Background Long-term natural and artificial selection has resulted in many genetic footprints within the genomes of pig breeds across distinct agroecological zones.Nevertheless,the mechanisms by which these signatures...Background Long-term natural and artificial selection has resulted in many genetic footprints within the genomes of pig breeds across distinct agroecological zones.Nevertheless,the mechanisms by which these signatures contribute to phenotypic diversity and facilitate environmental adaptation remain unclear.Results Here,we leveraged whole-genome sequencing data from 82 individuals from 6 domestic pig breeds originating in tropical,high-altitude,and frigid regions.Population genetic analysis suggested that habitat isolation significantly shaped the genetic diversity and contributed to population stratification in local Chinese pig breeds.Analysis of selection signals revealed regions under selection for adaptation in tropical(55.5 Mb),high-altitude(43.6 Mb),and frigid(17.72 Mb)regions.The potential functions of the selective sweep regions were linked to certain complex traits that might play critical roles in different geographic environments,including fat coverage in frigid environments and blood indicators in tropical and high-altitude environments.Candidate genes under selection were significantly enriched in biological pathways involved in environmental adaptation.These pathways included blood circulation,protein degradation,and inflammation for adaptation to tropical environments;heart and lung development,hypoxia response,and DNA damage repair for high-altitude adaptation;and thermogenesis,cold-induced vasodilation(CIVD),and the cell cycle for adaptation to frigid environments.By examining the chromatin state of the selection signatures,we identified the lung and ileum as two candidate functional tissues for environmental adaptation.Finally,we identified a mutation(chr1:G246,175,129A)in the cis-regulatory region of ABCA1 as a plausible promising variant for adaptation to tropical environments.Conclusions In this study,we conducted a genome-wide exploration of the genetic mechanisms underlying the adaptability of local Chinese pig breeds to tropical,high-altitude,and frigid environments.Our findings shed light on the prominent role of cis-regulatory elements in environmental adaptation in pigs and may serve as a valuable biological model of human plateau-related disorders and cardiovascular diseases.展开更多
Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in mitochondria.In a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is...Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in mitochondria.In a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is essential for the survival of sea cucumbers.Six MnSODs were identified from the transcriptomes of deep and shallow-sea sea cucumbers.To explore their environmental adaptation mechanism,we conducted environmental selection pressure analysis through the branching site model of PAML software.We obtained night positive selection sites,and two of them were significant(97F→H,134K→V):97F→H located in a highly conservative characteristic sequence,and its polarity c hange might have a great impact on the function of MnSOD;134K→V had a change in piezophilic a bility,which might help MnSOD adapt to the environment of high hydrostatic pressure in the deepsea.To further study the effect of these two positive selection sites on MnSOD,we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and PyMOL.Results show that 97F→H,134K→V might improve MnSOD’s efficiency of scavenging superoxide a nion and its ability to resist high hydrostatic pressure by moderately reducing its stability.The above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity,piezophilic behavior,and local stability.This study revealed the correlation between MnSOD and extreme environment,and will help improve our understanding of the organism’s adaptation mechanisms in deep sea.展开更多
Although advances in wireless technologies such as miniature and wearable electronics have improved the quality of our lives,the ubiquitous use of electronics comes at the expense of increased exposure to electromagne...Although advances in wireless technologies such as miniature and wearable electronics have improved the quality of our lives,the ubiquitous use of electronics comes at the expense of increased exposure to electromagnetic(EM)radiation.Up to date,extensive efforts have been made to develop high-performance EM absorbers based on synthetic materials.However,the design of an EM absorber with both exceptional EM dissipation ability and good environmental adaptability remains a substantial challenge.Here,we report the design of a class of carbon heterostructures via hierarchical assembly of graphitized lignocellulose derived from bamboo.Specifically,the assemblies of nanofibers and nanosheets behave as a nanometer-sized antenna,which results in an enhancement of the conductive loss.In addition,we show that the composition of cellulose and lignin in the precursor significantly influences the shape of the assembly and the formation of covalent bonds,which affect the dielectric response-ability and the surface hydrophobicity(the apparent contact angle of water can reach 135°).Finally,we demonstrate that the obtained carbon heterostructure maintains its wideband EM absorption with an effective absorption frequency ranging from 12.5 to 16.7 GHz under conditions that simulate the real-world environment,including exposure to rainwater with slightly acidic/alkaline pH values.Overall,the advances reported in this work provide new design principles for the synthesis of high-performance EM absorbers that can find practical applications in real-world environments.展开更多
Visual odometry is critical in visual simultaneous localization and mapping for robot navigation.However,the pose estimation performance of most current visual odometry algorithms degrades in scenes with unevenly dist...Visual odometry is critical in visual simultaneous localization and mapping for robot navigation.However,the pose estimation performance of most current visual odometry algorithms degrades in scenes with unevenly distributed features because dense features occupy excessive weight.Herein,a new human visual attention mechanism for point-and-line stereo visual odometry,which is called point-line-weight-mechanism visual odometry(PLWM-VO),is proposed to describe scene features in a global and balanced manner.A weight-adaptive model based on region partition and region growth is generated for the human visual attention mechanism,where sufficient attention is assigned to position-distinctive objects(sparse features in the environment).Furthermore,the sum of absolute differences algorithm is used to improve the accuracy of initialization for line features.Compared with the state-of-the-art method(ORB-VO),PLWM-VO show a 36.79%reduction in the absolute trajectory error on the Kitti and Euroc datasets.Although the time consumption of PLWM-VO is higher than that of ORB-VO,online test results indicate that PLWM-VO satisfies the real-time demand.The proposed algorithm not only significantly promotes the environmental adaptability of visual odometry,but also quantitatively demonstrates the superiority of the human visual attention mechanism.展开更多
