Association of tumor budding with clinicopathological features and prognostic value in stage III-IV colorectal cancer

BACKGROUND Tumor budding(TB)has emerged as a promising independent prognostic biomarker in colorectal cancer(CRC).The prognostic role of TB has been extensively studied and currently affects clinical decision making in patients with stage I and II CRC.However,existing prognostic studies on TB in stage III CRC have been confined to small retrospective cohort studies.Consequently,this study investigated the correlation among TB categories,clinicopathological features,and prognosis in stage III-IV CRC to further enhance the precision and individualization of treatment through refined prognostic risk stratification.AIM To analyze the relationship between TB categories and clinicopathological characteristics and assess their prognostic value in stage III-IV CRC to further refine the prognostic risk stratification of stage III-IV CRC.METHODS The clinical data of 547 CRC patients were collected for this retrospective study.Infiltration at the front edge of the tumor buds was counted according to the 2016 International Tumor Budding Consensus Conference guidelines.RESULTS Multivariate Cox proportional hazards regression analysis demonstrated that chemotherapy(P=0.004),clinical stage IV(P<0.001),≥4 regional lymph node metastases(P=0.004),left-sided colonic cancer(P=0.040),and Bd 2-3(P=0.002)were independent prognostic factors in patients with stage III-IV CRC.Moreover,the density of tumor infiltrating lymphocytes was higher in Bd 1 than in Bd 2-3,both in the tumor stroma and its invasive margin.CONCLUSION TB has an independent predictive prognostic value in patients with stage III-IV CRC.It is recommended to complete the TB report of stage III-IV CRC cases in the standardized pathological report to further refine risk stratification.

Quantum Anomalous Hall Effect with Tunable Chern Numbers in High-Temperature 1T-PrN_(2) Monolayer

Quantum anomalous Hall(QAH) insulators have highly potential applications in spintronic device. However,available candidates with tunable Chern numbers and high working temperature are quite rare. Here, we predict a 1T-PrN_(2) monolayer as a stable QAH insulator with high magnetic transition temperature of above 600 K and tunable high Chern numbers of C = ±3 from first-principles calculations. Without spin-orbit coupling(SOC),the 1T-PrN_(2) monolayer is predicted to be a p-state Dirac half metal with high Fermi velocity. Rich topological phases depending on magnetization directions can be found when the SOC is considered. The QAH effect with periodical changes of Chern number(±1) can be produced when the magnetic moment breaks all twofold rotational symmetries in the xy plane. The critical state can be identified as Weyl half semimetals. When the magnetization direction is parallel to the z-axis, the system exhibits high Chern number QAH effect with C = ±3.Our work provides a new material for exploring novel QAH effect and developing high-performance topological devices.

Novel miR-490-3p/hnRNPA1-b/PKM2 axis mediates the Warburg effect and proliferation of colon cancer cells via the PI3K/AKT pathway

BACKGROUND Heterogeneous ribonucleoprotein A1(hnRNPA1)has been reported to enhance the Warburg effect and promote colon cancer(CC)cell proliferation,but the role and mechanism of the miR-490-3p/hnRNPA1-b/PKM2 axis in CC have not yet been elucidated.AIM To investigate the role and mechanism of a novel miR-490-3p/hnRNPA1-b/PKM2 axis in enhancing the Warburg effect and promoting CC cell proliferation through the PI3K/AKT pathway.METHODS Paraffin-embedded pathological sections from 220 CC patients were collected and subjected to immunohistochemical analysis to determine the expression of hnRNPA1-b.The relationship between the expression values and the clinicopathological features of the patients was investigated.Differences in mRNA expression were analyzed using quantitative real-time polymerase chain reaction,while differences in protein expression were analyzed using western blot.Cell proliferation was evaluated using the cell counting kit-8 and 5-ethynyl-2’-deoxyuridine assays,and cell cycle and apoptosis were detected using flow cytometric assays.The targeted binding of miR-490-3p to hnRNPA1-b was validated using a dual luciferase reporter assay.The Warburg effect was evaluated by glucose uptake and lactic acid production assays.RESULTS The expression of hnRNPA1-b was significantly increased in CC tissues and cells compared to normal controls(P<0.05).Immunohistochemical results demonstrated significant variations in the expression of the hnRNPA1-b antigen in different stages of CC,including stage I,II-III,and IV.Furthermore,the clinicopathologic characterization revealed a significant correlation between hnRNPA1-b expression and clinical stage as well as T classification.HnRNPA1-b was found to enhance the Warburg effect through the PI3K/AKT pathway,thereby promoting proliferation of HCT116 and SW620 cells.However,the proliferation of HCT116 and SW620 cells was inhibited when miR-490-3p targeted and bound to hnRNPA1-b,effectively blocking the Warburg effect.CONCLUSION These findings suggest that the novel miR-490-3p/hnRNPA1-b/PKM2 axis could provide a new strategy for the diagnosis and treatment of CC.

