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A scheme for regional rice yield estimation using ENVISAT ASAR data

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Science China Earth Sciences 2009年第8期52卷 1183-1194页

作者： le TOAN Thuy Centre d'Etudes Spatiales de la BIOsphère 18 Avenue Edouard Belin 31401 Toulouse Cedex 9 France

Information on rice growing areas and rice production is critical for most rice growing countries to make state and economic policies. However, the areas where rice crop is cultivated are often cloudy and rainy, which entails the use of radar remote sensing data for rice monitoring. In this paper, a practical scheme to integrate multi-temporal and multi-polarization ENVISAT ASAR data into rice crop model for regional rice yield estimation has been presented. To achieve this, rice distribution information should be obtained first by rice mapping method to retrieve rice fields from ASAR images, and then an assimilation method is applied to use the observed multi-temporal rice backscattering coefficients which are grouped for each rice pixel to re-initialize ORYZA2000 to predict rice yield. The assimilation method re-initializes the model with optimal input parameters, allowing a better temporal agreement between the rice backscattering coefficients retrieved from ASAR data and the rice backscattering coefficients simulated by a coupled model, i.e., the combination of ORYZA2000 and a semi-empirical rice backscatter model through LAI. The SCE-UA optimization algorithm is employed to determine the optimal set of input parameters. After the re-initialization, rice yield for each rice pixel is calculated, and the yield map over the area of interest is produced. The scheme was validated over Xinghua study area located in the middle of Jiangsu Province of China by using the data set of an experimental campaign carried out during the 2006 rice season. The result shows that the obtained rice yield map generally overestimates the actual rice production by 13% on average and with a root mean square error of approximately 1133 kg/ha on validation sites, but the tendency of rice growth status and spatial variation of the rice yield are well predicted and highly consistent with the actual production variation.

关键词： rice yield map crop model data assimilation optimization algorithm classification ASAR

A Conjecture Concerning the Pure Exponential Diophantine Equation a^x+b^y=c^z

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Acta Mathematica Sinica,English Series 2005年第4期21卷 943-948页

作者： Mao Hua le Department of Mathematics Zhanjiang Normal College Zhanfiang 524005 P. R. China

let a, b, c, r be fixed positive integers such that a^2 ＋ b^2 = c^r, min（a, b, c, r）〉 1 and 2 r. In this paper we prove that if a ≡ 2 （mod 4）, b ≡ 3 （mod 4）, c 〉 3.10^37 and r 〉 7200, then the equation a... 详细信息

关键词： Pure exponential diophantine equation Number of solutions Completely determine

On the Diophantine System a^2+b^2=c^3 and a^x+b^y=c^z for b is an Odd Prime

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Acta Mathematica Sinica,English Series 2008年第6期24卷 917-924页

作者： Mao Hua le Department of Mathematics Zhanjiang Normal College Zhanjiang 524048 P. R. China

let a, b and c be fixed coprime positive integers. In this paper we prove that if a^2 ＋ b^2 = c^3 and b is an odd prime, then the equation a^x ＋ b^y = c^z has only the positive integer solution （x, y, z） = （2,2,3）.

关键词： exponential diophantine equation positive integer solution generalized Fermat conjecture

Development and bioequivalence study of potassium chloride extended release tablets

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Asian Journal of Pharmaceutical Sciences 2018年第4期13卷 353-359页

作者： Thu Van le Thi Nghiem le Quan Hau le University of Medicine and Pharmacy at Ho Chi Minh city

The purposes of this study are to prepare the generic extended release tablet of potassiumchloride(PC) 600 mg and to compare the absorption of potassium ion from the experimen-tal tablets to that of Kaleorid? LP 600 mg(leo Pharmaceutical Products, Denmark). Car-nauba wax was used as retardant in the matrix core tablets. The core tablets were coatedwith blends of ethyl cellulose(EC) and hydroxypropyl methyl cellulose(HPMC) to modulatethe drug release. Results of a selective two-level, three-factor experiment design revealedthat a blend of 41.75% of EC and 58.25% of HPMC at 4.5% weight gained could produce thecoated tablets having dissolution profiles similar to those of Kaleorid?. A two-treatment,two-period, two-sequence crossover bioequivalence study was carried out on 24 healthyvolunteers to compare the absorption of potassium ion from experimental tablets to thatfrom Kaleorid?. The potassium ion in the urine was measured by a selective electrode of theADVIA 1650 system(Bayer) and used to calculate cumulative urinary excretion and urinaryexcretion rate. Results of 90 percent confidence interval analysis showed that the limits fornatural log-transformed cumulative urinary potassium excretion(Ln Ae 0-24) of test productwere in the range of 3.73–3.79 mEq, corresponding to 99.08%–100.92% of Kaleorid ?, respec-tively, and the limits for natural log-transformed maximal potassium excretion rate( R max) oftest product were in the range of 1.72–1.82 mEq/h, corresponding to 97.34%–102.66% of refer-ence product, respectively. Both of them fell within the bioequivalence interval(80%–125%)of reference product, proving that experimental product is bioequivalent to Kaleorid ?.

