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Problems and Countermeasures of Fruit and Vegetable Logistics Distribution Development in Guangxi Zhuang Autonomous Region
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作者 xi xu Bihong FENG 《Asian Agricultural Research》 2023年第10期1-5,9,共6页
The logistics transportation and distribution of fruits and vegetables has become one of the important links for people to obtain food,and it is also an important direction and emerging challenge in the logistics indu... The logistics transportation and distribution of fruits and vegetables has become one of the important links for people to obtain food,and it is also an important direction and emerging challenge in the logistics industry.As the social economy and transportation develop,the consumption ability of residents has been improved,and the high demand for fruits and vegetables has promoted the transportation of fruits and vegetables to meet the development conditions of the future fruit and vegetable industry.The study of fruit and vegetable logistics distribution can improve the efficiency of fruit and vegetable distribution,improve the construction of fruit and vegetable distribution system,and also meet the needs of people for different kinds of fruits and vegetables.Taking Guangxi fruit and vegetable distribution as an example,through empirical investigation,this paper studies the existing problems in the development of logistics distribution in the fruit and vegetable distribution industry,and puts forward corresponding measures and countermeasures according to the problems,so as to innovate the fruit and vegetable distribution mode in Guangxi Zhuang Autonomous Region. 展开更多
关键词 Fruit and vegetable distribution Fruit and vegetable logistics DEVELOPMENT
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EZH2-dependent myelination following sciatic nerve injury
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作者 Hui Zhu Li Mu +8 位作者 xi xu Tianyi Huang Ying Wang Siyuan xu Yiting Wang Wencong Wang Zhiping Wang Hongkui Wang Chengbin xue 《Neural Regeneration Research》 SCIE CAS 2025年第8期2382-2394,共13页
Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that ... Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that of native myelin.Silencing of enhancer of zeste homolog 2(EZH2)hinders the differentiation,maturation,and myelination of Schwann cells in vitro.To further determine the role of EZH2 in myelination and recovery post-peripheral nerve injury,conditional knockout mice lacking Ezh2 in Schwann cells(Ezh2^(fl/fl);Dhh-Cre and Ezh2^(fl/fl);Mpz-Cre)were generated.Our results show that a significant proportion of axons in the sciatic nerve of Ezh2-depleted mice remain unmyelinated.This highlights the crucial role of Ezh2 in initiating Schwann cell myelination.Furthermore,we observed that 21 days after inducing a sciatic nerve crush injury in these mice,most axons had remyelinated at the injury site in the control nerve,while Ezh2^(fl/fl);Mpz-Cre mice had significantly fewer remyelinated axons compared with their wild-type littermates.This suggests that the absence of Ezh2 in Schwann cells impairs myelin formation and remyelination.In conclusion,EZH2 has emerged as a pivotal regulatory factor in the process of demyelination and myelin regeneration following peripheral nerve injury.Modulating EZH2 activity during these processes may offer a promising therapeutic target for the treatment of peripheral nerve injuries. 展开更多
关键词 DEMYELINATION EZH2 MYELINATION peripheral nerve injury PRC2 REMYELINATION Schwann cells sciatic nerve crush sciatic nerve transection
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实验教育与3D打印合金:创新探索与学生培养
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作者 徐茜 朱潮恺 +2 位作者 曹镭清 吴擢钊 官操 《大学化学》 CAS 2024年第2期347-357,共11页