Deadlock-free Supervisor Design for Robotic Manufacturing Cells With Uncontrollable and Unobservable Events

In this paper,a deadlock prevention policy for robotic manufacturing cells with uncontrollable and unobservable events is proposed based on a Petri net formalism.First,a Petri net for the deadlock control of such systems is defined.Its admissible markings and first-met inadmissible markings(FIMs)are introduced.Next,place invariants are designed via an integer linear program(ILP)to survive all admissible markings and prohibit all FIMs,keeping the underlying system from reaching deadlocks,livelocks,bad markings,and the markings that may evolve into them by firing uncontrollable transitions.ILP also ensures that the obtained deadlock-free supervisor does not observe any unobservable transition.In addition,the supervisor is guaranteed to be admissible and structurally minimal in terms of both control places and added arcs.The condition under which the supervisor is maximally permissive in behavior is given.Finally,experimental results with the proposed method and existing ones are given to show its effectiveness.

SYMBOLIC COMPUTATION FOR THE QUALITATIVE THEORY OF DIFFERENTIAL EQUATIONS

This paper provides a survey on symbolic computational approaches for the analysis of qualitative behaviors of systems of ordinary differential equations,focusing on symbolic and algebraic analysis for the local stability and bifurcation of limit cycles in the neighborhoods of equilibria and periodic orbits of the systems,with a highlight on applications to computational biology.

Gas channeling control with an in-situ smart surfactant gel during water-alternating-CO_(2) enhanced oil recovery

Undesirable gas channeling always occurs along the high-permeability layers in heterogeneous oil reservoirs during water-alternating-CO_(2)(WAG)flooding,and conventional polymer gels used for blocking the“channeling”paths usually suffer from either low injectivity or poor gelation control.Herein,we for the first time developed an in-situ high-pressure CO_(2)-triggered gel system based on a smart surfactant,N-erucamidopropyl-N,N-dimethylamine(UC22AMPM),which was introduced into the aqueous slugs to control gas channeling inWAG processes.The water-like,low-viscosity UC22AMPM brine solution can be thickened by high-pressure CO_(2) owing to the formation of wormlike micelles(WLMs),as well as their growth and shear-induced structure buildup under shear flow.The thickening power can be further potentiated by the generation of denser WLMs resulting from either surfactant concentration augmentation or a certain range of heating,and can be impaired via pressurization above the critical pressure of CO_(2) because of its soaring solvent power.Core flooding tests using heterogeneous cores demonstrated that gas channeling was alleviated by plugging of high-capacity channels due to the in-situ gelation of UC22AMPM slugs upon their reaction with the pre-or post-injected CO_(2) slugs under shear flow,thereupon driving chase fluids into unrecovered low-permeability areas and producing an 8.0% higher oil recovery factor than the conventional WAG mode.This smart surfactant enabled high injectivity and satisfactory gelation control,attributable to low initial viscosity and the combined properties of one component and CO_(2)-triggered gelation,respectively.This work could provide a guide towards designing gels for reducing CO_(2) spillover and reinforcing the CO_(2) sequestration effect during CO_(2) enhanced oil recovery processes.

Immune function, gastrointestinal hormone levels, and their clinical significance in patients with gastric ulcers complicated with depression

