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Homogenous metallic deposition regulated by abundant lithiophilic sites in nickel/cobalt oxides nanoneedle arrays for lithium metal batteries
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作者 Fenqiang Luo dawei xu +4 位作者 Yongchao Liao Minghao Chen Shuirong Li Dechao Wang Zhifeng Zheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2023年第2期11-18,I0001,共9页
Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li util... Although lithium(Li)metal delivers the highest theoretical capacity as a battery anode,its high reactivity can generate Li dendrites and"dead"Li during cycling,resulting in poor reversibility and low Li utilization.Inducing uniform Li plating/stripping is the core of solving these problems.Herein,we design a highly lithiophilic carbon film with an outer sheath of the nanoneedle arrays to induce homogeneous Li plating/stripping.The excellent conductivity and 3D framework of the carbon film not only offer fast charge transport across the entire electrode but also mitigate the volume change of Li metal during cycling.The abundant lithiophilic sites ensure stable Li plating/stripping,thereby inhibiting the Li dendritic growth and"dead"Li formation.The resulting composite anode allows for stable Li stripping/plating under 0.5 mA cm^(-2) with a capacity of 0.5 mA h cm^(-2) for 4000 h and 3 mA cm^(-2) with a capacity of3 mA h cm^(-2) for 1000 h.The Ex-SEM analysis reveals that lithiophilic property is different at the bottom,top,or channel in the structu re,which can regulate a bottom-up uniform Li deposition behavior.Full cells paired with LFP show a stable capacity of 155 mA h g^(-1) under a current density of 0.5C.The pouch cell can keep powering light-emitting diode even under 180°bending,suggesting its good flexibility and great practical applications. 展开更多
关键词 Nickel/cobalt oxides Nanoneedle arrays Lithiophilic sites Lithium metal batteries
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Effectiveness of Post-Traumatic Growth Intervention to Promote Positive Post-Traumatic Traits in Chinese Breast Cancer Patients:A Randomized Controlled Trial
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作者 Cuirong xu Han Yan +7 位作者 dawei xu Guanjie Chen Qian xu Kunpeng Li Yehao Rui Zanmin Song Neeraj Gill Jing Sun 《International Journal of Mental Health Promotion》 2023年第10期1089-1102,共14页
Objective:The purpose of this study was to evaluate the effectiveness of post-traumatic growth(PTG)model-based intervention to improve positive psychological traits in Chinese breast cancer patients.Design:A randomize... Objective:The purpose of this study was to evaluate the effectiveness of post-traumatic growth(PTG)model-based intervention to improve positive psychological traits in Chinese breast cancer patients.Design:A randomized control trial of a psychological group intervention based on PTG model.Methods:The Clinical Trial was registered on 17 August 2019 at Chinese Clinical Trials.gov with Registration number ChiCTR1900025264.A total of 92 patients with breast cancer were recruited.The participants were randomly assigned to the experimental group(n=46)and the control group(n=46).A six-session psychological group intervention based on PTG model was implemented in the experimental group,and a six-session health education was implemented in the control group.The outcomes weremeasured at baseline(pre-intervention),3 weeks,6 weeks after the intervention.The primary outcome was posttraumatic growth assessed by the Chinese version of the Post-Traumatic Growth Inventory(PTGI);Secondary outcomes included psychological resilience,family resilience,rumination,and self-disclosure.Results:A total of 87 patients with breast cancer completed this study,including 44 patients in the experimental group and 43 patients in the control group.There was no significant difference in baseline data of breast cancer patients between the two groups except for the treatment regimen(p>0.05).The two groups were compared after the intervention;the interaction effects between the total scores of posttraumatic growth,family resilience,and self-disclosure and the time term were statistically significant(p<0.05),indicating that the trend of change in total scores of post-traumatic growth,family resilience,and self-disclosure differed between the experimental and control groups over time,and the scores improved in the experimental group were significantly higher than those in the control group.The comparison of psychological resilience and total score of rumination at each time point was statistically significant(p<0.05),indicating that group intervention based on the PTG model could improve the psychological recovery ability and rumination level of the experimental group.Conclusion:The psychological group intervention based on the PTG model significantly improved post-traumatic growth,family resilience,and self-disclosure in patients with breast cancer.However,the impact on psychological resilience and rumination was relatively small.Long-term intervention is needed to further test the effect of the PTG model on psychological resilience and rumination. 展开更多
