3D electromagnetic simulation of the coupling characteristics and double-stub Ferrite tuners impedance matching for EAST ICRH four-strap antenna

A program developed with COMSOL software integrates EAST four-strap antenna coupling with the double-stub Ferrite tuners(FT)impedance matching,obtaining physical quantities crucial for predicting the overall performance of the ion cyclotron resonance heating(ICRH)antenna and matching system.These quantities encompass S-matrix,port complex impedance,reflection coefficients,electric field and voltage distribution,and optimal matching settings.In this study,we explore the relationship between S-matrix,reflection coefficients,port complex impedance,and frequency.Then,we analyze the impact of Faraday screens placement position and transparency,the distance from the Faraday screen(FS)to the current straps(CS),the relative distance between ports,and the characteristic impedance of the transmission line on the coupling characteristic impedance of the EAST ICRH system.Finally,we simulate the electric field distribution and voltage distribution of the EAST ICRH system for plasma heating with double-stub FT impedance matching.Using optimized parameters,the coupling power of the ICRH system can be approximately doubled.The results present herein may offer guidance for the design of high-power,long-pulse operation ICRH antenna systems.

Detecting dopaminergic neuronal degeneration using diffusion tensor imaging in a rotenone-induced rat model of Parkinson's disease: fractional anisotropy and mean diffusivity values

Dopamine content in the basal ganglia is strongly associated with the degree of dopaminergic neuron loss in the substantia nigra pars com- pacta. Symptoms of Parkinson＇s disease might not arise until more than 50% of the substantia nigra pars compacta is lost and the dopamine content in the basal ganglia is reduced by more than 80%. Greater diagnostic sensitivity and specificity would allow earlier detection of Parkinson＇s disease. Diffusion tensor imaging is a recently developed magnetic resonance imaging technique that measures mean diffusiv- ity and fractional anisotropy, and responds to changes in brain microstructure. When the microscopic barrier （including cell membranes, microtubules and other structures that interfere with the free diffusion of water） is destroyed and extracellular fluid volume accumulates, the mean diffusivity value increases; when the integrity of the microstructure （such as myelin） is destroyed, fractional anisotropy value decreases. However, there is no consensus as to whether these changes can reflect the early pathological alterations in Parkinson＇s disease. Here, we established a rat model of Parkinson＇s disease by injecting rotenone （or sunflower oil in controls） into the right suhstantia nigra. Diffusion tensor imaging results revealed that in the stages of disease, at 1, 2, 4, and 6 weeks after rotenone injection, fiactional anisotropy value decreased, but mean diffusivity values increased in the right substantia nigra in the experimental group. Fractional anisotropy values were lower at 4 weeks than at 6 weeks in the right substantia nigra of rats from the experimental group. Mean diffusivity values were mark- edly greater at 1 week than at 6 weeks in the right corpus striatum of rats from the experimental group. These findings suggest that mean diffusivity and fractional anisotropy values in the brain of rat models of Parkinson＇s disease 4 weeks after model establishment can reflect early degeneration of dopaminergic neurons. ＇The change in fractional anisotropy values after destruction of myelin integrity is likely to be of greater early diagnostic significance than the change in mean diffusivity values.

Combined sevoflurane-dexmedetomidine and nerve blockade on post-surgical serum oxidative stress biomarker levels in thyroid cancer patients

BACKGROUND The incidence of thyroid cancer is increasing annually.Clinical routine thyroid surgery can be performed under a cervical plexus block,but cannot mediate the stress response during the surgery.If thyroid surgery is performed under nerve block,an inappropriate level of blockade may occur.Similarly,the stress response caused by surgery is more serious than that caused by conventional anesthesia.Therefore,it is important to combine blockade with more effective anesthesia methods.AIM To investigate the effects of combining sevoflurane-dexmedetomidine inhalation general anesthesia with the cervical plexus nerve block on the post-surgical levels of the serum oxidative stress biomarkers levels in thyroid cancer patients.METHODS We enrolled 96 thyroid cancer patients admitted to the hospital between January 2019 and December 2020.Participants were divided into a control group(n=47)and an experimental group(n=49).The experimental group received a combination of inhaled sevoflurane-dexmedetomidine and cervical plexus block,while the control group received conventional general anesthesia.The groups were compared for serum levels of monocyte chemotactic protein-1(MCP-1)and glutathione peroxidase(GSH-Px)before and after surgery,and the adrenocorticotropic hormone(ACTH)and norepinephrine(NE)levels at 1 and 12 h postsurgery.The Bispectral index(BIS)and the incidence of anesthesia side effects were also compared.RESULTS Following surgery,MCP-1 was significantly lower in the experimental group compared to the control group,whereas GSH-Px was significantly higher than that in the control group(P<0.001).The serum ACTH and NE levels were significantly lower in the experimental group than those the control group at 1 and 12 h post-surgery(P<0.001).BIS was significantly lower in the experimental group than that in the control group at 20 minutes into the operation,but the direction of the difference was reversed at eye opening(P<0.001).The incidence of side effects was 10.20%(5/49)and 12.76%(6/47)in the experimental and control groups,respectively,the difference being non-significant.CONCLUSION Sevoflurane-dexmedetomidine inhalation general anesthesia combined with cervical plexus nerve block can reduce the postoperative stress and inflammatory responses in thyroid cancer patients,while maintaining high anesthesia effectiveness and safety.

