Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mec...Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mechanism of sex diff erentiation in fl ower development,we conducted the transcriptome profi les of male and female fl owers at early,metaphase and late developmental stages.Approximately 123,335 unigenes with a total length of 83,996 Mb and an average length of 168 bp were assembled.The unigenes were blasted into Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,GO databases.Homology analysis demonstrated that I.polycarpa and black cottonwood had the highest homology with the alignment of 92,871 sequences.This study identifi ed 80 groups of transcription factor families with a total of 1475 unigenes,mainly including MYB,WRKY,AP2 and bHLH transcription factor families.KEGG pathway analysis showed that the expression of numerous plant hormones(cytokinin,gibberellin and ethylene)and fl avonoid biosynthesis pathway were diff erent at various stages of female and male fl ower development.In addition,a number of unigenes associated with fl owering were identifi ed which were key genes associated with photoperiodic,vernalization,thermosensory,gibberellin,and autonomic pathways.The results show that I.polycarpa fl oral organ development was in accordance with the ABCDE model,in which the down-regulation of the B gene family might aff ect stamen fertility in late stages of female fl ower development.qRTPCR experiments validated that the expression patterns of 15 unigenes were consistent with those in RNA-seq results.The results highlight a central role for plant sex identifi cation in seedling production and a sex-determining mechanism for dioecious plants.In addition,the transcriptome data provided a theoretical basis for I.polycarpa genetic diversity analysis and molecular-assisted breeding.展开更多
During the historical period of securing a decisive victory in building a moderately prosperous society in all respects and striving for the great success of socialism with Chinese characteristics for a new era, the 1...During the historical period of securing a decisive victory in building a moderately prosperous society in all respects and striving for the great success of socialism with Chinese characteristics for a new era, the 19 th National Congress of the CPC put forward the signi cant deployment of rural vitalization strategy, drawing a great blueprint for the prospect of China's "three issues" of agriculture, rural areas, and farmers and acting as an important focus of these "three issues" in the future. This paper discussed the relationships between farmers' role di erentiation and ve objectives of the rural vitalization strategy on the basis of farmers' role di erentiation and conversion in the process of agriculture and countryside modernization and the interpretation of farmers' role di erentiation and the rural vitalization strategy. Based on the logical relationships between farmers' role di erentiation and the rural vitalization strategy, we discuss the e ective implementation of the rural vitalization strategy in terms of its targets, processes and e ectiveness evaluations. We also propose that the implementation of the rural vitalization strategy can only be implemented when farmers are given the rst priority as strategy subjects, farmers' wills are respected in the implementation process, and farmers' satisfaction is highlighted in the strategy implementation e ectiveness evaluations.展开更多
BACKGROUND:To investigate the eff ects of early standardized enteral nutrition(EN)on the crosssectional area of erector spine muscle(ESMcsa),plasma growth diff erentiation factor-15(GDF-15),and 28-day mortality of acu...BACKGROUND:To investigate the eff ects of early standardized enteral nutrition(EN)on the crosssectional area of erector spine muscle(ESMcsa),plasma growth diff erentiation factor-15(GDF-15),and 28-day mortality of acute exacerbation of chronic obstructive pulmonary disease(AECOPD)patients with invasive mechanical ventilation(MV).METHODS:A total of 97 AECOPD patients with invasive MV were screened in the ICUs of the First People's Hospital of Lianyungang.The conventional EN group(stage Ⅰ)and early standardized EN group(stage Ⅱ)included 46 and 51 patients,respectively.ESMcsa loss and GDF-15 levels on days 1 and 7 of ICU admission and 28-day survival rates were analyzed.RESULTS:On day 7,the ESMcsa of the early standardized EN group was significantly higher than that of the conventional EN group,while the plasma GDF-15 levels were significantly lower than those in the conventional EN group(ESMcsa:28.426±6.130 cm^(2) vs.25.205±6.127 cm^(2);GDF-15:1661.608±558.820 pg/mL vs.2541.000±634.845 pg/mL;all P<0.001).The 28-day survival rates of the patients in the early standardized EN group and conventional EN group were 80.40%and 73.90%,respectively(P=0.406).CONCLUSION:ESMcsa loss in AECOPD patients with MV was correlated with GDF-15 levels,both of which indicated acute muscular atrophy and skeletal muscle dysfunction.Early standardized EN may prevent acute muscle loss and intensive care unit-acquired weakness(ICU-AW)in AECOPD patients.展开更多