实验教育是一种被广泛认可的教学方法,通过实践活动来培养学生的问题解决能力和创新思维。而3D打印多元合金材料是当前电催化中备受关注的领域。本文将实验教育与3D打印合金相结合,研究了其对学生的影响和教育效果。本文首先介绍了实验... 实验教育是一种被广泛认可的教学方法,通过实践活动来培养学生的问题解决能力和创新思维。而3D打印多元合金材料是当前电催化中备受关注的领域。本文将实验教育与3D打印合金相结合,研究了其对学生的影响和教育效果。本文首先介绍了实验教育的重要性和作用,以及合金材料的特点和应用前景。其次,讨论了3D打印技术在合金制备中的应用潜力。通过让学生参与实验设计和进行实验来提高学生的参与度、学习动机和科学素养。本研究旨在为教育实践提供新思路和方法,培养学生的科学思维和实践能力,为材料科学和工程领域培养更多的创新人才。 展开更多
关键词 实验教育 合金 电催化 3D打印
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Development and characteristics of a low rare-earth containing magnesium alloy with high strength-ductility synergy 被引量:4
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作者 Zijian Yu xi xu +6 位作者 Kang Shi Baotian Du xiuzhu Han Tao xiao Shubo Li Ke Liu Wenbo Du 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第5期1629-1642,共14页
In this study,we successfully developed a low RE containing Mg-3Y-2Gd-1Nd-0.5Zr(wt%)alloy with high strength-ductility synergy by combined processes of hot extrusion,hot rolling and ageing.This alloy exhibits an excel... In this study,we successfully developed a low RE containing Mg-3Y-2Gd-1Nd-0.5Zr(wt%)alloy with high strength-ductility synergy by combined processes of hot extrusion,hot rolling and ageing.This alloy exhibits an excellent strength-ductility balance(UTS of 345±2.0 MPa,TYS of 301±5.0 MPa and EL of 9.2±1.9%),which is better than that of many Mg-RE wrought alloys with higher RE concentration and even comparable to that of 6061 Al wrought alloy.A long-range chain-like structure consisting ofβphase,βH phase,βM phase and zig-zag atomic columns is observed for the first time in the studied alloy.The combined process of hot extrusion and hot rolling boosts the formation of deformed grains and low angle grain boundaries,and makes the deformed grains dominate in the alloy strengthening.Under this circumstance,the following ageing generates a novel heterogeneous structure comprising the long-range chain-like structure with broad interparticle spacing and the spacious precipitate-free zones in the deformed grains,which plays a key role in the concurrent strengthening and toughening of the alloy.The present study demonstrates that the deformed grains with long-range chain-like structures and precipitate-free zones is desirable microstructure for the low RE containing Mg alloys to achieve high strength-ductility synergy. 展开更多
关键词 Magnesium alloy Microstructure Mechanical properties Rare earth
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Diagnostic Value of Dual-Energy CT in Differentiating Malignant and Benign Thyroid Nodules: A Systematic Review and Meta-Analysis 被引量:2
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作者 Kunlin Ye Yongyao Kuang +6 位作者 Jianye Liang xi xu Changzheng Shi Qingqing Cheng Zijie Jiang Ziyun xiang Liangping Luo 《Journal of Biosciences and Medicines》 2021年第4期54-76,共23页
<strong>Objectives:</strong> To evaluate the diagnostic performance of the quantitative iodine parameters, including Iodine Concentration (IC), Normalized Iodine Concentration (NIC), and λ<sub>HU<... <strong>Objectives:</strong> To evaluate the diagnostic performance of the quantitative iodine parameters, including Iodine Concentration (IC), Normalized Iodine Concentration (NIC), and λ<sub>HU</sub>, in distinguishing malignant and benign thyroid nodules. <strong>Methods:</strong> Relevant studies were searched from Web of Science, PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure database and other complementary sources from inception to May 20, 2020. Study selection, data extraction, quality assessment, and data analyses were performed following the Cochrane standards and the PRISMA-DTA guideline. <strong>Results: </strong>Eight studies were included (595 patients with 737 thyroid nodules). The pooled sensitivity, specificity and summary diagnostic odds ratio of IC were 79% (95% CI: 69% - 86%), 76% (95% CI: 65% - 84%) and 11 (95% CI: 5 - 27) respectively;those of NIC were 78% (95% CI: 70% - 85%), 80% (95% CI: 74% - 85%) and 15 (95% CI: 9 - 24) respectively;those of λ<sub>HU</sub> were 80% (95% CI: 71% - 87%), 77% (95% CI: 70% - 83%) and 14 (95% CI: 8 - 24) respectively. <strong>Conclusion: </strong>DECT can be a potential evaluation tool for thyroid nodules. The NIC may be the most sensitive iodine parameter and could be comparable between different DECT machines in thyroid nodule assessment. 展开更多
