The regulation of ferrocene-based catalysts on heat transfer in highpressure combustion of ammonium perchlorate/hydroxyl-terminated polybutadiene/aluminum composite propellants

The regulation of the burning rate pressure exponent for the ammonium perchlorate/hydroxylterminated polybutadiene/aluminum(AP/HTPB/Al)composite propellants under high pressures is a crucial step for its application in high-pressure solid rocket motors.In this work,the combustion characteristics of AP/HTPB/Al composite propellants containing ferrocene-based catalysts were investigated,including the burning rate,thermal behavior,the local heat transfer,and temperature profile in the range of 7-28 MPa.The results showed that the exponent breaks were still observed in the propellants after the addition of positive catalysts(Ce-Fc-MOF),the burning rate inhibitor((Ferrocenylmethyl)trimethylammonium bromide,Fc Br)and the mixture of Fc Br/catocene(GFP).However,the characteristic pressure has increased,and the exponent decreased from 1.14 to 0.66,0.55,and 0.48 when the addition of Ce-FcMOF,Fc Br and Fc Br/GFP in the propellants.In addition,the temperature in the first decomposition stage was increased by 7.50℃ and 11.40℃ for the AP/Fc Br mixture and the AP/Fc Br/GFP mixture,respectively,compared to the pure AP.On the other hand,the temperature in the second decomposition stage decreased by 48.30℃ and 81.70℃ for AP/Fc Br and AP/Fc Br/GFP mixtures,respectively.It was also found that Fc Br might generate ammonia to cover the AP surface.In this case,a reaction between the methyl in Fc Br and perchloric acid caused more ammonia to appear at the AP surface,resulting in the suppression of ammonia desorption.In addition,the coarse AP particles on the quenched surface were of a concave shape relative to the binder matrix under low and high pressures when the catalysts were added.In the process,the decline at the AP/HTPB interface was only exhibited in the propellant with the addition of Ce-Fc-MOF.The ratio of the gas-phase temperature gradient of the propellants containing catalysts was reduced significantly below and above the characteristic pressure,rather than 3.6 times of the difference in the blank propellant.Overall,the obtained results demonstrated that the pressure exponent could be effectively regulated and controlled by adjusting the propellant local heat and mass transfer under high and low pressures.

Preparation of lactic acid bacteria compound starter cultures based on pasting properties and its improvement of glutinous rice flour and dough

The effects of 5 lactic acid bacteria(LAB)fermentation on the pasting properties of glutinous rice flour were compared,and suitable fermentation strains were selected based on the changes of viscosity,setback value,and breakdown value to prepare LAB compound starter cultures.The results revealed that Latilactobacillus sakei HSD004 and Lacticaseibacillus rhamnosus HSD005 had apparent advantages in increasing the viscosity and reducing the setback and breakdown values of glutinous rice flour.In particular,the compound starter created using the two abovementioned LAB in the ratio of 3:1 had better performance than that using a single LAB in improving the pasting properties and increasing the water and oil absorption capacity of glutinous rice flour.Moreover,the gelatinization enthalpy of the fermented samples increased significantly.For frozen glutinous rice dough stored for 28 days,the viscoelasticity of frozen dough prepared by compound starter was better than that of control dough,and the freezable water content was lower than that of control dough.These results indicate that compound LAB fermentation is a promising technology in the glutinous rice-based food processing industry,which has significance for its application.

Synthesis of flexible inter-plant heat exchanger networks:A decomposition method considering intermedium fluid circles

The traditional methods for synthesizing flexible heat exchanger networks(HENs)are not directly applicable to inter-plant HEN challenges,primarily due to the spread of system uncertainty across plants via intermedium fluid circles.This complicates the synthesis process significantly.To tackle this issue,this study proposes a decomposed stepwise methodology to facilitate the flexible synthesis of the interplant HENs performing indirect heat integration.A decomposition strategy is proposed to divide the overall network into manageable sub-networks by dissecting the intermedium fluid circles.To address the variability in intermedium fluid temperatures,a temperature fluctuation analysis approach is developed and a heuristic rule is introduced to maintain the temperature feasibility of the intermedium fluids.To ensure adequate flexibility and cost-effectiveness of the designed networks,flexibility analysis and network retrofit steps are conducted through model-based optimization techniques.The efficacy of the method is demonstrated through two case studies,showing its potential in achieving the desired operational flexibility for inter-plant HENs.