Static “self-optimising” control is an important concept, which provides a link between static optimisation and control. According to the concept, a dynamic control system could be configured in such a way that when...Static “self-optimising” control is an important concept, which provides a link between static optimisation and control. According to the concept, a dynamic control system could be configured in such a way that when a set of certain variables are maintained at their setpoints, the overall process operation is automatically optimal or near optimal at steady-state in the presence of disturbances. A novel approach using constrained gradient control to achieve “self-optimisation” has been proposed by Cao. However, for most process plants, the information required to get the gradient measure may not be available in real-time. In such cases, controlled variable selection has to be carried out based on measurable candidates. In this work, the idea of direct gradient control has been extended to controlled variable selection based on gradient sensitivity analysis (indirect gradient control). New criteria, which indicate the sensitivity of the gradient function to disturbances and implementation errors, have been derived for selection. The particular case study shows that the controlled variables selected by gradient sensitivity measures are able to achieve near optimal performance.展开更多
A number of high-temperature processes(e.g.,melt-rock reactions,metasomatism,partial melting)can produce signifi cant Ca isotopic fractionation and heterogeneity in the mantle,but the mechanism for such fractionation ...A number of high-temperature processes(e.g.,melt-rock reactions,metasomatism,partial melting)can produce signifi cant Ca isotopic fractionation and heterogeneity in the mantle,but the mechanism for such fractionation remains obscure.To investigate the eff ect of mantle partial melting on Ca isotopic fractionation,we reported high-precision Ca isotopic compositions of depleted mid-ocean ridge basalts(MORBs)from the East Pacifi c Rise and Ecuador Rift in the northeastern Pacifi c.Theδ44/40 Ca of these MORB samples exhibit a narrow variation from 0.84‰to 0.88‰with an average of 0.85‰±0.03‰,which are similar to those of reported MORBs(0.83‰±0.11‰)and back-arc basin basalts(BABBs,0.80‰±0.08‰)in literature,but are lower than the estimate value for the bulk silicate Earth(BSE,0.94‰±0.05‰).The lowδ44/40 Ca signatures of MORB samples in this study cannot be caused by fractional crystallization,since intermediate-mafi c diff erentiation has been demonstrated having only limited eff ects on Ca isotopic fractionation.Instead,the off set ofδ44/40 Ca between MORBs and the BSE is most likely produced by mantle partial melting.During this process,the light Ca isotopes are preferentially transferred to the melt,while the heavy ones tend to stay in the residue,which is consistent with the fact thatδ44/40 Ca of melt-depleted peridotites increases with partial melting in literature.The behavior of Ca isotopes during mantle partial melting is closely related to the inter-mineral(Cpx and Opx)Ca isotopic fractionation and melting mineral modes.Mantle partial melting is one of the common processes that can induce lowerδ44/40 Ca values in basalts and Ca isotopic heterogeneity in Earth’s mantle.展开更多
Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesi...Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesis, gametogenesis, fertilization and embryogenesis of I. sangumea, we developed fl owering regulation and control breeding. I. sangumea fl ower bud differentiation was observed in April for 21 days; in this stage, the early differentiation process was slow, temperature was more than 5 °C, if the temperature is shorter than this, most fl ower bud will have no differentiation, and turn to vegetative growth; later differentiation is faster and required temperature is from 5 to 8 °C and gradually rose to 10-12 °C. The temperature in April plays the defi nitely role in the number of bud differentiation. Three stamina contain tetrasporangiate anthers and a glandular tapetum. The anther wall is composed of four cell layers inclduding the epidermis, the endothecium, one middle layer and the secretory tapetum. The type of anther wall development the dicotyledonous type. After pollen maturation, the anther wall forms a double-layer containing only epidermis and endothecium. Simultaneous cytokinesis is of the continuous type during meiosis of microspore mother cell results in a zygomorphous or tetragonal tetrad. Mature pollen grains are two-celled. I. sangumea ’s stylar canal is hollow, open type style, and the gynoecium has three carpels. The ovaries have axial placentas. The ovule is anatropous, bitegmic and crassinucellate. The primary sporogenous cell differentiates directly as the megaspore. The megaspore tetrads are linear, T-shaped or juxtaposed. Generally, the fi rst of the tetrad megaspores at the chalaza becomes functional while the other three degenerate. A mature embryo sac with seven cells and eight nuclei embryo sac is of the polygonum type. For dichogamy, the male gametophyte matures about 2 days earlier than the female gametophyte. The pollen tube entered into the embryo sac for 22–24 h after pollination. The dormancy stage of fertilized ovules is 5-6 days, and the fusion of sperm and egg nucleus is of the premitotic type. The primary endosperm cell has shorter dormancy of 4-6 days, and endosperm formation is of the nuclear type.展开更多
Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one contro...Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.展开更多