关键词： Potassium chloride Ethyl cellulose Hydroxypropyl methyl cellulose Extended release tablet Cumulative urinary excretion Urinary excretion rate

Synthesis of hierarchically porous carbon materials by zinc salts-assisted carbonization of biomass and organic solid wastes

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Particuology 2024年第1期84卷 45-52页

作者： le-le Zhang lei Tong Yanwei Ding Wanqun Zhang Hai-Wei Liang Hefei National Research Center for Physical Sciences at the Microscale Department of ChemistryUniversity of Science and Technology of ChinaHefei230026China

Hierarchically porous carbons(HPCs)with multimodal pores have attracted considerable attention due to their unique physical and chemical properties and various application potentials in heterogeneous catalysis,environmental treatment,and energy storage and ***,we report a general and simple zinc salts-assisted method for the synthesis of HPCs with varied porosity and chemical func-tionalities by the direct carbonization of diverse biomass and *** the carbonization,zinc salts are thermally decomposed into nanoparticles that serve as in-situ templates to introduce nanopores in *** prepared HPCs exhibit high specific surface areas(up to 2432 m2 g-1),large pore volumes(up to 4.30 cm^(3)g^(-1)),and broad pore size ***,the zinc salts can be recovered and recycled,supporting the sustainable production of HPCs on large *** prepared HPCs-supported catalysts with atomically dispersed metal sites exhibit promising electrocatalytic performance for the oxygen reduction reaction.

关键词： Hierarchical porous carbon Zinc salts Biomass Wastes Electrocatalysis

A NOTE ON SINGULAR INTEGRALS WITH DOMINATING MIXED SMOOTHNESS IN TRIEBEL-LIZORKIN SPACES

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Acta Mathematica Scientia 2014年第4期34卷 1331-1344页

作者： Hung Viet le Faculty of Science and Technology Hoa Sen UniversityQuang Trung Software ParkSection 10Ward Tan Chanh HiepDistrict 12Ho Chi Minh CityViet Nam

let h, be a measurable function defined on R^＋ ×R^＋. let Ω ∈ L（log L^＋）^υq （S^n1-1 × S^n2-1）（1≤ υq ≤ 2） be homogeneous of degree zero and satisfy certain cancellation conditions. We show that the singular integral Tf（x1,x2）=p.v.∫∫R^n1＋n2 Ω（y′1,y′2）h（｜y1｜,｜y2｜）/｜y1｜^n1｜y2｜^n2 f（x1-y1,x2-y2）dy1dy2maps from Sp,q^α1,α2F（R^n1×R^n2）boundedly to itself for 1 〈 p, q 〈 ∞, α1, α2 ∈R.

关键词： singular integrals Marcinkiewicz integrals mixed smoothness Triebel-Lizorkin spaces

“Smart”nanomaterials for cancer therapy

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Science China Chemistry 2010年第11期53卷 2241-2249页

作者： le GUYADER Laurent Chinese Academy of Sciences Key Laboratory for Biological Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology

Recent development in nanotechnology has provided new tools for cancer therapy and *** of their small size,nanoscale devices readily interact with biomolecules both on the cell surface and inside the ***,such as fullerenes and their derivatives,are effective in terms of interactions with the immune system and have great potential as anticancer ***,other nanomaterials are able to load active drugs to cancer cells by selectively using the unique tumor environment,such as their enhanced permeability,retention effect and the specific acidic *** and multiplexed nanoparticles,as the next generation of nanoparticles,are now being extensively investigated and are promising tools to achieve personalized and tailored cancer treatments.

