Effects of Abscisic Acid on Cold Resistance in Digitaria sanguinalis(L.)Scop.

[Objectives]This study was conducted to detect the protective effect of abscisic acid on chilling injury of Digitaria sanguinalis(L.)Scop,and whether this effect is related to antioxidant enzymes and osmotic adjustment.[Methods]D.sanguinalis plants were sprayed with abscisic acid solution,and exposed to cold stress at 15℃for 3 d after one day and then at 5℃for 25 to 30 d in a growth chamber.The changes of plant osmotic potential under this treatment were detected.[Results]Under low temperature stress,the osmotic potential of plants in the abscisic acid treatment and the control increased,but the osmotic potential level of the abscisic acid treatment plants was lower.The SOD activity of plants in the ABA treatment and the control decreased under low temperature stress.Under low temperature stress,the activity of catalase and peroxidase in ABA-treated plants was higher than that in control plants.[Conclusions]This study provides a theoretical basis for the impact of abscisic acid on the physiological response of D.sanguinalis to cold injury.

Calcitriol attenuates liver fibrosis through hepatitis C virus nonstructural protein 3-transactivated protein 1-mediated TGF β1/Smad3 and NF-κB signaling pathways

BACKGROUND Hepatic fibrosis is a serious condition,and the development of hepatic fibrosis can lead to a series of complications.However,the pathogenesis of hepatic fibrosis remains unclear,and effective therapy options are still lacking.Our group identified hepatitis C virus nonstructural protein 3-transactivated protein 1(NS3TP1) by suppressive subtractive hybridization and bioinformatics analysis,but its role in diseases including hepatic fibrosis remains undefined.Therefore,additional studies on the function of NS3TP1 in hepatic fibrosis are urgently needed to provide new targets for treatment.AIM To elucidate the mechanism of NS3TP1 in hepatic fibrosis and the regulatory effects of calcitriol on NS3TP1.METHODS Twenty-four male C57BL/6 mice were randomized and separated into three groups,comprising the normal,fibrosis,and calcitriol treatment groups,and liver fibrosis was modeled by carbon tetrachloride(CCl4).To evaluate the level of hepatic fibrosis in every group,serological and pathological examinations of the liver were conducted.TGF-β1 was administered to boost the in vitro cultivation of LX-2 cells.NS3TP1,α-smooth muscle actin(α-SMA),collagen I,and collagen Ⅲ in every group were examined using a Western blot and real-time quantitative polymerase chain reaction.The activity of the transforming growth factor beta 1(TGFβ1)/Smad3 and NF-κB signaling pathways in each group of cells transfected with pcDNA-NS3TP1 or siRNA-NS3TP1 was detected.The statistical analysis of the data was performed using the Student’s t test.RESULTS NS3TP1 promoted the activation,proliferation,and differentiation of hepatic stellate cells(HSCs)and enhanced hepatic fibrosis via the TGFβ1/Smad3 and NF-κB signaling pathways,as evidenced by the presence of α-SMA,collagen I,collagen Ⅲ,p-smad3,and p-p65 in LX-2 cells,which were upregulated after NS3TP1 overexpression and downregulated after NS3TP1 interference.The proliferation of HSCs was lowered after NS3TP1 interference and elevated after NS3TP1 overexpression,as shown by the luciferase assay.NS3TP1 inhibited the apoptosis of HSCs.Moreover,both Smad3 and p65 could bind to NS3TP1,and p65 increased the promoter activity of NS3TP1,while NS3TP1 increased the promoter activity of TGFβ1 receptor I,as indicated by coimmunoprecipitation and luciferase assay results.Both in vivo and in vitro,treatment with calcitriol dramatically reduced the expression of NS3TP1.Calcitriol therapy-controlled HSCs activation,proliferation,and differentiation and substantially suppressed CCl4-induced hepatic fibrosis in mice.Furthermore,calcitriol modulated the activities of the above signaling pathways via downregulation of NS3TP1.CONCLUSION Our results suggest that calcitriol may be employed as an adjuvant therapy for hepatic fibrosis and that NS3TP1 is a unique,prospective therapeutic target in hepatic fibrosis.