Internet of Things （IoT） refers to an infrastructure which enables the forms of com- munication and collaboration between people and things, and between things themselves. In order to improve its performance, we pre...Internet of Things （IoT） refers to an infrastructure which enables the forms of com- munication and collaboration between people and things, and between things themselves. In order to improve its performance, we present a tradeoff between bandwidth and energy con- sumption in the loT in this paper. A service providing model is built to find the relation- ship between bandwidth and energy consump- tion using a cooperative differential game mo- del. The game solution is gotten in the condi- tion of grand coalition, feedback Nash equili- brium and intermediate coalitions and an allo- cation policy is obtain by Shapley theory. The results are shown as follows. Firstly, the per- formance of IoT decreases with the increasing of bandwidth cost or with the decreasing of en- ergy cost; secondly, all the nodes in the IoT com- posing a grand coalition can save bandwidth and energy consumption; thirdly, when the fac- tors of bandwidth cost and energy cost are eq- ual, the obtained number of provided services is an optimised value which is the trade-off between energy and bandwidth consumption.展开更多
The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iter...The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iteration algorithm for regional magnetic anomalies transformations to derive the vertical-component data from the total-field measurements with the variation in the core-fi eld direction over the region.Additionally,we use the same algorithm to convert the calculated vertical-component data into the corresponding data at the pole and realize the processing of diff erential reduction to the pole(DRTP).Unlike Arkani-Hamed’s DRTP method,the two types of iterative algorithms have the same forms,and DRTP is realized by implementing this algorithm twice.The synthetic model’s calculation results show that the method has high accuracy,and the fi eld data processing confi rms its practicality.展开更多
In this paper, we present a brief survey on the updated theory of backward stochas-tic Volterra integral equations （BSVIEs, for short）. BSVIEs are a natural generalization of backward stochastic diff erential equati...In this paper, we present a brief survey on the updated theory of backward stochas-tic Volterra integral equations （BSVIEs, for short）. BSVIEs are a natural generalization of backward stochastic diff erential equations （BSDEs, for short）. Some interesting motivations of studying BSVIEs are recalled. With proper solution concepts, it is possible to establish the corresponding well-posedness for BSVIEs. We also survey various comparison theorems for solutions to BSVIEs.展开更多
Larix olgensis A.Henry is a fast-growing tree used for aff orestation in northeastern China and has great ecological and economic value.For studying developmental genes in the xylem of this species,we investigated the...Larix olgensis A.Henry is a fast-growing tree used for aff orestation in northeastern China and has great ecological and economic value.For studying developmental genes in the xylem of this species,we investigated the Myb transcription factor family,one of the largest families of transcription factors in plants,which plays an important role in the regulation of lignifi cation in plant secondary walls.By sequencing a L.olgensis cDNA library using the Illumina HiSeq2500 high-throughput sequencing platform,we obtained 58,683 unigene sequences,of which 16,554 unigenes were longer than 1000 bp,accounting for 28.2%of the total database.The alignment of these genes with the GO,COG,KEGG,Swiss-Prot and NR databases resulted in annotated 29,350 unigenes.We obtained a total of 1460 differentially expressed genes,of which 453 were upregulated and 1007 were downregulated at the two developmental stages analyzed.The gene annotations showed a wide range of biological functions and metabolic pathways.The 10 Myb transcription factors that were obtained from the diff erentially expressed genes were analyzed by real-time quantitative PCR(qRT-PCR).The results showed that four Myb transcription factors may be associated with xylem development in L.olgensis.Due to the large genome size of conifers,genomics research on these species has lagged behind that for other plant groups.Our data provide the basis for further studies on xylem development in L.olgensis.展开更多
Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-c...Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-color formation has not been reported.Thus,the pigment composition and comparative transcriptome analyses of H.discus hannai with green and gray egg color were conducted using high-performance liquid chromatography(HPLC)and RNA-Seq methods.Results show that individuals with green and gray eggs both possess the fucoxanthin.Lutein existed in gray-egged individuals,but not in green-egged individuals.In transcriptome analysis,272310 unigenes were received from 461162 transcripts with a mean length of 985 bp and N50 of 1524 bp,respectively.A total of 185 unigenes were identifi ed as diff erentially expressed genes(DEGs).The DEGs involved in“fl avin-containing compound metabolic process”,“melanosome”,“glutathione metabolism”,and“cytochrome b6f complex”were likely related to the formation of the egg color.Our results provide foundational information for the functional analysis of egg-color related genes and are benefi cial to the selective breeding of H.discus hannai.展开更多
