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Effects of Long-term Located Fertilization on Wheat Yield and Soil Nutrients of Three Types of Soils in Shandong Province 被引量:1
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作者 张英鹏 刘兆辉 +3 位作者 李彦 仲子文 孙明 井永苹 《Agricultural Science & Technology》 CAS 2014年第3期400-406,426,共8页
[Objective] This study aimed to investigate the effects of long-term differ- ent fertilization in three types of soils on wheat yield and soil nutrient variation in Shandong Province. [Method] A 30-year located experi... [Objective] This study aimed to investigate the effects of long-term differ- ent fertilization in three types of soils on wheat yield and soil nutrient variation in Shandong Province. [Method] A 30-year located experiment in Jinan of Shandong Province was selected and the results of soil nutrient and crop yield in 1984, 1987, 1988, 1989, 1990, 2001, 2005, 2006, 2007 and 2010 were measured and collected. In this study, five treatments: CK, NP, NK, PK and NPK of the located experiment were selected. [Result] The three types of soils in wheat yields decreased signifi- cantly in the first several years and in 2006. Wheat yields of the treatments with P fertilizers were obviously higher than those without P fertilizers; it was shown that phosphorus is the primary nutritional factor for high-yielding of wheat. The highest yield is from cinnamon soil, followed by that from brown soil, and the lowest pro- duction is from fluvo-aquic soil. Under the same fertilization, the influence of other factors on wheat yield of brown soil is the smallest, while cinnamon soil is vulnera- ble to the influence of external conditions, resulting in larger fluctuation of annual wheat yield. The alkali-hydro nitrogen contents of three kinds of soils first de- creased, then raised, and at last reduced apparently. Since 2007, the change of al- kali-hydro nitrogen content appeared rebounded. The available P contents of no- phosphorus treatments decreased over time while those of the treatments with P fertilizers increased at first, then decreased, and after that kept relatively stable. The available K contents of no K treatments decreased slowly. The treatments of PK and NK had higher available K content than NPK treatment. [Conclusion] Thus, it is an effective fertilization measure to improve the wheat yield by supplying reasonable phosphate fertilizer and nitrogen fertilizer and making up potassium fertilizer. 展开更多
关键词 long-term located fertilization Brown soil Fluvo-aquic soil Cinnamon soil Wheat yield Soil nutrient
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Effects of Long-term Located Fertilization on the Contents and Composition of Organic Matter in Paddy Soil
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作者 卢志红 嵇素霞 +2 位作者 张美良 刘经荣 张结刚 《Agricultural Science & Technology》 CAS 2015年第10期2238-2242,共5页
To reveal variation of organic matter content in red paddy soil, Through a 27 years-located fertilization experiment in red paddy soil, the content and composi- tion of organic matter in paddy soil were studied in thi... To reveal variation of organic matter content in red paddy soil, Through a 27 years-located fertilization experiment in red paddy soil, the content and composi- tion of organic matter in paddy soil were studied in this paper. The result showed that: the dynamics of soil organic matter of the different fertilization treatments showed significant differences, in the premise of equal nutrient (nitrogen and phos- phorus and potassium), combining application of organic-inorganic was benefited for the accumulation of organic matter in paddy soil than without fertilizer treatment or chemical fertilizer treatment; the dynamics of soil humic acid, HA and FA of chemi- cal fertilizer only and Combining application of organic-inorganic treatments had basi- cally the same trend, But the contents of humic acid, HA and FA of combining ap- plication of organic-inorganic treatments had been higher than that without fertilizer and chemical fertilizer treatment. Moreover combining application of organic-inorganic treatments was benefited for improving the contents of HA and FA, but decreasing HA/FA ratio as an extension of time. Combining application of organic-inorganic was benefited for improving the contents ol readily oxidizable organic matter. And the contents of soil organic matter in long-term experiment and the contents of readily oxidizable O.M were highly significant positive correlation and the contents of soil total nitrogen, avail nitrogen and potassium were significant positive correlation; the contents of soil readily oxidizable O.M and the contents of soil total nitrogen, avail- able P and rice yield were significant positive correlation. Thereinto, the correlation (r=0.818 1 ) between the rice yield and soil readily oxidizable O.M was higher than the correlation (r=0.802 0) between the rice yield and soil organic matter. It showed the soil readily oxidized organic matter had greater contribution to the rice yield. 展开更多
关键词 long-term located fertilization Paddy soil Organic matter
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Effects of Long-term Located Fertilization on Evolution of Available Phosphorus and Phosphorus Pool in Shandong Fluvo-aquic Soil 被引量:1
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作者 Yingpeng ZHANG Gang DUAN +6 位作者 Cuiping SUN Ziwen ZHONG Ming SUN Yongping JING Jiafa LUO Luji BO Yan LI 《Agricultural Biotechnology》 CAS 2018年第2期74-80,共7页