Based on specimens collected in Yinggehai, Hainan, China from 2013 to 2016, a stable epiphytic taxon is found on the surface of the individual of marine green alga Cladophora aokii Yamada. According to the morphologic...Based on specimens collected in Yinggehai, Hainan, China from 2013 to 2016, a stable epiphytic taxon is found on the surface of the individual of marine green alga Cladophora aokii Yamada. According to the morphological characteristics, the taxonomy of Cl. aokii and its epiphytes is carried out. There are some epiphytes attached on Cl. aokii Yamada including Cl. fascicularis (Mertens ex C. Agardh) Kfitzing, Chaetomorpha pachynerna (Montagne) Kiitzing, Cerarniurn carnouii Dawson, Licmophora abbreviata Agardh, Lyngbya sp. and Chattonella sp.. The formation of the individual of Cl. aokii is dissected and explained, which can help to analyze the adaption in details among this species, its epiphytes and native marine environment. The results reveal the marine macroepiphytic taxonomy in Ha/nan, China, and preliminarily explain the adaptive relationship between macroalgae and environment.展开更多
We designed two types of pre-adaption plans for this study. One was a pre-adaption training with progressive intermittent hypoxia, with a constant lower pressure oxygen tank used in the plain before arriving at the pl...We designed two types of pre-adaption plans for this study. One was a pre-adaption training with progressive intermittent hypoxia, with a constant lower pressure oxygen tank used in the plain before arriving at the plateau (PG). The other was by progressively increasing the time of exposure to hypoxia with oxygen supplied in stages after radical plateau (RG). By testing the blood oxygen saturation (SpO2), heart rate (HR), and quality of sleep after arriving at the 3800 m high plateau, results showed that the pre-acclimatization and radical groups performed better than the control group (CG). Both strategies were equivalent in terms of effects and principles in providing more flexible choices for acclimatization.展开更多
It has been widely recognized that biological invasion has become one of the greatest threats to the ecosystem.Codium fragile is an invasive species which exhibits a variety of attributes like parthenogenesis,winter f...It has been widely recognized that biological invasion has become one of the greatest threats to the ecosystem.Codium fragile is an invasive species which exhibits a variety of attributes like parthenogenesis,winter fragment,and vegetative reproduction;and therefore,it has become a successful invader,colonizing most subtropical regions.In China’s southeast coastal aquaculture waters,the green algal bloom caused by C.fragile will probably become a serious problem.In order to understand more details about the species,an experiment focused on its reproductive characteristics was conducted using culture established from a sample collected in the aquaculture raft of the Nan’ao Island in the South China Sea.The results showed that there were two types of gametes resembling aplanospores and zoospores respectively,both of which were able to germinate.During the gametes liberation,a long mucilage tube was formed out of the mouth of the gametangium assisting dispersal of gametes away from the parent plant.This tube was adapted not only to its surrounding flowing water environment but also to its parent plant’s outer gelatinous structure.In general,the optimum temperature for gametes release and germination was 15-20℃ and 15℃,respectively,which corresponded to the local offshore marine water.The plant was observed to produce vegetative buds under favourable reproductive conditions which were called propagules.They were capable of developing into filamentous thalli.The results will provide some scientific evidences for revealing the biological mechanism of bloom and control strategies of invasive green algae.展开更多
Turpan traditional residences are primitive green buildings adaptive to the climate, materials and geographical conditions of the arid regions. The environmental adaptability of local residences and the construction m...Turpan traditional residences are primitive green buildings adaptive to the climate, materials and geographical conditions of the arid regions. The environmental adaptability of local residences and the construction methods was elaborated to provide references for building new oasis settlements in the local area.展开更多
Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some...Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some scholars tend to believe that the unfavorable factors play a dominant role. This conclusion comes from the "new moonshape encirclement" already existing since the Cold War in America,展开更多
Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for sma...Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for smart biointegrated electronics,environment-adaptive electrochemical energy storage(EES)devices with complementary adaptability and functions have garnered huge interest in the past decade.Owing to the advancements in autonomous chemistry,which regulate the constitutional dynamic networks in materials,EES devices have witnessed higher freedom of autonomous adaptability in terms of mechano-adaptable,biocompatibility,and stimuli-response properties for biointegrated and smart applications.In this mini-review,we summarize the recent progress in emerging environmentadaptive EES devices enabled by the constitutional dynamic network of mechanical adaptable materials,biocompatible materials,and stimuli-responsive supramolecular polymer materials.Finally,the challenges and perspectives of autonomous chemistry on the environment-adaptive EES devices are discussed.展开更多
Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and...Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and the lossless medium,it is difficult to achieve effective microwave absorption in a broad-band frequency range.Hence,an ultra-wideband metamaterial absorber(UWMA)composed of two mag-netic media and a metasurface was designed,and the absorption bandwidth of 2.9 to 18 GHz for 90%absorptivity under normal incidence was achieved,covering almost the entire S,C,X,and Ku bands.Through detailed investigation of equivalent circuit,equivalent medium theory,electromagnetic field dis-tribution and front-back interface interference,the internal physical working mechanism was clarified essentially.In addition,the multi-environment adaptabilities of the proposed absorber,including polariza-tion sensitivity,large angle incidence,dual-station radar stealth,bearing capacity and corrosion resistance,were analyzed.The proposed metamaterial absorber presents an effective way to achieve ultra-wideband absorption and compatibility with environmental adaptability,and provides a new way of thinking for intelligent full-band stealth technology.展开更多