法医学专业本科生科研素养与创新能力培养的思考和实践路径探索

法医学专业本科生科研素养与创新能力的培养是当前司法改革与发展的需要,也是我国教育教学改革的要求。近年来,法医学专业本科生科研素养与创新能力的培养取得了一定的成效,但仍然存在很多问题。本文从法医学专业本科生科研素养与创新能力培养的现状入手,分析我国法医学人才培养面临的挑战,提出促进法医学专业本科生科研素养与创新能力培养的实践路径,不断优化和完善人才培养体系,为法医学专业本科生科研素养与创新能力的培养提供借鉴,以期为法治社会培养出更多高素质应用型的法医学拔尖创新人才。

突发公共卫生事件中风险信息对公众情绪的唤醒机制——基于新冠肺炎疫情的实证研究

本文基于“信息框架—风险感知—情绪唤醒—信息行为”模型,以社会化媒体为公众信息接触的载体环境,对新冠肺炎疫情暴发早期的风险信息如何唤醒公众情绪展开研究,以期为突发公共卫生事件的舆情疏导、秩序维持提供实证参考。研究发现,新冠肺炎疫情信息主要采用的指导、后果与缓解三类框架会差异化地激活能量与紧张两种情绪唤醒机制,受信息框架影响的公众对新冠肺炎疫情的风险感知在此过程中发挥中介作用。在情绪唤醒之下,公众的后续信息行为也会发生变化:能量唤醒能够促进公众的信息转发行为,而紧张唤醒则会显著激发公众通过原创发言进行情绪分享的意愿。

情感驱动的实践——城市居民绿色低碳行为促进机制的ARI模型检验

本文以“情感—理性—卷入度”模型为基础,面向城市居民检验绿色低碳信息对提升其绿色低碳行为态度与行为水平的作用路径和效果,以期为引导公众践行绿色低碳行为、构建绿色低碳生活方式的信息传播与社会倡导优化提供实证参考。研究发现,政策与知识信息、行动反馈信息与社交示范信息等三类关键的绿色低碳信息主要通过激发个体生成积极正面的情感体验,改善公众对绿色低碳行为的态度。基于理性与情感两种认知机制形成的公众对信息质量的评价在此过程中发挥中介作用。绿色低碳行为态度的提升会促进公众践行绿色低碳行为,私人领域的绿色低碳实践还会促进公众在公共领域中参与更广泛的绿色低碳行动。

信迪利单抗致肺癌患者免疫性血小板减少1例并文献复习

免疫检查点抑制剂(immune checkpoint inhibitors,ICIs)在肺癌的治疗中显示出独特优势,使肺癌的治疗进入了免疫治疗时代,但是ICIs也会出现不良反应,免疫治疗导致的血液系统毒性发病率并不是很高,其中免疫治疗导致的血小板减少是一种罕见的不良反应。我们报道1例使用ICIs导致血小板减少患者的病例资料,并对ICIs相关血小板减少进行文献复习,讨论相关临床特点、可能的机制及最佳治疗方式。

Maintenance of mesophyll potassium and regulation of plasma membrane H^+-ATPase are associated with physiological responses of tea plants to drought and subsequent rehydration