关键词 THYROID NODULES Differential Diagnosis Dual-Energy CT Iodine Concentration META-ANALYSIS
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The health principle of TaiChi pile under fascia static pull
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作者 Zi-Li Zhang Ye Zhao +2 位作者 xi xu Zhen Wang Lu-Lu Wang 《TMR Non-Drug Therapy》 2023年第3期16-17,共2页
TaiChi pile function originated from the ancient health guidance method in China.Practice has proved that it plays a good role in removing diseases and fitness,prolonging life.Fascia is an anatomical structure formed ... TaiChi pile function originated from the ancient health guidance method in China.Practice has proved that it plays a good role in removing diseases and fitness,prolonging life.Fascia is an anatomical structure formed by connective tissue,one of the four tissues.It is an independent sensory organ and a tension network system running through the whole body[1]. 展开更多
关键词 removing originated TAI
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基于零水印与脆弱水印的矢量地理数据多重水印算法 被引量:7
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作者 梁伟东 张新长 +1 位作者 奚旭 张鹏程 《中山大学学报(自然科学版)》 CAS CSCD 北大核心 2018年第4期1-8,共8页
为了兼顾矢量地理数据的版权保护与内容认证,同时保证数据的精度,提出一种基于零水印与脆弱水印的无损嵌入的多重水印算法。该算法以矢量图元节点数据为基础,根据需求对数据进行不同程度的点约束数据分块,针对数据版权保护,利用道格拉... 为了兼顾矢量地理数据的版权保护与内容认证,同时保证数据的精度,提出一种基于零水印与脆弱水印的无损嵌入的多重水印算法。该算法以矢量图元节点数据为基础,根据需求对数据进行不同程度的点约束数据分块,针对数据版权保护,利用道格拉斯算法和Delaunay三角网提取特征点和特征信息,结合Arnold置乱算法,构造大容量的零水印;针对数据内容认证,通过空间排序与零比特动态扩展,设计一种无损嵌入的用于精确认证的脆弱水印。实验结果表明,本研究提出的零水印算法可对常见的地图攻击与组合攻击具有较强鲁棒性;脆弱水印算法能对数据进行有效认证,并精确标记出被篡改的要素。 展开更多
关键词 矢量地理数据 多重水印 零水印 脆弱水印 无损嵌入
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The effects of claudin 14 during early Wallerian degeneration after sciatic nerve injury 被引量:7
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作者 Leilei Gong Yun Zhu +4 位作者 xi xu Huaiqin Li Weimin Guo Qin Zhao Dengbing Yao 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第24期2151-2158,共8页
Claudin 14 has been shown to promote nerve repair and regeneration in the early stages of Wallerian degeneration (0-4 days) in rats with sciatic nerve injury, but the mechanism underlying this process remains poorly... Claudin 14 has been shown to promote nerve repair and regeneration in the early stages of Wallerian degeneration (0-4 days) in rats with sciatic nerve injury, but the mechanism underlying this process remains poorly understood. This study reported the effects of claudin 14 on nerve degeneration and regeneration during early Wallerian degeneration. Claudin 14 expression was up-regulated in sciatic nerve 4 days after Wallerian degeneration. The altered expression of claudin 14 in Schwann cells resulted in expression changes of cytokines in vitro. Expression of claudin 14 affected c-Jun, but not Akt anal ERK1/2 patl^ways, l^urther studies reve^ed that enhanced expression of claudin 14 could promote Schwann cell proliferation and migration. Silencing of claudin 14 expression resulted in Schwann cell apoptosis and reduction in Schwann cell proliferation. Our data revealed the role of claudin 14 in early Wallerian degeneration, which may provide new insights into the molecular mechanisms of Wallerian degeneration. 展开更多