BACKGROUND Gastric ulcer(GU)is a common digestive tract disease,and medical records of GU combined with depression are increasingly common.Currently,the risk factors and pathogenesis of GU complicated with depression remain unclear.Low immune function and gastrointestinal hormone levels may also be significant risk factors.Therefore,this study explored the immune function and gastrointestinal hormone levels in patients with GU combined with depression.AIM To explore the immune function,gastrointestinal hormone level,and clinical significance of patients with GU combined with depression.METHODS A retrospective analysis was conducted on 300 patients with GU combined with depression admitted to Guizhou Provincial People’s Hospital from January 2021 to June 2022 as the study subjects.According to the Hamilton Depression Scale(HAMD)score,patients were divided into mild-to-moderate(n=210)and heavy(n=90)groups.Basic data,immune function indices[immunoglobulin A(IgA),IgM,IgG,serum CD4+and CD8+percentage,and CD4+/CD8+ratio],and gastrointestinal hormone indices[serum gastrin(GAS),cholecystokinin(CCK),and motilin(MTL)levels]were collected.The basic data of the two groups were compared,and the immune function and gastrointestinal hormone indices were analyzed.Multivariate logistic regression was used to analyze the factors influencing the severity of GU complicated with depression.The receiver operating characteristic(ROC)curve and area under the ROC curve(AUC)were used to analyze the value of the immune function index,gastrointestinal hormone index,and combined index in predicting the severity of GU complicated with depression.RESULTS There were no marked differences in sex,age,body mass index,abdominal distension,abdominal pain,belching,nausea,vomiting,or sleep disorders between the heavy and mild-to-moderate groups(P>0.05).There was a marked difference in the family history of depression between the heavy and mild-to-moderate groups(P<0.05).There were significant differences in serum IgA and IgM levels and serum CD4+,CD8+,and CD4+/CD8+ratios between the heavy and mild-to-moderate groups(P<0.05).Multivariate analysis showed that IgA,IgM,GAS,and CCK serum levels influenced the severity of GU with depression(P<0.05).The AUC of the ROC curve for serum IgA level predicting GU with depression severity was 0.808[95%confidence interval(CI):0.760-0.857],the AUC of the serum IgM level was 0.757(95%CI:0.700-0.814),the AUC of the serum GAS level was 0.853(95%CI:0.810-0.897),the AUC of the serum CCK level was 0.762(95%CI:0.709-0.822),the AUC of immune function(IgA,IgM)and gastrointestinal hormone levels(GAS,CCK)for the prediction of GU with depression severity was 0.958(95%CI:0.933-0.976).CONCLUSION Important factors influencing GU complicated with depression are serum IgA,IgM,GAS,and CCK indicators.They can be used as indicators to predict the severity of GU complicated with depression.

Characterizations of gas-liquid interface distribution and slug evolution in a vertical pipe

Large vertical pipes are key structures connecting subsea wells to offshore platforms.However,existing studies mainly focus on small vertical pipes.In a vertical acrylic pipe with 80 mm inner diameter and 11 m height,a high-speed camera was used to visually research the influences of pipe diameters,liquid properties and inlet effect on air-water co-flow characteristic.Different flow regime maps of vertical pipes(diameters are in the range of 50e189 mm)were compared and the critical gas velocity of the transition boundary from bubble to slug flow tended to increase with the increase of diameters at D≥80 mm.Drift-flux models were established in different flow regimes and liquid properties have a significant effect on drift coefficients of bubble flow and slug flow(void fraction a≤0.4).The influence of inlet turbulent effect on the gas-liquid interface distribution gradually weakened and disappeared from the pipe base to 85D,where the flow was fully developed.Slug frequency has a trend of increase first and then decrease with the gas Weber numbers increasing at low liquid superficial velocities(J_(L)≤0.31 m/s).And on the basis of this law,a new slug frequency correlation was proposed.It was found that there was an exponential relationship between the ratio of lengths of Taylor bubble to slug and the void fraction.

Biofuel Recovery from Plantain and Banana Plant Wastes:Integration of Biochemical and Thermochemical Approach

Globally,fossil fuel dependence has created several environmental challenges and climate change.Hence,creating other alternative renewable and ecologically friendly bio-energy sources is necessary.Lignocellulosic biomass has gained significant attention recently as a renewable material for biofuel production.The large amounts of plantain and banana plant parts wasted after harvesting,as well as the peels generated daily by the fruit market and industries,demonstrate the potential of bioenergy resources.This review briefly assesses plantain and banana plant biomass(PBB)generated in the developing,developed,and underdeveloped countries,the consumable parts,and feasible products yield.It emphasized the advantages and disadvantages of the commonly adopted treatment technologies of composting,incineration,and landfilling.Further,the utilization of PBB as catalysts in biodiesel synthesis was briefly highlighted.To optimize recovery of biofuel,different integration routes of pyrolysis,anaerobic digestion,fermentation,hydrothermal carbonization,hydrothermal liquefaction,and hydrothermal gasification for the valorization of the PBB were proposed.The complex compounds present in the PBB(hemicellulose,cellulose,and lignin)can be converted into valuable bio-products such as methane gas and bio-ethanol for bioenergy,and nutrients to promote bioactive ingredients.The investigation of the viability and innovation potential of the integrated routes’technology is necessary to improve the circular bio-economy and the recovery of biofuels from biomass waste,particularly PBB.

