检索结果-南通市图书馆

Modelling the crop yield gap with a remote sensing-based process model:A case study of winter wheat in the North China Plain

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2023年第10期22卷 2993-3005页

作者： YANG Xu zhang jia-hua YANG Shan-shan WANG Jing-wen BAI Yun zhang Sha Research Center for Remote Sensing and Digital Earth College of Computer Science and TechnologyQingdao UniversityQingdao 266071P.R.China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094P.R.China

Understanding the spatial distribution of the crop yield gap(YG)is essential for improving crop *** studies have typically focused on the site scale,which may lead to considerable uncertainties when scaled to the regional *** mitigate this issue,this study used a process-based and remote sensing driven crop yield model for winter wheat(PRYM-Wheat),which was derived from the boreal ecosystem productivity simulator(BEPS),to simulate the YG of winter wheat in the North China Plain from 2015 to *** validation based on statistical yield data revealed good performance of the PRYM-Wheat Model in simulating winter wheat actual yield(Ya).The distribution of Ya across the North China Plain showed great heterogeneity,decreasing from southeast to *** remote sensing-estimated results show that the average YG of the study area was 6400.6 kg ha^(–1).The YG of jiangsu Province was the largest,at7307.4 kg ha^(–1),while the YG of Anhui Province was the smallest,at 5842.1 kg ha^(–1).An analysis of the responses of YG to environmental factors showed no obvious correlation between YG and precipitation,but there was a weak negative correlation between YG and accumulated *** addition,the YG was positively correlated with *** general,studying the specific features of the YG can provide directions for increasing crop yields in the future.

关键词： remote sensing PRYM-Wheat Model yield gap environmental factors North China Plain

在线全文

学校读者我要写书评

暂无评论

稀土钢产品规模化生产研究与实践

包钢科技 2024年第1期50卷 28-31页

作者：张嘉华王皓魏晓东张建陈冰晶内蒙古包钢钢联股份有限公司技术中心内蒙古包头014010

稀土钢产品在连铸机浇注时经常发生水口絮流,无法满足正常拉速的浇注作业,严重时中间包水口絮死,造成生产中断,严重影响连铸生产。通过研究稀土元素加入钢水后的反应机理,分析钢水的氧含量、炉渣的氧化性、连铸机的保护浇注及浇注温度... 详细信息

稀土钢产品在连铸机浇注时经常发生水口絮流,无法满足正常拉速的浇注作业,严重时中间包水口絮死,造成生产中断,严重影响连铸生产。通过研究稀土元素加入钢水后的反应机理,分析钢水的氧含量、炉渣的氧化性、连铸机的保护浇注及浇注温度等对稀土Ce元素收得率的影响,优化稀土钢炼钢工艺,提高了稀土在钢水的收得率和可浇性,稀土钢产品的连浇炉数达到25炉,最终实现稀土钢产品规模化生产。

关键词：稀土钢产品絮钢可浇性规模化生产

Integrating a novel irrigation approximation method with a process-based remote sensing model to estimate multi-years'winter wheat yield over the North China Plain

在线全文

学校读者我要写书评

暂无评论

农业科学学报:英文版 2023年第9期22卷 2865-2881页

作者： zhang Sha YANG Shan-shan WANG Jing-wen WU Xi-fang Malak HENCHIRI Tehseen JAVED zhang jia-hua BAI Yun Research Center for Space Information and Big Earth Data College of Computer Science and TechnologyQingdao UniversityQingdao 266071P.R.China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094P.R.China School of Surveying and Land Information Engineering Henan Polytechnic UniversityJiaozuo 454000P.R.China Department of Environmental Sciences Kohat University of Science and TechnologyKohat 26000Pakistan

Accurate estimation of regional winter wheat yields is essential for understanding the food production status and ensuring national food ***,using the existing remote sensing-based crop yield models to accurately reproduce the inter-annual and spatial variations in winter wheat yields remains challenging due to the limited ability to acquire irrigation information in water-limited ***,we proposed a new approach to approximating irrigations of winter wheat over the North China Plain(NCP),where irrigation occurs extensively during the winter wheat growing *** approach used irrigation pattern parameters(IPPs)to define the irrigation frequency and ***,they were incorporated into a newly-developed process-based and remote sensing-driven crop yield model for winter wheat(PRYM–Wheat),to improve the regional estimates of winter wheat over the *** IPPs were determined using statistical yield data of reference years(2010–2015)over the *** findings showed that PRYM–Wheat with the optimal IPPs could improve the regional estimate of winter wheat yield,with an increase and decrease in the correlation coefficient(R)and root mean square error(RMSE)of 0.15(about 37%)and 0.90 t ha–1(about 41%),*** data in validation years(2001–2009 and 2016–2019)were used to validate PRYM–*** addition,our findings also showed R(RMSE)of 0.80(0.62 t ha–1)on a site level,0.61(0.91 t ha–1)for Hebei Province on a county level,0.73(0.97 t ha–1)for Henan Province on a county level,and 0.55(0.75 t ha–1)for Shandong Province on a city ***,PRYM–Wheat can offer a stable and robust approach to estimating regional winter wheat yield across multiple years,providing a scientific basis for ensuring regional food security.