Coloration is an important phenotypic trait for multiple adaptive functions.It is interesting to fi nd white-eye(AW)and orange-eye(AO)phenotypes in the shrimp Alvinocaris longirostris inhabiting the deep-sea cold seep...Coloration is an important phenotypic trait for multiple adaptive functions.It is interesting to fi nd white-eye(AW)and orange-eye(AO)phenotypes in the shrimp Alvinocaris longirostris inhabiting the deep-sea cold seep and hydrothermal vent areas of the northwestern Pacifi c.By comparative transcriptome analyses,1491 diff erentially expressed genes(DEGs)were identified between AW and AO.Among them,many DEGs were associated with immunity,antioxidation,and detoxifi cation.Two signifi cant enzyme encoding genes,xanthine dehydrogenase,and tryptophan oxidase involved in pigment biosynthesis pathways were up-regulated in AW and AO,respectively,which might be related to the diff erences of white and orange eye phenotypes.Moreover,single nucleotide polymorphism(SNP)calling detected that genotypes of 28 SNP distributing in 14 unigenes were completely diff erent between AW and AO.Particularly,there were three and two non-synonymous mutations in immune genes crustin Pm5 and antimicrobial peptide,respectively.Results indicate that the diff erence in eye color is probably resulted from immune response to variable micro-environmental stressors encountered in the dispersal process of the shrimps,such as symbiotic microbes,pathogens,and toxic substances,and might be genetically fi xed at last.The suggested pathway preliminarily explained the formation mechanism of diff erent eye phenotypes in Alvinocaridid shrimps,providing a basis for further study on adaptive evolution of eyes in deep-sea chemosynthetic faunas.展开更多
We investigate the growth of solutions of the following complex linear di er-ential equation f″+A(z)f′+B(z)f=0,where A(z)and B(z)are analytic functions in -C-{z0},z0∈C.Some estimations of lower bounded of growth of...We investigate the growth of solutions of the following complex linear di er-ential equation f″+A(z)f′+B(z)f=0,where A(z)and B(z)are analytic functions in -C-{z0},z0∈C.Some estimations of lower bounded of growth of solutions of the di erential equation are obtained by using the concept of lower order.展开更多
The present paper is devoted to a preliminary study towards the establishment of an ergodic theory for stochastic di erential equations(SDEs)with less regular coecients and degenerate noises.These equations are often ...The present paper is devoted to a preliminary study towards the establishment of an ergodic theory for stochastic di erential equations(SDEs)with less regular coecients and degenerate noises.These equations are often derived as mesoscopic limits of complex or huge microscopic systems.By studying the associated Fokker-Planck equation(FPE),we prove the convergence of the time average of globally de ned weak solutions of such an SDE to the set of stationary measures of the FPE under Lyapunov conditions.In the case where the set of stationary measures consists of a single element,the unique stationary measure is shown to be physical.Similar convergence results for the solutions of the FPE are established as well.Some of our convergence results,while being special cases of those contained in Ji et al.(2019)for SDEs with periodic coecients,have weaken the required Lyapunov conditions and are of much simpli ed proofs.Applications to stochastic damping Hamiltonian systems and stochastic slow-fast systems are given.展开更多
Implicit-explicit Runge-Kutta-Rosenbrock methods are proposed to solve nonlinear sti ordinary di erential equations by combining linearly implicit Rosenbrock methods with explicit Runge-Kutta methods.First,the general...Implicit-explicit Runge-Kutta-Rosenbrock methods are proposed to solve nonlinear sti ordinary di erential equations by combining linearly implicit Rosenbrock methods with explicit Runge-Kutta methods.First,the general order conditions up to order 3 are obtained.Then,for the nonlinear sti initial-value problems satisfying the one-sided Lipschitz condition and a class of singularly perturbed initial-value problems,the corresponding errors of the implicit-explicit methods are analysed.At last,some numerical examples are given to verify the validity of the obtained theoretical results and the e ectiveness of the methods.展开更多
文摘Idesia polycarpa Maxim.var vestita Diels.is a dioecious tree species native to eastern Asia.There are diffi culties associated with distinguishing the sex of the plant at the seedling stage.In order to explore the mechanism of sex diff erentiation in fl ower development,we conducted the transcriptome profi les of male and female fl owers at early,metaphase and late developmental stages.Approximately 123,335 unigenes with a total length of 83,996 Mb and an average length of 168 bp were assembled.The unigenes were blasted into Nr,Nt,Pfam,KOG/COG,Swiss-prot,KEGG,GO databases.Homology analysis demonstrated that I.polycarpa and black cottonwood had the highest homology with the alignment of 92,871 sequences.This study identifi ed 80 groups of transcription factor families with a total of 1475 unigenes,mainly including MYB,WRKY,AP2 and bHLH transcription factor families.KEGG pathway analysis showed that the expression of numerous plant hormones(cytokinin,gibberellin and ethylene)and fl avonoid biosynthesis pathway were diff erent at various stages of female and male fl ower development.In addition,a number of unigenes associated with fl owering were identifi ed which were key genes associated with photoperiodic,vernalization,thermosensory,gibberellin,and autonomic pathways.The results show that I.polycarpa fl oral organ development was in accordance with the ABCDE model,in which the down-regulation of the B gene family might aff ect stamen fertility in late stages of female fl ower development.qRTPCR experiments validated that the expression patterns of 15 unigenes were consistent with those in RNA-seq results.The results highlight a central role for plant sex identifi cation in seedling production and a sex-determining mechanism for dioecious plants.In addition,the transcriptome data provided a theoretical basis for I.polycarpa genetic diversity analysis and molecular-assisted breeding.
