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印支造山带:Song Chay构造带
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作者 林伟 王印 +4 位作者 刘飞 孟令通 吴钦颖 郭钊 李金雁 《岩石学报》 SCIE EI CAS CSCD 北大核心 2024年第1期1-28,共28页
印支运动是二十世纪初法国地质学家根据越南北部晚三叠世大规模角度不整合所提出。越南北部的Song Chay构造带作为印支造山带概念的提出地,记录了大量经典的印支造山相关的信息,是理解印支造山带构造演化的关键地区。本文在课题组对Song... 印支运动是二十世纪初法国地质学家根据越南北部晚三叠世大规模角度不整合所提出。越南北部的Song Chay构造带作为印支造山带概念的提出地,记录了大量经典的印支造山相关的信息,是理解印支造山带构造演化的关键地区。本文在课题组对Song Chay地区十多年研究基础上,结合前人研究成果,系统厘定了Song Chay构造带的几何空间格架、运动学特征及其演化过程。详细的野外地质考察表明,Song Chay构造带从SW向NE依次可以划分成:新生代的大象山单元、代表缝合带的Song Chay蛇绿混杂岩单元,以及越南东北部褶皱冲断系统。其中蛇绿混杂岩单元和褶皱冲断系统中发育NE-SW向矿物拉伸线理,并具有顶部向NE方向的剪切变形特征,指示了Song Chay洋壳向SW的俯冲以及向NE的逆冲过程。精确的年代学工作表明,Song Chay蛇绿混杂岩中斜长花岗岩的结晶年龄为356.4±2.9Ma,表明至少在早石炭世Song Chay洋就已经形成了成熟的大洋地壳。褶皱冲断带内部的低温年代学数据约束了顶部向NE的剪切变形年龄在250~245Ma之间,表明为华南和印支板块碰撞时间。另外,Song Chay蛇绿混杂岩基质中碎屑锆石物源研究表明,Song Chay蛇绿混杂岩基质中碎屑锆石主要是来自于俯冲的华南板块,只有很少一部分来自印支板块,因此推测Song Chay洋可能为一个十分有限的小洋盆。构造几何学、运动学以及碎屑锆石物源研究表明,在Song Chay构造带内的“滇-琼缝合带”两侧构造特征可对比,并未因“滇琼洋”的闭合而造成差异。因此,我们认为“滇-琼缝合带”并不能代表一个大洋。根据我们及前人的构造学、岩石学、年代学工作,建立了一个初步的Song Chay洋从晚石炭世至中三叠世的构造演化模型:(1)310~270Ma,Song Chay洋开始向SW俯冲到印支板块之下,此时岩浆弧并不发育,蛇绿混杂岩物源主要为华南板块;(2)270~250Ma,Song Chay洋继续俯冲,此时弧岩浆岩大量发育,蛇绿混杂岩同时接受弧岩浆岩及华南板块碎屑物质;(3)250~245Ma,Song Chay洋闭合,华南板块与印支板块碰撞;(4)245~230Ma,印支造山带进入碰撞后伸展阶段。 展开更多
关键词 印支运动 song Chay构造带 构造解析 碎屑锆石 滇-琼缝合带
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Winter wheat yield improvement by genetic gain across different provinces in China 被引量:1
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作者 Wei Chen Jingjuan Zhang Xiping Deng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期468-483,共16页
The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in China.Drawing on two sets of data,production yield from the National Bureau of Statist... The replacement of winter wheat varieties has contributed significantly to yield improvement worldwide,with remarkable progress in China.Drawing on two sets of data,production yield from the National Bureau of Statistics of China and experimental yield from literature,this study aims to(1)illustrate the increasing patterns of production yield among different provinces from 1978 to 2018 in China,(2)explore the genetic gain in yield and yield relevant traits through the variety replacement based on experimental yield from 1937 to 2016 in China,and(3)compare the yield gap between experimental yield and production yield.The results show that both the production and experimental yields significantly increased along with the variety replacement.The national annual yield increase ratio for the production yield was 1.67%from 1978 to 2018,varying from 0.96%in Sichuan Province to 2.78%in Hebei Province;such ratio for the experimental yield was 1.13%from 1937 to 2016.The yield gap between experimental and production yields decreased from the 1970s to the 2010s.This study reveals significant increases in some yield components consequent to variety replacement,including thousand-grain weight,kernel number per spike,and grain number per square meter;however,no change is shown in spike number per square meter.The biomass and harvest index consistently and significantly increased,whereas the plant height decreased significantly. 展开更多
关键词 genetic gain winter wheat YIELD yield components
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Preweaning period is a critical window for rumen microbial regulation of average daily gain in Holstein heifer calves 被引量:1
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作者 Shengyang Xu Chong Jiao +1 位作者 Qiyu Diao Yan Tu 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第1期396-411,共16页
Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fer... Background Rumen bacterial groups can affect growth performance,such as average daily gain(ADG),feed intake,and efficiency.The study aimed to investigate the inter-relationship of rumen bacterial composition,rumen fermentation indicators,serum indicators,and growth performance of Holstein heifer calves with different ADG.Twelve calves were chosen from a trail with 60 calves and divided into higher ADG(HADG,high pre-and post-weaning ADG,n=6)and lower ADG(LADG,low pre-and post-weaning ADG,n=6)groups to investigate differences in bacterial composition and functions and host phenotype.Results During the preweaning period,the relative abundances of propionate producers,including g_norank_f_Butyricicoccaceae,g_Pyramidobacter,and g_norank_f_norank_o_Clostridia_vadin BB60_group,were higher in HADG calves(LDA>2,P<0.05).Enrichment of these bacteria resulted in increased levels of propionate,a gluconeogenic precursor,in preweaning HADG calves(adjusted P<0.05),which consequently raised serum glucose concentrations(adjusted P<0.05).In contrast,the relative abundances of rumen bacteria in post-weaning HADG calves did not exert this effect.Moreover,no significant differences were observed in rumen fermentation parameters and serum indices between the two groups.Conclusions The findings of this study revealed that the preweaning period is the window of opportunity for rumen bacteria to regulate the ADG of calves. 展开更多