The chemical diversity of scleractinian corals is closely related to their physiological,ecological,and evolutionary status,and can be influenced by both genetic background and environmental variables.To investigate i...The chemical diversity of scleractinian corals is closely related to their physiological,ecological,and evolutionary status,and can be influenced by both genetic background and environmental variables.To investigate intraspecific variation in the metabolites of these corals,the metabolomes of four species(Pocillopora meandrina,Seriatopora hystrix,Acropora formosa,and Fungia fungites)from the South China Sea were analyzed using untargeted mass spectrometry-based metabolomics.The results showed that a variety of metabolites,including amino acids,peptides,lipids,and other small molecules,were differentially distributed among the four species,leading to their significant separation in principal component analysis and hierarchical clustering plots.The higher content of storage lipids in branching corals(P.meandrina,S.hystrix,and A.formosa)compared to the solitary coral(F.fungites)may be due to the high densities of zooxanthellae in their tissues.The high content of aromatic amino acids in P.meandrina may help the coral protect against ultraviolet damage and promote growth in shallow seawater,while nitrogen-rich compounds may enable S.hystrix to survive in various challenging environments.The metabolites enriched in F.fungites,including amino acids,dipeptides,phospholipids,and other small molecules,may be related to the composition of the coral's mucus and its life-history,such as its ability to move freely and live solitarily.Studying the chemical diversity of scleractinian corals not only provides insight into their environmental adaptation,but also holds potential for the chemotaxonomy of corals and the discovery of novel bioactive natural products.展开更多
High-speed trains rely on pantograph-catenary systems(PCSs)to collect electrical energy from power systems.However,the dynamic interaction between the pantograph and the catenary system may become mismatched once ice ...High-speed trains rely on pantograph-catenary systems(PCSs)to collect electrical energy from power systems.However,the dynamic interaction between the pantograph and the catenary system may become mismatched once ice accumulates on the overhead conductors.More frequent arcing may occur within the PCS during train operation,posing an unpredictable threat to operational safety.Therefore,it is crucial to evaluate the ability of overhead contact system(OCS)to withstand ice-covered variability during line desgin.A new strategy is proposed to evaluate the adaptive performance of an OCS under various icing conditions.First,a dynamic model considering icing conditions is constructed to simulate the interaction within the PCS.Five different OCS structures with various icing thicknesses are studied.The parameters of the contact force within the PCS and proportion of high-possibility arcing moments are obtained.The dependence of the contact force on the icing thickness and pantograph displacement has been illustrated in the form of cloud maps.Finally,the OCS sensitivity coefficient is calculated,and ice-covered environmental adaptability assessments for the five different OCS structures are compared.展开更多
A quantitative and comprehensive method of product life cycle assessment(LCA) with fuzzy theory is developed, which will help designers to select the optimum design scheme for product life cycle design(LCD). Based on ...A quantitative and comprehensive method of product life cycle assessment(LCA) with fuzzy theory is developed, which will help designers to select the optimum design scheme for product life cycle design(LCD). Based on the theory of multiple attribute decision making, an algorithm of comprehensive and comparative evaluation for product environmental adaptability is presented. A program is built and used in an example of design improvement. The result shows that the proposed method and algorithm are practical and effective to the development of green products.展开更多
A portable shape-shifting mobile robot system named as Amoeba Ⅱ(A-Ⅱ) is developed for the urban search and rescue application. It is designed with three degrees of freedom and two tracked drive systems. This robot...A portable shape-shifting mobile robot system named as Amoeba Ⅱ(A-Ⅱ) is developed for the urban search and rescue application. It is designed with three degrees of freedom and two tracked drive systems. This robot consists of two modular mobile units and a joint unit. The mobile unit is a tracked mechanism to enforce the propulsion of robot. And the joint unit can transform the robot shape to get high environment adaptation. A-Ⅱ robot can not only adapt to the environment but also change its body shape according to the locus space. It behaves two work states including the linear state (named as I state) and the parallel state (named as Ⅱ state). With the linear state the robot can climb upstairs and go through narrow space such as the pipe, cave, etc. The parallel state enables the robot with high mobility on rough ground. Also, the joint unit can propel the robot to roll in sidewise direction. Two modular A-Ⅱ robots can be connected through jointing common interfaces on the joint unit to compose a stronger shape-shifting robot, which can transform the body into four wheels-driven vehicle. The experimental results validate the adaptation and mobility of A-Ⅱ robot.展开更多
Based on the data of four seasonal marine surveys in the East China Sea (23°30′-33°N, 118°30′-128°E)during 1997-2000, the author studied the ecological characters of dominant Pteropoda species ...Based on the data of four seasonal marine surveys in the East China Sea (23°30′-33°N, 118°30′-128°E)during 1997-2000, the author studied the ecological characters of dominant Pteropoda species in the area. Results showed that there were five dominant Pteropoda species, more in summer, less in autumn and even in other seasons. These species, though belonging warm water species, can be categorized into two different groups in habitability. The first group was acicula, Desmopterus papilio and Creseis virgule, while adapted in summer and autumn, including Creseis the second group in winter and spring, represented by Limacina trochiformis and Agadina syimpsoni. The first group was more abundant than the second one. Besides, the first group contributed more to the Pteropoda abundance having higher occurrence frequency and aggregation intensity than the second. In horizontal distribution, the first group species reside in nearshore, and they could migrate to shallow place near estuary and aggregated in high density, while the second one was different: lower abundance, less occurred and aggregated because they were halophilic warm water species, and they were usually abundant in offshore area.展开更多