关键词 nerve regeneration peripheral nerve injury Wallerian degeneration sciatic nerve injury Claudin 14 rat Schwann cell Signal pathways C-JUN Akt ERK1/2 NSFC grant neural regeneration
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Prospects for the application of transcranial magnetic stimulation in diabetic neuropathy 被引量:4
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作者 xi xu Dong-Sheng xu 《Neural Regeneration Research》 SCIE CAS CSCD 2021年第5期955-962,共8页
Encouraging results have been reported for the use of transcranial magnetic stimulationbased nerve stimulation in studies of the mechanisms of neurological regulation,nerve injury repair,and nerve localization.However... Encouraging results have been reported for the use of transcranial magnetic stimulationbased nerve stimulation in studies of the mechanisms of neurological regulation,nerve injury repair,and nerve localization.However,to date,there are only a few reviews on the use of transcranial magnetic stimulation for diabetic neuropathy.Patients with diabetic neuropathy vary in disease progression and show neuropathy in the early stage of the disease with mild symptoms,making it difficult to screen and identify.In the later stage of the disease,irreversible neurological damage occurs,resulting in treatment difficulties.In this review,we summarize the current state of diabetic neuropathy research and the prospects for the application of transcranial magnetic stimulation in diabetic neuropathy.We review significant studies on the beneficial effects of transcranial magnetic stimulation in diabetic neuropathy treatment,based on the outcomes of its use to treat neurodegeneration,pain,blood flow change,autonomic nervous disorders,vascular endothelial injury,and depression.Collectively,the studies suggest that transcranial magnetic stimulation can produce excitatory/inhibitory stimulation of the cerebral cortex or local areas,promote the remodeling of the nervous system,and that it has good application prospects for the localization of the injury,neuroprotection,and the promotion of nerve regeneration.Therefore,transcranial magnetic stimulation is useful for the screening and early treatment of diabetic neuropathy.transcranial magnetic stimulation can also alleviate pain symptoms by changing the cortical threshold and inhibiting the conduction of sensory information in the thalamo-spinal pathway,and therefore it has therapeutic potential for the treatment of pain and pain-related depressive symptoms in patients with diabetic neuropathy.Additionally,based on the effect of transcranial magnetic stimulation on local blood flow and its ability to change heart rate and urine protein content,transcranial magnetic stimulation has potential in the treatment of autonomic nerve dysfunction and vascular injury in diabetic neuropathy.Furthermore,oxidative stress and the inflammatory response are involved in the process of diabetic neuropathy,and transcranial magnetic stimulation can reduce oxidative damage.The pathological mechanisms of diabetic neuropathy should be further studied in combination with transcranial magnetic stimulation technology. 展开更多
关键词 autonomic neuropathy central nervous system DEPRESSION inflammation oxidative stress PAIN peripheral nerve PLASTICITY recovery regeneration VASCULAR
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笔法与结构对楷书文字美学品质影响的量化研究
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作者 律睿慜 张陶洁 +3 位作者 席旭 王濛濛 孟磊 张克俊 《浙江大学学报(理学版)》 CAS CSCD 北大核心 2022年第3期261-270,共10页
笔法与结构对文字观感的影响是中国书法文化的重要研究命题,也与数字书法领域审美评价技术相关联。但以往对该命题主要为定性讨论。本文结合计算机样条曲线及审美量表等技术,设计了一种实验方法对其进行量化研究。首先,选取78个高频字的... 笔法与结构对文字观感的影响是中国书法文化的重要研究命题,也与数字书法领域审美评价技术相关联。但以往对该命题主要为定性讨论。本文结合计算机样条曲线及审美量表等技术,设计了一种实验方法对其进行量化研究。首先,选取78个高频字的6种有代表性的楷书体文字作为样品,自编软件并招募测试人员对其标注结构特征点,并用参数曲线建模输出“去除笔法”后的样品图,再进一步经严格定义的“统一结构”操作进行处理,共获得3组样品图,每组468幅。然后,编制审美量表,招募测试者以随机分配的方式对3组样品评测美感和风格。最后,对评测数据进行统计分析。结果显示,对于楷书文字的风格而言,笔法的影响远高于结构;对于文字的美感而言,笔法的作用也大于结构,但影响有限。该结果局限于实验选定的几种经典的楷书文字,且其定义的“去除笔法”和“统一结构”并不能完全涵盖以往经验理论中的相关概念范围。研究表明,自然学科的方法可用于研究书法学中的命题。 展开更多
