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Current controversies in glia-to-neuron conversion therapy in neurodegenerative diseases
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作者 Peng Cao jianan li +1 位作者 Zhuxi liu Guobiao liang 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第4期723-724,共2页
Loss of neurons and disruption of neural circuits are associated with many neurological diseases,including neurodegenerative diseases and mental disorders.The most prevalent pathological feature of neurodegenerative d... Loss of neurons and disruption of neural circuits are associated with many neurological diseases,including neurodegenerative diseases and mental disorders.The most prevalent pathological feature of neurodegenerative diseases is the aggregate loss of certain neuronal populations.For example,the loss of dopamine(DA)neurons in the substantia nigra pars compacta has been defined as a pathological hallmark of Parkinson’s disease(PD;Kamath et al.,2022). 展开更多
关键词 DISEASES DEGENERATIVE al.
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Research progress and application of deep in-situ condition preserved coring and testing
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作者 Heping Xie Yunqi Hu +14 位作者 Mingzhong Gao ling Chen Ru Zhang Tao liu Feng Gao Hongwei Zhou Xiaobo Peng Xiongjun li Jianbo Zhu Cunbao li Ruidong Peng Yanan Gao Cong li jianan li Zhiqiang He 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第11期1319-1337,共19页
With the depletion of shallow resources,the exploration of deep earth resources has become a global strategy.The study of the different patterns in the physical mechanical properties of rocks at different occurrence d... With the depletion of shallow resources,the exploration of deep earth resources has become a global strategy.The study of the different patterns in the physical mechanical properties of rocks at different occurrence depths is the basis for exploring deep into the earth,with the core and premise being the acquisition and testing of deep in-situ core specimens.Based on the original idea of deep in-situ condition preserved coring(ICP-Coring)and testing,combined with theoretical modeling,numerical analysis,test platform development,indoor testing and engineering application,the principles and technologies of deep ICP-Coring are developed.This principle and technology consists of five parts:in-situ pressurepreserved coring(IPP-Coring),in-situ substance-preserved coring(ISP-Coring),in-situ temperaturepreserved coring(ITP-Coring),in-situ light-preserved coring(ILP-Coring),and in-situ moisturepreserved coring(IMP-Coring).The theory and technology of temperature and pressure reconstruction at different occurrence depths and in different environments are proposed,and prototype trial production was completed by following the principle of displacement and tests based on the in-situ reconstructed environment.The notable advances are as follows:(1)Deep in-situ coring system:A pressure-preserved controller with an ultimate bearing capacity greater than 140 MPa,highperformance(temperature-resistant,pressure-resistant,and low thermally conductive)temperaturepreserved materials,an active temperature control system,and high-barrier quality-preserved membrane materials were developed;a deep ICP-Coring capacity calibration platform was independently developed,a deep in-situ coring technology system was developed,and the acquisition of deep in-situ cores was realized.(2)In-situ storage displacement system:Following the dual-circuit hydraulic design idea,a single-drive source push-pull composite grabbing mechanism was designed;the design of the overall structure for the deep in-situ displacement storage system and ultrahigh pressure cabin structure was completed,which could realize docking the coring device and core displacement in the in-situ reconstructed environment.(3)Test analysis system:A noncontact acoustic-electric-magnetic test system was developed under the in-situ reconstructed environment,and the errors between the test results and traditional contact test results were mostly less than 10%;a detachable deep in-situ core true triaxial test system was developed,which could perform loading tests for deep in-situ cores.The relevant technological achievements were successfully applied to the exploration and development of deep resources,such as deep mines,deep-sea natural gas hydrates,and deep oil and gas.The research results provide technical and equipment support for the construction of a theoretical system for deep in-situ rock mechanics,the development of deep earth resources and energy,and the scientific exploration of different layers and occurrence depths(deep and ultradeep)of the Earth. 展开更多