Psilorhynchus homaloptera mainly inhabits turbulent waters in the lower reach of the Yarlung Zangbo River,Tibet,China,and it is the only species of Psilorhynchus in China.However,many important aspects of its biology ...Psilorhynchus homaloptera mainly inhabits turbulent waters in the lower reach of the Yarlung Zangbo River,Tibet,China,and it is the only species of Psilorhynchus in China.However,many important aspects of its biology remain poorly documented,which hinders the conservation eff orts.Therefore,we studied its reproduction using 801 specimens from the Motuo sector of the lower Yarlung Zangbo River from December 2015 to November 2016.The sex ratio was 0.68꞉1(male꞉female)for the overall population.Females reached a larger total length and weight(134 mm and 18.6 g)than males did(113 mm and 12.2 g).Lengths at maturity were estimated 80.0 mm for males and 93.1 mm for females.Our analyses of gonad development and the size distribution of oocytes suggest that P.homaloptera is a single spawner with the peak spawning period between September and October.Furthermore,the estimated mean absolute fecundity was 557±204 eggs per fish,and mean relative fecundity was 50.9±10.9 eggs per g of female weight.The fecundity of P.homaloptera increased linearly with increasing total length,total weight,ovary weight,and age.This study on the reproductive biology of P.homaloptera demonstrates that the fish was in a vulnerable state due to the increasing anthropogenic activities in the lower Yarlung Zangbo River.展开更多
The cold atom gravimeter offers the prospect of a new generation of inertial sensors for field applications. We ac- complish a mobile atom gravimeter. With the compact and stable system, a sensitivity of 1.4× 10-...The cold atom gravimeter offers the prospect of a new generation of inertial sensors for field applications. We ac- complish a mobile atom gravimeter. With the compact and stable system, a sensitivity of 1.4× 10-7 g.Hz-1/2 is achieved. Moreover, a continuous gravity monitoring of 80 h is carried out. However, the harsh outdoor environment is a big challenge for the atom gravimeter when it is for field applications. In this paper, we present the preliminary investigation of the thermal adaptability for our mobile cold atom gravimeter. Here, we focus on the influence of the air temperature on the performance of the atom gravimeter. The responses to different factors (such as laser power, fiber coupling efficiency, etc.) are evaluated when there is a great temperature shift of 10 ℃. The result is that the performances of all the factors deteriorate to different extent, nevertheless, they can easily recover as the temperature comes back. Finally, we conclude that the variation of air temperature induces the increase of noise and the system error of the atom gravimeter as well, while the process is reversible with the recovery of the temperature.展开更多
Genus Pseudoalteromonas belongs to Family Pseudoalteromonadaceae in Gammaproteobacteria. A cold-adapted gram-negative bacterium, hydrocarbon-degrading Pseudoalteromonas sp. NJ289, was isolated from sea-ice of the Anta...Genus Pseudoalteromonas belongs to Family Pseudoalteromonadaceae in Gammaproteobacteria. A cold-adapted gram-negative bacterium, hydrocarbon-degrading Pseudoalteromonas sp. NJ289, was isolated from sea-ice of the Antarctica region, and sequenced the whole genome through the next generation sequencing platform. The assembly yielded three contigs representing two chromosomes and one plasmid with the sizes of 3.2 Mb, 636 kb and 1.8 kb, respectively. The G+C contents of genome were 40.83% and included 3 589 ORFs. Functional annotation indicated some potential roles in enzymatic activity and environmental adaptability. This study may help for understanding the population diverse, evolutionary ecology and the microbial interaction.展开更多
基金supported by the National Key Research and Development Program of China(2021YFF1000600)the National Natural Science Foundation of China(32002150 and U23A20229)+3 种基金the Basic and Applied Basic Research Foundation of Guangdong Province(2020B1515120053)the Shenzhen Science and Technology Innovation Commission(JCYJ20190813114401691)the Central Government Guiding Funds for Local Science and Technology Development of China(He-Ke ZY220603)the Open Project of Hainan Provincial Key Laboratory of Tropical Animal Reproduction&Breeding and Epidemic Disease Research(HKL2020101)。
文摘Background Long-term natural and artificial selection has resulted in many genetic footprints within the genomes of pig breeds across distinct agroecological zones.Nevertheless,the mechanisms by which these signatures contribute to phenotypic diversity and facilitate environmental adaptation remain unclear.Results Here,we leveraged whole-genome sequencing data from 82 individuals from 6 domestic pig breeds originating in tropical,high-altitude,and frigid regions.Population genetic analysis suggested that habitat isolation significantly shaped the genetic diversity and contributed to population stratification in local Chinese pig breeds.Analysis of selection signals revealed regions under selection for adaptation in tropical(55.5 Mb),high-altitude(43.6 Mb),and frigid(17.72 Mb)regions.The potential functions of the selective sweep regions were linked to certain complex traits that might play critical roles in different geographic environments,including fat coverage in frigid environments and blood indicators in tropical and high-altitude environments.Candidate genes under selection were significantly enriched in biological pathways involved in environmental adaptation.These pathways included blood circulation,protein degradation,and inflammation for adaptation to tropical environments;heart and lung development,hypoxia response,and DNA damage repair for high-altitude adaptation;and thermogenesis,cold-induced vasodilation(CIVD),and the cell cycle for adaptation to frigid environments.By examining the chromatin state of the selection signatures,we identified the lung and ileum as two candidate functional tissues for environmental adaptation.Finally,we identified a mutation(chr1:G246,175,129A)in the cis-regulatory region of ABCA1 as a plausible promising variant for adaptation to tropical environments.Conclusions In this study,we conducted a genome-wide exploration of the genetic mechanisms underlying the adaptability of local Chinese pig breeds to tropical,high-altitude,and frigid environments.Our findings shed light on the prominent role of cis-regulatory elements in environmental adaptation in pigs and may serve as a valuable biological model of human plateau-related disorders and cardiovascular diseases.