关键词 Post-traumatic growth psychological group intervention resilience RUMINATION SELF-DISCLOSURE breast cancer Tech Science Press
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Research and Application of Meteorological Response Measures for Civil Engineering and Data Acquisition System
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作者 dawei xu Zhimin ZHANG Feng PAN 《Meteorological and Environmental Research》 CAS 2023年第3期54-59,共6页
Meteorological conditions have a very important impact on the development of construction projects.In order to assist project site managers to quickly and accurately deal with the engineering risks brought by meteorol... Meteorological conditions have a very important impact on the development of construction projects.In order to assist project site managers to quickly and accurately deal with the engineering risks brought by meteorological conditions,meteorological risk assessment indicators for civil construction are established based on the actual impact of different meteorological conditions on each sub-project of civil engineering.A meteorological intelligent management system is created,and it will select reasonable countermeasures from the integrated existing database and push them to on-site construction managers based on meteorological risk assessment indicators.Through the pre-set construction log module,the managers can give feedback on the application effect of the pushed measures,and achieve the effect of construction data collection,correction and expansion of the existing database. 展开更多
关键词 METEOROLOGY Construction measures DATABASE Information collection Management system
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聚乙烯醇中空容器的制备及热处理 被引量:1
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作者 左文强 李莉 +1 位作者 徐大伟 王琪 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2022年第7期77-83,共7页
以含水和多羟基化合物的复合改性剂,通过分子复合和增塑,实现聚乙烯醇(PVA)的热塑加工,制备了PVA中空容器。采用高压毛细管流变、X射线衍射、动态力学热分析、阻隔性能、水接触角等测试方法,研究了复合改性PVA体系的熔体流变行为,以及... 以含水和多羟基化合物的复合改性剂,通过分子复合和增塑,实现聚乙烯醇(PVA)的热塑加工,制备了PVA中空容器。采用高压毛细管流变、X射线衍射、动态力学热分析、阻隔性能、水接触角等测试方法,研究了复合改性PVA体系的熔体流变行为,以及不同热处理条件对所得PVA中空容器综合性能的影响。结果表明,复合改性体系熔体黏度满足吹塑要求,吹塑所得中空容器外观良好;热处理可调控PVA中空容器的水含量,进而调控其结晶度、熔点(Tm)和玻璃化转变温度(Tg),改善其力学性能和阻隔性能。120℃热处理2 h后,PVA容器的结晶度从22.2%提升至34.7%,Tg从-3℃提升至30℃,拉伸强度从30.4 MPa增加至80.3 MPa,石油醚的渗透速率由2.33 g·mm/(m2·d)减少至0.73 g·mm/(m2·d),水接触角从31.0°增加至78.1°。 展开更多
关键词 聚乙烯醇 热塑加工 中空容器 热处理
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Bitcoin Network Measurement and a New Approach to Infer the Topology 被引量:1
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作者 Ruiguang Li Jiawei Zhu +3 位作者 dawei xu Fudong Wu Jiaqi Gao Liehuang Zhu 《China Communications》 SCIE CSCD 2022年第10期169-179,共11页
Bitcoin has made an increasing impact on the world's economy and financial order,which attracted extensive attention of researchers and regulators from all over the world.Most previous studies had focused more on ... Bitcoin has made an increasing impact on the world's economy and financial order,which attracted extensive attention of researchers and regulators from all over the world.Most previous studies had focused more on the transaction layer,but less on the network layer.In this paper,we developed BNS(Bitcoin Network Sniffer),which could find and connect nodes in the Bitcoin network,and made a measurement in detail.We collected nearly 4.1 million nodes in 1.5 hours and identified 9,515 reachable nodes.We counted the reachable nodes'properties such as:service type,port number,client version and geographic distribution.In addition,we analyzed the stability of the reachable nodes in depth and found nearly 60%kept stable during 15 days.Finally,we proposed a new approach to infer the Bitcoin network topology by analyzing the Neighbor Addresses of Adjacent Nodes and their timestamps,which had an accuracy over 80%. 展开更多