深海多金属结核集矿装置水力输送流场分析与试验

对深海多金属结核集矿装置水力输送流场进行了理论计算,得到了多金属结核粒径与输送通道最小输送速度的关系;仿真分析了喷嘴射流速度分别为15、20、25 m/s时输送通道内水流流态分布,给出了流道下表面30 mm处的流速。在实验室进行了输送喷嘴不同射流速度的采集试验,实验结果与理论计算及仿真分析结果相符。

基于金属-介质-金属的可调谐窄带完美吸收的研究

为了实现窄带完美吸收,本文提出了一种简单的三层金-二氧化硅-金薄膜(MDM)结构。通过电磁波时域差分算法(FDTD)进行模拟仿真和理论计算,详细分析了该结构的可调谐吸收特性,同时建立了理论模型,分析了其中存在的电磁模式以及窄带完美吸收的物理机制。首先,利用电磁波时域差分算法和传输矩阵算法(TMM)对该结构进行了理论计算,详细地分析了各个结构参数对吸收光谱的影响。然后,对该结构形成的窄带完美吸收物理机制进行了分析讨论。最后,利用磁控溅射制备手段,成功制备了三层结构的样片。实验观测到的结果与理论仿真一致。实验结果表明:本文提出的窄带完美吸收结构,最窄带宽约为21 nm,最高吸收可达99.51%,基本实现了窄带完美吸收。本文研究成果为相关应用奠定了基础。

信息技术推动乡村绿色发展的要求、实践及趋势

信息成为数字、数据和产生价值是由信息技术的应用来实现的。我国乡村应用信息技术的硬体条件已经初步具备,应用信息技术的软体条件尚需作较大的改进。政府的主要职责是为乡村绿色发展和乡村生态系统保护应用信息技术提供更好的宏观政策环境和更多的信息技术产品,使信息技术成为乡村振兴、农业绿色发展的推动力,成为规范各利益相关者行为的评价工具,让农民手中的智能手机在推动乡村绿色发展方面发挥更大的作用。乡村应用信息技术的重点要由协调政府与农民的关系拓展到协调农民和市场的关系。信息技术的突破和信息技术服务的创新,是一个不断有新起点,不断出新人才的领域,它是年轻科技人员,包括大学生、研究生施展才华,为推动中国乡村和农业绿色发展作贡献的重要平台。

The dissolution of total suspended solids and treatment strategy of tailwater in a Litopenaeus vannamei recirculating aquaculture system

In recirculating aquaculture systems(RASs),the effective treatment of aquaculture tailwater is essential to maintain the health of the RAS.This study investigated the optimal time and method for tailwater treatment during three periods of the aquaculture of the Litopenaeus vannamei:nursery(0–26 d),middle(27–57 d),and later(57–104 d).The variation of several water parameters during the dissolution of total suspended solid(TSS)in tailwater,applied with the effects of ozone on the microorganism and water quality parameters were investigated.Results showed that the TSS concentrations in tailwater decreased with time,although not significantly(P>0.05),whereas total ammonia nitrogen(TAN),nitrite(NO-2-N),and nitrate(NO_(3)^(-)-N)increased significantly(P<0.05).Therefore,TSS should be removed from the tailwater as early as possible,being most optimal within 4 h.Ozone removed 38.24%–48.95%of TSS,17.78%–90.14%of TAN,and 87.50%–98.90%of NO-2-N after 4 h of treatment.However,it resulted in the significant accumulation of NO_(3)^(-)-N.Moreover,the total number of Vibrio and bacterial counts in aquaculture tailwater was reduced completely by ozone within 4 h.Thus,these results provided technical details and data support for the effective treatment of tailwater from shrimp RAS.

Rapid authentication of different herbal medicines by heating online extraction electrospray ionization mass spectrometry

The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10–15 s,with minimal sample(<0.5 mg)and solvent consumption(<20μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R^(2)X>0.87,R^(2)Y>0.91,and Q^(2)>0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.

2D Nb_(2)CT_(x) MXene/MoS_(2) heterostructure construction for nonlinear optical absorption modulation

Two-dimensional(2D)nonlinear optical mediums with high and tunable light modulation capability can significantly stimulate the development of ultrathin,compact,and integrated optoelectronics devices and photonic elements.2D carbides and nitrides of transition metals(MXenes)are a new class of 2D materials with excellent intrinsic and strong light-matter interaction characteristics.However,the current understanding of their photo-physical properties and strategies for improving optical performance is insufficient.To address this issue,we rationally designed and in situ synthesized a 2D Nb_(2)C/MoS_(2) heterostructure that outperforms pristine Nb2C in both linear and nonlinear optical performance.Excellent agreement between experimental and theoretical results demonstrated that the Nb_(2)C/MoS_(2) inherited the preponderance of Nb_(2)C and MoS_(2) in absorption at different wavelengths,resulting in the broadband enhanced optical absorption characteristics.In addition to linear optical modulation,we also achieved stronger near infrared nonlinear optical modulation,with a nonlinear absorption coefficient of Nb_(2)C/MoS_(2) being more than two times that of the pristine Nb_(2)C.These results were supported by the band alinement model which was determined by the X-ray photoelectron spectroscopy(XPS)experiment and first-principal theory calculation.The presented facile synthesis approach and robust light modulation strategy pave the way for broadband optoelectronic devices and optical modulators.

