耐盐耐洗涤剂海藻纤维的制备及性能

不耐盐和不耐洗涤剂一直是困扰海藻纤维制备的难题。针对这一问题文中采用四硼酸钠对海藻纤维进行改性,通过红外光谱、X射线衍射对改性海藻纤维进行了结构表征,并利用吸液量、纤维钙离子含量、纤维断裂强度、纤维和纺丝液微观形貌测试,研究了改性海藻纤维的耐盐、耐洗涤剂性能。结果表明,利用四硼酸钠对海藻纤维进行改性可以提高海藻纤维的交联程度和结晶度,从而降低生理盐水和洗涤剂中的钙钠离子交换对海藻纤维结构的破坏,有利于保持纤维形貌。经生理盐水和洗涤剂浸泡后,海藻纤维的吸液量仅为10.2%和10.1%,断裂强度损失仅为5.1%和9.0%,显著提升了海藻纤维的耐盐、耐洗涤剂性能。

熟化过程中结构与组分的变化对天然橡胶性能的影响

熟化是天然橡胶加工过程中的重要工序之一,过程中往往伴随着天然橡胶的结构与组分变化,从而引起天然橡胶性能的改变。但是,天然橡胶的结构和组分随着熟化的进行而同步发生改变,因此二者各自对天然橡胶性能的影响大小尚不明确。文中采用TSR 10,TSR 10CV和TSR 3CV不同样品来对比分析天然网络和非胶组分各自对NR性能的影响。结果表明,熟化过程中天然网络结构的增加对门尼黏度值和塑性初值的升高有较大的贡献,而非胶组分含量的减少则对其影响较小。对于未填充天然橡胶硫化胶而言,非胶组分的分解是力学性能提高的重要来源;而天然网络结构对有效交联密度和力学性能的贡献具有一定协同效应,但贡献幅度相对有限。对于填充炭黑天然橡胶硫化胶而言,3个样品的常规力学性能无明显差异,但TSR 10的整体动态疲劳性能最优,TSR 10CV其次,TSR 3CV最差。说明非胶组分的降解和天然网络结构的存在均有利于填充炭黑天然橡胶硫化胶动态力学性能的提高。

Construction of 1D Heterostructure NiCo@C/ZnO Nanorod with Enhanced Microwave Absorption

Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing materials from LDHs.Herein,we designed heterostructure NiCo-LDHs@ZnO nanorod and then subsequent heat treating to derive NiCo@C/ZnO composites.Finally,with the synergy of excellent dielectric loss and magnetic loss,an outstanding absorption performance could be achieved with the reflection loss of−60.97 dB at the matching thickness of 2.3 mm,and the widest absorption bandwidth of 6.08 GHz was realized at 2.0 mm.Moreover,this research work provides a reference for the development and utilization of LDHs materials in the field of microwave absorption materials and can also provide ideas for the design of layered structural absorbers.

Gecko Active Components Regulates Endoplasmic Reticulum Stress to Induce the Apoptosis of KYSE150 Cells through PERK Pathway

Objective: Gecko active components (GACs), extracted from the powder of whole Gecko, have been reported to be effective against esophageal squamous cell carcinoma (ESCC). Endoplasmic reticulum stress (ERs) has been regarded as an important cause for pathogenesis of esophageal squamous cell carcinoma (ESCC). In this paper, we aimed to study the effect of GACS on apoptosis of human esophageal carcinoma KYSE150 cells and to analyze the underlying signaling pathway. Methods: MTT assay was used to detect the viability of KYSE150 cells, and Flow cytometry was applied to detect reactive oxygen species (ROS), calcium generation, and the level of mitochondrial membrane potential (MMP). Western blot analysis was applied to observe the expression of apoptosis-related proteins and endoplasmic reticulum stress (ERs)-related proteins in KYSE150 cells. Results: The results showed that GACs inhibited KYSE150 cell vitality in a dose- and time-dependent manner. Not only that, GACs could up-regulated ERs-related and apoptosis-related proteins expression, and the content of ROS and calcium were significantly increased, and also, the level of MMP was significantly decreased. Conclusion: The results of this report suggested that induction of apoptosis occurs through the ERs dependent signaling pathways.