Differences in brain pathological changes between rotenone and 6-hydroxydopamine Parkinson＇s disease models

Rotenone and 6-hydroxydopamine are two drugs commonly used to generate Parkinson＇s disease animal models.They not only achieve degenerative changes of dopaminergic neurons in the substantia nigra,but also satisfy the requirements for iron deposition.However,few studies have compared the characteristics of these two models by magnetic resonance imaging.In this study,rat models of Parkinson＇s disease were generated by injection of 3 μg rotenone or 10 μg 6-hydroxydopamine into the right substantia nigra.At 1,2,4,and 6 weeks after injection,coronal whole-brain T2-weighted imaging,transverse whole-brain T2-weighted imaging,and coronal diffusion tensor weighted imaging were conducted to measure fractional anisotropy and T2＊ values at the injury site.The fractional anisotropy value on the right side of the substantia nigra was remarkably lower at 6 weeks than at other time points in the rotenone group.In the 6-hydroxydopamine group,the fractional anisotropy value was decreased,but T2＊ values were increased on the right side of the substantia nigra at 1 week.Our findings confirm that the 6-hydroxydopamine-induced model is suitable for studying dopaminergic neurons over short periods,while the rotenone-induced model may be appropriate for studying the pathological and physiological processes of Parkinson＇s disease over long periods.

Iron-Imprinted Single-Atomic Site Catalyst-Based Nanoprobe for Detection of Hydrogen Peroxide in Living Cells

Fe-based single-atomic site catalysts(SASCs),with the natural metalloproteases-like active site structure,have attracted widespread attention in biocatalysis and biosensing.Precisely,controlling the isolated single-atom Fe-N-C active site structure is crucial to improve the SASCs’performance.In this work,we use a facile ion-imprinting method(IIM)to synthesize isolated Fe-N-C single-atomic site catalysts(IIM-Fe-SASC).With this method,the ion-imprinting process can precisely control ion at the atomic level and form numerous well-defined single-atomic Fe-N-C sites.The IIM-Fe-SASC shows better peroxidase-like activities than that of non-imprinted references.Due to its excellent properties,IIM-Fe-SASC is an ideal nanoprobe used in the colorimetric biosensing of hydrogen peroxide(H_(2)O_(2)).Using IIM-Fe-SASC as the nanoprobe,in situ detection of H_(2)O_(2)generated from MDA-MB-231 cells has been successfully demonstrated with satisfactory sensitivity and specificity.This work opens a novel and easy route in designing advanced SASC and provides a sensitive tool for intracellular H_(2)O_(2)detection.

Cell polarity protein Par3 complexes with DNA-PK via Ku70 and regulates DNA double-strand break repair

The partitioning-defective 3 （Par3）, a key component in the conserved Par3/Par6/aPKC complex, plays fundamental roles in cell polarity. Herein we report the identification of Ku70 and Ku80 as novel Par3-interacting proteins through an in vitro binding assay followed by liquid chromatography-tandem mass spectrometry. Ku70/Ku80 proteins are two key regulatory subunits of the DNA-dependent protein kinase （DNA-PK）, which plays an essential role in repairing double-strand DNA breaks （DSBs）. We determined that the nuclear association of Par3 with Ku70/Ku80 was enhanced by γ-irradiation （IR）, a potent DSB inducer. Furthermore, DNA-PKcs, the catalytic subunit of DNA-PK, interacted with the Par3/Ku70/Ku80 complex in response to IR. Par3 over-expression or knockdown was capable of up- or downregulating DNA-PK activity, respectively. Moreover, the Par3 knockdown cells were found to be defective in random plasmid integration, defective in DSB repair following IR, and radiosensitive, phenotypes similar to that of Ku70 knockdown cells. These findings identify Par3 as a novel component of the DNA-PK complex and implicate an unexpected link of cell polarity to DSB repair.