关键词 Average daily gain CALVES Preweaning period Rumen microbiota
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Economic significance and environmental impacts of the Song Dam Drinking Water Project(SDDWP)in Garhwal Himalaya
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作者 Vishwambhar Prasad SATI 《Regional Sustainability》 2024年第2期140-152,共13页
With the population growth through natural growth and migration,coupled with the city expansion,it is the fact that Dehradun City in India faces severe water scarcity.Therefore,the Song Dam Drinking Water Project(SDDW... With the population growth through natural growth and migration,coupled with the city expansion,it is the fact that Dehradun City in India faces severe water scarcity.Therefore,the Song Dam Drinking Water Project(SDDWP)is proposed to provide ample drinking water to Dehradun City and its suburban areas.This paper examined economic significance and environmental impacts of the SDDWP in Garhwal Himalaya,India.To conduct this study,we collected data from both primary and secondary sources.There are 12 villages and 3 forest divisions in the surrounding areas of the proposed dam project,of which 3 villages will be fully submerged and 50 households will be affected.For this study,50 heads of the households were interviewed in the 3 submerged villages.The questions mainly focused on economic significance,environmental impacts,and rehabilitation issues of the dam project.The findings of this study indicate that economic significance of the dam project is substantial,including providing ample water for drinking and irrigation,contributing to groundwater recharge,creating job opportunities,and promoting the development of tourism and fisheries in the Doon Valley.In terms of the rehabilitation of the affected people,there are only 50 households in need of rehabilitation.Currently,the arable land of these affected people is not sufficient to sustain their livelihoods.The entire landscape is fragile,rugged,and precipitous;therefore,the affected people are willing to rehabilitate to more suitable areas in the Doon Valley.Moreover,it is essential to provide them with sufficient compensation packages including the compensation of arable land,houses,cash,common property resources,institutions,belongingness,and cultural adaptation.On the other hand,the proposed dam project will have adverse environmental impacts including arable land degradation,forest degradation,loss of fauna and flora,soil erosion,landslides,and soil siltation.These impacts will lead to the ecological imbalances in both upstream and downstream areas.This study suggests that the affected people should be given sufficient compensation packages in all respects.Afforestation programs can be launched in the degraded areas to compensate for the loss of forest in the affected areas. 展开更多
关键词 Water scarcity Rehabilitation issues song Dam Drinking Water Project(SDDWP) Dehradun City song River BASIN
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Topological laser on square lattice with gain–loss-induced higher-order corner modes
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作者 廖明杰 韦梅松 +2 位作者 王帅领 许静平 羊亚平 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期189-195,共7页
We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degen... We investigate the higher-order topological laser in the two-dimensional(2D) coupled-cavity array. By adding staggered on-site gain and loss to the 2D Hermitian array with a trivial phase, the system will emerge degenerate topological corner modes, which are protected by bulk band gap. For such a non-Hermitian model, by adjusting the parameters of the system and introducing the pumping into the cavity at the corner, a single-mode lasing with topological protection emerges.Furthermore, single-mode lasing exists over a wide range of pumping strengths. No matter where the cavity is initially stimulated, after enough time evolution, all the cavities belonging to the topological corner mode can emit a stable laser. 展开更多
关键词 topological corner modes nonlinear saturated gain single-mode lasing
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Case Records as Medical Stories: A Song-dynasty Doctor’s Narration of His Own Medicine-Xu Shuwei (1080-1154)
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作者 Asaf Goldschmidt 《Chinese Medicine and Culture》 2024年第2期95-103,共9页