Langerhans cell histiocytosis misdiagnosed as thyroid malignancy: A case report

BACKGROUND The incidence of Langerhans cell histiocytosis(LCH) is low, and involvement of the thyroid is even rarer, which results in high missed diagnosis or misdiagnosis rates.CASE SUMMARY We report a young woman with a thyroid nodule. Thyroid malignancy was suggested by fine needle aspiration, but she was eventually diagnosed with multisystem LCH, thus avoiding thyroidectomy.CONCLUSION The clinical manifestations of LCH involving the thyroid are atypical, and the diagnosis depends on pathology. Surgery is the main method for treating primary thyroid LCH, while chemotherapy is the main treatment method for multisystem LCH.

Effects of Polygonatum odoratum Polysaccharides on the Quality of White Chili Peppers in Jars

[Objectives]This study was conducted to investigate the effects of Polygonatum odoratum polysaccharides on the quality of white chili peppers in jars.[Methods]White chili peppers were pickled by adding different concentrations of P.odoratum polysaccharides with traditional pickling technology,and its nitrite content,pH and sensory quality were analyzed and detected.[Results]The results showed that,compared with the control group without adding P.odoratum polysaccharides,the nitrite content in white chili peppers in jars decreased after adding P.odoratum polysaccharides.When the addition amount of P.odoratum polysaccharides was 0.002%,the inhibition rate of nitrite reached the maximum.Under the same fermentation time,P.odoratum polysaccharides could significantly reduce the pH value of pickles.When the addition amount of P.odoratum polysaccharide was 0.002%and the pickling time was 3 months,the sensory quality of white chili peppers in jars was the best.At this point,white chili peppers in jars had rich aroma and tasted soft and sour,and the sour and salinity were suitable.As the fermentation time continued to increase,the chili aroma of white chili peppers in jars gradually decreased,and the sour taste became more pronounced.[Conclusions]This study can provide reference for the safety and quality control of white chili peppers in jars.

Effect of Resistance Training,Aerobic Exercise Before Doula-Assisted Delivery on the Psychological Well-Being and Labor Duration of Parturients

Objective:To investigate the impact of resistance training and aerobic exercise before doula-assisted delivery on the psychological well-being and labor duration of parturients.Methods:105 cases of parturients who gave birth in our hospital from February 2021 to April 2023 were included in this study.The patients were divided into a control group of 52 cases and an observation group of 53 cases.The patients in the control group received no particular intervention before delivery and only received doula assistance.The patients in the observation group received resistance training,aerobic exercise,and doula assistance prior to giving birth.After delivery,the mothers were observed for 2 hours in the delivery room and then returned to the maternal and infant ward.The observation indicators of the two groups were compared.Results:In comparison to the control group,the observation group exhibited shorter durations in the first,second,and third stages of labor,as well as the total delivery time.Additionally,the amount of postpartum blood loss at 2 hours was smaller in the observation group.The rate of cesarean section was lower,and the rate of vaginal natural delivery was higher in the observation group.Following the intervention,both groups of postpartum women showed decreased SAS and SDS scores compared to before the intervention.Moreover,the observation group had lower scores than the control group.These differences were all statistically significant(P<0.05).Conclusion:Resistance training and aerobic exercise before doula-assisted delivery can effectively improve the psychological state of parturients,shorten labor duration,increase the rate of natural vaginal delivery,and reduce pain and postpartum hemorrhage.