Association of maternal hypertensive disorders in pregnancy with infant neurodevelopment

Inconsistent findings have been reported regarding the associations between hypertensive disorders in pregnancy (HDP) and infant neurodevelopment. Leveraging data from the Jiangsu Birth Cohort, in the present study, we re-visited such associations in one-year-old infants from 2 576 singleton pregnancies and 261 twin pregnancies. We first assessed infant neurodevelopment by the Bayley Scales of Infant and Toddler Development Screening Test (the Third Edition), and then estimated its association with maternal HDP using general linear regression models and Poisson regression models. In singleton pregnancies, compared with mothers unexposed to HDP, infants born to mothers with chronic hypertension exhibited a lower score (β, −0.67;95% confidence interval [CI], −1.19-−0.15) and a higher risk of "non-optimal" gross motor development (risk ratio [RR], 2.21;95% CI, 1.02-4.79);in twin pregnancies, infants born to mothers with HDP exhibited lower scores in cognition (β, −0.49;95% CI, −0.96-−0.01), receptive communication (β, −0.55;95% CI, −1.03-−0.06), and gross motor (β, −0.44;95% CI, −0.86-−0.03), and at a higher risk of "non-optimal" gross motor development (RR, 2.12;95% CI, 1.16-3.88). These findings indicate that infants born to mothers with HDP may have inferior neurodevelopment outcomes at the age of one year.

Research Progress in Biological Control of Soft Rot of Amorphophallus konjac

In this paper,the main control methods of soft rot of Amorphophallus konjac are reviewed,with a focus on the current research status of using plant growth promoting rhizobacteria for biological control of soft rot of A.konjac,and future research directions are looked forward to.

Metabolic plasticity of T cell fate decision

The efficacy of adaptive immune responses in cancer treatment relies heavily on the state of the T cells.Upon antigen exposure,T cells undergo metabolic reprogramming,leading to the development of functional effectors or memory populations.However,within the tumor microenvironment(TME),metabolic stress impairs CD8+T cell anti-tumor immunity,resulting in exhausted differentiation.Recent studies suggested that targeting T cell metabolism could offer promising therapeutic opportunities to enhance T cell immunotherapy.In this review,we provide a comprehensive summary of the intrinsic and extrinsic factors necessary for metabolic reprogramming during the development of effector and memory T cells in response to acute and chronic inflammatory conditions.Furthermore,we delved into the different metabolic switches that occur during T cell exhaustion,exploring how prolonged metabolic stress within the TME triggers alterations in cellular metabolism and the epigenetic landscape that contribute to T cell exhaustion,ultimately leading to a persistently exhausted state.Understanding the intricate relationship between T cell metabolism and cancer immunotherapy can lead to the development of novel approaches to improve the efficacy of T cell-based treatments against cancer.

Variation in Bombyx mori immune response against fungal pathogen Beauveria bassiana with variability in cell wallβ-1,3-glucan

Entomopathogenic fungi are protected by a cell wall with dynamic structure for adapting to various environmental conditions.β-1,3-Glucan recognition proteins activate the innate immune system of insects by recognizing surface molecules of fungi.However,the associations between pathogenicity and the different components of entomopathogenic fungal cell walls remain unclear.Three Beauveria bassiana strains were selected that have significantly differing virulence against Bombyx mori.The molecular mechanisms underlying the immune response in B.mori were investigated using RNA sequencing,which revealed differences in the immune response to different B.bassiana strains at 12 h post-infection.Immunofluorescence assays revealed thatβ-1,3-glucan content had an opposite trend to that of fungal virulence.β-1,3-Glucan injection upregulated BmβGRP4 expression and significantly reduced the virulence of the high-virulence strain but not that of the medium-virulence or low-virulence strains.BmβGRP4 silencing in B.mori with RNA interference resulted in the opposite virulence pattern,indicating that the virulence of B.bassiana was affected by the cell walls’content ofβ-1,3-glucan,which could be recognized by BmβGRP4.Furthermore,interference with the gene CnA(calcineurin catalytic A subunit)involved inβ-1,3-glucan synthesis eliminated differences in virulence between B.bassiana strains.These results indicate that strains of a single species of pathogenic fungi that have differing cell wall components are recognized differently by the innate immune system of B.mori.