This study was conducted to investigate the effects of long-term located fertilization on soil phosphorus,the changes of soil available phosphorus(OlsenP),the evolution of soil total phosphorus(TP)and the ratio change... This study was conducted to investigate the effects of long-term located fertilization on soil phosphorus,the changes of soil available phosphorus(OlsenP),the evolution of soil total phosphorus(TP)and the ratio change of Olsen-P to TP(PAC)by 33-year fertilization experiments in winter wheat-summer maize rotation system in Shandong fluvo-aquic soil.Eight treatments were designed as no fertilization(CK),nitrogen fertilizer(N),nitrogen and phosphate fertilizer(NP),nitrogen and potassium fertilizer(NK),phosphate and potassium fertilizer(PK),nitrogen-phosphate-potassium fertilizer(NPK),reduced NPK fertilizer(N(15)PK),and increased NPK fertilizer(N_(25)PK).Meanwhile,eight organic fertilizer-added treatments were designed based on the application of inorganic fertilizer the same as the above ones.The results showed that TP,Olsen-P and PAC of treatments added with organic fertilizer were higher than those without organic fertilizer,and those of the treatments applied with phosphate fertilizer were higher than those of no phosphate fertilizer.With the increase of years,soil P pool decreased due to crop absorption,nutrient loss and morphological transformation and other causes under the treatments of without and only phosphate fertilizer,while remained stable under the treatments added with organic fertilizer.The PAC values were generally lower in fluvo-aquic soil,and it could be improved by the application of organic fertilizer.On the whole,the application of chemical phosphate fertilizer combined with organic fertilizer could improve the phosphorus content in soil and ensure the supply of phosphorus nutrition.This study would provide scientific basis for fertilization management and soil fertility in fluvo-aquic soil. 展开更多
关键词 long-term located fertilization Fluvo-aquic soil Total phosphorus Available phosphorus Phosphorus pool Activity coefficient
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Effects of Long-term Located Fertilization on the Physico-chemical Property of Soil Humus
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作者 SHI Ji-ping, ZHANG Fu-dao and LIN Bao(School of Agriculture, Shanghai Jiao Tong University, Shanghai 201101 , P.R. China Soil and Fertilizer Inst. CAAS , Beijing 100081 , P.R. China ) 《Agricultural Sciences in China》 CAS CSCD 2002年第4期424-431,共8页
A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red s... A systematic study concerning the effects of a long-term stationary fertilization on content and property of soil humus in fluvo-aquic soil sampled from Malan Farm, Xinji City, Hebei, and arid red soil and paddy red soil sampled from the Institute of Red Soil, Jinxian County, Jiangxi was conducted. The results showed that long-term fertilization had effects not only on the content and composition of soil humus, but also on the physico-chemical property of humus. With applying organic manure or combined application of organic manure and chemical fertilizer, E4 and E6 values of humic acid decreased in fluvo-aquic soil and arid red soil, but increased in paddy red soil. In paddy red soil, E4 and E6 values of humic acid increased also with a single application of chemical fertilizer, but E4 and E6 values had less change of humic acid in fluvo-aquic soil and arid red soil. The effects on the visible spectroscopic property of f ulvic acid were different from that of humic acid. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase E4 and E6 values of f ulvic acid in three types of soil. Single application of chemical fertilizer had less effect on the E4 and E6. Long-term fertilization could also influence the ultraviolet spectroscopic property of humus. With a single application of organic manure or combined application of organic manure and chemical fertilizer, the ultraviolet absorbance of humic acid and f ulvic acid increased in the three types of soil. But this effect was obvious only in short wave length, and the effect could decrease if the wave length increased. With a single application of chemical fertilizer the ultraviolet absorbance of fulvic acid could increase, but it of humic acid increased only in fluvo-aquic soil. Long-term application of organic manure or combined application of organic manure and chemical fertilizer could increase the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil. Single application of chemical fertilizer had less effect on the content of total acidic groups, carboxy groups and phenolic hydroxy groups of humic acid and fuvic acid in the three types of soil. 展开更多
关键词 long-term located fertilization Soil humus Fluvo-aquic soil Arid red soil Paddy red soil
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Reviewer Locator模块在科技期刊中的应用实践与发展前景——以《中国肺癌杂志》为例 被引量:1
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作者 南娟 丁燕 《天津科技》 2024年第1期37-40,44,共5页
科技期刊作为科技传播的重要力量,其对重要科研成果的发布速度影响着科学技术的传播效力,而编辑工作效率直接决定稿件发表周期,提高编辑工作效率是科技期刊发展的推进器。为此,从同行评议审稿人储备和遴选方面入手,重点阐述如何准确高... 科技期刊作为科技传播的重要力量,其对重要科研成果的发布速度影响着科学技术的传播效力,而编辑工作效率直接决定稿件发表周期,提高编辑工作效率是科技期刊发展的推进器。为此,从同行评议审稿人储备和遴选方面入手,重点阐述如何准确高效地多维度遴选优质审稿人,归纳并探析Reviewer Locator模块在科技期刊办刊工作中的实际应用经验,助力出版业实现质量更好、效率更高的发展。 展开更多
关键词 Reviewer locator模块 科技期刊 编辑 工作效率
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Clinical manifestations,diagnosis and long-term prognosis of adult autoimmune enteropathy:Experience from Peking Union Medical College Hospital 被引量:2
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作者 Mu-Han Li Ge-Chong Ruan +9 位作者 Wei-Xun Zhou Xiao-Qing Li Sheng-Yu Zhang Yang Chen Xiao-Yin Bai Hong Yang Yu-Jie Zhang Peng-Yu Zhao Ji Li Jing-Nan Li 《World Journal of Gastroenterology》 SCIE CAS 2024年第19期2523-2537,共15页