Drought stress is one of the main factors limiting yield in tea plants. The plant cell's ability to preserve K^+homeostasis is an important strategy for coping with drought stress. Plasma membrane H^+-ATPase in the mesophyll cell is important for maintaining membrane potential to regulate K^+transmembrane transport. However, no research to date has investigated the possible relationship between plasma membrane H^+-ATPase and mesophyll K^+retention in tea plants under drought and subsequent rehydration conditions. In our experiment, drought stress inhibited plasma membrane H^+-ATPase activities and induced net H^+influx, leading to membrane potential depolarization and inducing a massive K^+efflux in tea plant mesophyll cells. Subsequent rehydration increased plasma membrane H^+-ATPase activity and induced net H^+efflux, leading to membrane potential hyperpolarization and thus lowering K^+loss. A first downregulated and then upregulated plasma membrane H^+-ATPase protein expression level was also observed under drought and subsequent rehydration treatment, a finding in agreement with the change of measured plasma membrane H^+-ATPase activities. Taken together, our results suggest that maintenance of mesophyll K^+in tea plants under drought and rehydration is associated with regulation of plasma membrane H^+-ATPase activity.

Heat exchanger network synthesis integrated with flexibility and controllability

Over the last three decades,flexibility and controllability considerations for heat exchanger networks(HENs)have received great attention,respectively.However,they should be simultaneously incorporated in HEN synthesis to allow the economic performance to be achievable in a practical operating environment.This paper proposes a method for simultaneous synthesis of flexible and controllable HEN by considering their coupling.The key idea is to add the bypasses with optimized initial fractions and positions to explore such coupling,and consequently enabling HENs to be operated successfully over a range of disturbance variations.These are implemented by identifying and quantifying disturbance propagations,and then examining the sensitivity of bypasses to the entire HEN.In this way,the superstructurebased mixed integer non-linear programming(MINLP)with objective function of minimizing the total annual cost is formulated.A case study is used to demonstrate the application of the proposed method.Quantitative measures and dynamic simulation show the ability to provide the satisfactory flexibility and controllability of the obtained HEN.

GOLDEN 2-LIKE transcription factors regulate chlorophyll biosynthesis and flavonoid accumulation in response to UV-B in tea plants

Flavonoids are critical secondary metabolites that determine the health benefits and flavor of tea,while chlorophylls are important contributors to the appearance of tea.However,transcription factors(TFs)that can integrate both chlorophyll biosynthesis and flavonoid accumulation in response to specific light signals are rarely identified.In this study,we report that the GOLDEN 2-LIKE TF pair,CsGLK1 and CsGLK2,orchestrate UV-B-induced responses in the chlorophyll biosynthesis and flavonoid accumulation of tea leaves.The absence of solar UV-B reduced the transcriptional expression of CsGLKs in the tea leaves and was highly correlated with a decrease in flavonoid levels(especially flavonol glycosides)and the expression of genes and TFs involved in chlorophyll biosynthesis and flavonoid accumulation.In vivo and in vitro molecular analyses showed that CsGLKs could be regulated by the UV-B signal mediator CsHY5,and could directly bind to the promoters of gene and TF involved in light-harvesting(CsLhcb),chlorophyll biosynthesis(CsCHLH,CsHEMA1,and CsPORA),and flavonoid accumulation(CsMYB12,CsFLSa,CsDFRa,and CsLARa),eventually leading to UV-B-induced responses in the chlorophylls and flavonoids of tea leaves.Furthermore,UV-B exposure increased the levels of total flavonoids,CsGLK1 protein,and expression of CsGLKs and target genes in the tea leaves.These results indicate that CsGLKs may modulate tea leaf characteristics by regulating chlorophyll biosynthesis and flavonoid accumulation in response to solar UV-B.As the first report on UV-B-induced changes in flavonoid and chlorophyll regulation mediated by CsGLKs,this study improves our understanding of the environmental regulations regarding tea quality and sheds new light on UV-B-induced flavonoid responses in higher plants.