关键词： approximating irrigations process-based model remote sensing winter wheat yield North China Plain

少孢节丛孢菌几丁质酶AO-492对线虫的降解作用研究

在线全文

学校读者我要写书评

暂无评论

生物技术通报 2024年第5期40卷 261-268页

作者：张嘉华张慧梅马喜喜孙焱森李若冰李柠杏才学鹏乔军孟庆玲石河子大学动物科技学院石河子832003 中国兽医药品监察所北京100081

【目的】为探究捕食线虫真菌少孢节丛孢菌几丁质诱导过程中分泌蛋白AO-492的生物学功能。【方法】对少孢节丛孢菌几丁质酶AO-492主要结构域编码区进行基因克隆及分子特征分析,并在毕赤酵母中进行表达。利用镍柱亲和层析法纯化重组蛋白Re... 详细信息

【目的】为探究捕食线虫真菌少孢节丛孢菌几丁质诱导过程中分泌蛋白AO-492的生物学功能。【方法】对少孢节丛孢菌几丁质酶AO-492主要结构域编码区进行基因克隆及分子特征分析,并在毕赤酵母中进行表达。利用镍柱亲和层析法纯化重组蛋白ReAO-Z492,采用NAG检测法分析了该重组蛋白在不同温度、pH及金属离子条件下的酶学活性,并将其作用于秀丽隐杆线虫及虫卵分析其生物学功能。【结果】几丁质酶AO-492有信号肽,无跨膜结构域,含有两个几丁质结合结构域和一个糖苷水解酶18家族结构域,并含有糖苷水解酶18家族几丁质酶高度保守的底物结合位点-SVGGWT-和水解酶活性位点-FDGGDLDWE-,含有典型的TIM桶形分子结构。系统进化分析显示,该蛋白与坚粘孢单顶孢几丁质酶(EPS35099.1)的亲缘关系相对最近。SDS-PAGE和Western Blot分析表明,ReAO-Z492分子量约为59 kD,可与小鼠抗少孢节丛孢菌多克隆抗体发生特异性反应。ReAO-Z492最适温度为40℃,最适pH为7.0;Mg^(2+)对其酶活有促进作用,而Ag^(+)、Cu^(2+)、Fe^(3+)和Zn^(2+)有抑制作用。ReAO-Z492对秀丽隐杆线虫体壁及其虫卵卵壳有较强的降解活性。【结论】少孢节丛孢菌几丁质酶 AO-492 对秀丽隐杆线虫及虫卵具有较强的降解作用。

关键词：少孢节丛孢菌几丁质酶 ReAO-Z492 酶学活性捕食线虫真菌

同方期刊数据库

On the Pathwise Uniqueness of Solutions of One-dimensional Reflected Stochastic Differential Equations with Jumps

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2024年第1期40卷 149-163页

作者： hua zhang School of Statistics and Data Science&Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang330013China

In this paper, we are concerned with the problem of the pathwise uniqueness of one-dimensional reflected stochastic differential equations with jumps under the assumption of non-Lipschitz continuous coefficients whose... 详细信息

关键词： reflected diffusion processes with jumps pathwise uniqueness local time Meyer It?'s formula

Equation of State of Protoneutron Star with Trapped Neutrinos

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2006年第5期45卷 901-905页

作者： zhang hua jia huan-Yu Institute of Morden Physics Southwest Jiaotong University Chengdu 610031 China

proto 中子星上的套住的中微子的领带影响在相对论的平均数的框架被学习 -- 删除理论。结果显示出那套住的中微子增加质子部分并且做中子星物质的状态的方程更软什么时候 neglectinghyperonic 自由，当时压制重核子的外观并且当在 proto... 详细信息

proto 中子星上的套住的中微子的领带影响在相对论的平均数的框架被学习 -- 删除理论。结果显示出那套住的中微子增加质子部分并且做中子星物质的状态的方程更软什么时候 neglectinghyperonic 自由，当时压制重核子的外观并且当在 protoneutron 星包括重核子时，使状态的方程更生硬。与在贝它平衡的冷中子星相比，当当套住的中微子的相对数字是 0.4 时，由为 protoneutron 的 0.21_( 太阳的团) 的增加与重核子担任主角时，最大的团为非奇怪的 protoneutron 星由 0.06_( 太阳的团) 减少。