BACKGROUND Autoimmune enteropathy(AIE)is a rare disease whose diagnosis and long-term prognosis remain challenging,especially for adult AIE patients.AIM To improve overall understanding of this disease’s diagnosis an... BACKGROUND Autoimmune enteropathy(AIE)is a rare disease whose diagnosis and long-term prognosis remain challenging,especially for adult AIE patients.AIM To improve overall understanding of this disease’s diagnosis and prognosis.METHODS We retrospectively analyzed the clinical,endoscopic and histopathological characteristics and prognoses of 16 adult AIE patients in our tertiary medical center between 2011 and 2023,whose diagnosis was based on the 2007 diagnostic criteria.RESULTS Diarrhea in AIE patients was characterized by secretory diarrhea.The common endoscopic manifestations were edema,villous blunting and mucosal hyperemia in the duodenum and ileum.Villous blunting(100%),deep crypt lymphocytic infiltration(67%),apoptotic bodies(50%),and mild intraepithelial lymphocytosis(69%)were observed in the duodenal biopsies.Moreover,there were other remarkable abnormalities,including reduced or absent goblet cells(duodenum 94%,ileum 62%),reduced or absent Paneth cells(duodenum 94%,ileum 69%)and neutrophil infiltration(duodenum 100%,ileum 69%).Our patients also fulfilled the 2018 diagnostic criteria but did not match the 2022 diagnostic criteria due to undetectable anti-enterocyte antibodies.All patients received glucocorticoid therapy as the initial medication,of which 14/16 patients achieved a clinical response in 5(IQR:3-20)days.Immunosuppressants were administered to 9 patients with indications of steroid dependence(6/9),steroid refractory status(2/9),or intensified maintenance medication(1/9).During the median of 20.5 months of followup,2 patients died from multiple organ failure,and 1 was diagnosed with non-Hodgkin’s lymphoma.The cumulative relapse-free survival rates were 62.5%,55.6%and 37.0%at 6 months,12 months and 48 months,respectively.CONCLUSION Certain histopathological findings,including a decrease or disappearance of goblet and Paneth cells in intestinal biopsies,might be potential diagnostic criteria for adult AIE.The long-term prognosis is still unsatisfactory despite corticosteroid and immunosuppressant medications,which highlights the need for early diagnosis and novel medications. 展开更多
关键词 Autoimmune enteropathy Clinical manifestations Diagnostic criteria Pathological features long-term prognosis
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Long-term outcomes after endoscopic removal of malignant colorectal polyps:Results from a 10-year cohort 被引量:1
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作者 Anna Fábián Renáta Bor +13 位作者 Béla Vasas Mónika Szűcs Tibor Tóth Zsófia Bősze Kata Judit Szántó Péter Bacsur Anita Bálint Bernadett Farkas Klaudia Farkas Ágnes Milassin Mariann Rutka Tamás Resál Tamás Molnár Zoltán Szepes 《World Journal of Gastrointestinal Endoscopy》 2024年第4期193-205,共13页
BACKGROUND Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging,and evidence regarding a surveillance-only strategy is limited.AIM To evaluate long-term outcomes after... BACKGROUND Choosing an optimal post-polypectomy management strategy of malignant colorectal polyps is challenging,and evidence regarding a surveillance-only strategy is limited.AIM To evaluate long-term outcomes after endoscopic removal of malignant colorectal polyps.METHODS A single-center retrospective cohort study was conducted to evaluate outcomes after endoscopic removal of malignant colorectal polyps between 2010 and 2020.Residual disease rate and nodal metastases after secondary surgery and local and distant recurrence rate for those with at least 1 year of follow-up were invest-igated.Event rates for categorical variables and means for continuous variables with 95%confidence intervals were calculated,and Fisher’s exact test and Mann-Whitney test were performed.Potential risk factors of adverse outcomes were RESULTS In total,135 lesions(mean size:22.1 mm;location:42%rectal)from 129 patients(mean age:67.7 years;56%male)were enrolled.The proportion of pedunculated and non-pedunculated lesions was similar,with en bloc resection in 82%and 47%of lesions,respectively.Tumor differentiation,distance from resection margins,depth of submucosal invasion,lymphovascular invasion,and budding were reported at 89.6%,45.2%,58.5%,31.9%,and 25.2%,respectively.Residual tumor was found in 10 patients,and nodal metastasis was found in 4 of 41 patients who underwent secondary surgical resection.Univariate analysis identified piecemeal resection as a risk factor for residual malignancy(odds ratio:1.74;P=0.042).At least 1 year of follow-up was available for 117 lesions from 111 patients(mean follow-up period:5.59 years).Overall,54%,30%,30%,11%,and 16%of patients presented at the 1-year,3-year,5-year,7-year,and 9-10-year surveillance examinations.Adverse outcomes occurred in 9.0%(local recurrence and dissemination in 4 patients and 9 patients,respectively),with no difference between patients undergoing secondary surgery and surveillance only.CONCLUSION Reporting of histological features and adherence to surveillance colonoscopy needs improvement.Long-term adverse outcome rates might be higher than previously reported,irrespective of whether secondary surgery was performed. 展开更多
关键词 Malignant colorectal polyps T1 tumor Endoscopic removal OUTCOMES long-term SURVEILLANCE
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Dissimilar survival and clinicopathological characteristics of mucinous adenocarcinoma located in pancreatic head and body/tail
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作者 Zheng Li Xiao-Jie Zhang +3 位作者 Chong-Yuan Sun Ze-Feng Li He Fei Dong-Bing Zhao 《World Journal of Gastrointestinal Surgery》 SCIE 2023年第6期1178-1190,共13页