基金Supported by the Guangdong Province Basic and Applied Basic Research Fund Project(No.2020A1515110826)the National Natural Science Foundation of China(No.42006115)the Major Scientific and Technological Projects of Hainan Province(No.ZDKJ2021036)。
文摘Manganese superoxide dismutase(MnSOD)is an antioxidant that exists in mitochondria and can effectively remove superoxide anions in mitochondria.In a dark,high-pressure,and low-temperature deep-sea environment,MnSOD is essential for the survival of sea cucumbers.Six MnSODs were identified from the transcriptomes of deep and shallow-sea sea cucumbers.To explore their environmental adaptation mechanism,we conducted environmental selection pressure analysis through the branching site model of PAML software.We obtained night positive selection sites,and two of them were significant(97F→H,134K→V):97F→H located in a highly conservative characteristic sequence,and its polarity c hange might have a great impact on the function of MnSOD;134K→V had a change in piezophilic a bility,which might help MnSOD adapt to the environment of high hydrostatic pressure in the deepsea.To further study the effect of these two positive selection sites on MnSOD,we predicted the point mutations of F97H and K134V on shallow-sea sea cucumber by using MAESTROweb and PyMOL.Results show that 97F→H,134K→V might improve MnSOD’s efficiency of scavenging superoxide a nion and its ability to resist high hydrostatic pressure by moderately reducing its stability.The above results indicated that MnSODs of deep-sea sea cucumber adapted to deep-sea environments through their amino acid changes in polarity,piezophilic behavior,and local stability.This study revealed the correlation between MnSOD and extreme environment,and will help improve our understanding of the organism’s adaptation mechanisms in deep sea.
基金the startup fund of the Ohio State University(OSU)OSU Sustainability Institute Seed Grant+2 种基金OSU Institute for Materials Research Kickstart Facility Grantthe National Natural Science Foundation of China(No.31971740)the Science and technology project of Jiangsu Province(BE2018391).
文摘Although advances in wireless technologies such as miniature and wearable electronics have improved the quality of our lives,the ubiquitous use of electronics comes at the expense of increased exposure to electromagnetic(EM)radiation.Up to date,extensive efforts have been made to develop high-performance EM absorbers based on synthetic materials.However,the design of an EM absorber with both exceptional EM dissipation ability and good environmental adaptability remains a substantial challenge.Here,we report the design of a class of carbon heterostructures via hierarchical assembly of graphitized lignocellulose derived from bamboo.Specifically,the assemblies of nanofibers and nanosheets behave as a nanometer-sized antenna,which results in an enhancement of the conductive loss.In addition,we show that the composition of cellulose and lignin in the precursor significantly influences the shape of the assembly and the formation of covalent bonds,which affect the dielectric response-ability and the surface hydrophobicity(the apparent contact angle of water can reach 135°).Finally,we demonstrate that the obtained carbon heterostructure maintains its wideband EM absorption with an effective absorption frequency ranging from 12.5 to 16.7 GHz under conditions that simulate the real-world environment,including exposure to rainwater with slightly acidic/alkaline pH values.Overall,the advances reported in this work provide new design principles for the synthesis of high-performance EM absorbers that can find practical applications in real-world environments.
基金Supported by Tianjin Municipal Natural Science Foundation of China(Grant No.19JCJQJC61600)Hebei Provincial Natural Science Foundation of China(Grant Nos.F2020202051,F2020202053).