关键词： nanotechnology nanomaterials nanocarrier cancer therapy drug delivery passive target active target

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深部强矿压工作面水力压裂裂纹扩展规律研究

河南理工大学学报（自然科学版） 2025年第1期44卷 18-28页

作者：陈立伟王东杰边乐河南理工大学安全科学与工程学院河南焦作454000 煤炭安全生产与清洁高效利用省部共建协同创新中心河南焦作454000 煤矿灾害预防与抢险救灾教育部工程研究中心河南焦作454000

目的为了研究深部强矿压工作面水力压裂裂纹扩展规律,方法以余吾煤矿的3号煤层S5207回风巷为工程背景,首先建立水力压裂力学模型,分析最大周向拉应变准则和裂纹扩展准则,其次通过三维数值模拟,分析水力压裂裂纹扩展影响因子D和地应力对... 详细信息

目的为了研究深部强矿压工作面水力压裂裂纹扩展规律,方法以余吾煤矿的3号煤层S5207回风巷为工程背景,首先建立水力压裂力学模型,分析最大周向拉应变准则和裂纹扩展准则,其次通过三维数值模拟,分析水力压裂裂纹扩展影响因子D和地应力对水力压裂裂纹扩展规律的影响,并根据现场情况设计水力压裂试验方案,实施水力压裂增透技术,分析现场施工效果。结果结果表明:预制裂纹沿着与原裂纹呈一定角度开裂并向外延伸,其扩展方向最终与最小主应力方向垂直;随着D增大,裂纹与原裂纹的夹角越来越小,当D较大时,裂纹呈现自相似的扩展状态;不同应力场下,裂纹扩展轨迹主要取决于主应力方向,最终与最小主应力方向垂直,水力裂缝为垂直缝,且在裂纹尖端有应力集中现象;现场监测发现,裂纹扩展符合最大周向拉应变准则,裂纹尖端沿着环向拉应变最大的地方扩展,环向拉应变达到最大时裂纹开始扩展,压裂过程中出现了较大环向裂隙,裂纹沿垂直于最小主应力方向延伸,与S5207回风巷的最大水平主应力方向大致相同,与数值模拟结果接近。结论研究结果可为深部强矿压工作面水力压裂提供参考和依据。

关键词：水力压裂裂纹扩展强矿压深部岩体数值模拟回风巷

Nursing Care in Patient with Advanced Cancer: The Experience of the Adult Oncology Unit of Lomé

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Journal of Cancer Therapy 2023年第7期14卷 307-316页

作者： Ablavi Adani-Ifè Mathias Ayivi gisèle Agbanouvi Kouéssan Edoh Tibéname Kombaté Mohaman Djibril Department of Oncology University Teaching Hospital of Lomé Lomé Togo Department of Internal Medicine University Teaching Hospital of Lomé Lomé Togo

Background: Cancer patients suffer physical, psychological, spiritual, and social pains, especially in the advanced stage. Nurses spend more time with patients than any other healthcare team member. This study aimed to assess nurses’ behavior and care experiences in patients with advanced cancer and explore patients’ perceptions of nursing care. Methods: A cross-sectional study was conducted with eight nurses and thirty patients with advanced cancer hospitalized in the oncology unit at Sylvanus Olympio Teaching Hospital of Lomé from July to August 2020. Results: The mean age of nurses was 34.3 years ranging from 23 to 48 years. There were five men (62.5%) and three women (37.5%). The mean duration of working in oncology nursing of all was less than two years. Only one nurse has training in palliative care. Stress (100%), sadness (100%), and fear (50%) were the most frequently expressed feeling of nurses. The frequently expressed difficulties were the lack of training in palliative care (87.5%), insufficiency of nursing staff (75%), and helplessness in front of the patient’s distress (75%). Among the thirty patients, were 22 women (72.7%) and 8 men (27.3%). The needs expressed by the patients were psychological support (n = 11;36.7%), pain relief (n = 10;33.3%), and moral support (n = 9;30%). Most of the patients (73.3%) affirmed that nurses did not inform them well about their disease. Three (10%) were very satisfied with the care provided, 23 patients (76.7%) were satisfied and 4 (13.3%) were unsatisfied. Conclusion: This study revealed that nursing care in Togolese patients with cancer faces many difficulties and there is a need for providing specialized oncology nursing.

关键词： Nursing Care Cancer Patient Oncology Togo