BACKGROUND Growing evidence shows that pancreatic tumors in different anatomical locations have different characteristics,which have a significant impact on prognosis.However,no study has reported the differences betw... BACKGROUND Growing evidence shows that pancreatic tumors in different anatomical locations have different characteristics,which have a significant impact on prognosis.However,no study has reported the differences between pancreatic mucinous adenocarcinoma(PMAC)in the head vs the body/tail of the pancreas.AIM To investigate the differences in survival and clinicopathological characteristics between PMAC in the head and body/tail of pancreas.METHODS A total of 2058 PMAC patients from the Surveillance,Epidemiology,and End Results database diagnosed between 1992 and 2017 were retrospectively reviewed.We divided the patients who met the inclusion criteria into pancreatic head group(PHG)and pancreatic body/tail group(PBTG).The relationship between two groups and risk of invasive factors was identified using logistic regression analysis.Kaplan-Meier analysis and Cox regression analysis were conducted to compare the overall survival(OS)and cancer-specific survival(CSS)of two patient groups.RESULTS In total,271 PMAC patients were included in the study.The 1-year,3-year,and 5-year OS rates of these patients were 51.6%,23.5%,and 13.6%,respectively.The 1-year,3-year,and 5-year CSS rates were 53.2%,26.2%,and 17.4%,respectively.The median OS of PHG patients was longer than that of PBTG patients(18 vs 7.5 mo,P<0.001).Compared to PHG patients,PBTG patients had a greater risk of metastases[odds ratio(OR)=2.747,95%confidence interval(CI):1.628-4.636,P<0.001]and higher staging(OR=3.204,95%CI:1.895-5.415,P<0.001).Survival analysis revealed that age<65 years,male sex,low grade(G1-G2),low stage,systemic therapy,and PMAC located at the pancreatic head led to longer OS and CSS(all P<0.05).The location of PMAC was an independent prognostic factor for CSS[hazard ratio(HR)=0.7,95%CI:0.52-0.94,P=0.017].Further analysis demonstrated that OS and CSS of PHG were significantly better than PBTG in advanced stage(stage III-IV).CONCLUSION Compared to the pancreatic body/tail,PMAC located in the pancreatic head has better survival and favorable clinicopathological characteristics. 展开更多
关键词 Pancreatic mucinous adenocarcinoma Anatomical location Pancreatic head Pancreatic body/tail SURVIVAL
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Tailoring Iron-Ion Release of Cellulose-Based Aerogel-Coated Iron Foam for Long-Term High-Power Microbial Fuel Cells
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作者 Zhengyang Ni Huitao Yu +6 位作者 Haoran Wang Mengmeng Qin Feng Li Hao Song Xiangyu Chen Yiyu Feng Wei Feng 《Transactions of Tianjin University》 EI CAS 2024年第5期436-447,共12页
The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended ... The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended operating periods. In this study, we developed a composite anode(A/IF) by coating iron foam with cellulose-based aerogel. The concentration of Fe ions in the anode solution of A/IF anode reaches 0.280 μg/mL(Fe^(2+) vs. Fe^(3+) = 61%:39%) after 720 h of aseptic primary cell operation. This value was significantly higher than that(0.198 μg/mL, Fe^(2+) vs. Fe^(3+) = 92%:8%) on uncoated iron foam(IF), indicating a continuous release of Fe ions over long-term operation. Notably, the resulting MFCs hybrid cell exhibited a 23% reduction in Fe ion concentration(compared to a 47% reduction for the IF anode) during the sixth testing cycle(600-720 h). It achieved a high-power density of 301 ± 55 mW/m^(2) at 720 h, which was 2.62 times higher than that of the IF anode during the same period. Furthermore, a sedimentary microbial fuel cell(SMFCs) was constructed in a marine environment, and the A/IF anode demonstrated a power density of 103 ± 3 mW/m^(2) at 3240 h, representing a 75% improvement over the IF anode. These findings elucidate the significant enhancement in long-term power production performance of MFCs achieved through effective tailoring of Fe ions release during operation. 展开更多
关键词 Microbial fuel cells Coating Fe ions Tailor release long-term
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Microseismic source location using deep learning:A coal mine case study in China
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作者 Yue Song Enyuan Wang +3 位作者 Hengze Yang Chengfei Liu Baolin Li Dong Chen 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3407-3418,共12页
Microseismic source location is crucial for the early warning of rockburst risks.However,the conventional methods face challenges in terms of the microseismic wave velocity and arrival time accuracy.Intelligent techni... Microseismic source location is crucial for the early warning of rockburst risks.However,the conventional methods face challenges in terms of the microseismic wave velocity and arrival time accuracy.Intelligent techniques,such as the full convolutional neural network(FCNN),can capture spatial information but struggle with complex microseismic sequence.Combining the FCNN with the long shortterm memory(LSTM)network enables better time-series signal classification by integrating multiscale information and is therefore suitable for waveform location.The LSTM-FCNN model does not require extensive data preprocessing and it simplifies the microseismic source location through feature extraction.In this study,we utilized the LSTM-FCNN as a regression learning model to locate the seismic focus.Initially,the method of short-time-average/long-time-average(STA/LTA)arrival time picking was employed to augment spatiotemporal information.Subsequently,oversampling the on-site data was performed to address the issue of data imbalance,and finally,the performance of LSTM-FCNN was tested.Meanwhile,we compared the LSTM-FCNN model with previous deep-learning models.Our results demonstrated remarkable location capabilities with a mean absolute error(MAE)of only 7.16 m.The model can realize swift training and high accuracy,thereby significantly improving risk warning of rockbursts. 展开更多