文摘Visual odometry is critical in visual simultaneous localization and mapping for robot navigation.However,the pose estimation performance of most current visual odometry algorithms degrades in scenes with unevenly distributed features because dense features occupy excessive weight.Herein,a new human visual attention mechanism for point-and-line stereo visual odometry,which is called point-line-weight-mechanism visual odometry(PLWM-VO),is proposed to describe scene features in a global and balanced manner.A weight-adaptive model based on region partition and region growth is generated for the human visual attention mechanism,where sufficient attention is assigned to position-distinctive objects(sparse features in the environment).Furthermore,the sum of absolute differences algorithm is used to improve the accuracy of initialization for line features.Compared with the state-of-the-art method(ORB-VO),PLWM-VO show a 36.79%reduction in the absolute trajectory error on the Kitti and Euroc datasets.Although the time consumption of PLWM-VO is higher than that of ORB-VO,online test results indicate that PLWM-VO satisfies the real-time demand.The proposed algorithm not only significantly promotes the environmental adaptability of visual odometry,but also quantitatively demonstrates the superiority of the human visual attention mechanism.
基金The National Natural Science Foundation of China under contract Nos 31400186 and 31670199the Scientific Research Plan of Tianjin Municipal Education Committee under contract No.JW1705the Research Fund for Talented Scholars of Tianjin Normal University(2016)
文摘Based on specimens collected in Yinggehai, Hainan, China from 2013 to 2016, a stable epiphytic taxon is found on the surface of the individual of marine green alga Cladophora aokii Yamada. According to the morphological characteristics, the taxonomy of Cl. aokii and its epiphytes is carried out. There are some epiphytes attached on Cl. aokii Yamada including Cl. fascicularis (Mertens ex C. Agardh) Kfitzing, Chaetomorpha pachynerna (Montagne) Kiitzing, Cerarniurn carnouii Dawson, Licmophora abbreviata Agardh, Lyngbya sp. and Chattonella sp.. The formation of the individual of Cl. aokii is dissected and explained, which can help to analyze the adaption in details among this species, its epiphytes and native marine environment. The results reveal the marine macroepiphytic taxonomy in Ha/nan, China, and preliminarily explain the adaptive relationship between macroalgae and environment.
基金supported in part by the national basic research program of China 973 program(NO.2012CB518200-G)Army major issue of comprehensive medical security research of flight crew in the plateau(N0.AKJ11J005)
文摘We designed two types of pre-adaption plans for this study. One was a pre-adaption training with progressive intermittent hypoxia, with a constant lower pressure oxygen tank used in the plain before arriving at the plateau (PG). The other was by progressively increasing the time of exposure to hypoxia with oxygen supplied in stages after radical plateau (RG). By testing the blood oxygen saturation (SpO2), heart rate (HR), and quality of sleep after arriving at the 3800 m high plateau, results showed that the pre-acclimatization and radical groups performed better than the control group (CG). Both strategies were equivalent in terms of effects and principles in providing more flexible choices for acclimatization.
基金The National Natural Science Foundation of China under contract Nos 31970216 and 31670199the Science and Technology Plan Project of Guangdong Province under contract No.2012A020200007+1 种基金the Scientific Research Plan of Tianjin Municipal Education Committee under contract No.JW1705the Research Fund for Talented Scholars of Tianjin Normal University(2016)。
文摘It has been widely recognized that biological invasion has become one of the greatest threats to the ecosystem.Codium fragile is an invasive species which exhibits a variety of attributes like parthenogenesis,winter fragment,and vegetative reproduction;and therefore,it has become a successful invader,colonizing most subtropical regions.In China’s southeast coastal aquaculture waters,the green algal bloom caused by C.fragile will probably become a serious problem.In order to understand more details about the species,an experiment focused on its reproductive characteristics was conducted using culture established from a sample collected in the aquaculture raft of the Nan’ao Island in the South China Sea.The results showed that there were two types of gametes resembling aplanospores and zoospores respectively,both of which were able to germinate.During the gametes liberation,a long mucilage tube was formed out of the mouth of the gametangium assisting dispersal of gametes away from the parent plant.This tube was adapted not only to its surrounding flowing water environment but also to its parent plant’s outer gelatinous structure.In general,the optimum temperature for gametes release and germination was 15-20℃ and 15℃,respectively,which corresponded to the local offshore marine water.The plant was observed to produce vegetative buds under favourable reproductive conditions which were called propagules.They were capable of developing into filamentous thalli.The results will provide some scientific evidences for revealing the biological mechanism of bloom and control strategies of invasive green algae.
基金Sponsored by National Natural Science Foundation of China(51668058)
文摘Turpan traditional residences are primitive green buildings adaptive to the climate, materials and geographical conditions of the arid regions. The environmental adaptability of local residences and the construction methods was elaborated to provide references for building new oasis settlements in the local area.
文摘Looking from China’s neighboring environment, the America factor is undoubtedly the most important factor in analyzing China’s neighboring security. Speaking of U. S. influence on China’s neighboring security, some scholars tend to believe that the unfavorable factors play a dominant role. This conclusion comes from the "new moonshape encirclement" already existing since the Cold War in America,
基金This work was financially supported by the Agency for Science,Technology and Research(A*STAR)under its AME Programmatic Funding Scheme of CyberPhysiochemical Interfaces Programme(Project No.A18A1b0045)。
文摘Next-generation electronics that are fused into the human body can play a key role in future intelligent communication,smart healthcare,and human enhancement applications.As a promising energy supply component for smart biointegrated electronics,environment-adaptive electrochemical energy storage(EES)devices with complementary adaptability and functions have garnered huge interest in the past decade.Owing to the advancements in autonomous chemistry,which regulate the constitutional dynamic networks in materials,EES devices have witnessed higher freedom of autonomous adaptability in terms of mechano-adaptable,biocompatibility,and stimuli-response properties for biointegrated and smart applications.In this mini-review,we summarize the recent progress in emerging environmentadaptive EES devices enabled by the constitutional dynamic network of mechanical adaptable materials,biocompatible materials,and stimuli-responsive supramolecular polymer materials.Finally,the challenges and perspectives of autonomous chemistry on the environment-adaptive EES devices are discussed.