关键词 Deep mining Deep in-situ CORING DISPLACEMENT Test
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Straw return increases crop production by improving soil organic carbon sequestration and soil aggregation in a long-term wheat-cotton cropping system
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作者 Changqin Yang Xiaojing Wang +6 位作者 jianan li Guowei Zhang Hongmei Shu Wei Hu Huanyong Han Ruixian liu Zichun Guo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期669-679,共11页
Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cott... Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system. 展开更多
关键词 straw return crop yields SOC soil aggregates wheat-cotton cropping system
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International Society of Physical and Rehabilitation Medicine (ISPRM): strengthening Physical and Rehabilitation Medicine (PRM) worldwide
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作者 Gerold Stucki Jan D. Reinhardt +2 位作者 Marta Imamura jianan li Joel A. De lisa 《中国康复医学杂志》 CAS CSCD 北大核心 2011年第6期501-503,共3页
Physiral and Rehabilitation Medicine (PRM) is the Medicine of Functioning in light of health conditions, under consideration of the person and in interaction with the environment[1-2].PRM focuses on the application of... Physiral and Rehabilitation Medicine (PRM) is the Medicine of Functioning in light of health conditions, under consideration of the person and in interaction with the environment[1-2].PRM focuses on the application of rehabilitation, the third health strategy which complements the preventive and curative health strategies.Thanks to the increasing survival of people after injury and formerly conditions as well as aging populations and an associated increase in chronic conditions, PRM as the leader of the rehabilitation will, over the next decades, assume an ever more important role in the health care systems worldwide. 展开更多
关键词 《中国康复医学杂志》 期刊 摘要 编辑部
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Based on Multimedia and Network Social Environment--A study of Pragmatic Acquisition in College English Teaching
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作者 jianan li 《Journal of Contemporary Educational Research》 2021年第4期55-58,共4页
With the progress of the times,the number of college students is growing exponentially.But the students who enter the university are various and have their own advantages and disadvantages.Among them,the polarization ... With the progress of the times,the number of college students is growing exponentially.But the students who enter the university are various and have their own advantages and disadvantages.Among them,the polarization of students'English level is particularly obvious and serious.Therefore,in view of the contradiction between"not enough to learn"and"unable to learn",this paper makes a preliminary exploration on the pragmatic acquisition mode of College English teaching based on multimedia and network social environment.This paper mainly discusses and analyzes the concept of pragmatic acquisition mode and about how to implement it in practical teaching.In addition,this paper is only for reference in the English teaching industry. 展开更多
关键词 The pragmatic acquisition model College English Teaching Multimedia and network social environment
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Study of a low-disturbance pressure-preserving corer and its coring performance in deep coal mining conditions