洞察电子运动的阿秒光脉冲——2023年诺贝尔物理学奖评述

2023年的诺贝尔物理学奖授予了美国俄亥俄州立大学的皮埃尔·阿戈斯蒂尼(Pierre Agostini)、德国马普量子光学研究所及慕尼黑大学的费伦茨·克劳斯(Ferenc Krausz)和瑞典隆德大学的安妮·卢利尔(Anne L'Huillier)三位教授,以表彰他们在产生阿秒光脉冲的实验方法研究中所做出的贡献。由于物质中电子运动的时间尺度就是阿秒量级,因此阿秒光源及阿秒物理打开了人们探索微观世界超快过程的大门,并给宏观物理现象的理解带来新的希望。

中国实体经济与金融的互溢效应及其政策应对

双支柱政策在应对实体经济和金融之间的复杂关系及多调控目标方面发挥重要作用。文章使用Diebold-Yilmaz溢出指数方法,分析我国实体经济和金融之间的动态溢出效应。在此基础上,构建TVP-SV-FAVAR模型,将实体经济和金融的关系划分为紧耦合溢出区制和松耦合溢出区制,实证研究双支柱政策对实体经济和金融的调控效果。研究发现,我国实体经济和金融之间表现出显著的双向溢出效应,在松耦合溢出区制下,双支柱政策对实体经济和金融的调控效果更强,货币政策对实体经济和金融的调控效果均强于宏观审慎政策,我国双支柱政策对实体经济和金融的逆周期调控效果良好。文章归纳了稳增长、防过热、防风险、防收缩相互组合的不同政策目标下货币政策和宏观审慎政策的最优政策组合形式。现阶段,我国政策目标总体属于“稳增长+防风险”的范畴,应当采取力度适中的宽松货币政策和力度适中的从紧宏观审慎政策组合,为经济高质量发展提供实体经济支撑和稳定的金融环境。

Advances in coastal ocean boundary layer detection technology and equipment in China

Accurate and comprehensive knowledge of the atmospheric environment and its evolution within the coastal ocean boundary layer are necessary for understanding the sources,chemical mechanisms,and transport processes of air pollution in land,sea,and atmosphere.We present an overview of coastal ocean boundary layer detection technology and equipment in China and summarize the progress and main achievements in recent years.China has developed a series of coastal ocean boundary layer detection technologies,including Light Detection and Ranging(LIDAR),turbulent exchange analyzer,air-sea flux analyzer,stereoscopic remote sensing of air pollutants,and oceanic aerosol detection equipment to address the technical bottleneck caused by harsh environmental conditions in coastal ocean regions.Advances in these technologies and equipment have provided scientific assistance for addressing air pollution issues and understanding land-sea-atmosphere interactions over coastal ocean regions in China.In the future,routine atmospheric observations should cover the coastal ocean boundary layer of China.

Flexible Vis/NIR wireless sensing system for banana monitoring

Objectives:The quality of the fruit seriously affects the economic value of the fruit.Fruit quality is related to many ripening parameters,such as soluble solid content(SSC),pH,and firmness(FM),and is a complex process.Traditional methods are inefficient,do not guarantee quality,and do not adapt to the current rhythm of the fruit market.In this paper,a was designed and implemented for quality prediction and maturity level classification of Philippine Cavendish bananas.Materials and Methods:The quality changes of bananas in different stages were analyzed.Twelve light intensity reflectance values for each maturity stage were compared to conventionally measured SSC,FM,PH,and color space.Results:Our device can be compared with traditional forms of quality measurement.The experimental results show that the established predictive model with specific preprocessing and modeling algorithms can effectively determine various banana quality parameters(SSC,pH,FM,L^(*),a^(*),and b^(*)).The RPD values of SSC and a^(*)were greater than 3.0,the RPD values of L^(*)and b^(*)were between 2.5 and 3.0,and the pH and FM were between 2.0 and 2.5.In addition,a new banana maturity level classification method(FSC)was proposed,and the results showed that the method could effectively classify the maturity level classes(i.e.four maturity levels)with an accuracy rate of up to 97.5%.Finally,the MLR and FSC models are imported into the MCU to realize the near-range and long-range real-time display of data.Conclusions:These methods can also be applied more broadly to fruit quality detection,providing a basic framework for future research.