The key point in studying or teaching the history of Chinese medicine is on the doctrines underlying it and on its perception of the body,physiology,pathology,and its treatment.Namely,there is often a tendency to focu... The key point in studying or teaching the history of Chinese medicine is on the doctrines underlying it and on its perception of the body,physiology,pathology,and its treatment.Namely,there is often a tendency to focus on reading and analysing the classical canons and therapy-related texts including formularies and materia medica collections.However,focusing on these sources provides us with a one-sided presentation of Chinese medicine.These primary sources lack the clinical down-to-earth know-how that encompasses medical treatment,which are represented,for instance,in the clinical rounds of modern medical schools.Our traditional focus on the medical canons and formularies provides almost no clinical knowledge,leaving us with a one-sided narrative that ignores how medicine and healing are actually practiced in the field.This paper focuses on the latter aspect of medicine from a historical perspective.Using written and visual sources dating to the Song dynasty,clinical encounters between doctors and patients including their families are depicted based on case records recorded by a physician,members of the patient’s family,and bystanders.This array of case records or case stories will enable us to narrate the interaction between physicians and patients both from the clinical perspective and from the social interaction.This paper will also discuss visual depictions of the medical encounter to provide another perspective for narrating medicine during the Song dynasty.Medical case records and paintings depicting medical encounters are exemplary of the potential of Chinese primary sources for narrative medicine. 展开更多
关键词 Clinical encounter Medical practice song dynasty Xu Shuwei Case records
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A Stroke-Limitation AMD Control System with Variable Gain and Limited Area for High-Rise Buildings
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作者 Zuo-Hua Li Qing-Gui Wu +1 位作者 Jun Teng Chao-Jun Chen 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第1期865-884,共20页
Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a ... Collisions between a moving mass and an anti-collision device increase structural responses and threaten structural safety.An active mass damper(AMD)with stroke limitations is often used to avoid collisions.However,a strokelimited AMD control system with a fixed limited area shortens the available AMD stroke and leads to significant control power.To solve this problem,the design approach with variable gain and limited area(VGLA)is proposed in this study.First,the boundary of variable-limited areas is calculated based on the real-time status of the moving mass.The variable gain(VG)expression at the variable limited area is deduced by considering the saturation of AMD stroke.Then,numerical simulations of a stroke-limited AMD control system with VGLA are conducted on a high-rise building structure.These numerical simulations show that the proposed approach has superior strokelimitation performance compared with a stroke-limited AMD control system with a fixed limited area.Finally,the proposed approach is validated through experiments on a four-story steel frame. 展开更多
关键词 High-rise buildings active control stroke limitations variable gain variable limited area
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基于GAIN-LSTM网络的雷达PRI序列还原及识别方法
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作者 李忠媛 鲜果 +1 位作者 龚晓峰 雒瑞森 《电讯技术》 北大核心 2024年第3期343-349,共7页
开展脉冲重复间隔(Pulse Repetition Interval,PRI)模式识别工作是电子支援系统的一项重要任务。现代复杂电磁环境下,受雷达辐射源部署和接收设备本身影响,雷达脉冲丢失率极高,导致分选后PRI序列调制规律被破坏,现有的PRI模式识别方法... 开展脉冲重复间隔(Pulse Repetition Interval,PRI)模式识别工作是电子支援系统的一项重要任务。现代复杂电磁环境下,受雷达辐射源部署和接收设备本身影响,雷达脉冲丢失率极高,导致分选后PRI序列调制规律被破坏,现有的PRI模式识别方法准确率不足。针对上述问题,从PRI序列还原角度出发,并结合PRI序列本质是时序序列的特点,提出GAIN-LSTM(Generative Adversarial Imputation Nets and Long Short Term Memory)网络架构,其先对丢失脉冲位置进行补全操作,恢复PRI调制规律,然后对还原后PRI序列进行调制模式识别。仿真结果表明,提出的GAIN-LSTM网络架构在脉冲丢失率70%时仍保持95%的正确识别率。 展开更多
关键词 脉冲重复间隔调制 数据补全 模式识别 gain-LSTM
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ANovel Non-Isolated Cubic DC-DC Converter with High Voltage Gain for Renewable Energy Power Generation System
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作者 Qin Yao Yida Zeng Qingui Jia 《Energy Engineering》 EI 2024年第1期221-241,共21页