关键词 Microseismic source location ROCKBURST Deep learning Intelligent early warning
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A Secure Device Management Scheme with Audio-Based Location Distinction in IoT
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作者 Haifeng Lin Xiangfeng Liu +5 位作者 Chen Chen Zhibo Liu Dexin Zhao Yiwen Zhang Weizhuang Li Mingsheng Cao 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期939-956,共18页
Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using a... Identifying a device and detecting a change in its position is critical for secure devices management in the Internet of Things(IoT).In this paper,a device management system is proposed to track the devices by using audio-based location distinction techniques.In the proposed scheme,traditional cryptographic techniques,such as symmetric encryption algorithm,RSA-based signcryption scheme,and audio-based secure transmission,are utilized to provide authentication,non-repudiation,and confidentiality in the information interaction of the management system.Moreover,an audio-based location distinction method is designed to detect the position change of the devices.Specifically,the audio frequency response(AFR)of several frequency points is utilized as a device signature.The device signature has the features as follows.(1)Hardware Signature:different pairs of speaker and microphone have different signatures;(2)Distance Signature:in the same direction,the signatures are different at different distances;and(3)Direction Signature:at the same distance,the signatures are different in different directions.Based on the features above,amovement detection algorithmfor device identification and location distinction is designed.Moreover,a secure communication protocol is also proposed by using traditional cryptographic techniques to provide integrity,authentication,and non-repudiation in the process of information interaction between devices,Access Points(APs),and Severs.Extensive experiments are conducted to evaluate the performance of the proposed method.The experimental results show that the proposedmethod has a good performance in accuracy and energy consumption. 展开更多
关键词 Acoustic hardware fingerprinting device management IOT location distinction
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Long-Term Performance and Microstructural Characterization of Dam Concrete in the Three Gorges Project
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作者 Chen Lyu Cheng Yu +3 位作者 Chao Lu Li Pan Wenwei Li Jiaping Liu 《Engineering》 SCIE EI CAS CSCD 2024年第2期237-262,共26页
This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled ... This study investigates the long-term performance of laboratory dam concrete in different curing environments over ten years and the microstructure of 17-year-old laboratory concrete and actual concrete cores drilled from the Three Gorges Dam.The mechanical properties of the laboratory dam concrete,whether cured in natural or standard environments,continued to improve over time.Furthermore,the laboratory dam concrete exhibited good resistance to diffusion and a refined microstructure after 17 years.However,curing and long-term exposure to the local natural environment reduced the frost resistance.Microstructural analyses of the laboratory concrete samples demonstrated that moderate-heat cement and fine fly ash(FA)particles were almost fully hydrated to form compact micro structures consisting of large quantities of homogeneous calcium(alumino)silicate hydrate(C-(A)-S-H)gels and a few crystals.No obvious interfacial transition zones were observed in the microstructure owing to the longterm pozzolanic reaction.This dense and homogenous microstructure was the crucial reason for the excellent long-term performance of the dam concrete.A high FA volume also played a significant role in the microstructural densification and performance growth of dam concrete at a later age.The concrete drilled from the dam surface exhibited a loose microstructure with higher microporosity,indicating that concrete directly exposed to the actual service environment suffered degradation caused by water and wind attacks.In this study,both macro-performance and microstructural analyses revealed that the application of moderate-heat cement and FA resulted in a dense and homogenous microstructure,which ensured the excellent long-term performance of concrete from the Three Gorges Dam after 17 years.Long-term exposure to an actual service environment may lead to microstructural degradation of the concrete surface.Therefore,the retained long-term dam concrete samples need to be further researched to better understand its microstructural evolution and development of its properties. 展开更多
关键词 Three Gorges Dam long-term performance Microstructural analysis Moderate-heat cement Fly ash
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Soil bacterial and fungal communities resilience to long-term nitrogen addition in subtropical forests in China
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作者 Xinlei Fu Yunze Dai +3 位作者 Jun Cui Pengfei Deng Wei Fan Xiaoniu Xu 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第2期95-108,共14页
Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have no... Atmospheric nitrogen(N)deposition is predicted to increase,especially in the subtropics.However,the responses of soil microorganisms to long-term N addition at the molecular level in N-rich subtropical forests have not been clarified.A long-term nutrient addition experiment was conducted in a subtropical evergreen old-growth forest in China.The four treatments were:control,low N(50 kg N ha^(-1)a^(-1)),high N(100 kg N ha^(-1)a^(-1)),and combined N and phosphorus(P)(100 kg N ha^(-1)a^(-1)+50 kg P ha^(-1)a^(-1)).Metagenomic sequencing characterized diversity and composition of soil microbial communities and used to construct bacterial/fungal co-occurrence networks.Nutrient-treated soils were more acidic and had higher levels of dissolved organic carbon than controls.There were no significant differences in microbial diversity and community composition across treatments.The addition of nutrients increased the abundance of copiotrophic bacteria and potentially beneficial microorganisms(e.g.,Gemmatimonadetes,Chaetomium,and Aureobasidium).Low N addition increased microbiome network connectivity.Three rare fungi were identified as module hubs under nutrient addition,indicating that low abundance fungi were more sensitive to increased nutrients.The results indicate that the overall composition of microbial communities was stable but not static to long-term N addition.Our findings provide new insights that can aid predictions of the response of soil microbial communities to long-term N addition. 展开更多
关键词 long-term nitrogen addition Old-growth subtropical forest METAGENOMICS Beneficial microorganisms Co-occurrence network
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Long-term thinning decreases the contribution of heterotrophic respiration to soil respiration in subalpine plantations
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作者 Longfei Chen Zhibin He +7 位作者 Wenzhi Zhao Xi Zhu Qin Shen Mingdan Song Zhengpeng Li Junqia Kong Shuping Yang Yuan Gao 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第3期189-204,共16页
Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicult... Interest in the dynamics of soil respiration(R_(S))in subalpine forest ecosystems is increasing due to their high soil carbon density and potential sensitivity to environmental changes.However,as a principal silvicultural practice,the long-term impacts of thinning on R_(S) and its heterotrophic and autotrophic respiration components(R_(h) and Ra,respectively)in subalpine plantations are poorly understood,espe-cially in winter.A 3-year field observation was carried out with consideration of winter CO_(2) efflux in middle-aged sub-alpine spruce plantations in northwestern China.A trench-ing method was used to explore the long-term impacts of thinning on Rs,Rn and R_(a).Seventeen years after thinning,mean annual Rs,Rn and R_(a) increased,while the contribu-tion of R_(h) to R_(s) decreased with thinning intensity.Thinning significantly decreased winter R,because of the reduction in R_(n) but had no significant effect on Ra.The temperature sensitivity(Q_(10))of R_(h) and R_(a) also increased with thinning intensity,with lower Q_(10) values for R_(h)(2.1-2.6)than for Ra(2.4-2.8).The results revealed the explanatory variables and pathways related to R_(n) and R_(a) dynamics.Thinning increased soil moisture and nitrate nitrogen(NO_(3)^(-)-N),and the enhanced nitrogen and water availability promoted R_(h) and R_(a) by improving fine root biomass and microbial activity.Our results highlight the positive roles of NO_(3)^(-)-N in stimulating R_(s) components following long-term thinning.Therefore,applications of nitrogen fertilizer are not recommended while thinning subalpine spruce plantations from the perspective of reducing soil CO_(2) emissions.The increased Q_(10) values of R_(s) components indicate that a large increase in soil CO_(2) emissions would be expected following thinning because of more pronounced climate warming in alpineregions. 展开更多
关键词 Heterotrophic respiration Autotrophic respiration long-term thinning impacts Cold seasons Subalpine plantations Temperature sensitivity
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Using Improved Particle Swarm Optimization Algorithm for Location Problem of Drone Logistics Hub
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作者 Li Zheng Gang Xu Wenbin Chen 《Computers, Materials & Continua》 SCIE EI 2024年第1期935-957,共23页
Drone logistics is a novel method of distribution that will become prevalent.The advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption,resulting in cost savings for ... Drone logistics is a novel method of distribution that will become prevalent.The advantageous location of the logistics hub enables quicker customer deliveries and lower fuel consumption,resulting in cost savings for the company’s transportation operations.Logistics firms must discern the ideal location for establishing a logistics hub,which is challenging due to the simplicity of existing models and the intricate delivery factors.To simulate the drone logistics environment,this study presents a new mathematical model.The model not only retains the aspects of the current models,but also considers the degree of transportation difficulty from the logistics hub to the village,the capacity of drones for transportation,and the distribution of logistics hub locations.Moreover,this paper proposes an improved particle swarm optimization(PSO)algorithm which is a diversity-based hybrid PSO(DHPSO)algorithm to solve this model.In DHPSO,the Gaussian random walk can enhance global search in the model space,while the bubble-net attacking strategy can speed convergence.Besides,Archimedes spiral strategy is employed to overcome the local optima trap in the model and improve the exploitation of the algorithm.DHPSO maintains a balance between exploration and exploitation while better defining the distribution of logistics hub locations Numerical experiments show that the newly proposed model always achieves better locations than the current model.Comparing DHPSO with other state-of-the-art intelligent algorithms,the efficiency of the scheme can be improved by 42.58%.This means that logistics companies can reduce distribution costs and consumers can enjoy a more enjoyable shopping experience by using DHPSO’s location selection.All the results show the location of the drone logistics hub is solved by DHPSO effectively. 展开更多