薄板弯曲分析的高阶高效无网格法

与传统有限元法相比,无网格法具有节点形函数高度光滑、易于形成高阶近似等优势,更适合于以薄板弯曲问题为代表的高阶偏微分方程的数值求解.然而,高阶无网格法的形函数是非多项式的有理函数,导致弱形式的区域积分难以得到精确计算,通常采用的高阶高斯积分方法需使用大量积分点,计算效率低且精度不高.论文针对薄板弯曲问题的高阶（三阶）无网格法分析,首次发展了与该高阶近似相一致的曲率光顺方案,并基于背景三角形积分单元建立了相应的数值积分格式,大幅度减少了所需的积分点数目.所发展方法的关键在于计算刚度阵所需的形函数的二阶导数由形函数及其一阶导数通过散度定理确定,而非对形函数直接求导获得.数值结果表明,基于标准的高斯积分方案的高阶无网格法精度不高,不能精确再现纯弯曲和线性弯曲模式,且得到的弯矩场分布存在严重的虚假数值振荡.而论文所建议的基于曲率光顺方案的高阶无网格法能够方便高效地求解薄板弯曲问题,尤其是它能精确反映纯弯曲和线性弯曲模式.与标准的高斯积分方法和目前主流的常曲率光顺方法相比,论文方法在计算效率、精度、弯矩分布等方面均展现出显著优势,因而具有较好的应用价值.

Analysis of the Innovation of Zhuang Medical Culture from the Perspective of a Comprehensive Well-Off Society: Insights from Social Research and Public Engagement

Based on the inheritance and development of Zhuang medicine culture from the perspective of a comprehensive well-off society,traditional Chinese medicine is a treasure of Chinese civilization.The inheritance,innovation,and development of traditional Chinese medicine are crucial to the cause of socialism with Chinese characteristics in the new era.By engaging young people,reducing the aging of the medical team,and understanding the views and suggestions of various groups on Zhuang medicine culture,questionnaire surveys,field interviews,literature searches,and other methods were employed to gather and analyze public opinions and suggestions on Zhuang medicine.Additionally,online consultations were conducted to assess the popularity of Zhuang medicine and identify existing problems.Based on these findings,recommendations and strategies for improvement were formulated.Furthermore,the design of an online consultation app is proposed to enhance the role and effectiveness of Zhuang medicine’s inheritance and development.

肝素硫酸转移酶优化表达及其在动物源肝素硫酸化中的应用

肝素是一种重要的凝血药物,目前主要依赖于动物小肠粘膜的提取。动物源肝素含有的抗凝血活性五糖单位GlcNS6S-GlcA-GlcNS6S3S-Ido2S-GlcNS6S少,抗凝血活性低下。文中提出并验证了一种基于酶法催化动物源肝素,提高其硫酸化程度和抗凝血活性的方法。通过比较3种硫酸转移酶肝素-2-硫酸转移酶(Heparan sulfate-2-O-sulfotransferase,HS2ST)、肝素-6-硫酸转移酶(Heparan sulfate-6-O-sulfotransferase,HS6ST)、肝素-3-硫酸转移酶(Heparan sulfate-3-O-sulfotransferase,HS3ST)在重组大肠杆菌及重组毕赤酵母中表达,确定了毕赤酵母作为3种硫酸转移酶的表达宿主;进一步通过N端融合麦芽糖融合蛋白MBP和硫氧还蛋白Trx A,HS2ST和HS6ST的酶表达水平分别提高至(839?14) U/L和(792?23) U/L。通过3种硫酸转移酶HS2ST、HS6ST和HS3ST共同催化动物源肝素,其抗凝血活性由(76?2) IU/mg提高至(189?17) IU/mg。