关键词 笔法 结构 书法风格 实验美学 实证美学
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基于自编码器的矢量地图零水印算法 被引量:3
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作者 奚旭 张新长 梁伟东 《地理与地理信息科学》 CSCD 北大核心 2022年第4期1-6,共6页
现有矢量地图零水印算法研究主要集中于空间统计特征信息的挖掘,方式单一导致安全性不足。深度学习可提取数据隐蔽的内蕴特征信息,为数字水印研究提供了新思路。该文利用深度学习中的自编码器模型挖掘深层、稳健的特征信息,提出基于自... 现有矢量地图零水印算法研究主要集中于空间统计特征信息的挖掘,方式单一导致安全性不足。深度学习可提取数据隐蔽的内蕴特征信息,为数字水印研究提供了新思路。该文利用深度学习中的自编码器模型挖掘深层、稳健的特征信息,提出基于自编码器的鲁棒性矢量地图零水印算法。首先,提取矢量地图的特征点并计算特征点集的坐标差序列,按进制转换和补位操作构建自编码器的训练图像;然后,通过迭代训练和模型优化得到模型训练后的特征信息矩阵,将特征信息矩阵与置乱加密后的水印图像异或操作得到零水印图像。实验结果表明,该水印算法能抵抗常见的几何攻击、坐标点攻击、压缩攻击等,具有较强的鲁棒性和实用性,可为矢量地图的版权保护提供技术参考。 展开更多
关键词 矢量地图 零水印 自编码器 鲁棒性
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3D Printing of Next-generation Electrochemical Energy Storage Devices: from Multiscale to Multimaterial 被引量:2
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作者 xi xu Yong Hao Tan +1 位作者 Jun Ding Cao Guan 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2022年第2期427-438,共12页
The increasing energy requirements to power the modern world has driven active research into more advanced electrochemical energy storage devices(EESD)with both high energy densities and power densities.Wide range of ... The increasing energy requirements to power the modern world has driven active research into more advanced electrochemical energy storage devices(EESD)with both high energy densities and power densities.Wide range of newly discovered materials with promising electrochemical properties has shown great potential for next-generation devices,but their performance is normally associated with contradicting demands of thin electrodes and high mass loading that can be hardly achieved for practical applications.Design of three-dimensional(3D)porous electrodes can increase the mass loading while maintaining the effective charge transport even with thick electrodes,which has proven to be efficient to overcome the limitations.3D structures have also been demonstrated excellent structural stability to withstand strong strains and stresses generated during charge/discharge cycle.3D printing,which can fabricate various delicate and complex structural designs,thus offering brand-new opportunities for the rational design and facile construction of next-generation EESDs.The recent developments in 3D printing of next-generation EESDs with high performance are reviewed.Advanced/multiscale electrode structures,such as hierarchically porous structure that can be constructed via high-resolution 3D printing or with post-treatment,are further emphasized.The ability of current 3D printing techniques to fulfill multimaterial printing to fulfill simple packaging will be covered. 展开更多
关键词 3d printing electrochemical energy storage devices multimaterial multiscale
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Baculoviral inhibitor of apoptosis protein repeatcontaining protein 3 delays early Wallerian degeneration after sciatic nerve injury 被引量:1
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作者 Min Cai Jian Shao +6 位作者 Bryant Yung Yi Wang Nan-Nan Gao xi xu Huan-Huan Zhang Yu-Mei Feng Deng-Bing Yao 《Neural Regeneration Research》 SCIE CAS CSCD 2022年第4期845-853,共9页
