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A sustainable process to 100%bio-based nylons integrated chemical and biological conversion of lignocellulose

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Green Energy & Environment 2024年第2期9卷 390-402页

作者： Ruijia Hu Ming Li Tao Shen Xin wang Zhuohua Sun Xinning Bao Kequan Chen Kai Guo Lei Ji hanjie Ying Pingkai Ouyang Chenjie Zhu College of Biotechnology and Pharmaceutical Engineering Nanjing Tech UniversityNanjingChina National Engineering Research Center for Biotechnology Nanjing Tech UniversityNanjingChina Beijing Key Laboratory of Lignocellulosic Chemistry Beijing Forestry UniversityBeijingChina

Considerable progress has been made in recent years to the development of sustainable polymers from bio-based feedstocks.In this study,100%bio-based nylons were prepared via an integrated chemical and biological process from lignocellulose.These novel nylons were obtained by the melt polymerization of 3-propyladipic acid derived from lignin and 1,5-pentenediamine/1,4-butanediamine derived from carbohydrate sugar.Central to the concept is a three-step noble metal free catalytic chemical funnelling sequence(Raney Ni mediated reductive catalytic fractionation-reductive funnelling-oxidative funnelling),which allowed for obtaining a single component 3-propyladipic acid from lignin with high efficiency.The structural and thermodynamic properties of the obtained nylons have been systematically investigated,and thus obtained transparent bio-based nylons exhibited higher Mw(>32,000)and excellent thermal stability(Td5%>265℃).Considering their moderate Tg and good melt strength,these transparent bio-based nylons could serve as promising functional additives or temperature-responsive materials.

关键词： Lignocellulose Lignin Reductive catalytic fractionation Bio-based nylon

Braille Character Segmentation Algorithm Based on Gaussian Diffusion

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Computers, Materials & Continua 2024年第4期79卷 1481-1496页

作者： Zezheng Meng Zefeng Cai Jie Feng hanjie Ma Haixiang Zhang Shaohua Li School of Computer Science and Technology Zhejiang Sci-Tech UniversityHangzhou310018China

Optical braille recognition methods typically employ existing target detection models or segmentation modelsfor the direct detection and recognition of braille characters in original braille images. However, these methodsneed improvement in accuracy and generalizability, especially in densely dotted braille image environments. Thispaper presents a two-stage braille recognition framework. The first stage is a braille dot detection algorithmbased on Gaussian diffusion, targeting Gaussian heatmaps generated by the convex dots in braille images. Thisis applied to the detection of convex dots in double-sided braille, achieving high accuracy in determining thecentral coordinates of the braille convex dots. The second stage involves constructing a braille grid using traditionalpost-processing algorithms to recognize braille character information. Experimental results demonstrate that thisframework exhibits strong robustness and effectiveness in detecting braille dots and recognizing braille charactersin complex double-sided braille image datasets. The framework achieved an F1 score of 99.89% for Braille dotdetection and 99.78% for Braille character recognition. Compared to the highest accuracy in existing methods,these represent improvements of 0.08% and 0.02%, respectively.

关键词： Computer vision image recognition optical braille recognition

In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA

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Acta Geochimica 2024年第3期43卷 478-488页

作者： Yi Cui hanjie Wen Zhengbing Zhou Kunyue Ling Lin Xu Shirong Liu Fei Xu School of Earth Sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences and Resources Chang’an UniversityXi’an 710054China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for Li.The McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,respectively.However,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous research.Here,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic resonance.Our results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic minerals.Within the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay minerals.Owing to the octahedral sites of Mg-smectite bounded in Li,it is referred to be hectorite.We interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt tuffdissolution.This conclusion can be supported by the coexistence of spherulitic calcite and hectorite.Overall,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.

关键词： McDermitt caldera Lithium occurrence Tuffaceous sediments Mineralogy Hectorite neoformation

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数字素养与农户收入:兼论数字不平等的形成

中国农村经济 2024年第3期 86-106页

作者：王汉杰西南大学经济管理学院

本文基于2021年中国农村经济与农村金融调查数据,实证考察数字素养对农户收入的影响。研究结论表明,数字素养提升能够显著促进农户收入增长。进一步机制分析发现,数字素养提升显著促进农户创业,并缓解农户信贷约束,进而实现农户收入增... 详细信息

本文基于2021年中国农村经济与农村金融调查数据,实证考察数字素养对农户收入的影响。研究结论表明,数字素养提升能够显著促进农户收入增长。进一步机制分析发现,数字素养提升显著促进农户创业,并缓解农户信贷约束,进而实现农户收入增长。值得注意的是,这一增收效应并不具备包容性。相比高收入、高人力资本、低年龄组和男性户主的农户而言,低收入、低人力资本、高年龄组和女性户主的农户获益十分有限。上述发现印证了数字素养提升有助于实现农户收入增长,但也揭示了农村数字经济发展过程中的不平等问题。据此,本文认为新发展阶段中国数字乡村战略的推进不仅要注重农户数字素养的培育,更要加快构建乡村数字经济的包容性发展路径。