应用纤维支气管镜诊断和治疗小儿肺不张的效果探讨

目的探讨纤维支气管镜在小儿肺不张诊断和治疗中的临床价值。方法回顾性分析2013年1月-2016年12月在遵义市第一人民医院儿科行纤维支气管镜检查和治疗的86例肺不张患儿的临床资料,统计肺不张发生原因,观察治疗效果。结果 86例患儿的肺不张病因以炎症和异物最多,分别有39例(45.35%)和34例(39.53%)。不同年龄肺不张病因分布:0～1岁患儿肺不张病因以异物最多,2～3岁及以上患儿中异物和炎症所占比例较高;结核感染主要分布在0～3岁患儿中;痰液堵塞集中在4～6岁和7～9岁患儿中,10～12岁肺不张分布最少,主要为炎症和支气管扩张。经纤维支气管镜支气管肺泡灌洗治疗1个月后,总复张率为88.37%;治疗3个月后,总复张率为97.67%。结论小儿肺不张病因复杂,其中炎症和异物是其主要病因,纤维支气管镜不仅能够帮助临床医生诊断小儿肺不张病因,还能够同时完成针对性治疗,在临床上具有应用价值。

Rho/ROCK激酶信号通路在大鼠宫腔粘连中的作用

目的 复制宫腔粘连大鼠模型,探讨Rho/ROCK信号通路相关蛋白的表达及其在宫腔粘连中的作用机制。方法 SD大鼠宫腔注入0.5 ml 95%乙醇,复制宫腔粘连模型;对照组注入等量生理盐水。术后15?d观察两组子宫内膜形态学变化,免疫组织化学法检测子宫内膜角蛋白、波形蛋白、Rho(RhoA、RhoB、RhoC)、Rho激酶(ROCKI、ROCKII)及TGF-β1表达。结果 与对照组比较,模型组大鼠子宫内膜厚度变薄(P<0.05);两组腺体数目比较,模型组腺体数目减少(P<0.05);两组角蛋白比较,模型组表达下降(P<0.05);两组波形蛋白比较,差异无统计学意义(P>0.05);两组大鼠子宫内膜RhoA、RhoB、RhoC、ROCKI、ROCKII的表达比较,差异有统计学意义(P<0.05),模型组均高于对照组;模型组大鼠子宫内膜TGF-β1的表达高于对照组(P<0.05)。结论 注射无水乙醇可复制稳定的大鼠宫腔粘连动物模型,其Rho/ROCK信号通路处于激活状态,TGF-β1通过激活Rho/ROCK信号通路促使子宫内膜损伤后组织纤维化,参与宫腔粘连的发生、发展。

一种水溶性石墨烯及其聚氨酯复合材料的制备与性能

将甲苯二异氰酸酯三聚体(IL)与聚乙二醇单甲醚(MPEG)按摩尔比1∶3充分反应,制备了一种水溶性大分子单体(IL-MPEG),将其与氧化石墨烯(GO)按质量比2∶1混合后经水合肼还原制备了一种水溶性石墨烯IL-MPEG/RGO。采用红外光谱仪、拉曼光谱仪、原子力显微镜、透射电镜、扫描电镜和X射线衍射仪等对其结构、形貌和分散性进行了表征。结果发现,IL-MPEG中六元环及苯环疏水结构通过范德华作用力吸附在石墨烯表面,而聚氧乙烯(PEO)亲水链段在水相伸展为其提供水溶性。研究发现,IL-MPEG/RGO在水性聚氨酯(WPU)中具有良好的分散性,能显著改善聚氨酯膜的氧气阻隔性能,当IL-MPEG/RGO在WPU中的含量为0.5%时,氧气透过率(OTR值)低至3.6 cm^3/(m^2·d)。

Influence of Different Gonadotropin-releasing Hormone Agonist Administration Methods on Pregnancy Outcomes of Patients Undergoing In-vitro Fertilization-embryo Transfer