Characterization and Candidate Gene Analysis of the Yellow-Green Leaf Mutant ygl16 in Rice(Oryza sativa L.)

Leaf color mutants are ideal materials for studying many plant physiological and metabolic processes such as photosynthesis,photomorphogenesis,hormone physiology and disease resistance.In this study,the genetically stable yellow-green leaf mutant ygl16 was identified from mutated“Xinong 1B”.Compared with the wild type,the pigment concentration and photosynthetic capacity of the ygl16 decreased significantly.The ultrastructural observation showed that the distribution of thylakoid lamellae was irregular in ygl16 chloroplasts,and the grana and matrix lamellae were blurred and loose in varied degrees,and the chloroplast structure was disordered,while the osmiophilic corpuscles increased.The results of the genetic analysis and mapping showed that the phenotype of ygl16 was controlled by a pair of recessive nuclear gene.The gene located in the 56Kb interval between RM25654 and R3 on the long arm of chromosome 10.The sequencing results showed that the 121st base of the first intron of the candidate gene OsPORB/FGL changed from A to T in the interval.qRT-PCR results showed that the expression of chlorophyll synthase-related genes in the mutant decreased.

Comparison on the phytoextraction efficiency of Bidens pilosa at heavy metal contaminated site in natural and electrokinetic conditions

The plant samples of Bidens pilosa were collected from a coal gangue vacant site and its surrounding area,located in central China,to study the remediation effect of the plant species on heavy metal(HM)contamination in both natural and electrokinetic(EK)conditions.The analytical results showed that the effect of phytoextraction and bioconcentration on the heavy metals in the sample of the EK group is more significant than those in the other control group.Compared with the results of natural condition,under the EK condition the concentrations of cadmium(Cd),lead(Pb),copper(Cu)and zinc(Zn)in the stems and leaves of the Bidens pilosa increased to 0.40 mg/kg,4.23 mg/kg,7.27 mg/kg,830.24 mg/kg,respectively,with their increments of 292%,1731%,141%,2076%.For root samples,the Cd,Pb,Cu and Zn concentrations increased to 0.52 mg/kg,4.36 mg/kg,10.87 mg/kg,and 98.12 mg/kg and the increase rates were 1034%,140%,29%,and 181%,respectively.The phytoextraction efficiency of the Bidens pilosa was significantly higher than that of control group.The removal efficiency of Cd,Pb,Cu and Zn in soil increased to 26%,72%,27%,and 79%with the EK applied.In addition,the mechanism of HM migration,extraction and enrichment in Bidens pilosa under the EK condition was discussed.

Zeptomole Imaging of Cytosolic MicroRNA Cancer Biomarkers with A Light-Controlled Nanoantenna

Detecting and quantifying intracellular microRNAs(miRNAs)are a critical step in resolving a cancer diagnostic and resolving the ensemble of gene products that orchestrate the living state of cells.However,the nanoprobe for detecting low abundance miRNAs in cell cytosol is restricted by either the"one-to-one"signaltrigger model or di culty for cytosol delivery.To address these challenges,we designed a lightharvesting nanoantenna-based nanoprobe,which directs excitation energy to a single molecule to sensitively detect cytosolic miRNA.With light irradiation,the light-harvesting nanoantenna e ectively disrupted lysosomal structures by generationof reactive oxygen species,substantially achieved cytosol delivery.The nanoantenna containing>4000 donor dyes can e ciently transfer excitation energy to one or two acceptors with 99%e ciency,leading to unprecedented signal amplification and biosensing sensitivity.The designed nanoantenna can quantify cytosolic miR-210 at zeptomolar level.The fluorescence lifetime of the donor exhibited good relationship with miR-210 concentration in the range of 0.032 to 2.97 amol/ngRNA.The zeptomole sensitivity of nanoantenna provides accurate bioimaging of miR-210 both in multiple cell lines and in vivo assay,which creates a pathway for the creation of miRNA toolbox for quantitative epigenetics and personalized medicine.