关键词 Bitcoin network reachable nodes node properties node stability network topology
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Measure of Watershed Ecological Compensation Standard Based on WTP and WTA 被引量:1
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作者 dawei xu Jinfang RONG +1 位作者 Na YANG Wen ZHANG 《Asian Agricultural Research》 2013年第7期12-16,21,共6页
In this paper,Liao River Basin was taken as the research object and field surveys were conducted in Fudedian,the source of Liao river mainstream and Panjin,the estuary of Liao River. Through the questionnaires,the wil... In this paper,Liao River Basin was taken as the research object and field surveys were conducted in Fudedian,the source of Liao river mainstream and Panjin,the estuary of Liao River. Through the questionnaires,the willingness to pay ( WTP) and willingness to accept ( WTA) of the residents in Liao River Basin were analyzed. Then based on analysis of the existing ecological compensation standard measuring methods,the WTP and WTA using contingent valuation method ( CVM) were measured and analyzed. Without considering other factors,and based on using the nonparametric estimation method,it was concluded the ecological compensation standard of Liao River Basin was 160. 72 yuan/person·years. When considering other factors,using the parametric estimation we obtain that the ecological compensation standard of Liao River Basin was 255. 97 yuan/person·years. Measuring the respondents' WTP and WTA at the same time and processing the average can actually reflect the respondents' real WTP,thus to a certain extent solving the problems of high compensation caused by formulating ecological compensation standards according to measuring WTP of respondents separately. In addition,the policy suggestions have been proposed from three aspects including financial transfer payment,ecological compensation forms and public participation system. This will not only protect residents' right to know and strengthen public participation and supervision,but also benefit the comprehensive implementation of ecological environment of Liao River Basin and establishment of a long-term mechanism of water resources protection. 展开更多
关键词 ECOLOGICAL Compensation WTP WTA CVM Liao River BAS
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Short-term effects of fire disturbance on CH4 emission from forested wetlands in the Xiaoxing’an Mountains, Northeast China
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作者 Han Gu Wenyu Zheng +1 位作者 dawei xu Changcheng Mu 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第3期969-979,共11页
Using static chamber gas chromatography, we determined the seasonal dynamics, controlling factors, and distribution patterns of forest swamp CH4 levels and related environmental factors (temperature, water level) afte... Using static chamber gas chromatography, we determined the seasonal dynamics, controlling factors, and distribution patterns of forest swamp CH4 levels and related environmental factors (temperature, water level) after fire disturbance in the Xiaoxing’an Mountains. The results showed the following: during the growing season, the annual CH4 emission distribution ranged from - 0.001 ± 0.012 to 22.373 ± 3.650 mg m^-2 h^-1;mild fire caused the swamp CH4 emission flux of tussock, shrub, Alnus sibirica and birch swamp to increase by 56.0–524.7%;at low water levels, temperature had a significant influence on the swamp type, and the correlation between the methane emission flux and temperature was significantly strengthened;after a fire disturbance, methane emissions from all types of marsh were highest in summer and second highest in autumn, with a weak absorption in spring;and along the water environment gradient of the transition zone, the CH4 emission flux presented a decreasing trend in its spatial distribution pattern. 展开更多
关键词 Xiaoxing’an MOUNTAINS FOREST SWAMP CH4 emission Fire DISTURBANCE
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Metal-Support Interactions on Ag/Co_(3)O_(4)Nanowire Monolithic Catalysts Promoting Catalytic Soot Combustion
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作者 Xingwang Yi Yuexi Yang +4 位作者 dawei xu Ye Tian Song Song Chunmei Cao Xingang Li 《Transactions of Tianjin University》 EI CAS 2022年第3期174-185,共12页