Wallerian degeneration is a complex biological process that occurs after nerve injury,and involves nerve degeneration and regeneration.Schwann cells play a crucial role in the cellular and molecular events of Walleria... Wallerian degeneration is a complex biological process that occurs after nerve injury,and involves nerve degeneration and regeneration.Schwann cells play a crucial role in the cellular and molecular events of Wallerian degeneration of the peripheral nervous system.However,Wallerian degeneration regulating nerve injury and repair remains largely unknown,especially the early response.We have previously reported some key regulators of Wallerian degeneration after sciatic nerve injury.Baculoviral inhibitor of apoptosis protein repeat-containing protein 3(BIRC3)is an important factor that regulates apoptosis-inhibiting protein.In this study,we established rat models of right sciatic nerve injury.In vitro Schwann cell models were also established and subjected to gene transfection to inhibit and overexpress BIRC3.The data indicated that BIRC3 expression was significantly up-regulated after sciatic nerve injury.Both BIRC3 upregulation and downregulation affected the migration,proliferation and apoptosis of Schwan cells and affected the expression of related factors through activating c-fos and ERK signal pathway.Inhibition of BIRC3 delayed early Wallerian degeneration through inhibiting the apoptosis of Schwann cells after sciatic nerve injury.These findings suggest that BIRC3 plays an important role in peripheral nerve injury repair and regeneration.The study was approved by the Institutional Animal Care and Use Committee of Nantong University,China(approval No.2019-nsfc004)on March 1,2019. 展开更多
关键词 apoptosis baculoviral inhibitor of apoptosis protein repeat-containing protein 3 nerve degeneration rat Schwann cell sciatic nerve injury signal pathway Wallerian degeneration
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Ionomer Toughened Polyolefine 被引量:1
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作者 xi xu xiangshen ZENG Shaoyun GUO and Huilin LI (Polymer Research Institute and the State Key Laboratory of Polymer Materials Engineering,Chengdu Uuiversity of Science and Technology, Chengdu, 610065, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1995年第6期391-397,共7页
The morphology and properties of HDPE blends with Zn-SEPDM and GR were studied through SEM and mechanical property test. The results show that as Zn-SEPDM/GR content amounts to 20%, the blend becomes an IPN in structu... The morphology and properties of HDPE blends with Zn-SEPDM and GR were studied through SEM and mechanical property test. The results show that as Zn-SEPDM/GR content amounts to 20%, the blend becomes an IPN in structure, and that a rather high impact and tensile strength of HDPE may be obtained after blending. The antistatic effect, the softening point,and HDT of the blend are higher as compared to HDPE/Zn-SEPDM/ZnSt (zinc stearate).The effect of Zn-SEPDM on the compatibility the morphology and properties of IPP blends were studied by DSC, TEM and mechanical properties test. The results show that as Zn-SEPDM content exceeds 20%. Zn-SEPDM in the blend becomes continuous and an abrupt change in impact strength is incurred there from. Owing to the incorporation of ionic groups into EPDM.the strong interactions betWeen the chains make both the impact and the tensile strength of IPP remarkably higher 展开更多
关键词 Zn EPDM HDPE PP GR Ionomer Toughened Polyolefine
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Novel pneumatically assisted atomization device for living cell delivery:application of sprayed mesenchymal stem cells for skin regeneration 被引量:1
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作者 Lixing Zhang xintao Yan +7 位作者 Li An Meijia Wang xi xu Zhonglin Ma Mengting Nie Fangzhou Du Jingzhong Zhang Shuang Yu 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2022年第1期220-232,共13页