In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effec... In recent years,switched inductor(SL)technology,switched capacitor(SC)technology,and switched inductor-capacitor(SL-SC)technology have been widely applied to optimize and improve DC-DC boost converters,which can effectively enhance voltage gain and reduce device stress.To address the issue of low output voltage in current renewable energy power generation systems,this study proposes a novel non-isolated cubic high-gain DC-DC converter based on the traditional quadratic DC-DC boost converter by incorporating a SC and a SL-SC unit.Firstly,the proposed converter’s details are elaborated,including its topology structure,operating mode,voltage gain,device stress,and power loss.Subsequently,a comparative analysis is conducted on the voltage gain and device stress between the proposed converter and other high-gain converters.Then,a closed-loop simulation system is constructed to obtain simulation waveforms of various devices and explore the dynamic performance.Finally,an experimental prototype is built,experimental waveforms are obtained,and the experimental dynamic performance and conversion efficiency are analyzed.The theoretical analysis’s correctness is verified through simulation and experimental results.The proposed converter has advantages such as high voltage gain,low device stress,high conversion efficiency,simple control,and wide input voltage range,achieving a good balance between voltage gain,device stress,and power loss.The proposed converter is well-suited for renewable energy systems and holds theoretical significance and practical value in renewable energy applications.It provides an effective solution to the issue of low output voltage in renewable energy power generation systems. 展开更多
关键词 Cubic DC-DC converter high voltage gain low device stress high efficiency renewable energy
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Design of a Low Power Low-Noise Amplifier with Improved Gain/Noise Ratio
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作者 Raja Mahmou Khalid Faitah 《World Journal of Engineering and Technology》 2024年第1期80-91,共12页
This work details the development of a broad-spectrum LNA (Low Noise Amplifier) circuit using a 65 nm CMOS technology. The design incorporates an inductive degeneracy circuit, employing a theoretical approach to enhan... This work details the development of a broad-spectrum LNA (Low Noise Amplifier) circuit using a 65 nm CMOS technology. The design incorporates an inductive degeneracy circuit, employing a theoretical approach to enhance gain, minimize noise levels, and uphold low power consumption. The progression includes a shift to a cascode structure to further refine LNA parameters. Ultimately, with a 1.8 V bias, the achieved performance showcases a gain-to-noise figure ratio of 16 dB/0.5 dB, an IIP3 linearity at 5.1 dBm, and a power consumption of 3 mW. This architecture is adept at operating across a wide frequency band spanning from 0.5 GHz to 6 GHz, rendering it applicable in diverse RF scenarios. 展开更多
关键词 LNA DEGENERACY Noise Figure LINEARITY Power Consumption gain
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Analysis of the Effects of Maternal Body Mass Index and Gestational Weight Gain on Maternal and Neonatal Outcomes in Twin Pregnancy
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作者 Fanhua Shi Yuanyuan Li 《Journal of Clinical and Nursing Research》 2024年第3期127-133,共7页
Objective:To investigate the effects of maternal body mass index(BMI)and gestational weight gain on maternal and neonatal outcomes in twin pregnancies.Methods:Five hundred cases of twin pregnancies were divided into a... Objective:To investigate the effects of maternal body mass index(BMI)and gestational weight gain on maternal and neonatal outcomes in twin pregnancies.Methods:Five hundred cases of twin pregnancies were divided into a low body weight group(68 cases),a normal weight group(355 cases),an overweight group(65 cases),and an obesity group(12 cases)according to the World Health Organization(WHO)Body Mass Index(BMI)classification guidelines Results:Comparison of weight gain during different pregnancies revealed that pregnant women were mainly of low weight and average weight.The higher the BMI before pregnancy,the higher the incidence of excessive weight gain during pregnancy.The incidences of gestational diabetes mellitus(GDM)and premature rupture of membranes in women with low weight gain were significantly higher than those in women with average weight gain and high weight gain(P<0.05).The incidences of gestational hypertension,preeclampsia,and anemia in women with high weight gain were significantly higher than those in women with low weight gain and average weight gain(P<0.05).The incidence of neonatal birth weight,fetal distress,and macrosomia in the high weight gain group was significantly higher than those in the low weight gain and average weight gain groups(P<0.05).The birth weight of newborns in low-weight gain mothers was significantly lower than that of normal-weight gain mothers(P<0.05).Conclusion:Poor maternal and infant outcomes were common in women with insufficient or excessive weight gain during pregnancy.Therefore,for women with twin pregnancies,weight management is crucial to ensure maternal and infant health. 展开更多