基金“Study on Farmers’Participation in the Management of Field Irrigation System:Resource Endowment,Organization Support,and Governance Performance,”National Natural Science Foundation of China Project(Code:71773092)“Studies on the Weakness of Poverty of Rural Residents in Closely Grouped Areas,”Social Science Foundation of Ministry of Education Project(Code:17YJA790102)
文摘During the historical period of securing a decisive victory in building a moderately prosperous society in all respects and striving for the great success of socialism with Chinese characteristics for a new era, the 19 th National Congress of the CPC put forward the signi cant deployment of rural vitalization strategy, drawing a great blueprint for the prospect of China's "three issues" of agriculture, rural areas, and farmers and acting as an important focus of these "three issues" in the future. This paper discussed the relationships between farmers' role di erentiation and ve objectives of the rural vitalization strategy on the basis of farmers' role di erentiation and conversion in the process of agriculture and countryside modernization and the interpretation of farmers' role di erentiation and the rural vitalization strategy. Based on the logical relationships between farmers' role di erentiation and the rural vitalization strategy, we discuss the e ective implementation of the rural vitalization strategy in terms of its targets, processes and e ectiveness evaluations. We also propose that the implementation of the rural vitalization strategy can only be implemented when farmers are given the rst priority as strategy subjects, farmers' wills are respected in the implementation process, and farmers' satisfaction is highlighted in the strategy implementation e ectiveness evaluations.
基金funded by the Social Development Project of Jiangsu Provincial Department of Science and Technology(BE2020670)the Social Development Project of Lianyungang Science and Technology(SF2117).
文摘BACKGROUND:To investigate the eff ects of early standardized enteral nutrition(EN)on the crosssectional area of erector spine muscle(ESMcsa),plasma growth diff erentiation factor-15(GDF-15),and 28-day mortality of acute exacerbation of chronic obstructive pulmonary disease(AECOPD)patients with invasive mechanical ventilation(MV).METHODS:A total of 97 AECOPD patients with invasive MV were screened in the ICUs of the First People's Hospital of Lianyungang.The conventional EN group(stage Ⅰ)and early standardized EN group(stage Ⅱ)included 46 and 51 patients,respectively.ESMcsa loss and GDF-15 levels on days 1 and 7 of ICU admission and 28-day survival rates were analyzed.RESULTS:On day 7,the ESMcsa of the early standardized EN group was significantly higher than that of the conventional EN group,while the plasma GDF-15 levels were significantly lower than those in the conventional EN group(ESMcsa:28.426±6.130 cm^(2) vs.25.205±6.127 cm^(2);GDF-15:1661.608±558.820 pg/mL vs.2541.000±634.845 pg/mL;all P<0.001).The 28-day survival rates of the patients in the early standardized EN group and conventional EN group were 80.40%and 73.90%,respectively(P=0.406).CONCLUSION:ESMcsa loss in AECOPD patients with MV was correlated with GDF-15 levels,both of which indicated acute muscular atrophy and skeletal muscle dysfunction.Early standardized EN may prevent acute muscle loss and intensive care unit-acquired weakness(ICU-AW)in AECOPD patients.
基金supported by the EPSRC UK under grant GR/R57324.
文摘Static “self-optimising” control is an important concept, which provides a link between static optimisation and control. According to the concept, a dynamic control system could be configured in such a way that when a set of certain variables are maintained at their setpoints, the overall process operation is automatically optimal or near optimal at steady-state in the presence of disturbances. A novel approach using constrained gradient control to achieve “self-optimisation” has been proposed by Cao. However, for most process plants, the information required to get the gradient measure may not be available in real-time. In such cases, controlled variable selection has to be carried out based on measurable candidates. In this work, the idea of direct gradient control has been extended to controlled variable selection based on gradient sensitivity analysis (indirect gradient control). New criteria, which indicate the sensitivity of the gradient function to disturbances and implementation errors, have been derived for selection. The particular case study shows that the controlled variables selected by gradient sensitivity measures are able to achieve near optimal performance.