Tuning metal-support interactions(MSIs)is an important strategy in heterogeneous catalysis to realize the desirable metal dispersion and redox ability of metal catalysts.Herein,we use pre-reduced Co_(3)O_(4)nanowires(... Tuning metal-support interactions(MSIs)is an important strategy in heterogeneous catalysis to realize the desirable metal dispersion and redox ability of metal catalysts.Herein,we use pre-reduced Co_(3)O_(4)nanowires(Co-NWs)in situ grown on monolithic Ni foam substrates to support Ag catalysts(Ag/Co-NW-R)for soot combustion.The macroporous structure of Ni foam with crossed Co_(3)O_(4)nanowires remarkably increases the soot-catalyst contact effi ciency.Our characterization results demonstrate that Ag species exist as Ag 0 because of the equation Ag^(+)+Co^(2+)=Ag^(0)+Co^(3+),and the pre-reduction treatment enhances interactions between Ag and Co_(3)O_(4).The number of active oxygen species on the Ag-loaded catalysts is approximately twice that on the supports,demonstrating the signifi cant role of Ag sites in generating active oxygen species.Additionally,the strengthened MSI on Ag/Co-NW-R further improves this number by increasing metal dispersion and the intrinsic activity determined by the turnover frequency of these oxygen species for soot oxidation compared with the catalyst without pre-reduction of Co-NW(Ag/Co-NW).In addition to high activity,Ag/Co-NW-R exhibits high catalytic stability and water resistance.The strategy used in this work might be applicable in related catalytic systems. 展开更多
关键词 Metal-support interaction Monolithic catalysts AG Co_(3)O_(4)nanowires Soot oxidation
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BUES: A Blockchain-Based Upgraded Email System
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作者 dawei xu Fudong Wu +3 位作者 Liehuang Zhu Ruiguang Li Jiaqi Gao Yijie She 《China Communications》 SCIE CSCD 2022年第10期250-264,共15页
This paper focuses on the improvement of traditional email system architecture with the help of blockchain technology in the existing network environment. The improved system architecture can better improve the securi... This paper focuses on the improvement of traditional email system architecture with the help of blockchain technology in the existing network environment. The improved system architecture can better improve the security and stability of the system. The email content is extracted and stored in the blockchain network to achieve regulatory traceability between the email service provider and the higher-level organization. In turn, A Blockchain-based Upgraded Email System(BUES) is proposed. The defects of the existing traditional email system are addressed. Firstly, the threat model of the traditional email system is analyzed, and solutions are proposed for various threats. Then a system architecture consisting of the blockchain network, email servers, and users are constructed. The implementation of BUES is carried out, and the related experimental process and algorithm steps are given. After the experimental analysis, it is shown that BUES can ensure the security, reliability, efficiency, and traceability of email transmission. 展开更多
关键词 blockchain email service chaincode hyperledger fabric
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The Content of Modern Landscape Architecture Discipline and Its Forming Process
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作者 Xi Chen dawei xu +1 位作者 Safa Fadelelseed Lianying Li 《Journal of Environmental & Earth Sciences》 2019年第1期49-52,共4页
Modem landscape architecture discipline is not an emerging discipline.It has a very long history.After a long period of multidisciplinary integra-tion,it has formed a modem landscape architecture.In recent years,with ... Modem landscape architecture discipline is not an emerging discipline.It has a very long history.After a long period of multidisciplinary integra-tion,it has formed a modem landscape architecture.In recent years,with the development of society,the problems of environmental problems and economic structural imbalances have become more and more prominent and serious.Therefore,modern landscape architecture is also facing tremendous changes and is at the crossroads of discipline development.This paper analyzes and discusses the content and formation of modem landscape architecture,and points out the characteristics and importance of landscape architecture. 展开更多
关键词 LANDSCAPE ARCHITECTURE LANDSCAPE ARCHITECTURE DISCIPLINE DISCIPLINE development HISTORY Characteristics ERA Chinese style 21st CENTURY
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Application of Decoration Culture of Traditional Manchu Residence in Architectural Landscape Design