Large cutaneous wounds pose a severe medical problem and may be deadly in cases when regeneration is impaired.Recently,topical stem cell therapy has been realized as a promising strategy for wound healing and skin reg... Large cutaneous wounds pose a severe medical problem and may be deadly in cases when regeneration is impaired.Recently,topical stem cell therapy has been realized as a promising strategy for wound healing and skin regeneration.However,stem cells must be administrated uniformly to the wound area,otherwise treatment will be ineffective,which has been a limitation of current administration methods.Specifically,the delivery pressure and nozzle features of most clinical cell spray devices are unknown,which may significantly affect the viability of sprayed cells and their capacity for proliferation.Herein,we developed a novel pneumatically assisted atomization device(PAAD)in which cell suspensions were uniformly atomized at a low delivery pressure.We optimized the applied fluidic pressure and air pressure to maximize cell survival and function for the application of multiple cell types,while ensuring uniform dispersal across the wound site.Moreover,we found that the application of sprayed umbilical cord-derived mesenchymal stem cells to wound sites significantly accelerated wound healing and promoted appendage regeneration on an excisional cutaneous wound model.Overall,the novel PAAD system delivered living cells uniformly and maintained the viability and differentiation of sprayed cells,strongly suggesting its potential for application in clinical cell therapy,especially for large,irregular,and severe skin wounds. 展开更多
关键词 Cell delivery Skin wound Wound healing Spray application Cell-spray autografting Stem cell therapy
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Soil moisture response to land use and topography across a semi-arid watershed: Implications for vegetation restoration on the Chinese Loess Plateau 被引量:1
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作者 xiA Lu BI Ru-tian +4 位作者 SONG xiao-yu HU Wei LYU Chun-juan xi xu LI Huai-you 《Journal of Mountain Science》 SCIE CSCD 2022年第1期103-120,共18页
Soil moisture is a limiting factor of ecosystem development in the semi-arid Loess Plateau. Characterizing the soil moisture response to its dominant controlling factors, such as land use and topography, and quantifyi... Soil moisture is a limiting factor of ecosystem development in the semi-arid Loess Plateau. Characterizing the soil moisture response to its dominant controlling factors, such as land use and topography, and quantifying the soil-water carrying capacity for revegetation is of great significance for vegetation restoration in this region. In this study, soil moisture was monitored to a depth of 2 m in three land use types(native grassland, introduced grassland,and forestland), two landforms(hillslope and gully),and two slope aspects(sunny and shady) in the Nanxiaohegou watershed of the Loess Plateau,Northwest China. The MIKE SHE model was then applied to simulate the soil moisture dynamics under different conditions and determine the optimal plant coverage. Results showed that the average soil moisture was higher in native grassland than in introduced grassland and Platycladus orientalis forestland for a given topographic condition;however,a high soil moisture content was found in Robinia pseudoacacia forestland, with a value that was even higher than the native grassland of a sunny slope. The divergent results in the two forestlands were likely attributed to the differences in plant coverage. Gully regions and shady slopes usually had higher soil moisture, while lower soil moisture was usually distributed on the hillslope and sunny slope.Furthermore, the mean absolute relative error and Nash-Sutcliffe efficiency coefficient of the MIKE SHE model ranged between 2.8%–7.8% and 0.550–0.902,respectively, indicating that the model could effectively simulate the soil moisture dynamics. The optimal plant coverage was thus determined for hillslope P. orientalis by the model, corresponding to a leaf area index(LAI) value of 1.92. Therefore, for sustainable revegetation on the Loess Plateau,selecting suitable land use types(natural vegetation),controlling the planting density/LAI, and selecting proper planting locations(gully and shady slope regions) should be considered by local policy makers to avoid the over-consumption of soil water resources. 展开更多