基金Supported by the National Natural Science Foundation of China(Nos.41773009,41873002)the Stake Key Laboratory of Geological Processes and Mineral Resources(No.GPMR201708)+2 种基金the National Science Foundation for Post-doctoral Scientists of China(No.2018M640660)the Taishan Scholar Program of Shandong(No.TS201712075)the AoShan Talents Cultivation Program Supported by Qingdao National Laboratory for Marine Science and Technology(No.2017ASTCP-OS07)。
文摘A number of high-temperature processes(e.g.,melt-rock reactions,metasomatism,partial melting)can produce signifi cant Ca isotopic fractionation and heterogeneity in the mantle,but the mechanism for such fractionation remains obscure.To investigate the eff ect of mantle partial melting on Ca isotopic fractionation,we reported high-precision Ca isotopic compositions of depleted mid-ocean ridge basalts(MORBs)from the East Pacifi c Rise and Ecuador Rift in the northeastern Pacifi c.Theδ44/40 Ca of these MORB samples exhibit a narrow variation from 0.84‰to 0.88‰with an average of 0.85‰±0.03‰,which are similar to those of reported MORBs(0.83‰±0.11‰)and back-arc basin basalts(BABBs,0.80‰±0.08‰)in literature,but are lower than the estimate value for the bulk silicate Earth(BSE,0.94‰±0.05‰).The lowδ44/40 Ca signatures of MORB samples in this study cannot be caused by fractional crystallization,since intermediate-mafi c diff erentiation has been demonstrated having only limited eff ects on Ca isotopic fractionation.Instead,the off set ofδ44/40 Ca between MORBs and the BSE is most likely produced by mantle partial melting.During this process,the light Ca isotopes are preferentially transferred to the melt,while the heavy ones tend to stay in the residue,which is consistent with the fact thatδ44/40 Ca of melt-depleted peridotites increases with partial melting in literature.The behavior of Ca isotopes during mantle partial melting is closely related to the inter-mineral(Cpx and Opx)Ca isotopic fractionation and melting mineral modes.Mantle partial melting is one of the common processes that can induce lowerδ44/40 Ca values in basalts and Ca isotopic heterogeneity in Earth’s mantle.
基金supported by the National Natural Science Foundation of China(No.31670344)the Fundamental Research Funds for the Central Universities(2572019DF08)
文摘Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesis, gametogenesis, fertilization and embryogenesis of I. sangumea, we developed fl owering regulation and control breeding. I. sangumea fl ower bud differentiation was observed in April for 21 days; in this stage, the early differentiation process was slow, temperature was more than 5 °C, if the temperature is shorter than this, most fl ower bud will have no differentiation, and turn to vegetative growth; later differentiation is faster and required temperature is from 5 to 8 °C and gradually rose to 10-12 °C. The temperature in April plays the defi nitely role in the number of bud differentiation. Three stamina contain tetrasporangiate anthers and a glandular tapetum. The anther wall is composed of four cell layers inclduding the epidermis, the endothecium, one middle layer and the secretory tapetum. The type of anther wall development the dicotyledonous type. After pollen maturation, the anther wall forms a double-layer containing only epidermis and endothecium. Simultaneous cytokinesis is of the continuous type during meiosis of microspore mother cell results in a zygomorphous or tetragonal tetrad. Mature pollen grains are two-celled. I. sangumea ’s stylar canal is hollow, open type style, and the gynoecium has three carpels. The ovaries have axial placentas. The ovule is anatropous, bitegmic and crassinucellate. The primary sporogenous cell differentiates directly as the megaspore. The megaspore tetrads are linear, T-shaped or juxtaposed. Generally, the fi rst of the tetrad megaspores at the chalaza becomes functional while the other three degenerate. A mature embryo sac with seven cells and eight nuclei embryo sac is of the polygonum type. For dichogamy, the male gametophyte matures about 2 days earlier than the female gametophyte. The pollen tube entered into the embryo sac for 22–24 h after pollination. The dormancy stage of fertilized ovules is 5-6 days, and the fusion of sperm and egg nucleus is of the premitotic type. The primary endosperm cell has shorter dormancy of 4-6 days, and endosperm formation is of the nuclear type.
基金National Natural Science Foundation of China(Grant No.51505178)China Postdoctoral Science Foundation(Grant No.2014M561289)
文摘Di erential braking and active steering have already been integrated to overcome their shortcomings. However, existing research mainly focuses on two-axle vehicles and controllers are mostly designed to use one control method to improve the other. Moreover, many experiments are needed to improve the robustness; therefore, these control methods are underutilized. This paper proposes an integrated control system specially designed for multi-axle vehicles, in which the desired lateral force and yaw moment of vehicles are determined by the sliding mode control algorithm. The output of the sliding mode control is distributed to the suitable wheels based on the abilities and potentials of the two control methods. Moreover, in this method, fewer experiments are needed, and the robustness and simultaneity are both guaranteed. To simplify the optimization system and to improve the computation speed, seven simple optimization subsystems are designed for the determination of control outputs on each wheel. The simulation results show that the proposed controller obviously enhances the stability of multi-axle trucks. The system improves 68% of the safe velocity, and its performance is much better than both di erential braking and active steering. This research proposes an integrated control system that can simultaneously invoke di erential braking and active steering of multi-axle vehicles to fully utilize the abilities and potentials of the two control methods.
基金ACKNOWLEDGEMENT We gratefully acknowledge anonymous revie- wers who read drafts and made many helpful suggestions. This work was supported by the National Natural Science Foundation of China under Grant No. 61202079 the China Post- doctoral Science Foundation under Grant No. 2013M530526+2 种基金 the Foundation of Beijing En- gineering the Fundamental Research Funds for the Central Universities under Grant No. FRF-TP-13-015A and the Technology Centre for Convergence Networks and Ubiquitous Services.