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作者 Lianying Li dawei xu +1 位作者 Xi Chen Safa Fadelelseed 《Journal of Architectural Research and Development》 2020年第1期17-20,共4页
In recent years,China’s urban construction has been gradually influenced by Western culture and ideologies.The planning of urban development has been carried out in accordance with Western ideologies.As a result,this... In recent years,China’s urban construction has been gradually influenced by Western culture and ideologies.The planning of urban development has been carried out in accordance with Western ideologies.As a result,this has prevented our local buildings and architectures to showcase unique local style and characteristics.Even under the influence of global urbanization,the development trend has prevented the construction of global cities from displaying the characteristics of their respective cities.Therefore,it is highly important for a nation not to lose the direction in the design of the urban landscape,and not to blindly imitating the architectural style of other countries or other cities.In addition,the nation and its cities should show their respective unique cultural charm and cultural characteristics and present their best to the whole world in order to promote the popularity of the cities,expand their influence and get onto a better development path.This article mainly introduces the application of the decoration culture of the traditional Manchu residence in the architectural landscape design. 展开更多
关键词 TRADITIONAL MANCHU RESIDENCE DECORATION culture LANDSCAPE design
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Inheritance and Evolution of the Spatial Form of Traditional Rural Settlement
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作者 Lianying Li dawei xu +1 位作者 Xi Chen Safa Fadelelseed 《Journal of Architectural Research and Development》 2019年第5期5-8,共4页
As early as the farming era,traditional rural settlements have been deeply rooted in our country.The geographical location of rural settlements is inextricably linked to the natural environment,transportation and soci... As early as the farming era,traditional rural settlements have been deeply rooted in our country.The geographical location of rural settlements is inextricably linked to the natural environment,transportation and social forms.China has continuously increased its modernization and transformed rural settlements with the rapid development of society,which has led to the change in the spatial form of rural settlements and led to the demise of many traditional settlements.Therefore,the culture and traditions are inevitably deplorable.Settlement is the most primitive way of living in China.Therefore,it is necessary to understand and learn the culture as well as correctly transform the rural settlement.This paper aims to study the spatial form of traditional rural settlements.Based on the background research of traditional rural settlement spatial form,this paper discusses the influencing factors of settlement spatial form and the spatial form and evolution of rural settlements. 展开更多
关键词 TRADITIONAL VILLAGE RURAL SETTLEMENT Spatial FORM
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Analysis on Landscape Ecological Design in Landscape Architecture
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作者 Xi Chen dawei xu +1 位作者 Safa Fadelelseed Lianying Li 《Research in Ecology》 2019年第1期31-34,共4页
With the continuous improvement of China’s economic level, the people’s cultural literacy is gradually increasing, and the same people are increasingly pursuing new changes and changes in the quality of life. At pre... With the continuous improvement of China’s economic level, the people’s cultural literacy is gradually increasing, and the same people are increasingly pursuing new changes and changes in the quality of life. At present, most people are not only satisfied with the basic needs of life, but also have a new height and pursuit in the improvement of new life quality. In the current landscape design field, people are increasingly demanding landscape design. How to design urban landscape design that meets the real needs of people under current social conditions is one of the hottest topics in the current landscape design industry. As an important component in the construction of landscape architecture, effective landscape ecological design plays an important role in maintaining the sustainable development of urban ecological environment and enhancing