Synthesis of indirect work exchange networks considering both isothermal and adiabatic process together with exergy analysis

In this paper, an efficient methodology for synthesizing the indirect work exchange networks(WEN) considering isothermal process and adiabatic process respectively based on transshipment model is first proposed. In contrast with superstructure method, the transshipment model is easier to obtain the minimum utility consumption taken as the objective function and more convenient for us to attain the optimal network configuration for further minimizing the number of units. Different from division of temperature intervals in heat exchange networks,different pressure intervals are gained according to the maximum compression/expansion ratio in consideration of operating principles of indirect work exchangers and the characteristics of no pressure constraints for stream matches. The presented approach for WEN synthesis is a linear programming model applied to the isothermal process, but for indirect work exchange networks with adiabatic process, a nonlinear programming model needs establishing. Additionally, temperatures should be regarded as decision variables limited to the range between inlet and outlet temperatures in each sub-network. The constructed transshipment model can be solved first to get the minimum utility consumption and further to determine the minimum number of units by merging the adjacent pressure intervals on the basis of the proposed merging methods, which is proved to be effective through exergy analysis at the level of units structures. Finally, two cases are calculated to confirm it is dramatically feasible and effective that the optimal WEN configuration can be gained by the proposed method.

Research Progress on the Mechanism of Plant Disease Resistance Regulated by NPR1

NPR1 is an intersection of different disease resistance pathways and plays a key role in systemic-acquired resistance and induced systemic resistance. NPR1 regulates constitutive resistance and disease resistance determined by resistant genes. In this paper, the mechanism of disease resistance of NPR1 genes and its analogs were described. The research status and progress of NPR1 transgenic crops were systematically discussed. The application prospect of NPR1 transgenic crops was also forecasted.

Step-wise synthesis of work exchange networks involving heat integration based on the transshipment model

Due to the deterioration of serious energy dilemma,energy-conservation and emission–reduction have been the strategic target in the past decades,thus people have identified the vital importance of higher energy efficiency and the influence of lower carbon development.Since work exchange network is a significant part of energy recovery system,its optima design will have dramatically significant effect on energy consumption reduction in chemical process system.With an extension of the developed transshipment model in isothermal process,a novel step-wise methodology for synthesis of direct work exchange network(WEN)in adiabatic process involving heat integration is first proposed in this paper,where a nonlinear programming(NLP)model is formulated by regarding the minimum utility consumption as objective function and optimizing the initial WEN in accordance with the presented matching rules to get the optimized WEN configuration at first.Furthermore,we focus on the work exchange network synthesis with heat integration to attain the minimal total annual cost(TAC)with the introduction of heat-exchange equipment that is achieved by the following strategies in sequence:introducing heat-exchange equipment directly,adjusting the work quantity of the adjacent utility compressors or expanders,and approximating upper/lower pressure limits consequently to obtain considerable cost savings of expanders or compressors and work utility.Finally,a case taken from the literature is studied to illustrate the feasibility and effectiveness of the proposed method.

Effects of deltamethrin on the activation or expression of Nrf2 and on the GCS-HS protein level in primary astrocytes with laser scanning confocal microscope

Objective： To examine the effects of deltamethrin（DM） and tBHQ on the activation of Nrt2 and expression of GCS-HS in primary astrocytes. Methods： Rat primary astrocytes were treated with DM （10μmol/L） and tBHQ （40μmol/L）, for 1 and 6 h respectively. Results： Analysis using immunofluorescent confocal microscopy revealed that tBHQ treatment led to a dramatic increase in the level of Nrt2. The ratio of cytoplasmic Nrt2 protein to nuclear Nrt2 protein was markedly reduced in astrocytes by either tBHQ or DM treatment. The level of Nrf2 was reduced by combined tBHQ with DM treatment for 1 h, but treatment the ratio of cytoplasmic Nrf2 protein to nuclear Nrf2 protein was increased compared with that of the tBHQ only. The expression of GCS-HS in astrocytes was not altered by DM or tBHQ or both in astrocytes. Conclusion： These findings demonstrated for the first time that Nrf2 was activated by pesticides and antioxidants in astrocytes, implicating a tote of Nrf2 in response to pesticide neurotoxicity ingla.