肝素C5异构酶的表达优化及分子改造

肝素和硫酸乙酰肝素是一类应用于临床抗凝血的糖胺聚糖。肝素葡萄糖醛酸C5异构酶(Heparosan-N-sulfate-glucuronate 5-epimerase,C5,EC 5.1.3.17)是肝素和硫酸乙酰肝素合成过程中重要的修饰酶,催化N-硫酸化肝素前体(N-sulfoheparosan)的D-葡萄糖醛酸(D-GlcA)上5号位羧基翻转生成L-艾杜糖醛酸(L-iduronic acid,L-IdoA)。文中以大肠杆菌Escherichia coli为宿主对斑马鱼来源的肝素葡萄糖醛酸C5异构酶基因Glce进行重组表达优化与分子改造。比较了3种不同的表达载体pET20b(+)、pET28a(+)和pColdⅢ对C5表达的差异情况,其中以嗜冷启动型载体pColdⅢ表达酶活最高,达到(1873.61±5.42)U/L。为了进一步提高C5的可溶表达量,在N端融合促溶标签SET2后,可溶蛋白表达量比对照提高了50%,酶活达到(2409.25±6.43)U/L。在此基础上,通过理性设计对底物结合口袋进行定点突变,获得最优突变体(V153R)的酶活和比酶活分别为(5804.32±5.63)U/L和(145.14±2.33)U/mg,是原始酶的2.41倍和2.28倍。肝素C5异构酶改造与表达优化为酶法催化合成肝素奠定了基础。

Metal-organic framework-derived CoSn/NC nanocubes as absorbers for electromagnetic wave attenuation

Metal-organic framework-derived composites have been widely used in electromagnetic wave(EMW)absorption,but the traditional synthetic strategy greatly limits the structure and species of MOFs.This research provided a solvent-free method to synthesize Co-MOF and its derivatives.Using CoSnO_(3)as the precursor,the preparation of Co-MOF is achieved by bridging the cobalt(II)ion of CoSnO_(3)and the 2-methylimidazole skeleton.The CoSn/N-doped carbon(CoSn/NC)composites derived from CoSnO_(3)-MOF(Co-MOF with CoSnO_(3)as Co source)retain the original morphology of CoSnO_(3).Besides,the polarization effect produced by the N-doped carbon layers also benefits the excellent EMW absorption performance of the CoSn/NC composites.It is reflected in the minimum reflection loss(RL)of-48.2 dB at 2.2 mm and the effective bandwidth(EBA)of 5.84 GHz.This work provides a new channel to the construction of Co-MOFs,which could be extended to other Co-based oxides and vastly expand the species of MOFs based on metallic Co.

Synthesis of MnxOy@C hybrid composites for optimal electromagnetic wave absorption capacity and wideband absorption

The fabrication of high-performance electromagnetic(EM)wave absorption(EMA)materials is an effective strategy to deal with ever-increasing EM pollution.In this work,a series of manganese oxides/porous carbon(Mn_(x)O_(y)@C)hybrid composites are obtained by a two-step process.It is revealed that different manganese oxides play various influence on the dielectric properties of absorbers.Owing to the moderate complex permittivity of MnO@C hybrid composites,the optimal reflection loss could reach as high as-76.0 dB at the matching thickness of 2.0 mm with 5.2 GHz of effective absorption bandwidth at thickness of 2.1 mm.We demonstrated that the addition of porous carbon is vital for enhancing EMA performance of composites,which not only coordinates impedance matching allowing more EM waves enter the absorber,but also provides the path for electron movement,thus profiting conductive loss.Besides,different heterogeneous interfaces including porous carbon,manganese oxide and so on,are conducive to contribution of interface polarization.The most noteworthy is ingenious design of composite materials and systematic research of EM energy attenuation mechanism in this work will provide the possibility to realize high-performance EMA.