the visual beauty of landscape architecture. Therefore, it is necessary to pay more attention to the ecological design of the landscape, clarify the ideas and principles of ecological design, and realize the improvement of the safety and aesthetics of the landscape ecological design in the construction of landscape architecture. Then, this paper gives a brief overview and analysis of some design concepts, design principles and design points in landscape ecological design in current landscape architecture, which aims to promote the quality improvement of the landscape ecological design in the current Landscape architecture and promote the progress and development of the overall landscape ecological design industry. 展开更多
关键词 LANDSCAPE ARCHITECTURE LANDSCAPE ECOLOGICAL DESIGN DESIGN RESEARCH
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Thoughts on the Construction of Beautiful Villages with Poverty Alleviation in the Perspective
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作者 Yanxue Li Shu Zhu dawei xu 《Journal of Environmental & Earth Sciences》 2020年第1期7-13,共7页
Accurate poverty alleviation has become an important task in implementing the rural revitalization strategy.Since the 19th CPC National Congress,Chinese government institutions have been striving to take measures to l... Accurate poverty alleviation has become an important task in implementing the rural revitalization strategy.Since the 19th CPC National Congress,Chinese government institutions have been striving to take measures to lift poor rural areas out of poverty.This essay takes Tailai district as the blueprint to start the research on precision poverty alleviation,explores and discusses the construction of beautiful villages,proposes strategies for sustainable development,makes people change concepts to coordinate the relationship between interests and concepts.It also points out the target that using the industry as a guide,using technology to alleviate poverty and make the village vibrant.Therefore,the endogenous power will be derived from the roots,and the agriculture,farmer and rural area will be fed back,in order to provide a reference for the Construction of Beautiful Villages in Heilongjiang. 展开更多
关键词 Precise poverty alleviation Construction of beautiful villages Interests and concepts
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Advancing sustainable agriculture: Enhancing crop nutrition with next-generation nanotech-based fertilizers
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作者 Yiwen Liao dawei xu +1 位作者 Yuhong Cao Yong-Guan Zhu 《Nano Research》 SCIE EI CSCD 2023年第12期13205-13225,共21页
The pressing need to enhance nutrient use efficiency(NUE)in fertilizers has become increasingly urgent in light of food insecurity and climate-related issues.Nanotechnology offers promising prospects for the developme... The pressing need to enhance nutrient use efficiency(NUE)in fertilizers has become increasingly urgent in light of food insecurity and climate-related issues.Nanotechnology offers promising prospects for the development of effective and environmentally friendly alternatives in the field of fertilization.This review focuses on the impact of nanotechnology on conventional fertilizers,encompassing inorganic,organic,and microbial approaches.We emphasize the superior attributes of nano-fertilizers compared with their conventional counterparts and explore their potential and versatility in boosting crop productivity,reducing fertilizer expenses,and mitigating detrimental environmental impacts.In conclusion,given the significant challenges posed by food insecurity and climate change,the application of nano-fertilizers demonstrates immense potential for advancing sustainable and intelligent agricultural practices. 展开更多
关键词 NANOBIOTECHNOLOGY nano-fertilizers(NFs) nutrient use efficiency(NUE) slow release sustainable agriculture
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Research on medical data storage and sharing model based on blockchain
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作者 Jian Zhao Wenqian Qiang +4 位作者 Zisong Zhao Tianbo An Zhejun Kuang dawei xu Lijuan Shi 《High-Confidence Computing》 2023年第3期61-67,共7页