基金National Natural Science Foundation of China(Nos.52103334,52071053,and U1704253)China Postdoctoral Science Foundation(Nos.2020M680946 and 2020M670748)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT20GF111)Fundamental Research Funds of Shaanxi Key Laboratory of Artificially–Structured Functional Materials and Devices(No.AFMD–KFJJ–21102).
文摘Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and the lossless medium,it is difficult to achieve effective microwave absorption in a broad-band frequency range.Hence,an ultra-wideband metamaterial absorber(UWMA)composed of two mag-netic media and a metasurface was designed,and the absorption bandwidth of 2.9 to 18 GHz for 90%absorptivity under normal incidence was achieved,covering almost the entire S,C,X,and Ku bands.Through detailed investigation of equivalent circuit,equivalent medium theory,electromagnetic field dis-tribution and front-back interface interference,the internal physical working mechanism was clarified essentially.In addition,the multi-environment adaptabilities of the proposed absorber,including polariza-tion sensitivity,large angle incidence,dual-station radar stealth,bearing capacity and corrosion resistance,were analyzed.The proposed metamaterial absorber presents an effective way to achieve ultra-wideband absorption and compatibility with environmental adaptability,and provides a new way of thinking for intelligent full-band stealth technology.
基金The National Natural Science Foundation of China under contract Nos 22264003,42090041 and 42030502the Guangxi Natural Science Fund Project under contract Nos AD17129063,AA17204074 and 2018GXNSFAA281354the Innovation and Entrepreneurship Training Program of College Students from Guangxi University under contract Nos 202210593888 and202210593890。
文摘The chemical diversity of scleractinian corals is closely related to their physiological,ecological,and evolutionary status,and can be influenced by both genetic background and environmental variables.To investigate intraspecific variation in the metabolites of these corals,the metabolomes of four species(Pocillopora meandrina,Seriatopora hystrix,Acropora formosa,and Fungia fungites)from the South China Sea were analyzed using untargeted mass spectrometry-based metabolomics.The results showed that a variety of metabolites,including amino acids,peptides,lipids,and other small molecules,were differentially distributed among the four species,leading to their significant separation in principal component analysis and hierarchical clustering plots.The higher content of storage lipids in branching corals(P.meandrina,S.hystrix,and A.formosa)compared to the solitary coral(F.fungites)may be due to the high densities of zooxanthellae in their tissues.The high content of aromatic amino acids in P.meandrina may help the coral protect against ultraviolet damage and promote growth in shallow seawater,while nitrogen-rich compounds may enable S.hystrix to survive in various challenging environments.The metabolites enriched in F.fungites,including amino acids,dipeptides,phospholipids,and other small molecules,may be related to the composition of the coral's mucus and its life-history,such as its ability to move freely and live solitarily.Studying the chemical diversity of scleractinian corals not only provides insight into their environmental adaptation,but also holds potential for the chemotaxonomy of corals and the discovery of novel bioactive natural products.
基金China State Railway Group Co.,Ltd.(L2022G006)Chengdu Guojia Electrical Engineering Co.,Ltd.(NEEC-2022-A04)Natural Science Foundation of Sichuan Province(2022NSFSC1863).
文摘High-speed trains rely on pantograph-catenary systems(PCSs)to collect electrical energy from power systems.However,the dynamic interaction between the pantograph and the catenary system may become mismatched once ice accumulates on the overhead conductors.More frequent arcing may occur within the PCS during train operation,posing an unpredictable threat to operational safety.Therefore,it is crucial to evaluate the ability of overhead contact system(OCS)to withstand ice-covered variability during line desgin.A new strategy is proposed to evaluate the adaptive performance of an OCS under various icing conditions.First,a dynamic model considering icing conditions is constructed to simulate the interaction within the PCS.Five different OCS structures with various icing thicknesses are studied.The parameters of the contact force within the PCS and proportion of high-possibility arcing moments are obtained.The dependence of the contact force on the icing thickness and pantograph displacement has been illustrated in the form of cloud maps.Finally,the OCS sensitivity coefficient is calculated,and ice-covered environmental adaptability assessments for the five different OCS structures are compared.
文摘A quantitative and comprehensive method of product life cycle assessment(LCA) with fuzzy theory is developed, which will help designers to select the optimum design scheme for product life cycle design(LCD). Based on the theory of multiple attribute decision making, an algorithm of comprehensive and comparative evaluation for product environmental adaptability is presented. A program is built and used in an example of design improvement. The result shows that the proposed method and algorithm are practical and effective to the development of green products.