Energy intensity and its determinants in China:an empirical study based on ARDL-VECM approach

The present study aims to better understand the relationship between energy intensity and its determinants including energy price, technological progress, economic structure, and energy mix using the autoregressive distributed lag(ARDL) bounds approach and vector error correction model technique. Based on China's time series over 1985-2014, the ARDL bounds approach yields empirical evidence that confirms the existence of long run relationship between energy price, technological progress, economic structure, energy mix, and energy intensity. The results show that technological progress is an important driver for the declining energy intensity in short and long run. Energy price has not been demonstrated as an important role in decreasing energy intensity in the short run. The high share of coal use in total energy use may be responsible for China's high energy intensity.However, the relative change in economic sectors plays a minor role in energy intensity reduction during the past years. In the long run, technological progress, energy mix and energy prices Granger cause energy intensity, but not vice versa except for the energy mix.

Assembly of highly efficient aqueous light-harvesting system from sequence-defined peptoids for cytosolic microRNA detection

Precisely controlled spatial distributions of artificial light-harvesting systems in aqueous media are of significant importance for mimicking natural light-harvesting systems;however,they are often restrained by the solubility and the aggregation-caused quenching effect of the hydrophobic chromophores.Herein,we report one highly efficient artificial light-harvesting system based on peptoid nanotubes that mimic the hierarchical cylindrical structure of natural systems.The high crystallinity of these nanotubes enabled the organization of arrays of donor chromophores with precisely controlled spatial distributions,favoring an efficient Förster resonance energy transfer(FRET)process in aqueous media.This FRET system exhibits an extremely high efficiency of 98.6%with a fluorescence quantum yield of 40%and an antenna effect of 29.9.We further demonstrated the use of this artificial light-harvesting system for quantifying miR-210 within cancer cells.The fluorescence intensity ratio of donor to acceptor is linearly related to the concentration of intercellular miR-210 in the range of 3.3–156 copies/cell.Such high sensitivity in intracellular detection of miR-210 using this artificial light-harvesting system offers a great opportunity and pathways for biological imaging and detection,and for the further creation of microRNA(miRNA)toolbox for quantitative epigenetics and personalized medicine.

Inhibition of xanthine oxidase alleviated pancreatic necrosis via HIF-1α-regulated LDHA and NLRP3 signaling pathway in acute pancreatitis

Acute pancreatitis(AP)is a potentially fatal condition with no targeted treatment options.Although inhibiting xanthine oxidase(XO)in the treatment of AP has been studied in several experimental models and clinical trials,whether XO is a target of AP and what its the main mechanism of action is remains unclear.Here,we aimed to re-evaluate whether XO is a target aggravating AP other than merely generating reactive oxygen species that trigger AP.We first revealed that XO expression and enzyme activity were significantly elevated in the serum and pancreas of necrotizing AP models.We also found that allopurinol and febuxostat,as purine-like and non-purine XO inhibitors,respectively,exhibited protective effects against pancreatic acinar cell death in vitro and pancreatic damage in vivo at different doses and treatment time points.Moreover,we observed that conditional Xdh overexpression aggravated pancreatic necrosis and severity.Further mechanism analysis showed that XO inhibition restored the hypoxia-inducible factor 1-alpha(HIF-1α)-regulated lactate dehydrogenase A(LDHA)and NOD-like receptor family pyrin domain containing 3(NLRP3)signaling pathways and reduced the enrichment of^(13)C_(6)-glucose to^(13)C_(3)-lactate.Lastly,we observed that clinical circulatory XO activity was significantly elevated in severe cases and correlated with C-reactive protein levels,while pancreatic XO and urate were also increased in severe AP patients.These results together indicated that proper inhibition of XO might be a promising therapeutic strategy for alleviating pancreatic necrosis and preventing progression of severe AP by downregulating HIF-1α-mediated LDHA and NLRP3 signaling pathways.

Disease-derived circulating extracellular vesicle preconditioning:A promising strategy for precision mesenchymal stem cell therapy

Mesenchymal stem cell(MSC)-based therapies have emerged as promising methods for regenerative medicine;however,how to precisely enhance their tissue repair effects is still a major question in the field.Circulating extracellular vesicles(EVs)from diseased states carry diverse pathological information and affect the functions of recipient cells.Based on this unique property,we report that disease-derived circulating EV(disease-EV)preconditioning is a potent strategy for precisely enhancing the tissue repair potency of MSCs in diverse disease models.Briefly,plasma EVs from lung or kidney tissue injuries were shown to contain distinctly enriched molecules and were shown to induce tissue injury-specific gene expression responses in cultured MSCs.Disease-EV preconditioning improved the performance(including proliferation,migration,and growth factor production)of MSCs through metabolic reprogramming(such as via enhanced oxidative phosphorylation and lipid metabolism)without inducing an adverse immune response.Consequently,compared with normal MSCs,disease-EV-preconditioned MSCs exhibited superior tissue repair effects(including anti-inflammatory and antiapoptotic effects)in diverse types of tissue injury(such as acute lung or kidney injury).Disease-derived EVs may serve as a type of“off-the-shelf”product due to multiple advantages,such as flexibility,stability,long-term storage,and ease of shipment and use.This study highlights the idea that disease-EV preconditioning is a robust strategy for precisely enhancing the regenerative capacity of MSC-based therapies.