关键词 Body mass index Weight gain Pregnancy outcome
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Genetic gain and inbreeding from simulation of different genomic mating schemes for pig improvement 被引量:2
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作者 Fuping Zhao Pengfei Zhang +4 位作者 Xiaoqing Wang Deniz Akdemir Dorian Garrick Jun He Lixian Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第4期1363-1376,共14页
Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after mul... Background Genomic selection involves choosing as parents those elite individuals with the higher genomic estimated breeding values(GEBV)to accelerate the speed of genetic improvement in domestic animals.But after multi-generation selection,the rate of inbreeding and the occurrence of homozygous harmful alleles might increase,which would reduce performance and genetic diversity.To mitigate the above problems,we can utilize genomic mating(GM)based upon optimal mate allocation to construct the best genotypic combinations in the next generation.In this study,we used stochastic simulation to investigate the impact of various factors on the efficiencies of GM to optimize pairing combinations after genomic selection of candidates in a pig population.These factors included:the algorithm used to derive inbreeding coefficients;the trait heritability(0.1,0.3 or 0.5);the kind of GM scheme(focused average GEBV or inbreeding);the approach for computing the genomic relationship matrix(by SNP or runs of homozygosity(ROH)).The outcomes were compared to three traditional mating schemes(random,positive assortative or negative assortative matings).In addition,the performance of the GM approach was tested on real datasets obtained from a Large White pig breeding population.Results Genomic mating outperforms other approaches in limiting the inbreeding accumulation for the same expected genetic gain.The use of ROH-based genealogical relatedness in GM achieved faster genetic gains than using relatedness based on individual SNPs.The GROH-based GM schemes with the maximum genetic gain resulted in 0.9%-2.6%higher rates of genetic gainΔG,and 13%-83.3%lowerΔF than positive assortative mating regardless of heritability.The rates of inbreeding were always the fastest with positive assortative mating.Results from a purebred Large White pig population,confirmed that GM with ROH-based GRM was more efficient than traditional mating schemes.Conclusion Compared with traditional mating schemes,genomic mating can not only achieve sustainable genetic progress but also effectively control the rates of inbreeding accumulation in the population.Our findings demonstrated that breeders should consider using genomic mating for genetic improvement of pigs. 展开更多
关键词 Genetic gain Genomic mating Genomic selection INBREEDING PIG
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Intoxication Induced by Urea Containing Diets in Broiler Chickens: Effect on Weight Gain, Feed Conversion Ratio, Hematological and Biochemical Profiles
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作者 Mohammed Al-Zharani Mohammed Mubarak +2 位作者 Hassan Ahmed Rudayni Mahmoud M. Abdelwahab Mohammed Al-Eissa 《Advances in Bioscience and Biotechnology》 CAS 2023年第3期106-119,共14页
Urea as a source of cheap non-protein nitrogen is used to adulterate fish and meat meals which are basic components of broiler diets. The present study was carried out to elucidate the effects of urea on weight gain, ... Urea as a source of cheap non-protein nitrogen is used to adulterate fish and meat meals which are basic components of broiler diets. The present study was carried out to elucidate the effects of urea on weight gain, and hematological and biochemical profiles. A total of 48 broiler chicks were randomly allotted into 4 groups, designated Groups 1, 2, 3 and 4 of 12 birds each. Birds in Groups 2, 3 and 4 were fed on diets containing urea at the levels of 1%, 2.5% and 4%, respectively. Birds in Group 1 served as control and were not exposed to urea. Experimentation period was for 3 weeks and experiment was terminated when birds were 42 days of age. Body weight of all intoxicated birds at the various intervals was significantly decreased in comparison with that of the untreated control. Compared with control, all intoxicated broilers manifested significant (P ≤ 0.05) decrease in all hematological parameters involving erythrocytic and total leucocytic counts, Hemoglobin (Hb) and Packed Cell Volume (PCV) on a dose- and time-pattern. In comparison with the control levels, biochemical profile of the intoxicated birds disclosed significant decrease in blood glucose level and significant increase in serum uric acid, urea, Alkaline Phosphatase (ALP) and Lactate Dehydrogenase (LDH) levels. Based upon the present data, it was concluded that the addition of urea to broiler diets bears serious sequences concerning the general health condition, performance, weight gain, and hematological and biochemical profiles. 展开更多