Controllable synthesis of Ni/NiO@porous carbon hybrid composites towards remarkable electromagnetic wave absorption and wide absorption bandwidth

The reasonable design of the composition of the composite materials is of great significance to optimized the electromagnetic(EM)wave absorption performance.Herein,the Ni/NiO@C hybrid composites with tunable Ni proportion were successfully synthesized through a two-step process.With the assistance of X-ray diffraction with refinement treatment,the specific proportion of Ni of as-obtained hybrid composites could be obtained.Employing controlling calcination time to adjust the Ni content of Ni/NiO@C hybrid composites,it has been found that the composite carbonized at 500℃exhibited remarkable EM wave absorption with the minimum reflection loss(RLmin)of-49.1 dB at 4.9 mm and the widest effective absorption bandwidth(EABmax)of 4.56 GHz at 2.1 mm.Moreover,by adjusting the Ni source,the optimal EM wave absorption performance could be achieved.Results illustrated that the N3PC with the Ni proportion of 13.17%showed the RLm inas low as-51.1 dB at 2.4 mm and the EABmax was 5.12 GHz at 2.7 mm.It is worth noting that this work demonstrates the relevance of the composition and EM wave absorption performance of hybrid composites,which offers a feasible reference for the absorption mechanism of absorber.

同步辐射技术在大气科学领域的研究进展

作为新颖和独特的大型仪器,同步辐射装置正在越来越多地被应用到大气和环境科学的研究中。本文介绍了基于同步辐射的探测技术的理论原理、关键技术以及近期的主要研究成果。涉及的同步辐射技术包括:常压X射线光电子能谱(APXPS)、近边X射线吸收精细结构(NEXAFS)和扫描透射X射线显微镜(STXM)。本文按实验类型进行了分类,即APXPS实验、流体束实验和STXM实验。主要内容包括:(1)冰表面;(2)盐表面;(3)酸性溶液;(4)有机溶液;(5)盐溶液;(6)臭氧分解;(7)黑碳;(8)冰核;(9)吸湿性;(10)反应机理。同步辐射设施的发展为气溶胶科学和大气异相化学的研究提供了强大的工具。可以预见越来越多的重要大气过程和机制将通过基于同步辐射的研究所揭示,而这也将体现同步辐射装置在大气和环境领域的巨大潜力和价值。

Explanations of the DAMPE high energy electron/positron spectrum in the dark matter annihilation and pulsar scenarios

Many studies have shown that either the nearby astrophysical source or dark matter(DM)annihilation/decay can be used to explain the excess of high energy cosmic ray(CR)e~±,which is detected by many experiments,such as PAMELA and AMS-02.Recently,the dark matter particle explorer(DAMPE)collaboration has reported its first result of the total CR e~±spectrum from 25 Ge V to 4.6 Te V with high precision.In this work,we study the DM annihilation and pulsar interpretations of this result.We show that the leptonic DM annihilation channels toτ^+τ^-,4μ,4τ,and mixed charged lepton final states can well explain the DAMPE e~±spectrum.We also find that the mixed charged leptons channel would lead to a sharp drop structure at～Te V.However,the ordinary DM explanations have been almost excluded by the constraints from the observations of gamma-ray and CMB,unless some exotic DM models are introduced.In the pulsar scenario,we analyze 21 nearby known pulsars and assume that one of them dominantly contributes to the high energy CR e~±spectrum.Involving the constraint from the Fermi-LAT observation of the e~±anisotropy,we find that two pulsars could explain the DAMPE e~±spectrum.Our results show that it is difficult to discriminate between the DM annihilation and single pulsar explanations of high energy e~±with the current DAMPE result.