Template-directed synthesis of nitrogen- and sulfur- codoped carbon nanowire aerogels with enhanced electrocatalytic performance for oxygen reduction

Heteroatom doping, precise composition control and rational morphology design are efficient strategies for producing novel nanocatalysts for the oxygen reduction reaction （ORR） in fuel cells. Herein, a cost-effective approach to synthesize nitrogen- and sulfur-codoped carbon nanowire aerogels using a hard templating method is proposed. The aerogels prepared using a combination of hydrothermal treatment and carbonization exhibit good catalytic activity for the ORR in alkaline solution. At the optimal annealing temperature and mass ratio between the nitrogen and sulfur precursors, the resultant aerogels show comparable electrocatalytic activity to that of a commercial Pt/C catalyst for the ORR. Importantly, the optimized catalyst shows much better long-term stability and satisfactory tolerance for the methanol crossover effect. These codoped aerogels are expected to have potential applications in fuel cells.

Recent progress on rational design of catalysts for fermentative hydrogen production

The increasingly severe energy crisis has strengthened the determination to develop environmentally friendly energy.And hydrogen has emerged as a candi-date for clean energy.Among many hydrogen generation methods,biohydrogen stands out due to its environmental sustainability,simple operating environ-ment,and cost advantages.This review focuses on the rational design of catalysts for fermentative hydrogen production.The principles of microbial dark fermen-tation and photo-fermentation are elucidated exhaustively.Various strategies to increase the efficiency of fermentative hydrogen production are summa-rized,and some recent representative works from microbial dark fermentation and photo-fermentation are described.Meanwhile,perspectives and discussions on the rational design of catalysts for fermentative hydrogen production are provided.

A peroxidase-like single-atom Fe-N_(5)active site for effective killing human lung adenocarcinoma cells

Single-atom catalyst(SAC)is one of the newest catalysts,and attracts people’s wide attention in cancer therapy based on their characteristics of maximum specific catalytic activity and high stability.We designed and synthesized a Fe-N decorated graphene nanosheet(Fe-N5/GN SAC)with the coordination number of five.Through enzymology and theoretical calculations,the Fe-N5/GN SAC has outstanding intrinsic peroxidase-like catalytic activity due to single-atom Fe site with five-N-coordination structure.We explored its potential on lung cancer therapy,and found that it could kill human lung adenocarcinoma cells(A549)by decomposing hydrogen peroxide(H_(2)O_(2))into toxic reactive oxygen species(ROS)under acidic microenvironment in threedimensional(3D)lung cancer cell model.Our study demonstrates a promising application of SAC with highly efficient single-atom catalytic sites for cancer treatment.

Recent advances in carbon-supported non-precious metal singleatom catalysts for energy conversion electrocatalysis

Non-precious metal single-atom catalysts(NPM-SACs)with unique electronic structures and coordination environments have gained much attention in electrocatalysis owing to their low cost,high atomic utilization,and high performance.NPM-SACs on carbon support(NPM-SACs/CS)are promising because of the carbon substrate with a large surface area,excellent electrical conductivity,and high chemical stability.This review provides an overview of recent developments in NPM-SACs/CS for the electrocatalytic field.First,the state-of-the-art synthesis methods and advanced characterization techniques of NPM-SACs/CS are discussed in detail.Then,the structural adjustment strategy of NPM-SACs/CS for optimizing electrocatalytic performance is introduced concisely.Furthermore,we provide a comprehensive summary of recent advances in developing NPM-SACs/CS for important electrochemical reactions,including carbon dioxide reduction reaction,hydrogen evolution reaction,oxygen evolution reaction,oxygen reduction reaction,and nitrogen reduction reaction.In the end,the existing challenges and future opportunities of NPM-SACs/CS in the electrocatalytic field are highlighted.