关键词 UREA INTOXICATION Broiler Chickens Weight gain Feed Conversion Ratio
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Aspect Level Songs Rating Based Upon Reviews in English
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作者 Muhammad Aasim Qureshi Muhammad Asif +4 位作者 Saira Anwar Umar Shaukat Atta-ur-Rahman Muhammad Adnan Khan Amir Mosavi 《Computers, Materials & Continua》 SCIE EI 2023年第2期2589-2605,共17页
With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after ... With the advancements in internet facilities,people are more inclined towards the use of online services.The service providers shelve their items for e-users.These users post their feedbacks,reviews,ratings,etc.after the use of the item.The enormous increase in these reviews has raised the need for an automated system to analyze these reviews to rate these items.Sentiment Analysis(SA)is a technique that performs such decision analysis.This research targets the ranking and rating through sentiment analysis of these reviews,on different aspects.As a case study,Songs are opted to design and test the decision model.Different aspects of songs namely music,lyrics,song,voice and video are picked.For the reason,reviews of 20 songs are scraped from YouTube,pre-processed and formed a dataset.Different machine learning algorithms—Naïve Bayes(NB),Gradient Boost Tree,Logistic Regression LR,K-Nearest Neighbors(KNN)and Artificial Neural Network(ANN)are applied.ANN performed the best with 74.99%accuracy.Results are validated using K-Fold. 展开更多
关键词 Machine learning natural language processing songs reviews:sentiment analysis songs rating aspect level sentiment analysis reviews analysis text classification MUSIC
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Local and range-wide distribution of song types suggest Ovenbirds(Seiurus aurocapilla)have song neighborhoods but not macro-dialects
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作者 Patrick M.Jagielski Jennifer R.Foote 《Avian Research》 SCIE CSCD 2023年第2期191-199,共9页
The song systems of oscine passerines(songbirds)are complex and diverse.Because songs are used for both mate attraction and territory defense and are therefore important signals for survival and reproduction,comprehen... The song systems of oscine passerines(songbirds)are complex and diverse.Because songs are used for both mate attraction and territory defense and are therefore important signals for survival and reproduction,comprehensive knowledge of within and among species song structure and distribution is informative for understanding the evolution of song repertoires and vocal behaviour.In this study,we explored variation in the song structure of the Ovenbird(Seiurus aurocapilla),a widespread warbler(Family Parulidae)found in North American forests.We analyzed recordings from the 2021 breeding season to assess song type variation at a local(n=158 birds;Sault Ste.Marie,ON)and breeding range scale(n=512 birds;eBird).We characterized the local song types and tested whether Ovenbirds share song types with their neighbors more often than expected by chance.We then characterized song types of Ovenbirds across the breeding range to determine whether any geographic pattern of song clustering exists(i.e.,macro-dialects).We found 10 distinct song types and some evidence for song type clustering at the local study site(i.e.,song neighborhoods).We found 7 of those 10 song types throughout the breeding range and identified an additional 24 types that were not recorded in our local population.We found no evidence for song dialects across the Ovenbird breeding range.This study contributes to our understanding of Ovenbird song while simultaneously adding to our understanding of geographic structuring of warbler repertoires.Our work contributes to delineating a more comprehensive understanding of factors affecting dialect development for this diverse group of songbirds. 展开更多
关键词 DIALECTS eBird Geographic variation Ovenbird Parulidae Seiurus aurocapilla song type
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Fixed-Time Stabilization of a Class of Strict-Feedback Nonlinear Systems via Dynamic Gain Feedback Control
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作者 Chenghui Zhang Le Chang +1 位作者 Lantao Xing Xianfu Zhang 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2023年第2期403-410,共8页