This study aimed to investigate the effect of different gonadotropin-releasing hormone agonist (GnRH-a) administration methods on pregnancy outcomes of patients undergoing in-vitro fertilization-embryo transfer (IVF-ET). Clinical data of 5217 patients who underwent IVF-ET were retrospectively analyzed. Patients were divided into the long-acting GnRH-a group (n=1330) and the short-acting GnRH-a group (w=3887) based on their various treatment plans. The clinical and laboratory embryo data and clinical pregnancy outcomes were compared between the two groups. The results showed that there were no significant differences in the age, infertility, primary/secondary infertility rate, IVF rate, body mass index (BMI), antral follicle counting (AFC), folliclestimulating hormone (FSH) level, and the number of transplanted embryos between the two groups (P>0.05). There were no significant differences in the oocyte numbers, M II rate, fertilization rate, cleavage rate and blastocyst formation rate (P>0.05) between the two groups. The gonadotropin (Gn) using days, Gn dose and endometrial thickness were significantly greater in the long-acting GnRH-a group than those in the short-acting GnRH-a group (P<0.01). Additionally, the estradiol (E2) levels, blastocyst freezing rate, embryo utilization rate, transplant cancellation rate and abortion rate were significantly lower in the long-acting GnRH-a group than those in the shortacting GnRH-a group (P<0.01). The clinical pregnancy rate and embryo implantation rate were significantly higher in the long-acting GnRH-a group than in the short-acting GnRH-a group (P<O.Ol). It was concluded that use of long-acting GnRH-a can effectively reduce the transplant cancellation rate and improve the clinical pregnancy rate of the fresh cycle.

Developmental Potential and Clinical Value of Embryos with Abnormal Cleavage Rate

To investigate the developmental potential and clinical value of embryos with abnormal cleavage rate,a retrospective analysis was performed on 66 635 2-prokaryotic(2PN)and 1-pronuclear(1PN)embryos.The embryos were given conventionally in vitro fertilization(IVF)treatment and continuously cultured on the day 3(D3)at the Reproductive Medicine Center,Tongji Medical College,Huazhong University of Science and Technology from January 2016 to December 2017.The embryos were separated into the day-2(D2)undivided group with 106 cases,the arrested development group with 3482 cases,the blastomere reduction group with 541 cases,and the control group with 62 506 cases,respectively.The blastocyst utilization rates of these three abnormal groups were 2.83%,10.86%and 6.84%,respectively,which were significantly different from that in control group(39.46%).Furthermore,2 cases of anabiosis and 1 case of live birth were found in D2 undivided group.In arrested development group,there were 55 cases of anabiosis,11 cases of clinical pregnancy in single-embryo transplantation(including 6 cases of live birth),and 25 cases of clinical pregnancy in combination with one normal embryo transplantation(including 23 cases of live births and 15 cases of dizygotic twins under B-ultrasound).There were 13 case of anabiosis in blastomere reduction group:there was 1 case of single embryo transplantation and clinical pregnancy was obtained;there were also 6 cases of clinical pregnancy in combination with one single normal embryo transplantation(including 5 cases of live births and 2 cases of di2ygotic twins under B-ultrasound).In conclusion,embryos with abnormal cleavage rate still have the potential to continue to develop,and have certain blastocyst utilization rate and live birth.

对称季铵碱的烷基链长度对草酸电还原反应的影响

研究了四种不同烷基链长度的对称季铵碱对草酸电还原制备乙醛酸反应的影响。线性扫描测试考察了添加剂对铅电极上阴极反应的影响,结果表明对称季铵碱在电极表面的吸附对析氢反应的抑制程度大于其对草酸电还原反应的抑制程度,且随着对称季铵碱中烷基链长度的增加,添加剂抑制析氢反应效果更明显。计时安培法的结果证明添加剂可影响草酸向电极表面的扩散,随着对称季铵碱中烷基链长度的增加,草酸的扩散系数呈现出先增加后减小的趋势。恒流电解实验结果表明,添加剂能有效提高草酸电还原反应的电流效率,且提高效果随对称季铵碱所含烷基链长度的增加而增强。因此,添加剂的吸附对阴极表面析氢反应的抑制作用是草酸电还原反应电流效率提高的主要原因。本研究表明,四丁基氢氧化铵为添加剂时,草酸还原为乙醛酸的电流效率最高。

Simulation and photoelectron track reconstruction of soft X-ray polarimeter

The soft X-ray polarimeter(SXP)is a detector with a wide energy range,large area,and large field of view.A SXP will be mounted on the Chinese Space Station and will mainly focus on detecting the polarization of transient soft X-ray(2–10 keV)sources,especially gamma-ray bursts(GRBs).In this work,a polarimeter detector unit is taken as an example,and Geant4 and Garfield++software are used to simulate the detection efficiency and track production.An improved track reconstruction algorithm is proposed and used to reconstruct two-dimensional images of the tracks.In this method,the initial emission angle of photoelectrons is reconstructed from the initial part of the track by shortening or extending the initial part of the track until the remaining track is straight,and the number of pixels is within an adjustable threshold.The modulation factor of the photoelectronic tracks after reconstruction reaches approximately 57%in the photon energy range of 7–10 keV.