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作者 Wei Huang jianan li +3 位作者 Zhiqiang liu Mingqing Yang Zhenxi You Heping Xie 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2023年第11期1397-1410,共14页
With the increasing depth of coal mining,the requirements for coring devices that maintain pressure are increasing.To adapt to the special environment in deep coal seams and improve the accuracy of testing gas content... With the increasing depth of coal mining,the requirements for coring devices that maintain pressure are increasing.To adapt to the special environment in deep coal seams and improve the accuracy of testing gas content,a low-disturbance pressure-preserving corer was developed.The measurement of gas content using this corer was analyzed.The coring test platform was used to complete a coring function test.A pressurized core with a diameter of 50 mm was obtained.The pressure was 0.15 MPa,which was equal to the pressure of the liquid column of the cored layer,indicating that the corer can be successfully used in a mud environment.Next,a pressure test of the corer was conducted.The results showed that under conditions of low pressure(8 MPa)and high pressure(25 MPa),the internal pressure of the corer remained stable for more than 1 h,indicating that the corer has good ability to maintain pressure.Therefore,the corer can be applied at deep coal mine sites.The results of this research can be used to promote the safe exploitation of deep coal mines and the exploitation of methane resources in coalbeds. 展开更多
关键词 Pressure-preserving corer Low-disturbance Coring performance Deep coal mining conditions
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Modified halloysite nanotubes reduce the toxic effects of zearalenone in gestating sows on growth and muscle development of their offsprings 被引量:3
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作者 Rui Gao Qingwei Meng +4 位作者 jianan li Min liu Yuanyuan Zhang Chongpeng Bi Anshan Shan 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2016年第4期570-578,共9页
Background: Zearalenone(ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experiment w... Background: Zearalenone(ZEN) is an estrogenic mycotoxin that is primarily produced by Fusarium fungi and has been proven to affect the reproductive capacity of many species to varying degrees. The present experiment was designed to study the maternal persistent effects of zearalenone toxicity in gestating sows on growth and muscle development of their offsprings, and the alleviation of zearalenone toxicity by modified halloysite nanotubes(MHNTs).Methods: Eighteen sows were fed with one of three dietary treatments that included the following:(1) a control diet,(2) a contaminated grain diet(with 50 % moldy corn, 2.77 mg/kg ZEN), and(3) a contaminated grain diet(with 50 %moldy corn, 2.76 mg/kg ZEN) + 1 % MHNTs. Each sow was exclusively fed its experimental diets from 35 to 70 d of gestation at a total of 2 kg daily. Muscle samples were collected from six piglets per treatment at birth, weaning and finishing.Results: The results showed that feeding the sows with the ZEN-contaminated diets from 35 to 70 d of gestation decreased the ADG, ADFI and G:F of their offsprings(P < 0.05). The muscle fiber numbers in the newborn, weaning and growing-finishing pigs and the muscle fiber diameters at birth and weaning were also decreased by maternal ZEN exposure(P < 0.05). The expressions of IGF-I, IGF-II, Myf-5 and Mstn at birth and IGF-II, Pax7, Myf-5 and Myo D1 at weaning were altered by feeding gestating sows with ZEN-contaminated diets(P < 0.05). The MHNTs reduced most of the ZEN-induced toxic effects: the ADG and ADFI on growth performance, the muscle fiber numbers at weaning and finishing and the muscle fiber diameters at weaning(P < 0.05). The expression levels of IGF-II and Mstn in newborn piglets and IGF-II and Myf-5 in weaning piglets were also prevented by adding 1 % MHNTs(P < 0.05).Conclusions: The present study demonstrated that the offsprings of sows fed with ZEN-contaminated diets from 35 to 70 day of gestation exhibited weakening on growth performance, physiological changes in their muscle fibers and alterations of m RNA expression in their muscle tissues, and also indicated that MHNTs prevented most of the ZENinduced weakening in the muscle tissues. 展开更多