1980-2020年贵州省草地空间分布格局演变及驱动力分析

草地在喀斯特地区石漠化治理和畜牧业发展中发挥重要作用,探明草地空间分布格局演变特征及其驱动力,对维护区域草地生态功能,实现可持续发展具有重要意义。本研究基于土地利用数据集,分析贵州省1980-2020年草地空间转移特征,将景观格局与空间自相关相结合,深入识别草地空间分布格局演化规律及有效管理区域,并利用地理探测器量化草地空间分布格局演变的驱动力。结果表明:1)40年来,贵州省草地面积变化可划分为增长期(1980-2000年)、衰退期(2000-2015年)、恢复期(2015-2020年)3个阶段,草地面积总体上减少了176.88 km^(2)。发生变化区域集中在西部与南部地区,以草地和林地、耕地之间的转移为主,草地总体空间分布格局表现出“西部与南部高,东部与北部低”的特征;2)草地整体景观破碎程度增加,聚合度降低,形状趋于复杂,区县尺度的草地斑块更破碎和分散,但形状更规则;3)草地全局空间自相关程度减弱,局部自相关存在高-高聚集和低-高聚集的空间聚类现象,且集中分布在西部与南部地区;4)草地空间分布格局主要受自然因素的影响,海拔是主导因子,解释力最高,为42.9%。双因子的交互作用可增强对草地空间分布格局的解释力,海拔与牧业产值、年平均气温、人口密度、GDP均存在较强的交互作用,在海拔主导的草地总体分布格局下,区域间社会经济因素的不同和变化显著影响草地空间分布格局的演变,同时地区政策起重要导向作用。

河控浅水三角洲平原亚相沉积模式探讨——以鄂尔多斯盆地S59区块山西组一段为例

鄂尔多斯盆地S59区块山一段,整体具有构造稳定、地势平坦、古水深较浅、湖平面频繁升降、物源充足等特点,发育浅水三角洲沉积体系。本文在前人研究的基础上,通过对取心井岩心分析及侧井相分析,探讨了浅水三角洲的沉积特征,建立了浅水三角洲平原亚相沉积模式。研究结果表明,山西组山一段为河控浅水三角洲沉积,浅水三角洲的陆上部分沉积过程与曲流河沉积具有一致性,发育边滩、“渐弃型”废弃河道、决口扇和洪泛平原等微相,平面上河道在凹岸不断侵蚀,凸岸不断堆积形成边滩微相。此外在凹岸发育一定规模的废弃河道,河道砂体呈南北向分布,发育少量的决口扇沉积,在河道间发育细粒沉积洪泛平原亚相。三角洲平原亚相沉积模式的建立为预测优质砂体发育位置提供地质依据。

可见光波段高温标定的简化方法

为了提高可见光波段(0.3μm~0.9μm)高温标定的效率,提出了可见光波段高温标定的简化方法。本文提出了带有曝光时间变量的可见光波段的高温标定模型,通过大量实验发现,RGB相机各个通道的灰度值不仅随曝光时间递增呈线性变化,且随黑体辐射亮度的递增也呈线性变化,进而确定了可见光波段高温标定模型的具体形式。为了求解简化后的可见光波段高温标定模型中的未知数,在两个黑体辐射亮度下,分别采集两个曝光时间下的图像数据,接着,对图像数据进行处理,便可以得到任意曝光时间下的RGB相机高温标定曲线。最后,对本文提出的简化可见光波段高温标定方法与常规按曝光时间进行可见光波段高温标定法进行比较。实验结果表明:R、G、B通道计算值与标定值的相对误差最大值分别为3.38%、2.56%和−1.14%,且各通道的计算值与标定值的相对误差均未超过3.50%。本文提出的数学模型可以有效地简化传统的高温标定法,进而大大缩短了高温标定时间,提高了高温标定的标定效率。

安塞油田致密砂岩油藏补孔压裂措施效果分析

安塞油田PQ油藏属于特低渗透油藏,油藏开发递减快、稳产难度大。区域砂体发育、油层厚度大,存在纵向油层未动用状况,为了进一步挖潜剩余油,提高PQ油藏开发效果,油井补孔已成为油田老区稳产及挖潜的主要途径之一。针对不同层位的历年措施进行效果进行分析,总结出各层位出油下限;分析地层系数、孔隙度、原始含油饱和度以及地层压力对补孔效果的影响,建议下步补孔措施选井时,优选油层物性好、地层系数为4~10、孔隙度大于11%、含油饱和度大于45%、地层压力大于7 MPa的油井,也为后期补孔压裂措施达到更好的效果提供理论依据。

基于改进ViBe算法以及改进CLAHE算法的烟雾信息增强技术

对于在火灾刚开始发生时,烟雾信息较弱且不明显的问题,提出了一种使用视频图像序列进行烟雾信息增强的技术。使用改进的ViBe算法对整个视频进行检测,获得每帧图像的运动蒙板。采用去除离群值的帧间差分放大算法对烟雾信息进行放大。通过改进后的限制对比度的自适应直方图均衡化算法(CLAHE)来提高烟雾区域对比度,并使用合并蒙板保存烟雾信息,用翻转蒙板保留原始图像背景信息,最后进行烟雾区域与背景区域的融合,得到最终图像。实验结果表明,算法可以将烟雾泄漏区域的对比度进行较大程度的提高,并且由于融合了原始图像背景,因此,背景噪声也处于较低水平。