文摘Internet of Things （IoT） refers to an infrastructure which enables the forms of com- munication and collaboration between people and things, and between things themselves. In order to improve its performance, we present a tradeoff between bandwidth and energy con- sumption in the loT in this paper. A service providing model is built to find the relation- ship between bandwidth and energy consump- tion using a cooperative differential game mo- del. The game solution is gotten in the condi- tion of grand coalition, feedback Nash equili- brium and intermediate coalitions and an allo- cation policy is obtain by Shapley theory. The results are shown as follows. Firstly, the per- formance of IoT decreases with the increasing of bandwidth cost or with the decreasing of en- ergy cost; secondly, all the nodes in the IoT com- posing a grand coalition can save bandwidth and energy consumption; thirdly, when the fac- tors of bandwidth cost and energy cost are eq- ual, the obtained number of provided services is an optimised value which is the trade-off between energy and bandwidth consumption.
基金supported by the National Key R&D Program of China (No. 2017YFC0602000)the China Geological Survey Project (Nos. DD20191001 and DD20189410)。
文摘The vector transformation and pole reduction from the total-field anomaly are signifi cant for the interpretation.We examined these industry-standard processing procedures in the Fourier domain.We propose a novel iteration algorithm for regional magnetic anomalies transformations to derive the vertical-component data from the total-field measurements with the variation in the core-fi eld direction over the region.Additionally,we use the same algorithm to convert the calculated vertical-component data into the corresponding data at the pole and realize the processing of diff erential reduction to the pole(DRTP).Unlike Arkani-Hamed’s DRTP method,the two types of iterative algorithms have the same forms,and DRTP is realized by implementing this algorithm twice.The synthetic model’s calculation results show that the method has high accuracy,and the fi eld data processing confi rms its practicality.
文摘In this paper, we present a brief survey on the updated theory of backward stochas-tic Volterra integral equations （BSVIEs, for short）. BSVIEs are a natural generalization of backward stochastic diff erential equations （BSDEs, for short）. Some interesting motivations of studying BSVIEs are recalled. With proper solution concepts, it is possible to establish the corresponding well-posedness for BSVIEs. We also survey various comparison theorems for solutions to BSVIEs.
文摘Larix olgensis A.Henry is a fast-growing tree used for aff orestation in northeastern China and has great ecological and economic value.For studying developmental genes in the xylem of this species,we investigated the Myb transcription factor family,one of the largest families of transcription factors in plants,which plays an important role in the regulation of lignifi cation in plant secondary walls.By sequencing a L.olgensis cDNA library using the Illumina HiSeq2500 high-throughput sequencing platform,we obtained 58,683 unigene sequences,of which 16,554 unigenes were longer than 1000 bp,accounting for 28.2%of the total database.The alignment of these genes with the GO,COG,KEGG,Swiss-Prot and NR databases resulted in annotated 29,350 unigenes.We obtained a total of 1460 differentially expressed genes,of which 453 were upregulated and 1007 were downregulated at the two developmental stages analyzed.The gene annotations showed a wide range of biological functions and metabolic pathways.The 10 Myb transcription factors that were obtained from the diff erentially expressed genes were analyzed by real-time quantitative PCR(qRT-PCR).The results showed that four Myb transcription factors may be associated with xylem development in L.olgensis.Due to the large genome size of conifers,genomics research on these species has lagged behind that for other plant groups.Our data provide the basis for further studies on xylem development in L.olgensis.
基金Supported by the Seed Improvement Project of Shandong Province of China(No.2017LZGC009)the Major Scientifi c and Technological Innovation Project of Shandong Provincial Key Research and Development Program(No.2019JZZY020706)。
文摘Haliotis discus hannai is an important marine economic species in China.Its egg color was found to be associated with economic traits,which provides a new idea for breeding.However,the molecular mechanism of the egg-color formation has not been reported.Thus,the pigment composition and comparative transcriptome analyses of H.discus hannai with green and gray egg color were conducted using high-performance liquid chromatography(HPLC)and RNA-Seq methods.Results show that individuals with green and gray eggs both possess the fucoxanthin.Lutein existed in gray-egged individuals,but not in green-egged individuals.In transcriptome analysis,272310 unigenes were received from 461162 transcripts with a mean length of 985 bp and N50 of 1524 bp,respectively.A total of 185 unigenes were identifi ed as diff erentially expressed genes(DEGs).The DEGs involved in“fl avin-containing compound metabolic process”,“melanosome”,“glutathione metabolism”,and“cytochrome b6f complex”were likely related to the formation of the egg color.Our results provide foundational information for the functional analysis of egg-color related genes and are benefi cial to the selective breeding of H.discus hannai.