关键词 玉米赤霉烯酮 生长肥育猪 妊娠母猪 肌肉组织 毒性作用 埃洛石 后代 改性
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Pencil-beam scanning catheter for intracoronary optical coherence tomography 被引量:2
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作者 Jiqiang Kang Rui Zhu +2 位作者 Yunxu Sun jianan li Kenneth K.Y.Wong 《Opto-Electronic Advances》 SCIE EI 2022年第3期69-75,共7页
Current gradient-index(GRIN)lens based proximal-driven intracoronary optical coherence tomography(ICOCT)probes consist of a spacer and a GRIN lens with large gradient constant.This design provides great flexibility to... Current gradient-index(GRIN)lens based proximal-driven intracoronary optical coherence tomography(ICOCT)probes consist of a spacer and a GRIN lens with large gradient constant.This design provides great flexibility to control beam profiles,but the spacer length should be well controlled to obtain desired beam profiles and thus it sets an obstacle in mass catheter fabrication.Besides,although GRIN lens with large gradient constant can provide tight focus spot,it has short depth of focus and fast-expanded beam which leads to poor lateral resolution for deep tissue.In this paper,a type of spacer-removed probe is demonstrated with a small gradient constant GRIN lens.This design simplifies the fabrica-tion process and is suitable for mass production.The output beam of the catheter is a narrow nearly collimated light beam,referred to as pencil beam here.The full width at half maximum beam size varies from 35.1μm to 75.3μm in air over 3-mm range.Probe design principles are elaborated with probe/catheter fabrication and performance test.The in vivo imaging of the catheter was verified by a clinical ICOCT system.Those results prove that this novel pencil-beam scanning catheter is potentially a good choice for ICOCT systems. 展开更多
关键词 optical coherence tomography endoscopic imaging intravascular imaging fiber optics imaging
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The evolving concept of physiological ischemia training vs. ischemia preconditioning 被引量:1
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作者 Jun Ni Hongjian Lu +6 位作者 Xiao Lu Minghui Jiang Qingyun Peng Caili Ren Jie Xiang Chengyao Mei jianan li 《The Journal of Biomedical Research》 CAS CSCD 2015年第6期445-450,共6页
Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide.Despite advances in revascularization techniques,angiogenic therapies remain highly attractive.Physiological ischemi... Ischemic heart diseases are the leading cause of death with increasing numbers of patients worldwide.Despite advances in revascularization techniques,angiogenic therapies remain highly attractive.Physiological ischemia training,which is first proposed in our laboratory,refers to reversible ischemia training of normal skeletal muscles by using a tourniquet or isometric contraction to cause physiologic ischemia for about 4 weeks for the sake of triggering molecular and cellular mechanisms to promote angiogenesis and formation of collateral vessels and protect remote ischemia areas.Physiological ischemia training therapy augments angiogenesis in the ischemic myocardium by inducing differential expression of proteins involved in energy metabolism,cell migration,protein folding,and generation.It upregulates the expressions of vascular endothelial growth factor,and induces angiogenesis,protects the myocardium when infarction occurs by increasing circulating endothelial progenitor cells and enhancing their migration,which is in accordance with physical training in heart disease rehabilitation.These findings may lead to a new approach of therapeutic angiogenesis for patients with ischemic heart diseases.On the basis of the promising results in animal studies,studies were also conducted in patients with coronary artery disease without any adverse effect in vivo,indicating that physiological ischemia training therapy is a safe,effective and non-invasive angiogenic approach for cardiovascular rehabilitation.Preconditioning is considered to be the most protective intervention against myocardial ischemia-reperfusion injury to date.Physiological ischemia training is different from preconditioning.This review summarizes the preclinical and clinical data of physiological ischemia training and its difference from preconditioning. 展开更多