基于关键点检测的坐姿识别方法

针对直接应用深度学习分类算法所得模型泛用性较差的问题,提出了一种分两个步骤完成人体坐姿识别的方法。所提方法首先提取图片中人体上身关键点的坐标信息,在关键点检测环节采用高分辨率主干网络,并进一步改进了模型结构,在下采样环节中引入SE(Squeeze-and-Excitation)注意力机制,加强了空间位置特征的表达,取得了更高的检测平均精准度;然后采用随机森林算法对关键点进行坐姿分类。实验结果表明:所提方法识别准确率可以达到94%以上,并且在陌生场景下有更好的泛用性,能适应实际应用中复杂的人物环境。

面向空间应用的高可靠以太网接口设计

针对时间触发以太网的信息网络能够满足高带宽、低延迟、高可靠的应用需求,文章提出了一种兼容传统以太网,实现关键流量降级传输的以太网接口设计方案,并完成接口逻辑实现。文章对数据帧的发送延迟、接收延迟等主要指标进行了仿真和实物测试,最后与1553B总线进行了对比,结果表明该接口能够满足当前飞行器数据传输要求,可以应用于面向空间应用的各类高带宽、低延迟、高可靠数据传输场景。

高阻型单相接地故障信号的暂态分量影响因素研究

高阻型单相接地故障信号的暂态分量,在故障过渡电阻这一主要影响因素之外,还受到以下影响因素的制约,进而影响暂态判据选线的准确度:配电网发生故障时所运用的系统接地方式、故障发生时的相角、故障发生点距母线的距离、故障发生出线的长度等。其中系统接地方式由于为配电网系统本身的设计所导致,不受故障本身随机性的影响,因而其影响对于研究高阻型单相接地故障特征的暂态分量具有基础意义。本文利用了Matlab-Simulink仿真平台,重点针对过渡电阻阻值、中性点接地方式对高阻型单相接地故障暂态分量的影响进行了仿真分析,着重探究了过渡电阻阻值以及几种中性点非有效接地方式,在接近真实情况的三相不平衡条件下对高阻型单相接地故障暂态分量的影响。结果表明高阻型单相接地故障的过渡电阻较小、系统消弧线圈补偿度较小或中性点不接地,将影响高阻型单相接地故障信号的暂态分量并使得其强度较大、信噪比较高。

涉氢环境及其对高温合金的影响:评述--面向航空发动机潜在应用

随着“双碳”目标的提出,氢作为绿色清洁能源成为未来航空业发展的重要趋势,近年来氢燃料航空发动机备受关注。高温合金是当前燃气涡轮发动机热端部件中应用最广泛的材料,本文综述现有其他领域涉氢环境对合金的影响,为未来氢燃料航空发动机用高温合金研制和应用提供参考。对内/外氢环境的引入、渗(充)氢方法、氢浓度/氢分布特征及氢稳定存在温度的测量、氢对拉伸、蠕变/持久和疲劳性能的影响以及氢脆的断裂机理进行分述,总结不同成分、制备工艺、原始组织状态、合金化程度以及不同应用领域高温合金在涉氢环境下的力学性能退化因素。结果表明,外氢环境下比内氢环境下力学性能下降更快;合金化程度更高的高温合金氢脆更明显,而高温氢环境下合金性能损伤(蠕变/持久、疲劳和拉伸)倾向较室温明显降低。就燃氢涡轮动力用高温合金在涉氢环境下的力学性能评价及适氢环境高温合金的研制进行展望。燃氢涡轮航空发动机可能面临的涉氢工作环境包括:液氢存储的低温氢环境;用于通道冷却的氢环境;经过气体压缩的高温高压氢环境;以及燃烧产物-高温水蒸气(高温潮湿)环境的影响。重点应关注氢在高温合金中的扩散和渗透、高温合金在高压氢环境下的脆性和腐蚀、高温潮湿环境下氧化和腐蚀行为以及上述多重耦合环境下合金和涂层的退化和防护机制。针对燃氢涡轮发动机工作环境,需要搭建近服役条件的高温合金燃氢环境实验装置,开展燃氢环境对高温合金及零部件的影响研究,建立现役叶片和盘件等热端部件关键用材在涉氢环境中的力学性能数据库和相关标准,并在此基础上适时研发适用于燃氢环境使用的高温结构材料,为氢燃料燃气涡轮航空发动机的应用提供支持。