)=12.30 kDa)and SPS-F2(Mw=19.40 kDa)were likely to contain HG and RG-I domain of pectic polysaccharide,respectively.SPS-F2(Mw=270.4 kDa)was mainly composed of rhamnose,galactose and arabinose.The treatment with SPS decreased body weight gain,glucose and TG levels in type 2 diabetes rats.Besides,25 differential metabolites were identified based on urinary metabolomics analysis,which are crucial to the anti-diabetic effect of SPS.The regulation of nicotinamide N-oxide,histamine,cis-aconitate,citrate,L-malic acid,3-(3-hydroxyphenyl)propanoic acid and N-acetyl-L-aspartic acid were mainly associated with energy metabolism,gut microbiota and inflammation.Study of surface plasmon resonance revealed the binding kinetics with galectin-3(Gal-3)and fibroblast growth factor 2(FGF2).The K_(D)values of SPS-F2 and SPS-F3 to Gal-3 were 4.97×10^(-3)and 1.48×10^(-3)mol/L,indicating a weak binding affinity.All 3 fractions showed moderate binding to FGF2 and the affinity was SPS-F3>SPS-F2>SPS-F1.Thus,the metabolomics and SPR approach were proved to be a promising tool in exploring the anti-diabetes effects of SPS and provided a deep understanding of the mechanisms.

Highly stable and antifouling graphene oxide membranes prepared by bio-inspired modification for water purification

Graphene oxide(GO)membranes show great potential in molecular separation for water treatment.However,the inferior stability of GO membranes is a major bottleneck for practical applications.In this study,bio-inspired polydopamine(PDA)deposition is reported for enhancing the stability of GO membranes.Through simple and mild immersion,PDA is self-polymerized on GO membranes.The blocking of PDA chains to membrane defects improves the rejections for various molecules.Because the inherently strong adhesion and crosslinking of PDA greatly strengthen the interactions of substrates to GO layers and the binding force of GO nanosheets,the prepared PDA-GO membranes exhibit impressive long-te rm stability in cross-flow filtration,and maintain good nanofiltration perfo rmance at various feed pressures,tangential velocities,and eve n after external scratching.Moreover,because the deposited PDA layers obstruct the direct contact between GO and contaminants,the antifouling property of the PDA-GO membranes increases substantially,with recovery ratio about 98%.

OBTAINING MULTI-AXIAL ELASTIC POTENTIALS FOR RUBBER-LIKE MATERIALS VIA AN EXPLICIT,EXACT APPROACH BASED ON SPLINE INTERPOLATION

An explicit, exact approach is proposed to obtain multi-axial elastic potentials for isotropic rubber-like materials undergoing large incompressible deformations. By means of two direct, explicit procedures, this approach reduces the problem of determining multi-axial poten- tials to that of determining one-dimensional elastic potentials. To this end, two one-dimensional potentials for uniaxial case and simple shear case are respectively determined via spline inter- polation and, then, the two potentials are extended to generate a multi-axial elastic potential using a novel method based on certain logarithmic invariants. Eventually, each of the multi-axial potentials will exactly match the finite strain data from four benchmark tests.

An Acetylcholinesterase Biosensor Based on Graphene/ Polyaniline Composite Film for Detection of Pesticides

This work reports a sensitive amperometric biosensor for organophosphate pesticides （OPs） fabricated through modifying glassy carbon electrode with acetylcholinesterase （ACHE） immobilized on graphene/polyaniline （G/PANI） composite film. The obtained G/PANI composite films show large specific area, high conductivity, good biocompatibility, and fast redox properties and have perfect layered and encapsulated structures. The as-prepared biosensor shows high affinity to acetylthiocholine （ATC1） with a Micbaelis-Menten constant value of 0.20 mmol/L. Furthermore, based on the inhibition of the enzymatic activity （immobilized ACHE） caused by the model compound of carbaryl （one kind of pesticides）, it is found that the inhibition activity of carbaryl is proportional to its concen- tration ranging from 38 to 194 ngomL-1. The developed biosensor shows a detection limit of 20 ngomL-1 （S/N~ 3） for OPs detection and exhibits good performance such as good reproducibility and acceptable stability, which makes it possible to provide a new and promising tool for the analysis of enzyme inhibitors.

Sulfonated Graphene Synthesized via a Green Route and Its Capacitive Properties

An environmentally friendly approach is presented to synthesize sulfonated reduced graphene oxide （S-rGO） by using L-ascorbic acid （L-AA） and aryl diazonium salt of sulfanilic acid. The preparation conditions have been optimized in order to obtain isolated and conductive S-rGO, and the products have been characterized by Ultraviolet-Visible spectroscopy, Fourier transformed infrared spectroscopy, Raman, X-ray photoelectron spectroscopy and X-ray powder diffraction and electrochemical methods. The results show that the S-rGO sheets possess excellent water-solubility and high electrical conductivity, which implies that the oxygen-containing functional groups have been removed and conjugated sp2 network has been restored. What＇s more, the electrochemical measurements reveal that the capacitive performance of the S-rGO has been improved compared with the graphene oxide （GO） and the reduced graphene oxide （rGO, reduced by L-AA）. The optimum S-rGO exhibits a specific capacitance of 205 F·g^-1 and good cycling stability （3.9% decreasing after 10000 cycles）, which are better than those for graphene oxide （109 F·g^-1 and decreasing 6.6% after 10000 cycles） and rGO （139 F·g^-1 and decreasing ll.3% after 10000 cycling）. This approach proves a new route to improve the capacitive properties of rGO.

Heat dissipation of carbon shell in ZrC-SiC/TaC coating to improve protective ability against ultrahigh temperature ablation

To efficiently decrease ablation heat accumulation and improve the ability of ZrC-SiC/TaC coatings to protect carbon/carbon(C/C)composites,a thermally conductive nanonetwork with a ceramic@carbon core-shell structure was designed and constructed.Polymer-derived SiC/TaC with a graphene carbon shell was synthesized and introduced into a ZrC coating by supersonic atmospheric plasma spraying(SAPS).Graphene shell paths increased the heat transfer capability by lowering the surface temperature to approximately 200℃during oxyacetylene ablation.The heat dissipation of the graphene shell in the ZrC-SiC/TaC@C coating reduced the volatilization of low-melting-point phases and delayed the sintering of ZrO2 particles.Thus,the graphene shell in ZrC-SiC/TaC@C coating decreased the mass and linear ablation rates by 91.4%and 93.7%compared to ZrC-SiC/TaC coating,respectively.This work provided a constructive idea for improving the ablation resistance of the coatings by incorporating carbon nanomaterials as a function of heat dissipation.