关键词 缺血预适应 生理性 训练 血管内皮生长因子 缺血性心脏病 心脏病患者 缺血再灌注损伤 血管生成
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Improvements to the retractor and muscle flap design for minimally invasive cochlear implantation 被引量:1
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作者 Riyuan liu Zhiping Tan +5 位作者 jianan li Yan Yan Wei Ren Miao Zhang Shiming Yang Hui Zhao 《Journal of Otology》 CSCD 2020年第1期41-44,共4页
Objective: The aim of this study was to improve muscle flaps and to evaluate surgical outcomes with the use of a novel specialized retractor, which is a surgical instrument used to locate and shape a bony seat for min... Objective: The aim of this study was to improve muscle flaps and to evaluate surgical outcomes with the use of a novel specialized retractor, which is a surgical instrument used to locate and shape a bony seat for minimally invasive cochlear implantation.Methods: 50 patients aged 1 e75 years with sensorineural hearing loss who required cochlear implantation were recruited. A small incision(<3 cm) was made, and the novel specialized retractor was used in the study group during cochlear implantation. The incision length, surgical outcomes and operative time were recorded and analyzed.Results: The incision length, total operative time and drilling bony time were shorter in the study group than in the control group(P < 0.05, respectively). All patients recovered well after the surgery without any severe complications.Conclusion: The use of a novel specialized retractor standardized the surgical processes of cochlear implantation. The retractor helped locate and control the size of the bony well during bone drilling. The tool reduced the technical difficulty and improved the efficacy of this minimally invasive operation. 展开更多
关键词 Minimally invasive surgery Cochlear implantation RETRACTOR Muscle flap
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Simulatingthe Effect of Temperature Gradient on Grain Growth of 6061-T6 Aluminum Alloy via Monte Carlo Potts Algorithm
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作者 Qi Wu jianan li +1 位作者 lianchun Long linao liu 《Computer Modeling in Engineering & Sciences》 SCIE EI 2021年第10期99-116,共18页
During heat treatment or mechanical processing,most polycrystalline materials experience grain growth,which significantly affects their mechanical properties.Microstructure simulation on a mesoscopic scale is an impor... During heat treatment or mechanical processing,most polycrystalline materials experience grain growth,which significantly affects their mechanical properties.Microstructure simulation on a mesoscopic scale is an important way of studying grain growth.A key research focus of this type of method has long been how to efficiently and accurately simulate the grain growth caused by a non-uniform temperature field with temperature gradients.In this work,we propose an improved 3D Monte Carlo Potts(MCP)method to quantitatively study the relationship between non-uniform temperature fields and final grain morphologies.Properties of the aluminum alloy AA6061-T6 are used to establish a trial calculation model and to verify the algorithms with existing experimental results in literature.The detailed grain growth process of the 6061-T6 aluminum alloy under different temperature fields is then obtained,and grain morphologies at various positions are analyzed.Results indicate that while absolute temperature and duration time are the primary factors determining the final grain size,the temperature gradient also has strong influence on the grain morphologies.The relationships between temperatures,temperature gradients and grain growth process have been established.The proposed MCP algorithm can be applied to different types of materials when the proper parameters are used. 展开更多
关键词 Grain growth temperature gradient polycrystalline materials Monte Carlo method aluminum alloy