CD34^(+)CD38^(-)subpopulation without CD123 and CD44 is responsible for LSC and correlated with imbalance of immune cell subsets in AML

Acute myeloid leukemia(AML)is regarded as a stem cell disease.However,no one unique marker is expressed on leukemia stem cells(LSC)but not on leukemic blasts nor normal hematopoietic stem cells(HSC).CD34^(+)CD38^(-)with or without CD123 or CD44 subpopulations are immunophenotypically defined as putative LSC fractions in AML.Nevertheless,markers that can be effectively and simply held responsible for the intrinsical heterogeneity of LSC is still unclear.In the present study,we examined the frequency of three different LSC subtypes(CD34^(+)CD38^(-),CD34^(+)CD38^(-)CD123^(+),CD34^(+)CD38^(-)CD44^(+))in AML at diagnosis.We then validated their prognostic significance on the relevance of spectral features for diagnostic stratification,immune status,induction therapy response,treatment effect maintenance,and long^(-)term survival.In our findings,high proportions of the above three different LSC subtypes were all significantly characterized with low complete remission(CR)rate,high relapse/refractory rate,poor overall survival(OS),frequent FLT3^(-)ITD mutation,the high level of regulatory T cells(Treg)and monocytic myeloid^(-)derived suppressor cells(M^(-)MDSC).However,there was no significant statistical difference in all kinds of other clinical performance among the three different LSC groups.It was demonstrated that CD34^(+)CD38^(-)subpopulation without CD123 and CD44 might be held responsible for LSC and correlated with an imbalance of immune cell subsets in AML.

Shading effects revisited:Comparisons of spring and autumn shading treatments reveal a seasonal-dependent regulation on amino acids in tea leaves

Shading is an effective way to improve tea quality by modulating the accumulation of the flavor-related secondary metabolites of tea leaves.However,shading effects on amino acids have been conflicting for years as both shading-induced increases and decreases have been detected.This study aims to investigate the effects of shading levels on catechins and amino acids,in particular,a comparison was made in April and August to better understand the involvement of seasonal environmental parameters.Shading reduced major catechins(catechin,gallocatechin,epicatechin,epigallocatechin,epicatechin gallate,and epigallocatechin gallate)in both seasons.Heavy shading(80%−90%)increased total and individual amino acids(threonine,glutamic acid,and alanine)in April but decreased those in August.In both seasons,ᴏ-Phosphoethanolamine increased under heavy shading,butα-aminoadipic acid,ornithine and glutamine showed decreases.Theanine showed no shading response in April but decreased under heavy shading in August.These results indicate that shading-induced reduction of leaf catechins is mainly determined by shading level,but the shading effects on amino acids are seasonally-dependent.As our first report focuses on the synergistic effects of seasons,this study improves our understanding of shading regulation on secondary metabolites of tea leaves and guides shading treatments to improve tea quality.

The effects of circadian rhythm on catechin accumulation in tea leaves

As the major bitter-and astringent-tasting components in tea leaves,catechins play an essential role in determining flavor characteristics and health benefits of tea products.This study analyzed the circadian rhythm effects on the accumulation pattern of catechins in tender leaves of three tea cultivars,'Huangkui'(HK),'Longjing43'(LJ43)and'Fuding Dabaicha'(FD).There were two major factors involved in the catechin regulation in tea plants:genetic background of the cultivar-specific regulation,and temporal effects of the circadian rhythm.Etiolated leaves of'HK'contained lower levels of catechins than'LJ43'and'FD'.The composition of EGCG in total catechins was significantly higher in'LJ43'leaves(65%)when compared with that in'HK'and'FD'(45%).The accumulation of individual catechins increased during the daytime but decreased overnight,especially over the time period of 22:00−02:00.The correlation analysis between catechins and environmental factors indicated catechin accumulation in tea leaves potentially resulted from a combined regulation of light and temperature.These findings provide new insights into our understanding of circadian rhythm regulation on flavor-important secondary metabolites in tea leaves.