关键词 Soil moisture MIKE SHE Optimal plant coverage Land use TOPOGRAPHY
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基于区间映射和最大扰动区域的矢量地图可逆水印算法 被引量:1
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作者 奚旭 张新长 《测绘学报》 EI CSCD 北大核心 2022年第11期2379-2389,共11页
针对传统矢量地图可逆水印算法往往因片面追求水印容量而容易暴露水印的问题,本文设计了一种扰动程度可控的矢量地图可逆水印算法。首先,基于量化索引调制的思想设计了坐标点的状态区间轴,利用水印信息调制坐标点的状态值实现水印的嵌入... 针对传统矢量地图可逆水印算法往往因片面追求水印容量而容易暴露水印的问题,本文设计了一种扰动程度可控的矢量地图可逆水印算法。首先,基于量化索引调制的思想设计了坐标点的状态区间轴,利用水印信息调制坐标点的状态值实现水印的嵌入;然后,利用最大扰动区域方法限定坐标点状态区间的范围,确保水印信息的嵌入对数据的扰动控制在合理范围内,不会对数据质量造成较大影响;最后,将二进制水印信息十进制化,利用十进制数在最大扰动区域范围内调制坐标点的状态值,实现水印信息的大容量嵌入。试验结果表明,本文提出的矢量地图可逆水印算法不仅容量大,而且扰动程度可控,对常规几何攻击、坐标点攻击等具备较强的稳健性,能够较好地处理水印容量、不可见性及稳健性之间的相互制约关系。 展开更多
关键词 矢量地图 可逆水印 区间映射 最大扰动区域
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地理信息科学专业GIS开发课程的学习难点及教学对策研究 被引量:2
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作者 奚旭 杜景龙 张委伟 《高教学刊》 2022年第30期1-4,共4页
在当前数字经济、智慧城市、人工智能等理念领衔的新时代发展背景下,社会对GIS开发人才有了更高的要求,然而,地理信息科学专业的学生普遍对GIS开发类课程的掌握程度有限,往往难以胜任实际开发任务。本教学团队通过教学调查的方式,从学... 在当前数字经济、智慧城市、人工智能等理念领衔的新时代发展背景下,社会对GIS开发人才有了更高的要求,然而,地理信息科学专业的学生普遍对GIS开发类课程的掌握程度有限,往往难以胜任实际开发任务。本教学团队通过教学调查的方式,从学生视角探讨学习GIS开发类课程存在的问题,从而掌握该类课程的教学难点,并通过翻转课堂、借助开源平台、实际项目实践及增设开源课程等方式提出应对教学策略。经实践,部分方案已取得显著效果,后续将持续完善,以期进一步提升GIS开发类课程的教学效果。 展开更多
关键词 地理信息科学 GIS开发课程 开源平台 学习难点 教学对策
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多喷嘴切圆燃烧式气化炉烧嘴定位法兰开孔位置的确定和烧嘴安装方法 被引量:1
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作者 奚旭 王云林 +2 位作者 龚雪莲 郑刚 彭东 《化工机械》 CAS 2020年第5期688-690,705,共4页
针对多喷嘴切圆燃烧式气化炉制造中的重点关注问题,介绍了3种烧嘴定位法兰开孔位置的确定方法,并对优缺点进行了比较,最后给出了烧嘴的安装注意事项。
关键词 多喷嘴气化炉 烧嘴定位法兰 开孔位置 烧嘴安装
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Development and Validation of an LC-MS/MS Method for Determination of Catalpol and Harpagide in Small Volume Rat Plasma: Application to a Pharmacokinetic Study 被引量:1
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作者 Shuangmin Chen Yijun Ren +3 位作者 xi xu Dandan Li Wenlian Li Zhenzhen Liu 《Yangtze Medicine》 2018年第2期95-107,共13页
A rapid and sensitive liquid chromatography-tandem mass chromatography (LC-MS/MS) method has been developed and validated for simultaneous determination of catalpol and harpagide in rat plasma. The samples were extrac... A rapid and sensitive liquid chromatography-tandem mass chromatography (LC-MS/MS) method has been developed and validated for simultaneous determination of catalpol and harpagide in rat plasma. The samples were extracted by one-step protein precipitation and separated on a SunFireTM C18 column (100 mm × 2.1 mm, 3.5 &mu;m;Waters) using acetonitrile-10 mM ammonium formate as mobile phase at a flow rate 0.3 mL/min in gradient mode. The analytes were detected without interference in Multiple Reaction Monitoring (MRM) mode with negative electrospray ionization. Linear responses were obtained for catalpol ranging from 20 to 5000 ng/mL and harpagide ranging from 10 to 2500 ng/mL. Coefficients of correlation (r) for the calibration curves were more than 0.99 for both analytes. Intra- and inter-day accuracy and precision were within the acceptable limits of less than 15.0% at all concentrations. The quantitation method was successfully applied for simultaneous estimation of catalpol and harpagide after oral administration of Zeng Ye Decoction. 展开更多
关键词 LC-MS/MS PHARMACOKINETICS CATALPOL HARPAGIDE Zeng Ye DECOCTION
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