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Inherent-attribute-aware dual-graph autoencoder for rating prediction
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作者 Yangtao Zhou Qingshan li +5 位作者 Hua Chu jianan li Lejia Yang Biaobiao Wei Luqiao Wang Wanqiang Yang 《Journal of Information and Intelligence》 2024年第1期82-97,共16页
Autoencoder-based rating prediction methods with external attributes have received wide attention due to their ability to accurately capture users'preferences.However,existing methods still have two significant li... Autoencoder-based rating prediction methods with external attributes have received wide attention due to their ability to accurately capture users'preferences.However,existing methods still have two significant limitations:i)External attributes are often unavailable in the real world due to privacy issues,leading to low quality of representations;and ii)existing methods lack considering complex associations in users'rating behaviors during the encoding process.To meet these challenges,this paper innovatively proposes an inherent-attribute-aware dual-graph autoencoder,named IADGAE,for rating prediction.To address the low quality of representations due to the unavailability of external attributes,we propose an inherent attribute perception module that mines inductive user active patterns and item popularity patterns from users'rating behaviors to strengthen user and item representations.To exploit the complex associations hidden in users’rating behaviors,we design an encoder on the item-item co-occurrence graph to capture the co-occurrence frequency features among items.Moreover,we propose a dual-graph feature encoder framework to simultaneously encode and fuse the high-order representations learned from the user-item rating graph and item-item co-occurrence graph.Extensive experiments on three real datasets demonstrate that IADGAE is effective and outperforms existing rating prediction methods,which achieves a significant improvement of 4.51%~41.63%in the RMSE metric. 展开更多
关键词 Rating prediction Graph convolutional network Autoencoder Inherent attribute aware
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Guidelines for burn rehabilitation in China 被引量:13
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作者 Chinese Burn Association Chinese Association of Burn Surgeons +32 位作者 Ying Cen Jiake Chai Huade Chen Jian Chen Guanghua Guo Chunmao Han Dahai Hu Jingning Huan Xiaoyuan Huang Chiyu Jia Cecilia WP li-Tsang jianan li Zongyu li Qun liu Yi liu Gaoxing Luo Guozhong Lv Xihua Niu Daizhi Peng Yizhi Peng Hongyan Qi Shunzhen Qi Zhiyong Sheng Dan Tang Yibing Wang Jun Wu Zhaofan Xia Weiguo Xie Hongming Yang Xianfeng Yi Lehua Yu Guoan Zhang The Chinese Burn Care and Rehabilitation Association 《Burns & Trauma》 SCIE 2015年第3期133-142,共10页
Quality of life and functional recovery after burn injury is the final goal of burn care,especially as most of burn patients survive the injury due to advanced medical science.However,dysfunction,disfigurement,contrac... Quality of life and functional recovery after burn injury is the final goal of burn care,especially as most of burn patients survive the injury due to advanced medical science.However,dysfunction,disfigurement,contractures,psychological problems and other discomforts due to burns and the consequent scars are common,and physical therapy and occupational therapy provide alternative treatments for these problems of burn patients.This guideline,organized by the Chinese Burn Association and Chinese Association of Burn Surgeons aims to emphasize the importance of team work in burn care and provide a brief introduction of the outlines of physical and occupational therapies during burn treatment,which is suitable for the current medical circumstances of China.It can be used as the start of the tools for burn rehabilitation. 展开更多
关键词 BURN REHABILITATION Physical therapy Occupational Therapy SCAR
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新型重组人源弹性蛋白交联凝胶快速修复光损伤皮肤
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作者 李佳楠 孙秀霞 肖建喜 《中国科学:化学》 CAS CSCD 北大核心 2023年第2期227-234,共8页