关键词 Drone logistics location problem mathematical model DIVERSITY particle swarm optimization
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Prognostic impact and reasons for variability by tumor location in gastric cancer
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作者 Yi-Xing Huang Han-Yi He +16 位作者 Ken Chen Hai-Dong Liu Dan Zu Chen Liang Qi-Mei Bao Yang-Chan Hu Guo-Xia Liu Yu-Ke Zhong Chun-Kai Zhang Ming-Cong Deng Yan-Hua He Ji Jing Yin Shi Sheng-Feng Xu Yao-Shu Teng Zu Ye Xiang-Dong Cheng 《World Journal of Gastroenterology》 SCIE CAS 2024年第44期4709-4724,共16页
BACKGROUND Gastric cancer(GC)is a highly prevalent gastrointestinal tract tumor.Several trials have demonstrated that the location of GC can affect patient prognosis.However,the factors determining tumor location rema... BACKGROUND Gastric cancer(GC)is a highly prevalent gastrointestinal tract tumor.Several trials have demonstrated that the location of GC can affect patient prognosis.However,the factors determining tumor location remain unclear.AIM To investigate the tumor location of patients,we went on to study the influencing factors that lead to changes in the location of GC.METHODS A retrospective evaluation was carried out on 3287 patients who underwent gastrectomy for GC in Zhejiang Cancer Hospital.The patients were followed up post-diagnosis and post-gastrectomy.The clinicopathological variables and overall survival of the patients were recorded.By analyzing the location of GC,the tumor location was divided into four categories:“Upper”,“middle”,“lower”,and“total”.Statistical software was utilized to analyze the relationship of each variable with the location of GC.RESULTS A total of 3287 patients were included in this study.The clinicopathological indices of gender,age,serum levels of carcinoembryonic antigen(CEA),carbohydrate antigen(CA19-9)and CA72-4 levels,were significantly associated with tumor location in patients with GC.In addition,there was a strong correlation between GC location and the prognosis of postoperative patients.Specifically,patients with“lower”and“middle”GC demonstrated a better prognosis than those with tumors in other categories.CONCLUSION The five clinicopathological indices of gender,age,CEA,CA19-9 and CA72-4 levels exhibit varying degrees of influence on the tumor location.The tumor location correlates with patient prognosis following surgery. 展开更多
关键词 Gastric cancer Clinicopathologic characteristics Tumor marker Tumor location Overall survival
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A data and physical model dual-driven based trajectory estimator for long-term navigation
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作者 Tao Feng Yu Liu +2 位作者 Yue Yu Liang Chen Ruizhi Chen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第10期78-90,共13页
Long-term navigation ability based on consumer-level wearable inertial sensors plays an essential role towards various emerging fields, for instance, smart healthcare, emergency rescue, soldier positioning et al. The ... Long-term navigation ability based on consumer-level wearable inertial sensors plays an essential role towards various emerging fields, for instance, smart healthcare, emergency rescue, soldier positioning et al. The performance of existing long-term navigation algorithm is limited by the cumulative error of inertial sensors, disturbed local magnetic field, and complex motion modes of the pedestrian. This paper develops a robust data and physical model dual-driven based trajectory estimation(DPDD-TE) framework, which can be applied for long-term navigation tasks. A Bi-directional Long Short-Term Memory(Bi-LSTM) based quasi-static magnetic field(QSMF) detection algorithm is developed for extracting useful magnetic observation for heading calibration, and another Bi-LSTM is adopted for walking speed estimation by considering hybrid human motion information under a specific time period. In addition, a data and physical model dual-driven based multi-source fusion model is proposed to integrate basic INS mechanization and multi-level constraint and observations for maintaining accuracy under long-term navigation tasks, and enhanced by the magnetic and trajectory features assisted loop detection algorithm. Real-world experiments indicate that the proposed DPDD-TE outperforms than existing algorithms, and final estimated heading and positioning accuracy indexes reaches 5° and less than 2 m under the time period of 30 min, respectively. 展开更多
关键词 long-term navigation Wearable inertial sensors Bi-LSTM QSMF Data and physical model dual-driven
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Dynamic Location Method for Shallow Ocean Bottom Nodes Using the Levenberg-Marquart Algorithm
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作者 TONG Siyou LI Junjie +2 位作者 XU Xiugang FANG Yunfen WANG Zhongcheng 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期953-960,共8页