Physicochemical properties and antioxidant activities of polysaccharides extracted from Panax ginseng C.A.Meyer with graded percipitation method

Ginseng polysaccharides were extracted by water decoction from Panax ginseng C.A.Meyer(Cultivated Ginseng),named CGPS.Four polysaccharide fractions,CGPS-20,CGPS-40,CGPS-60 and CGPS-80,were precipitated at final ethanol concentrations of 20%,40%,60%and 80%,respectively.Physicochemical properties,molecular weight,monosaccharide composition and antioxidant capacity of polysaccharide fractions were all investigated.The results indicated that changing the concentration of ethanol could precipitate polysaccharides into fractions with different molecular weights,functional group composition and physicochemical properties,eventually leading to differences in antioxidant activity,which would help to find a simple,efficient,and reliable method for rapid extraction and purification of antioxidant polysaccharides from Panax ginseng C.A.Meyer.Among the four polysaccharide fractions,CGPS-80 had lower molecular weight,higher contents of uronic acid and total phenolic,and stronger scavenging ability on DPPH∙and ABTS∙+radicals.

Experimental and numerical study on ignition and combustion characteristics of boron-magnesium composite powders

A high-pressure laser ignition and combustion system with adjustable oxidizer gas atmosphere is established to investigate the ignition and combustion characteristics of boron-magnesium(BM)com-posite powders.An ignition and combustion model of BM powders is established and validated in the present study.The results show that increasing water content,O_(2) content and Mg content all result in shorter ignition delay time of BM powders,among which the effect of water content is the most obvious.However,ignition delay time increases as pressure increases.The combustion time decreases with increasing Mg content and ambient pressure but increases with water content.With the increase of O_(2) content,combustion time of BM powders first increases and then decreases,which means a critical O_(2) content exists above which combustion time decreases.The results show that there exists a trade-off between ignition and combustion performance of BM composite powders.

Tal6b/AvrXa27A,a hidden TALE targeting the susceptibility gene OsSWEET11a and the resistance gene Xa27 in rice

Xanthomonas oryzae pv.oryzae(Xoo)secretes transcription activator-like effectors(TALEs)to activate rice susceptibility(S)genes,causing bacterial blight(BB),as well as resistance(R)genes,leading to de-fense against BB.This activation follows a gene-for-gene paradigm that results in an arms race between the TALE of the pathogen and effector-binding elements(EBEs)in the promoters of host genes.In this study,we characterized a novel TALE,designated Tal6b/AvrXa27A,that activates the rice S gene OsSWEET11a and the rice R gene Xa27.Tal6b/AvrXa27A is a member of the AvrXa27/TalAO class and contains 16 repeat variable diresidues(RVDs);one RVD is altered and one is deleted in Tal6b/AvrXa27A compared with AvrXa27,a known avirulence(avr)effector of Xa27.Tal6b/AvrXa27A can transcriptionally activate the expression of Xa27 and OsSWEET11a via EBEs in their corresponding promoters,leading to effector-triggered immunity and susceptibility,respectively.The 16 RVDs in Tal6b/AvrXa27A have no obvious similarity to the 24 RVDs in the effector PthXo1,but EBETal6b and EBEPthXo1 are overlapped in the OsSWEET11a promoter.Tal6b/AvrXa27A is prevalent among Asian Xoo isolates,but PthXo1 has only been reported in the Philippine strain PXO99A.Genome editing of EBETal6b in the OsSWEET11a pro-moter further confirmed the requirement for OsSWEET11a expression in Tal6b/AvrXa27A-dependent susceptibility to Xoo.Moreover,Tal6b/AvrXa27A resulted in higher transcription of Xa27 than of OsSWEET11a,which led to a strong,rapid resistance response that blocked disease development.Thesefindings suggest that Tal6b/AvrXa27A has a dual function:triggering resistance by activating Xa27 gene expression as an avirulence factor and inducing transcription of the S gene OsSWEET11a,resulting in virulence.Intriguingly,Tal6b/AvrXa27A,but not AvrXa27,can bind to the promoter of OsSWEET11a.The underlying recognition mechanism for this binding remains unclear but appears to deviate from the currently accepted TALE code.