光损伤是最常见的皮肤疾病,每年遭受皮肤光损伤的人次超过全球总人口的1/3.弹性蛋白是皮肤真皮层中的关键蛋白质,在维持皮肤形态中扮演着重要角色.弹性蛋白目前主要通过动物组织提取,它存在病毒传播隐患和容易降解等缺陷.本研究构建了... 光损伤是最常见的皮肤疾病,每年遭受皮肤光损伤的人次超过全球总人口的1/3.弹性蛋白是皮肤真皮层中的关键蛋白质,在维持皮肤形态中扮演着重要角色.弹性蛋白目前主要通过动物组织提取,它存在病毒传播隐患和容易降解等缺陷.本研究构建了一种新型的重组人源弹性蛋白及其交联凝胶,能够快速修复光损伤皮肤.该重组人源弹性蛋白由人弹性蛋白片段组成,具有与天然弹性蛋白类似的二级结构和可逆相变特性.该重组人源弹性蛋白经THPC交联形成凝胶,具有良好的机械强度.扫描电子显微镜结果表明,该重组弹性蛋白凝胶具有均匀分布的网孔结构.细胞实验表明,该凝胶无细胞毒性,并可以显著促进成纤维细胞的增殖.光损伤模型小鼠的动物实验表明,该凝胶可减轻光损伤小鼠的炎症反应,有效抑制表皮异常增生,并明显缩短皮肤愈合周期.本研究开发的高纯度重组人源弹性蛋白及其交联凝胶,对光损伤皮肤有显著的修复效果,在皮肤医学领域具有广泛的应用前景. 展开更多
关键词 重组人源弹性蛋白 弹性蛋白交联凝胶 紫外光损伤 皮肤修复
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Precipitation regulated soil nematode community and footprint in cropland ecosystems
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作者 Pingting Guan jianan li +6 位作者 Cao Hao Jingjing Yang lihong Song Ximei Niu Ping Wang Mohammad Mahamood Donghui Wu 《Soil Ecology Letters》 CSCD 2023年第4期19-28,共10页
●Nematode abundance and footprint show unimodal patterns with precipitation levels.●MAP governed nematode diversity along the precipitation gradient of agroecosystem.●Soil pH determined nematode abundance and footp... ●Nematode abundance and footprint show unimodal patterns with precipitation levels.●MAP governed nematode diversity along the precipitation gradient of agroecosystem.●Soil pH determined nematode abundance and footprint in low precipitation levels.Precipitation plays a crucial role in global biodiversity change across terrestrial ecosystems.Precipitation is proven to affect soil organism diversity in natural ecosystems.However,how precipitation change affects the function of the soil nematode community remains unclear in cropland ecosystems.Here,we tested soil nematode communities from different precipitation sites(300 mm to 900 mm)of the agricultural ecosystem.The abundance of total nematodes,fungivores,and plant parasites,together with the footprint of fungivores was significantly affected by mean annual precipitation(MAP)in cropland ecosystem.Plant parasites diversity and footprint showed negative relationships with MAP.The random forest suggested plant parasite footprint was the most responsive to MAP.The structural equation model revealed that MAP affected nematode abundance and footprint indirectly via soil pH;nematode diversity was affected by MAP directly.We conclude that precipitation could act as the main selection stress for nematode diversity among the large gradient of agricultural ecosystems.However,the soil pH may act as a stress factor in determining nematode community and carbon flow in the soil food web.Our study emphasized that using nematode value by trophic group would provide a deep understanding of nematode response to precipitation in cropland ecosystems. 展开更多
关键词 soil nematode community nematode carbon flux the Northeast China Transect agricultural ecosystem PRECIPITATION
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A"turn-on"fluorescent sensor for Pb^(2+)detection based on nitrogen doping carbon dots
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作者 jianan li Wenbo Sun +1 位作者 Xinyong li Chong Peng 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2023年第4期13-17,共5页
1.Introduction Due to the severe toxicity of heavy metal ions,human health and eco-system are threatened even at ultra-low concentrations[1].Specially,Pb^(2+)arouses more significant concern as its bio-accumulation se... 1.Introduction Due to the severe toxicity of heavy metal ions,human health and eco-system are threatened even at ultra-low concentrations[1].Specially,Pb^(2+)arouses more significant concern as its bio-accumulation seriously affects brain development,reproductive systems,and cardiovascular function,consequently resulting in an irreversible damage.According to World Health Organization(WHO),the maximum allowable Pb^(2+)con-centration on the surface water should be<0.01 mg/L.Thus,consid-ering such deleterious and carcinogenic effects,the Pb^(2+)amount should be monitored to guarantee the water environment safety.Conventional methods always need complicate pretreatment. 展开更多
关键词 CARDIOVASCULAR IRREVERSIBLE DOPING
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Automated optical inspection of FAST’s reflector surface using drones and computer vision