关键词：微中子态方程捕获原始中子恒星

Optical and electrical anisotropy regulation engineering of low-dimensional materials toward polarized detection and imaging applications

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第7期43卷 2968-2993页

作者： jian-Bin zhang Nan Zhou Li-Hui zhang Cong-Hui Shang jia-Xuan Li Yi Zhao Guo-Hui jia Ru-Sen Yang hua Xu Xiao-Bo Li Shaanxi Joint Key Laboratory of Graphene Shaanxi Key Laboratory of High-Orbits-Electron Materials and Protection Technology for AerospaceShaanxi Joint Key Laboratory of GrapheneSchool of Advanced Materials and NanotechnologyXidian UniversityXi'an710126China Guangzhou Institute of Technology Xidian UniversityGuangzhou 710068China Xi'an Thermal Power Research Institute Co. LtdXi'an 710054China Key Laboratory of Applied Surface and Colloid Chemistry Ministry of EducationShaanxi Key Laboratory for Advanced Energy DevicesShaanxi Engineering Lab for Advanced Energy TechnologySchool of Materials Science and EngineeringShaanxi Normal UniversityXi'an Xi'an 710119China

Polarized-sensitive image sensors are a kind of photodetector with great development potential due to their enhanced ability to detect and identify the target objects from the aspect of spatial,spectral and polarized ***,low-dimensional anisotropic materials with inherent anisotropic properties,ultrathin thickness,tunable bandgap and feasible integration with complementary metal oxide semiconductor(CMOS)fabrication processes have attracted great interest for their facilitation of polarized photodetector devices *** the polarized detection performance of low-dimensional materials to satisfy realistic needs stimulates the exploration of modulation of anisotropic *** this review,we comprehensively introduce the latest research progress in modulating the optical and optoelectronic anisotropy characteristics of low-dimensional *** strategy of anisotropy regulation through crystal structure engineering and coupling system is discussed ***,the latest progress in image recognition applications using anisotropic low-dimensional materials is reviewed in ***,we summarize the challenge and propose future opportunities in the practical application of polarized-sensitive imaging photodetectors based on low-dimensional anisotropic materials.

关键词： Anisotropy Polarized detection Image recognition Low-dimensional materials

Developing a process-based and remote sensing driven crop yield model for maize(PRYM–Maize) and its validation over the Northeast China Plain

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2021年第2期20卷 408-423页

作者： zhang Sha BAI Yun zhang jia-hua Shahzad ALI School of Automation Qingdao UniversityQingdao 266071P.R.China College of Computer Science and Technology Qingdao UniversityQingdao 266071P.R.China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094P.R.China University of Chinese Academy of Sciences Beijing 100049P.R.China

Spatial dynamics of crop yield provide useful information for improving the production. High sensitivity of crop growth models to uncertainties in input factors and parameters and relatively coarse parameterizations in conventional remote sensing(RS) approaches limited their applications over broad regions. In this study, a process-based and remote sensing driven crop yield model for maize(PRYM–Maize) was developed to estimate regional maize yield, and it was implemented using eight data-model coupling strategies(DMCSs) over the Northeast China Plain(NECP). Simulations under eight DMCSs were validated against the prefecture-level statistics(2010–2012) reported by National Bureau of Statistics of China, and inter-compared. The 3-year averaged result could give more robust estimate than the yearly simulation for maize yield over space. A 3-year averaged validation showed that prefecture-level estimates by PRYM–Maize under DMCS8, which coupled with the development stage(DVS)-based grain-filling algorithm and RS phenology information and leaf area index(LAI), had higher correlation(R, 0.61) and smaller root mean standard error(RMSE, 1.33 t ha^(–1)) with the statistics than did PRYM–Maize under other DMCSs. The result also demonstrated that DVS-based grain-filling algorithm worked better for maize yield than did the harvest index(HI)-based method, and both RS phenology information and LAI worked for improving regional maize yield estimate. These results demonstrate that the developed PRYM–Maize under DMCS8 gives reasonable estimates for maize yield and provides scientific basis facilitating the understanding the spatial variations of maize yield over the NECP.

关键词： process-based and remote sensing model maize yield simulation development stage grain filling harvest index

Road map for, and technical challenges of, carbon-nanotube integrated circuit technology

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 14-16页

作者： jia Si Panpan zhang Zhiyong zhang Key Laboratory for the Physics and Chemistry of Nanodevices and Center for Carbon-based Electronics School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

The past decade has witnessed an explosion of research on carbon-nanotube(CNT) electronics due to their outstanding properties, including an ultrathin body, a high carrier mobility and a high saturation velocity.

关键词： TRANSISTORS