Stimulants and donors promote megaplasmid pND6-2 horizontal gene transfer in activated sludge

The activated sludge process is characterized by high microbial density and diversity,both of which facilitate antibiotic resistance gene transfer.Many studies have suggested that antibiotic and non-antibiotic drugs at sub-inhibitory concentrations are major inducers of conjugative gene transfer.The self-transmissible plasmid pND6-2 is one of the endogenous plasmids harbored in Pseudomonas putida ND6,which can trigger the transfer of another co-occurring naphthalene-degrading plasmid pND6-1.Therefore,to illustrate the potential influence of stimulants on conjugative transfer of pND6-2,we evaluated the effects of four antibiotics (ampicillin,gentamycin,kanamycin,and tetracycline) and naphthalene,on the conjugal transfer efficiency of pND6-2 by filter-mating experiment.Our findings demonstrated that all stimulants within an optimal dose promoted conjugative transfer of pND6-2from Pseudomonas putida GKND6 to P.putida KT2440,with tetracycline being the most effective (100μg/L and 10μg/L),as it enhanced pND6-2-mediated intra-genera transfer by approximately one hundred-fold.Subsequently,seven AS reactors were constructed with the addition of donors and different stimulants to further elucidate the conjugative behavior of pND6-2 in natural environment.The stimulants positively affected the conjugal process of pND6-2,while donors reshaped the host abundance in the sludge.This was likely because stimulant addition enhanced the expression levels of conjugation transfer-related genes.Furthermore,Blastocatella and Chitinimonas were identified as the potential receptors of plasmid pND6-2,which was not affected by donor types.These findings demonstrate the positive role of sub-inhibitory stimulant treatment on pND6-2 conjugal transfer and the function of donors in re-shaping the host spectrum of pND6-2.

Single-Atomic Site Catalyst Enhanced Lateral Flow Immunoassay for Point-of-Care Detection of Herbicide

Point-of-care(POC)detection of herbicides is of great importance due to their impact on the environment and potential risks to human health.Here,we design a single-atomic site catalyst(SASC)with excellent peroxidase-like(POD-like)catalytic activity,which enhances the detection performance of corresponding lateral flow immunoassay(LFIA).The iron single-atomic site catalyst(Fe-SASC)is synthesized from hemin-doped ZIF-8,creating active sites that mimic the Fe active center coordination environment of natural enzyme and their functions.Due to its atomically dispersed iron active sites that result in maximum utilization of active metal atoms,the Fe-SASC exhibits superior POD-like activity,which has great potential to replace its natural counterparts.Also,the catalytic mechanism of Fe-SASC is systematically investigated.Utilizing its outstanding catalytic activity,the Fe-SASC is used as label to construct LFIA(Fe-SASC-LFIA)for herbicide detection.The 2,4-dichlorophenoxyacetic acid(2,4-D)is selected as a target here,since it is a commonly used herbicide as well as a biomarker for herbicide exposure evaluation.A linear detection range of 1-250 ng/mL with a low limit of detection(LOD)of 0.82 ng/mL has been achieved.Meanwhile,excellent specificity and selectivity towards 2,4-D have been obtained.The outstanding detection performance of the Fe-SASC-LFIA has also been demonstrated in the detection of human urine samples,indicating the practicability of this POC detection platform for analyzing the 2,4-D exposure level of a person.We believe this proposed Fe-SASC-LFIA has potential as a portable,rapid,and high-sensitive POC detection strategy for pesticide exposure evaluation.

临近空间飞行平台青藏高原大气NO_(x)原位观测实验

大气NO_(x)气体分析仪是中国科学院战略性先导科技专项“临近空间科学实验系统”“太阳风暴在临近空间环境的响应”任务的主载荷之一,是我国自主研发的原位探测临近空间大气NO_(x)的载荷,并已成功测量临近空间高空气球飞行路径NO、NO_(2)、NO_(x)混合比.分析仪基于可见-紫外光谱吸收法原理,用动态流导法将飞行路径上1×103~1×10^(5) Pa的自然大气压缩至8×10^(4)~1×10^(5) Pa,构建了长期稳定的常压工作环境,把商用氮氧化物光谱仪的适用范围从地表拓展到高空.2019和2020年夏季,中纬度青藏高原大柴旦地区开展的两次高空气球科学实验均搭载了大气NO_(x)气体分析仪,实现了对流层5 km到平流层30 km大气NO_(x)的原位测量,并获取了青藏高原上空NO、NO_(2)、NO_(x)混合比的科学探测数据.