Ocean bottom node(OBN)data acquisition is the main development direction of marine seismic exploration;it is widely promoted,especially in shallow sea environments.However,the OBN receivers may move several times beca... Ocean bottom node(OBN)data acquisition is the main development direction of marine seismic exploration;it is widely promoted,especially in shallow sea environments.However,the OBN receivers may move several times because they are easily affected by tides,currents,and other factors in the shallow sea environment during long-term acquisition.If uncorrected,then the imaging quality of subsequent processing will be affected.The conventional secondary positioning does not consider the case of multiple movements of the receivers,and the accuracy of secondary positioning is insufficient.The first arrival wave of OBN seismic data in shallow ocean mainly comprises refracted waves.In this study,a nonlinear model is established in accordance with the propagation mechanism of a refracted wave and its relationship with the time interval curve to realize the accurate location of multiple receiver movements.In addition,the Levenberg-Marquart algorithm is used to reduce the influence of the first arrival pickup error and to automatically detect the receiver movements,identifying the accurate dynamic relocation of the receivers.The simulation and field data show that the proposed method can realize the dynamic location of multiple receiver movements,thereby improving the accuracy of seismic imaging and achieving high practical value. 展开更多
关键词 OBN dynamic location method Levenberg-Marquart algorithm seismic exploration of shallow sea
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RuO_(2)/CoMO_(2)O_(x) Catalyst with Low Ruthenium Loading for Long-Term Acidic Oxygen Evolution
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作者 Yingying Wang Hui Pan +1 位作者 Zhikun Liu Peng Kang 《Transactions of Tianjin University》 EI CAS 2024年第5期395-405,共11页
We must urgently synthesize highly efficient and stable oxygen-evolution reaction(OER) catalysts for acidic media. Herein, we constructed a series of Ti mesh(TM)-supported RuO_(2)/CoMo_(y)O_(x) catalysts(RuO_(2)/CoMo_... We must urgently synthesize highly efficient and stable oxygen-evolution reaction(OER) catalysts for acidic media. Herein, we constructed a series of Ti mesh(TM)-supported RuO_(2)/CoMo_(y)O_(x) catalysts(RuO_(2)/CoMo_(y)O_(x)/TM) with heterogeneous structures. By optimizing the ratio of Co to Mo, RuO_(2)/CoMO_(2)O_(x)/TM with low Ru loading(0.079 mg/cm^(2)) achieves remarkable OER performance(η = 243 mV at 10 mA/cm^(2)) and high stability(300 h @ 10 mA/cm^(2)) in 0.5 mol/L H_(2)SO_(4) electrolyte. The activity of RuO_(2)/CoMo_yO_x/TM can be maintained for 50 h at 100 mA/cm^(2), and a water electrolyzer with RuO_(2)/CoMO_(2)O_(x)/TM as anode can operate for 40 h at 100 mA/cm~2, suggesting the remarkable OER durability of RuO_(2)/CoMo__(y)O__(x)/TM in acidic electrolyte. Owing to the heterogeneous interface between CoMO_(2)O_(x) and RuO_(2), the electronic structure of Ru atoms was optimized and electron-rich Ru was formed. With modulated electronic properties, the dissociation energy of H_(2)O is weakened, and the OER barrier is lowered. This study provides the design of low-cost noble metal catalysts with long-term stability in an acidic environment. 展开更多
关键词 Oxygen-evolution reaction Ru-based catalyst Acidic media Heterostructure long-term electrolysis Low precious metal
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A Trajectory Privacy Protection Method to Resist Long-Term Observation Attacks
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作者 Qixin Zhan 《Journal of Computer and Communications》 2024年第5期53-70,共18页
Users face the threat of trajectory privacy leakage when using location-based service applications, especially when their behavior is collected and stored for a long period of time. This accumulated information is exp... Users face the threat of trajectory privacy leakage when using location-based service applications, especially when their behavior is collected and stored for a long period of time. This accumulated information is exploited by opponents, greatly increasing the risk of trajectory privacy leakage. This attack method is called a long-term observation attack. On the premise of ensuring lower time overhead and higher cache contribution rate, the existing methods cannot utilize cache to answer subsequent queries while also resisting long-term observation attacks. So this article proposes a trajectory privacy protection method to resist long-term observation attacks. This method combines caching technology and improves the existing differential privacy mechanism, while incorporating randomization factors that are difficult for attackers to recognize after long-term observation to enhance privacy. Search for locations in the cache of both the mobile client and edge server that can replace the user’s actual location. If there are replacement users in the cache, the query results can be obtained more quickly. Simultaneously obfuscating the spatiotemporal correlation of actual trajectories by generating confusion regions. If it does not exist, the obfuscated location generation method that resists long-term observation attacks is executed to generate the real anonymous area and send it to the service provider. The above steps can comprehensively protect the user’s trajectory privacy. The experimental results show that this method can protect user trajectories from long-term observation attacks while ensuring low time overhead and a high cache contribution rate. 展开更多
关键词 location Privacy long-term Observation Attacks K-ANONYMITY location Caching
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