With the process of medical informatization,medical diagnosis results are recorded and shared in the form of electronic data in the computer.However,the security of medical data storage cannot be effectively protected... With the process of medical informatization,medical diagnosis results are recorded and shared in the form of electronic data in the computer.However,the security of medical data storage cannot be effectively protected and the unsafe sharing of medical data among different institutions is still a hidden danger that cannot be underestimated.To solve the above problems,a secure storage and sharing model of private data based on blockchain technology and homomorphic encryption is constructed.Based on the idea of blockchain decentralization,the model maintains a reliable medical alliance chain system to ensure the safe transmission of data between different institutions;A privacy data encryption and computing protocol based on homomorphic encryption is constructed to ensure the safe transmission of medical data;Using its complete anonymity to ensure the Blockchain of medical data and patient identity privacy;A strict transaction control management mechanism of medical data based on Intelligent contract automatic execution of preset instructions is proposed.After security verification,compared with the traditional medical big data storage and sharing mode,the model has better security and sharing. 展开更多
关键词 Blockchain Encryption algorithm Medical data Secure message processing systems storage MODELS Shared-resource systems
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The polyketide synthase OsPKS2 is essential for pollen exine and Ubisch body patterning in rice 被引量:14
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作者 Xiaolei Zhu Jing Yu +7 位作者 Jianxin Shi Takayuki Tohge Alisdair R.Fernie Sagit Meir Asaph Aharoni dawei xu Dabing Zhang Wanqi Liang 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2017年第9期612-628,共17页
Lipid and phenolic metabolism are important for pollen exine formation. In Arabidopsis, polyketide synthases (PKSs) are essential for both sporopollenin biosynthesis and exine formation. Here, we characterized the r... Lipid and phenolic metabolism are important for pollen exine formation. In Arabidopsis, polyketide synthases (PKSs) are essential for both sporopollenin biosynthesis and exine formation. Here, we characterized the role of a polyketide synthase (OsPKS2) in male reproduction of rice (Oryza sativa). Recombinant OsPKS2 catalyzed the condensation of fatty acyl-CoA with malonyl- CoA to generate triketide and tetraketide α-pyrones, the main components of pollen exine. Indeed, the ospks2 mutant had defective exine patterning and was male sterile. However, the mutant showed no significant reduction in sporopollenin accumulation. Compared with the WT (wild type), ospks2 displayed unconfined and amorphous tectum and nexine layers in the exine, and less organized Ubisch bodies. Like the pksb/lap5 mutant of the Arabidopsis ortholog, ospks2 showed broad alterations in the profiles of anther-related phenolic compounds. However, unlike pksb/laps, in which most detected phenolics were substantially decreased, ospks2 accumu- lated higher levels of phenolics. Based on these results and our observation that OsPKS2 is unable to fully restore the exine defects in the pksb/laps, we propose that PKS proteins have functionally diversified during evolution. Collectively, our results suggest that PKSs represent a conserved and diversified biochemical pathway for anther and pollen development in higher plants. 展开更多
关键词 PKS The polyketide synthase OsPKS2 is essential for pollen exine and Ubisch body patterning in rice Figure
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Managed grassland alters soil N dynamics and N2O emissions in temperate steppe 被引量:2
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作者 Lijun xu Xingliang xu +7 位作者 xuejuan Tang Xiaoping Xin Liming Ye Guixia Yang Huajun Tang Shijie Lv dawei xu Zhao Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第4期20-30,共11页
Reclamation of degraded grasslands as managed grasslands has been increasingly accelerated in recent years in China. Land use change affects soil nitrogen(N) dynamics and nitrous oxide(N2O) emissions. However, it ... Reclamation of degraded grasslands as managed grasslands has been increasingly accelerated in recent years in China. Land use change affects soil nitrogen(N) dynamics and nitrous oxide(N2O) emissions. However, it remains unclear how large-scale grassland reclamation will impact the grassland ecosystem as a whole. Here, we investigated the effects of the conversion from native to managed grasslands on soil N dynamics and N2O emissions by field experiments in Hulunber in northern China. Soil(0-10 