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作者 jianan li Shenwang Jiang +5 位作者 liqiang Song Peiran Peng Feng Mu Hui li Peng Jiang Tingfa Xu 《Light(Advanced Manufacturing)》 2023年第1期1-11,共11页
The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the world’s largest single-dish radio telescope.Its large reflecting surface achieves unprecedented sensitivity but is prone to damage,such as dents a... The Five-hundred-meter Aperture Spherical radio Telescope(FAST)is the world’s largest single-dish radio telescope.Its large reflecting surface achieves unprecedented sensitivity but is prone to damage,such as dents and holes,caused by naturally-occurring falling objects.Hence,the timely and accurate detection of surface defects is crucial for FAST’s stable operation.Conventional manual inspection involves human inspectors climbing up and examining the large surface visually,a time-consuming and potentially unreliable process.To accelerate the inspection process and increase its accuracy,this work makes the first step towards automating the inspection of FAST by integrating deep-learning techniques with drone technology.First,a drone flies over the surface along a predetermined route.Since surface defects significantly vary in scale and show high inter-class similarity,directly applying existing deep detectors to detect defects on the drone imagery is highly prone to missing and misidentifying defects.As a remedy,we introduce cross-fusion,a dedicated plug-in operation for deep detectors that enables the adaptive fusion of multi-level features in a point-wise selective fashion,depending on local defect patterns.Consequently,strong semantics and fine-grained details are dynamically fused at different positions to support the accurate detection of defects of various scales and types.Our AI-powered drone-based automated inspection is time-efficient,reliable,and has good accessibility,which guarantees the long-term and stable operation of FAST. 展开更多
关键词 FAST DRONE Deep learning Feature fusion
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援助与冲突--基于中国对外援助的证据 被引量:25
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作者 李嘉楠 龙小宁 姜琪 《经济学(季刊)》 CSSCI 北大核心 2021年第4期1123-1146,共24页
本文使用2000-2014年中国对外援助数据和乌普萨拉冲突数据,发现中国"其他官方援助"可以显著减少受援国冲突。针对内生性问题,本文使用中国优势产能指标作为工具变量。在考虑样本选择偏误和不同类型国际援助后,结果保持稳健。... 本文使用2000-2014年中国对外援助数据和乌普萨拉冲突数据,发现中国"其他官方援助"可以显著减少受援国冲突。针对内生性问题,本文使用中国优势产能指标作为工具变量。在考虑样本选择偏误和不同类型国际援助后,结果保持稳健。在机制部分,我们发现中国援助显著提高了受援国的基础设施水平和工业就业率,提高了参与冲突的"机会成本"。本文的发现支持了中国援助模式的有效性,也支持了基础设施建设对于经济发展的重要性。 展开更多
关键词 中国对外援助 地区冲突 基础设施建设
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灾异、天人感应与政治权力——来自东汉的证据 被引量:1
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作者 孙程九 焦建华 +1 位作者 代谦 李嘉楠 《经济学(季刊)》 CSSCI 北大核心 2021年第3期1103-1122,共20页
本文利用东汉时期的历史数据,考察了在"天人感应"文化背景下,"灾异"冲击(自然灾害与天文异象)对中央政治权力结构的影响。实证结果显示,灾异出现显著增加了三公(东汉宰相)遭到罢免的概率,并且大幅缩短了三公任期。... 本文利用东汉时期的历史数据,考察了在"天人感应"文化背景下,"灾异"冲击(自然灾害与天文异象)对中央政治权力结构的影响。实证结果显示,灾异出现显著增加了三公(东汉宰相)遭到罢免的概率,并且大幅缩短了三公任期。进一步研究发现,当灾异发生时,那些与当权外戚、宦官交恶的三公面临更高的政治风险,而精通儒学并无助于他们在权力斗争中获得有利地位。这些证据表明,"天人感应灾异说"的现实应用背离了创立者的思想初衷,改变了政治权力的平衡,成为服务于当权者的政治工具。 展开更多
关键词 灾异 天人感应 政治权力
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多肽荧光探针特异性识别细胞中的Cu^(2+)和Cys 被引量:2
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作者 胡悦 权思齐 +2 位作者 李佳楠 孙秀霞 肖建喜 《中国科学:化学》 CAS CSCD 北大核心 2022年第1期117-124,共8页
Cu^(2+)作为生物体内含量第三多的必需微量金属元素,在生物体新陈代谢和正常的生命活动中扮演着重要角色,而体内Cu^(2+)的过度积累可能是唐氏综合征、阿尔兹海默症等许多疾病的关键诱因.Cys作为生物体内不可或缺的氨基酸,参与调控体内... Cu^(2+)作为生物体内含量第三多的必需微量金属元素,在生物体新陈代谢和正常的生命活动中扮演着重要角色,而体内Cu^(2+)的过度积累可能是唐氏综合征、阿尔兹海默症等许多疾病的关键诱因.Cys作为生物体内不可或缺的氨基酸,参与调控体内蛋白质的合成、翻译后修饰等基本的生理过程,它的富集可能会引起神经中毒、肝脏损伤、肾结石等疾病.因此,实现Cu^(2+)和Cys的高效检测对相关疾病的机理研究和治疗至关重要.本文利用赖氨酸侧链的两个氨基,与多肽序列中的天冬氨酸反应,成功合成了发夹式的多肽荧光探针P((Dansyl-Glu-Asp)2-Lys)).研究发现,多肽荧光探针P通过荧光淬灭效应可以高特异性地识别溶液中的Cu^(2+),而不受其他金属离子的干扰;并以1:1的比例结合形成P-Cu平台,该平台可以高选择性地检测Cys.实验结果表明,多肽荧光探针P可以"OnOff-On"型响应模式实现对Cu^(2+)和Cys的高灵敏检测,检测限分别为52和43 nmol/L.并且,多肽荧光探针P可成功用于He La细胞中Cu^(2+)和Cys的成像.这种新型多肽荧光探针P具有优秀的生物相容性、较低的细胞毒性等优点,可以用于活细胞中Cu^(2+)和Cys的特异性检测,为Cu^(2+)和Cys相关疾病的治疗和诊断提供新的手段. 展开更多
关键词 多肽荧光探针 Cu^(2+) CYS 特异性检测 HELA细胞
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