关键词：数字素养农户收入数字鸿沟数字不平等

A micro-nano optogenetic system based on probiotics for in situ host metabolism regulation

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Nano Research 2023年第2期16卷 2829-2839页

作者： Xinyu Zhang Ning Ma Wei Ling Gaoju Pang Tao Sun Jing Liu Huizhuo Pan Meihui Cui Chunli Han Chun Yang Jin Chang Xian Huang hanjie wang School of Life Sciences Tianjin UniversityTianjin 300072China School of Precision Instrument and Optoelectronics Engineering Tianjin UniversityTianjin 300072China School of Chemical Engineering&Technology Tianjin UniversityTianjin 300072China

Genetically engineered bacteria have aroused attention as micro-nano drug delivery systems in situ.However,conventional designs of engineered bacteria usually function constantly or autonomously,which might be non-specific or imprecise.Therefore,designing and optimizing in situ control strategy are important methodological progress for therapeutic researches of intestinal engineered bacteria.Here,a micro-nano optogenetic system based on probiotic was developed combining microelectronics,nanotechnology,and synthetic biology to achieve in situ controllable drug delivery.Firstly,optogenetic engineered Lactococcus lactis was orally administrated in the intestinal tract.A wearable optical device was designed to control optical signals remotely.Then,L.lactis could be customized to secrete peptides according to optical signals.As an example,optogenetic L.lactis system can be constructed to secrete glucagon-like peptide-1(GLP-1)under the control of the wearable optical device to regulate metabolism.To improve the half-life of GLP-1 in vivo,Fc-domain fused GLP-1 was optimally used.Using this strategy,blood glucose,weight,and other features were well controlled in rats and mice models.Furthermore,upconversion microcapsules were introduced to increase the excitation wavelength of the optogenetic system for better penetrability.This strategy has biomedical potential to expand the toolbox for intestinal engineered bacteria.

关键词： synthetic biology optogenetics upconversion nanoparticles microelectronics diabetics

全面抗战时期沦陷区青年奔赴后方的交通与体验

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抗日战争研究 2024年第1期 135-143页

作者：朱汉杰中国社会科学院大学历史学院

全面抗战时期,不断有沦陷区青年奔赴后方,具体路线各异,随时兴废。行路体验艰苦,锻炼了青年能力,也塑造了他们的民族国家归属感。民族意识驱动各方为青年提供帮助,国民政府地下组织坚持斗争,协助青年前往后方。日伪对沦陷区的控制不甚扎... 详细信息

全面抗战时期,不断有沦陷区青年奔赴后方,具体路线各异,随时兴废。行路体验艰苦,锻炼了青年能力,也塑造了他们的民族国家归属感。民族意识驱动各方为青年提供帮助,国民政府地下组织坚持斗争,协助青年前往后方。日伪对沦陷区的控制不甚扎实,封锁线多成“虚线”。可见,沦陷区与非沦陷区的限隔并不严密,两地之间的联系、交通超乎一般认知。

关键词：抗日战争沦陷区日常生活人口流动民族意识

Gold nanorods-mediated efficient synergistic immunotherapy for detection and inhibition of postoperative tumor recurrence

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Acta Pharmaceutica Sinica B 2021年第7期11卷 1978-1992页

作者： Yingying Zhang Tiange wang Yu Tian Chaonan Zhang Kun Ge Jinchao Zhang Jin Chang hanjie wang School of Life Sciences Tianjin UniversityTianjin 300072China Tianjin Engineering Center of Micro-Nano Biomaterials and Detection-Treatment Technology Tianjin Key Laboratory of Function and Application of Biological Macromolecular StructuresTianjin 300072China College of Chemistry&Environmental Science Key Laboratory of Medicinal Chemistry and Molecular Diagnosis of the Ministry of EducationChemical Biology Key Laboratory of Hebei ProvinceHebei UniversityBaoding 071002China

Tumor recurrence after surgery is the main cause of treatment failure.However,the initial stage of recurrence is not easy to detect,and it is difficult to cure in the late stage.In order to improve the life quality of postoperative patients,an efficient synergistic immunotherapy was developed to achieve early diagnosis and treatment of post-surgical tumor recurrence,simultaneously.In this paper,two kinds of theranostic agents based on gold nanorods(AuNRs)platform were prepared.AuNRs and quantum dots(QDs)in one agent was used for the detection of carcinoembryonic antigen(CEA),using fluorescence resonance energy transfer(FRET)technology to indicate the occurrence of in situ recurrence,while AuNRs in the other agent was used for photothermal therapy(PTT),together with antiPDL1 mediated immunotherapy to alleviate the process of tumor metastasis.A series of assays indicated that this synergistic immunotherapy could induce tumor cell death and the increased generation of CD3;/CD4;T-lymphocytes and CD3+;CD8;T-lymphocytes.Besides,more immune factors(IL-2,IL-6,and IFN-γ)produced by synergistic immunotherapy were secreted than mono-immunotherapy.This cooperative immunotherapy strategy could be utilized for diagnosis and treatment of postoperative tumor recurrence at the same time,providing a new perspective for basic and clinical research.