cm), nitrate(NO3-),ammonium(NH4+), and microbial N were measured in plots in a temperate steppe(Leymus chinensis grassland) and two managed grasslands(Medicago sativa and Bromus inermis grasslands) in 2011 and 2012. The results showed conversion of L. chinensis grassland to M.sativa or B. inermis grasslands decreased concentrations of NO3--N, but did not change NH4-N . Soil microbial N was slightly decreased by the conversion of L. chinensis grassland to M.sativa, but increased by the conversion to B. inermis. The conversion of L. chinensis grassland to M. sativa(i.e., a legume grass) increased N2O emissions by 26.2%, while the conversion to the B. inermis(i.e., a non-legume grass) reduced N2O emissions by 33.1%. The conversion from native to managed grasslands caused large created variations in soil NO3-+-N and NH4-N concentrations. Net N mineralization rates did not change significantly in growing season or vegetation type, but to net nitrification rate. These results provide evidence on how reclamation may impact the grassland ecosystem in terms of N dynamics and N2O emissions. 展开更多
关键词 Temperate steppe Managed grassland Land use Nitrogen mobility N2O emissions
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Platinum nanowires catalyzed direct amidation of aldehydes and amines
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作者 dawei xu Linyan Shi +2 位作者 Danhua Ge xueqin Cao Hongwei Gu 《Science China Chemistry》 SCIE EI CAS CSCD 2016年第4期478-481,共4页
Different from the conventional synthesis methods and substrates, we designed a brand new method for synthesizing amides with platinum nanowires as catalysts and tert-butylhydroperoxide(TBHP) as the oxidant. Influence... Different from the conventional synthesis methods and substrates, we designed a brand new method for synthesizing amides with platinum nanowires as catalysts and tert-butylhydroperoxide(TBHP) as the oxidant. Influence of factors, such as the catalyst, solvents, and the reaction temperature, were studied to determine the optimal reaction conditions. In addition, we explored the substrate generality and observed excellent yields. 展开更多
关键词 直接胺化 纳米线 催化剂 叔丁基过氧化氢 最佳反应条件 合成方法 影响因素 反应温度
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Fabrication of self-assembling nanofibers with optimal cell uptake and therapeutic delivery efficacy
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作者 dawei xu Damien SKSamways He Dong 《Bioactive Materials》 SCIE 2017年第4期260-268,共9页
Effective strategies to fabricate finite organic nanoparticles and understanding their structure-dependent cell interaction is highly important for the development of long circulating nanocarriers in cancer therapy.In... Effective strategies to fabricate finite organic nanoparticles and understanding their structure-dependent cell interaction is highly important for the development of long circulating nanocarriers in cancer therapy.In this contribution,we will capitalize on our recent development of finite supramolecular nanofibers based on the self-assembly of modularly designed cationic multidomain peptides(MDPs)and use them as a model system to investigate structure-dependent cell penetrating activity.MDPs selfassembled into nanofibers with high density of cationic charges at the fiber-solvent interface to interact with the cell membrane.However,despite the multivalent charge presentation,not all fibers led to high levels of membrane activity and cellular uptake.The flexibility of the cationic charge domains on self-assembled nanofibers plays a key role in effective membrane perturbation.Nanofibers were found to sacrifice their dimension,thermodynamic and kinetic stability for a more flexible charge domain in order to achieve effective membrane interaction.The increased membrane activity led to improved cell uptake of membrane-impermeable chemotherapeutics through membrane pore formation.In vitro cytotoxicity study showed co-administering of water-soluble doxorubicin with membrane-active peptide nanofibers dramatically reduced the IC50 by eight folds compared to drug alone.Through these detailed structure and activity studies,the acquired knowledge will provide important guidelines for the design of a variety of supramolecular cell penetrating nanomaterials not limited to peptide assembly which can be used to probe various complex biological processes. 展开更多
关键词 Supramolecular assembly Cell penetrating peptide Drug delivery Cell uptake Membrane activity
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