This paper presents a novel fixed-time stabilization control(FSC)method for a class of strict-feedback nonlinear systems involving unmodelled system dynamics.The key feature of the proposed method is the design of two... This paper presents a novel fixed-time stabilization control(FSC)method for a class of strict-feedback nonlinear systems involving unmodelled system dynamics.The key feature of the proposed method is the design of two dynamic parameters.Specifically,a set of auxiliary variables is first introduced through state transformation.These variables combine the original system states and the two introduced dynamic parameters,facilitating the closed-loop system stability analyses.Then,the two dynamic parameters are delicately designed by utilizing the Lyapunov method,ensuring that all the closed-loop system states are globally fixed-time stable.Compared with existing results,the“explosion of complexity”problem of backstepping control is avoided.Moreover,the two designed dynamic parameters are dependent on system states rather than a time-varying function,thus the proposed controller is still valid beyond the given fixedtime convergence instant.The effectiveness of the proposed method is demonstrated through two practical systems. 展开更多
关键词 Dynamic gain feedback control fixed-time stabilization strict-feedback nonlinear system
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Planar InAlAs/InGaAs avalanche photodiode with 360 GHz gain×bandwidth product
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作者 王帅 叶焓 +4 位作者 耿立妍 肖帆 褚艺渺 郑煜 韩勤 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期103-107,共5页
This paper describes a guardring-free planar InAlAs/InGaAs avalanche photodiode(APD)by computational simulations and experimental results.The APD adopts the structure of separate absorption,charge,and multiplication(S... This paper describes a guardring-free planar InAlAs/InGaAs avalanche photodiode(APD)by computational simulations and experimental results.The APD adopts the structure of separate absorption,charge,and multiplication(SACM)with top-illuminated.Computational simulations demonstrate how edge breakdown effect is suppressed in the guardringfree structure.The fabricated APD experiment results show that it can obtain a very low dark current while achieving a high gain×bandwidth(GB)product.The dark current is 3 nA at 0.9Vb r,and the unit responsivity is 0.4 A/W.The maximum3 dB bandwidth of 24 GHz and a GB product of 360 GHz are achieved for the fabricated APD operating at 1.55μm. 展开更多
关键词 avalanche photodiode PLANAR gain×bandwidth product dark current
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High gain and circularly polarized substrate integrated waveguide cavity antenna array based on metasurface
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作者 白昊 王光明 邹晓鋆 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第1期298-304,共7页
Two substrate integrated waveguide(SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively... Two substrate integrated waveguide(SIW) cavity antenna arrays based on metasurface are proposed in this paper. By rotating the metasurface element, circularly polarized and high gain antennas are achieved respectively. Firstly, multi-mode resonance theory is employed to broaden the bandwidth of the slot antenna. And then, an SIW cavity composed of 4×4 cornercut elements is added on the top of the slot antenna to achieve the circular polarization and improve the front-to-back ratio. Thirdly, the metasurface elements are sequentially rotated and a high gain antenna with 2-dBi enhancement on average in the operation band is obtained. Based on the two antenna units, two 2×2 antenna arrays are designed. The circularly polarized and high gain antenna arrays are both fabricated to verify the correctness. Furthermore, the novel wideband phase shifter is employed in the circularly polarized antenna to obtain an operating bandwidth of 38%(4.05 GHz–5.95 GHz)and AR bandwidth of 24.9%(4.4 GHz–5.65 GHz). The bandwidth of the high gain antenna can reach 42.7%(3.95 GHz–6.1 GHz) and with the gain enhancement of 2 dBi compared with that of the circularly polarized antenna. The gain remains steady in most of operating band within a variation of 1 dBi. It is remarkable that the rotating of the metasurface element has a great influence on the antenna performance, which provides a new explication for the multi-function antenna design. 展开更多
关键词 substrate integrated waveguide(SIW) cavity antenna metasurface high gain circularly polarized
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Design of a High-Gain 2 × 1 Array Antenna for S-Band Applications
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作者 Md. Imran Hossain Md. Ariful Islam +1 位作者 Md. Tofail Ahmed Md. Humaun Kabir 《World Journal of Engineering and Technology》 2023年第2期293-302,共10页
Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of str... Antennas are an indispensable element in wireless networks. For long-distance wireless communication, antenna gains need to be very strong (highly directive) because the signal from the antenna loses a lot of strength as it travels over long distances. This is true in the military with missile, radar, and satellite systems, etc. Antenna arrays are commonly employed to focus electromagnetic waves in a certain direction that cannot be achieved perfectly with a single-element antenna. The goal of this study is to design a rectangular microstrip high-gain 2 × 1 array antenna using ADS Momentum. This microstrip patch array design makes use of the RT-DUROID 5880 as a substrate with a dielectric constant of 2.2, substrate height of 1.588 mm, and tangent loss of 0.001. To achieve efficient gain and return loss characteristics for the proposed array antenna, RT-Duroid is a good choice of dielectric material. The designed array antenna is made up of two rectangular patches, which have a resonance frequency of 3.3 GHz. These rectangular patches are excited by microstrip feed lines with 13 mm lengths and 4.8 mm widths. The impedance of the patches is perfectly matched by these transmission lines, which helps to get better antenna characteristics. At a resonance frequency of 3.3 GHz, the suggested antenna array has a directivity of 10.50 dB and a maximum gain of 9.90 dB in the S-band. The S parameters, 3D radiation pattern, directivity, gain, and efficiency of the constructed array antenna are all available in ADS Momentum. 展开更多
关键词 Microstrip Patch Antenna Array Antenna Microstrip Feed Rectangular Patch gain Efficiency DIRECTIVITY ADS
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Heterogeneity in song rates in the Collared Flycatcher(Ficedula albicollis)explained with the availability parameter in generalized N-mixture models:Its importance for abundance estimates in avian aural counts
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作者 Grzegorz Neubauer Arkadiusz Sikora 《Avian Research》 SCIE CSCD 2023年第1期38-44,共7页
Binomial N-mixture models are commonly applied to estimate abundance unaffected by imperfect detection,but are known to be sensitive to violations of assumptions.One of the model’s assumptions,the independence of det... Binomial N-mixture models are commonly applied to estimate abundance unaffected by imperfect detection,but are known to be sensitive to violations of assumptions.One of the model’s assumptions,the independence of detections has rarely been tested.It requires that during a survey,detection of one individual does not affect detection of another individual.This assumption can be frequently violated in passerine birds,which exhibit territorial behaviour by singing,since neighbouring individuals are likely to motivate each other to vocalize,leading to non-independence in singing activity and in the following detection rate.Here,we explored this phenomenon with the generalized,binomial version of the N-mixture model,where detection probability is decomposed into availability probability φ-which can be interpreted as per capita song rate or the probability of vocalising-and actual detection probability p,given vocalisations take place.Using repeated counts of the Collared Flycatcher(Ficedula albicollis)as a case study,and treating the maximum observed counts C_(maxi) at a site i as an explanatory covariate for φ,we showed that per capita song rates increased with observed counts at a site.Hence,if song rates vary due to local abundance,including C_(maxi)as an explanatory variable for song rate addressed with φ,helps to explain this variation(which otherwise goes undetected)and improves inferences under the model.This had strong effects on the resulting abundance estimates:if this relationship was ignored in the models,total estimated population sizes were consequently lower by as much as 22-27%,compared to when this effect was included.Since it is likely that song rates may commonly be density-dependent in birds manifesting territorial behaviours by singing,further tests addressing violations of independence assumptions in these models are needed.As suggested by Kery and Royle(2016),despite some form of circularity likely being involved,modelling heterogeneity in the detection process with the help of C_(maxi)in standard N-mixture models(which,given availability,conflate availability with detection in a single parameter)should be applicable as well. 展开更多
关键词 ABUNDANCE Awailabity Bird∞mt Dansity dpendent detection Ganerlizd N minture models Singing sactiwity song Tate
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