基金National Natural Science Foundation of China(No. 60375029)National Hi-tech Research and Development Program of China(863 Program,No.2006AA04Z254)
文摘A portable shape-shifting mobile robot system named as Amoeba Ⅱ(A-Ⅱ) is developed for the urban search and rescue application. It is designed with three degrees of freedom and two tracked drive systems. This robot consists of two modular mobile units and a joint unit. The mobile unit is a tracked mechanism to enforce the propulsion of robot. And the joint unit can transform the robot shape to get high environment adaptation. A-Ⅱ robot can not only adapt to the environment but also change its body shape according to the locus space. It behaves two work states including the linear state (named as I state) and the parallel state (named as Ⅱ state). With the linear state the robot can climb upstairs and go through narrow space such as the pipe, cave, etc. The parallel state enables the robot with high mobility on rough ground. Also, the joint unit can propel the robot to roll in sidewise direction. Two modular A-Ⅱ robots can be connected through jointing common interfaces on the joint unit to compose a stronger shape-shifting robot, which can transform the body into four wheels-driven vehicle. The experimental results validate the adaptation and mobility of A-Ⅱ robot.
基金This study was funded by Major Research Plan of the NSFC (No. 90511005), Major State Basic Research Development Program of China (973 Program, No. 2001CB409700-07).
文摘Based on the data of four seasonal marine surveys in the East China Sea (23°30′-33°N, 118°30′-128°E)during 1997-2000, the author studied the ecological characters of dominant Pteropoda species in the area. Results showed that there were five dominant Pteropoda species, more in summer, less in autumn and even in other seasons. These species, though belonging warm water species, can be categorized into two different groups in habitability. The first group was acicula, Desmopterus papilio and Creseis virgule, while adapted in summer and autumn, including Creseis the second group in winter and spring, represented by Limacina trochiformis and Agadina syimpsoni. The first group was more abundant than the second one. Besides, the first group contributed more to the Pteropoda abundance having higher occurrence frequency and aggregation intensity than the second. In horizontal distribution, the first group species reside in nearshore, and they could migrate to shallow place near estuary and aggregated in high density, while the second one was different: lower abundance, less occurred and aggregated because they were halophilic warm water species, and they were usually abundant in offshore area.
基金Supported by the Powerchina Chengdu Engineering Corporation Limited。
文摘Psilorhynchus homaloptera mainly inhabits turbulent waters in the lower reach of the Yarlung Zangbo River,Tibet,China,and it is the only species of Psilorhynchus in China.However,many important aspects of its biology remain poorly documented,which hinders the conservation eff orts.Therefore,we studied its reproduction using 801 specimens from the Motuo sector of the lower Yarlung Zangbo River from December 2015 to November 2016.The sex ratio was 0.68꞉1(male꞉female)for the overall population.Females reached a larger total length and weight(134 mm and 18.6 g)than males did(113 mm and 12.2 g).Lengths at maturity were estimated 80.0 mm for males and 93.1 mm for females.Our analyses of gonad development and the size distribution of oocytes suggest that P.homaloptera is a single spawner with the peak spawning period between September and October.Furthermore,the estimated mean absolute fecundity was 557±204 eggs per fish,and mean relative fecundity was 50.9±10.9 eggs per g of female weight.The fecundity of P.homaloptera increased linearly with increasing total length,total weight,ovary weight,and age.This study on the reproductive biology of P.homaloptera demonstrates that the fish was in a vulnerable state due to the increasing anthropogenic activities in the lower Yarlung Zangbo River.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174249 and 61475139)the National High Technology Research and Development Program of China(Grant No.2011AA060504)+1 种基金the National Basic Research Program of China(Grant No.2013CB329501)the Fundamental Research Funds for the Central Universities,China(Grant No.2016FZA3004)
文摘The cold atom gravimeter offers the prospect of a new generation of inertial sensors for field applications. We ac- complish a mobile atom gravimeter. With the compact and stable system, a sensitivity of 1.4× 10-7 g.Hz-1/2 is achieved. Moreover, a continuous gravity monitoring of 80 h is carried out. However, the harsh outdoor environment is a big challenge for the atom gravimeter when it is for field applications. In this paper, we present the preliminary investigation of the thermal adaptability for our mobile cold atom gravimeter. Here, we focus on the influence of the air temperature on the performance of the atom gravimeter. The responses to different factors (such as laser power, fiber coupling efficiency, etc.) are evaluated when there is a great temperature shift of 10 ℃. The result is that the performances of all the factors deteriorate to different extent, nevertheless, they can easily recover as the temperature comes back. Finally, we conclude that the variation of air temperature induces the increase of noise and the system error of the atom gravimeter as well, while the process is reversible with the recovery of the temperature.
基金The National Natural Science Foundation of China under contract Nos 31200097,41576187,U1406402-5 and31202024the Basic Scientific Fund for National Public Research Institutes of China under contract Nos 2013G33 and 2015G10
文摘Genus Pseudoalteromonas belongs to Family Pseudoalteromonadaceae in Gammaproteobacteria. A cold-adapted gram-negative bacterium, hydrocarbon-degrading Pseudoalteromonas sp. NJ289, was isolated from sea-ice of the Antarctica region, and sequenced the whole genome through the next generation sequencing platform. The assembly yielded three contigs representing two chromosomes and one plasmid with the sizes of 3.2 Mb, 636 kb and 1.8 kb, respectively. The G+C contents of genome were 40.83% and included 3 589 ORFs. Functional annotation indicated some potential roles in enzymatic activity and environmental adaptability. This study may help for understanding the population diverse, evolutionary ecology and the microbial interaction.