基金Supported by the National Key R&D Program of China(No.2018YFC0310802)the National Natural Science Foundation of China(No.31872215)+2 种基金the Senior User Project of R/V Kexue(No.KEXUE2019GZ02)the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(No.XDA22050302)the Key Research Program of Frontier Sciences,CAS(No.QYZDB-SSW-DQC036)。
文摘Coloration is an important phenotypic trait for multiple adaptive functions.It is interesting to fi nd white-eye(AW)and orange-eye(AO)phenotypes in the shrimp Alvinocaris longirostris inhabiting the deep-sea cold seep and hydrothermal vent areas of the northwestern Pacifi c.By comparative transcriptome analyses,1491 diff erentially expressed genes(DEGs)were identified between AW and AO.Among them,many DEGs were associated with immunity,antioxidation,and detoxifi cation.Two signifi cant enzyme encoding genes,xanthine dehydrogenase,and tryptophan oxidase involved in pigment biosynthesis pathways were up-regulated in AW and AO,respectively,which might be related to the diff erences of white and orange eye phenotypes.Moreover,single nucleotide polymorphism(SNP)calling detected that genotypes of 28 SNP distributing in 14 unigenes were completely diff erent between AW and AO.Particularly,there were three and two non-synonymous mutations in immune genes crustin Pm5 and antimicrobial peptide,respectively.Results indicate that the diff erence in eye color is probably resulted from immune response to variable micro-environmental stressors encountered in the dispersal process of the shrimps,such as symbiotic microbes,pathogens,and toxic substances,and might be genetically fi xed at last.The suggested pathway preliminarily explained the formation mechanism of diff erent eye phenotypes in Alvinocaridid shrimps,providing a basis for further study on adaptive evolution of eyes in deep-sea chemosynthetic faunas.
基金National Natural Science Foundation of China(11861023)the Foundation of Science and Technology project of Guizhou Province of China([2018]5769-05)。
文摘We investigate the growth of solutions of the following complex linear di er-ential equation f″+A(z)f′+B(z)f=0,where A(z)and B(z)are analytic functions in -C-{z0},z0∈C.Some estimations of lower bounded of growth of solutions of the di erential equation are obtained by using the concept of lower order.
基金The first author was supported by China Scholarship Council.The second author was supported by University of Alberta,and Natural Sciences and Engineering Research Council of Canada(Grant Nos.RGPIN-2018-04371 and DGECR-2018-00353)The third author was supported by Pacific Institute for the Mathematical Sciences-Canadian Statistical Sciences Institute Postdoctoral Fellowship,Pacific Institute for the Mathematical Sciences-Collaborative Research Group Grant,National Natural Science Foundation of China(Grant Nos.11771026 and 11471344)+2 种基金the Pacific Institute for the Mathematical Sciences-University of Washington site through National Science Foundation of USA(Grant No.DMS-1712701)The fourth author was supported by Natural Sciences and Engineering Research Council of Canada Discovery(Grant No.1257749)Pacific Institute for the Mathematical Sciences-Collaborative Research Group Grant,University of Alberta,and Jilin University.
文摘The present paper is devoted to a preliminary study towards the establishment of an ergodic theory for stochastic di erential equations(SDEs)with less regular coecients and degenerate noises.These equations are often derived as mesoscopic limits of complex or huge microscopic systems.By studying the associated Fokker-Planck equation(FPE),we prove the convergence of the time average of globally de ned weak solutions of such an SDE to the set of stationary measures of the FPE under Lyapunov conditions.In the case where the set of stationary measures consists of a single element,the unique stationary measure is shown to be physical.Similar convergence results for the solutions of the FPE are established as well.Some of our convergence results,while being special cases of those contained in Ji et al.(2019)for SDEs with periodic coecients,have weaken the required Lyapunov conditions and are of much simpli ed proofs.Applications to stochastic damping Hamiltonian systems and stochastic slow-fast systems are given.
基金The authors wish to thank the anonymous referees for their valuable comments and suggestions.The work is supported by the National Natural Science Foundation of China(Grant Nos.11671343,11701110)the Foundation for the Key Laboratory of Computational Physics,China(No.6142A05180103)the Scientific Research Fund of Science and Technology Department of Hunan Province in China(Grant No.2018WK4006).
文摘Implicit-explicit Runge-Kutta-Rosenbrock methods are proposed to solve nonlinear sti ordinary di erential equations by combining linearly implicit Rosenbrock methods with explicit Runge-Kutta methods.First,the general order conditions up to order 3 are obtained.Then,for the nonlinear sti initial-value problems satisfying the one-sided Lipschitz condition and a class of singularly perturbed initial-value problems,the corresponding errors of the implicit-explicit methods are analysed.At last,some numerical examples are given to verify the validity of the obtained theoretical results and the e ectiveness of the methods.