关键词： Synergistic immunotherapy Post-surgical tumor recurrence Theranostics Gold nanorods Phototherapy Lung metastasis Fluorescence resonance energy transfer Carcinoembryonic antigen

Climate change and agricultural trade in central Asia:evidence from Kazakhstan

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Ecosystem Health and Sustainability 2020年第1期6卷 83-91,82页

作者： Xiaohua Yu Hengrong Luo hanjie wang Jan-Henning Feil Department of Agricultural Economics and Rural Development University of GöttingenGöttingenGermany

Agriculture in Central Asia faces tremendous challenges due to climate change.International agricultural trade is seen in the literature as a potential adaption to climate change.However,little attention has been paid to the effect of climate change on cereal trade in Central Asia.This study takes Kazakhstan as an example to empirically analyze the effect of climate change on cereal trade by including them as determinants in the gravity model.Our results show that climatic changes in Kazakhstan,measured by precipitation and temperature,could increase the export of wheat and rice and the import of maize,and decrease the import of wheat.Specifically,as a major crop in Kazakhstan,increasing precipitation by 1 millimeter during the major cropping season from May to August,will significantly enhance export of wheat by 0.7%and reduce the import by 1.7%;increasing temperature by 1℃ during the same cropping season will significantly increase export of wheat by 21.9%and reduce the import by 49.4%.As an important cereal trade country in the world,the dramatic adjustments of cereal trade patterns resulting from climate change in Kazakhstan might affect global food security.

关键词： Climate change cereal trade adaptation gravity model Kazakhstan

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创新要素集聚、反腐与创新效率提升

重庆大学学报（社会科学版） 2024年第2期30卷 51-64页

作者：王汉杰温涛陈汭西南大学经济管理学院重庆400715 重庆大学公共管理学院重庆400044

如何实现经济高速增长向高质量发展的动能转变是新时代中国特色社会主义经济亟待破解的重要命题。既有理论研究与实践经验表明,创新驱动是实现经济高质量发展的关键突破点,而创新要素的有效集聚则是实现创新驱动的必要条件。因此,现阶... 详细信息

如何实现经济高速增长向高质量发展的动能转变是新时代中国特色社会主义经济亟待破解的重要命题。既有理论研究与实践经验表明,创新驱动是实现经济高质量发展的关键突破点,而创新要素的有效集聚则是实现创新驱动的必要条件。因此,现阶段从中央政府到地方政府均大力推进创新要素的有效集聚。从理论上看,在创新要素集聚过程中,政府扮演着十分重要的角色,而腐败作为一种阻碍资源有效配置的政府行为,可能不利于创新要素的有效集聚。文章将腐败行为引入创新要素集聚与创新效率的理论分析框架中,理论分析的结论初步表明创新要素集聚有利于创新效率提升,行政腐败则抑制了这一正向效应;当反腐力度加强时,这一抑制效应可能得到一定程度上的缓解。在理论分析的基础上,文章进一步基于2002—2016年我国省级面板数据,运用Tobit空间面板回归模型、IV-Tobit模型对上述结论进行了实证检验。实证结果表明,政府主导的创新要素集聚有效促进了创新效率的提升,而腐败行为的存在则抑制了这一正向效应。该研究结论在考虑内生性问题,并进行一系列稳健性检验后依然保持一致。同时,空间计量模型的分析结果显示创新要素集聚的空间溢出效应显著为负,即各地区之间存在“各自为政”的现象,缺乏区域协同创新。进一步研究发现,党的十八大之后反腐力度的加强有效地缓解了腐败所造成的负向效应,同时也使创新要素集聚的负向空间溢出效应得到了纠偏,表明党的十八大之后的反腐行动为“创新驱动发展战略”释放了制度红利,提供了有利于创新要素有效集聚与配置的生存土壤。以上研究发现对新发展阶段我国经济高质量发展的路径选择具有一定的参考价值。据此,文章认为腐败行为的创新抑制效应意味着加强反腐力度、简政放权能够改善创新要素集聚的制度环境。反腐虽然能够降低寻求政治关联的激励,提高创新效率,但市场机制扭曲才是腐败影响创新要素集聚的根源所在。因此,现阶段应从处理好政府与市场之间的关系入手,转变政府的职能,进一步完善市场机制,最终形成以市场配置为主、以政府引导为辅的创新要素集聚模式。

关键词：创新要素集聚腐败创新效率空间溢出效应反腐