Interfacial energy barrier tuning of hierarchical Bi_(2)O_(3)/WO_(3) heterojunctions for advanced triethylamine sensor

Traditional triethylamine(TEA)sensors suffer from the drawback of serious cross-sensitivity due to the low charge-transfer ability of gas-sensing materials.Herein,an advanced anti-interference TEA sensor is designed by utilizing interfacial energy barriers of hierarchical Bi_(2)O_(3)/WO_(3) composite.Benefiting from abundant slit-like pores,desirable defect features,and amplification effect of heterojunctions,the sensor based on Bi_(2)O_(3)/WO_(3) composite with 40%Bi_(2)O_(3)(0.4-Bi_(2)O_(3)/WO_(3))demonstrates remarkable performance in terms of faster response/recovery time(1.7-fold/1.2-fold),higher response(2.1-fold),and lower power consumption(30℃-decrement)as compared with the pristine WO_(3) sensor.Furthermore,the composite sensor exhibits long-term stability,reproducibility,and negligible response towards interfering molecules,indicating the promising potential of Bi_(2)O_(3)/WO_(3) heterojunctions in anti-interference detection of low-concentration TEA in real applications.This work not only offers a rational solution to design advanced gas sensors by tuning the interfacial energy barriers of heterojunctions,but also provides a fundamental understanding of hierarchical Bi_(2)O_(3) structures in the gas-sensing field.

High-quality genome assembly and pan-genome studies facilitate genetic discovery in mung bean and its improvement

Mung bean is an economically important legume crop species that is used as a food,consumed as a vegetable,and used as an ingredient and even as a medicine.To explore the genomic diversity of mung bean,we assembled a high-quality reference genome(Vrad_JL7)that was479.35 Mb in size,with a contig N50 length of 10.34 Mb.A total of 40,125 protein-coding genes were annotated,representing96.9%of the genetic region.We also sequenced 217 accessions,mainly landraces and cultivars from China,and identified 2,229,343 high-quality single-nucleotide polymorphisms(SNPs).Population structure revealed that the Chinese accessions diverged into two groups and were distinct from non-Chinese lines.Genetic diversity analysis based on genomic data from 750 accessions in 23 countries supported the hypothesis that mung bean was first domesticated in south Asia and introduced to east Asia probably through the Silk Road.We constructed the first pan-genome of mung bean germplasm and assembled 287.73 Mb of non-reference sequences.Among the genes,83.1%were core genes and 16.9%were variable.Presence/absence variation(PAV)events of nine genes involved in the regulation of the photoperiodic flowering pathway were identified as being under selection during the adaptation process to promote early flowering in the spring.Genomewide association studies(GWASs)revealed 2,912 SNPs and 259 gene PAV events associated with 33 agronomic traits,including a SNP in the coding region of the SWEET10 homolog(jg24043)involved in crude starch content and a PAV event in a large fragment containing 11 genes for color-related traits.This high-quality reference genome and pan-genome will provide insights into mung bean breeding.

Numerical simulation and parameter optimization of Coriolis force scale measurement process based on DEM

The Coriolis force method is a recently developed and highly regarded direct measurement technique that enables high-precision measurement of bulk materials.The operational parameters and variations thereof directly influence the measurement accuracy of the equipment.In this study,a measurement correction coefficient is introduced to improve the calculation method for mass flow rate of the materials.The DEM is employed to simulate the motion of particle groups within the Coriolis force scale under different parameters,and the effects of various structural and operational parameters on the measurement results are compared.The research findings indicate that a lower rotational speed leads to more stable instantaneous measurement results,although the measurement error is relatively large.When the rotational speed exceeds 300 rpm,the measurement error remains within 15%.For materials with a radius of 1–2 mm,the variation range of precision error is approximately 0.4%.Among the structural parameters,the radius of the measurement wheel has the most significant impact on the measurement results,wherein a larger measurement wheel radius corresponds to a smaller measurement error.The horizontal angle of the blades follows as the next influential parameter,with a clockwise rotation and a horizontal angle of 30°resulting in a measurement error below 2%.