期刊文献+
共找到120,061篇文章
< 1 2 250 >
每页显示 20 50 100
Congruent Feature Selection Method to Improve the Efficacy of Machine Learning-Based Classification in Medical Image Processing
1
作者 Mohd Anjum Naoufel Kraiem +2 位作者 Hong Min Ashit Kumar Dutta Yousef Ibrahim Daradkeh 《Computer Modeling in Engineering & Sciences》 SCIE EI 2025年第1期357-384,共28页
Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify sp... Machine learning(ML)is increasingly applied for medical image processing with appropriate learning paradigms.These applications include analyzing images of various organs,such as the brain,lung,eye,etc.,to identify specific flaws/diseases for diagnosis.The primary concern of ML applications is the precise selection of flexible image features for pattern detection and region classification.Most of the extracted image features are irrelevant and lead to an increase in computation time.Therefore,this article uses an analytical learning paradigm to design a Congruent Feature Selection Method to select the most relevant image features.This process trains the learning paradigm using similarity and correlation-based features over different textural intensities and pixel distributions.The similarity between the pixels over the various distribution patterns with high indexes is recommended for disease diagnosis.Later,the correlation based on intensity and distribution is analyzed to improve the feature selection congruency.Therefore,the more congruent pixels are sorted in the descending order of the selection,which identifies better regions than the distribution.Now,the learning paradigm is trained using intensity and region-based similarity to maximize the chances of selection.Therefore,the probability of feature selection,regardless of the textures and medical image patterns,is improved.This process enhances the performance of ML applications for different medical image processing.The proposed method improves the accuracy,precision,and training rate by 13.19%,10.69%,and 11.06%,respectively,compared to other models for the selected dataset.The mean error and selection time is also reduced by 12.56%and 13.56%,respectively,compared to the same models and dataset. 展开更多
关键词 Computer vision feature selection machine learning region detection texture analysis image classification medical images
下载PDF
Enhanced selectivity of catalytic hydrogenation of halogenated nitroaromatics by interfacial effects
2
作者 HUANG Rui LIU Shengjie +1 位作者 WU Qingyuan ZHENG Nanfeng 《无机化学学报》 北大核心 2025年第1期201-212,共12页
The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts c... The highly selective catalytic hydrogenation of halogenated nitroaromatics was achieved by employing Pd‑based catalysts that were co‑modified with organic and inorganic ligands.It was demonstrated that the catalysts contained Pd species in mixed valence states,with high valence Pd at the metal‑support interface and zero valence Pd at the metal surface.While the strong coordination of triphenylphosphine(PPh3)to Pd0 on the Pd surface prevents the adsorption of halogenated nitroaromatics and thus dehalogenation,the coordination of sodium metavanadate(NaVO3)to high‑valence Pd sites at the interface helps to activate H2 in a heterolytic pathway for the selective hydrogenation of nitro‑groups.The excellent catalytic performance of the interfacial active sites enables the selective hydrogenation of a wide range of halogenated nitroaromatics. 展开更多
关键词 halogenated nitroaromatic heterogeneous catalysis HYDROGENATION selectivity control interfacial effect
下载PDF
Corrosion resistance and antibacterial properties of Ti−3Cu alloy prepared by selective laser melting
3
作者 Meng-zhen ZHU Jing-lei MIAO +3 位作者 Xiong-wen ZHOU Er-lin ZHANG Zhi-lin LIU Hai-lin YANG 《中国有色金属学报》 北大核心 2025年第1期143-156,共14页
The corrosion resistance and antibacterial properties of Ti−3Cu alloy prepared by selective laser melting were evaluated using electrochemical experiments and a variety of antibacterial characterization.It is found th... The corrosion resistance and antibacterial properties of Ti−3Cu alloy prepared by selective laser melting were evaluated using electrochemical experiments and a variety of antibacterial characterization.It is found that the charge transfer resistance of Ti−3Cu alloy was 4.89×10^(5)Ω∙cm^(2),which was doubled the data obtained by CP-Ti alloy.The antibacterial rates of Ti−3Cu alloy against S.mutans and P.gingivalis were 45.0%and 54.5%.And the antibacterial rates increased with the prolongation of cultivation time,reaching up to 62.8%and 68.6%,respectively.The in-situ nano Ti_(2)Cu precipitates were homogeneously distributed in the matrix of the Ti−3Cu alloy,which was the key reason of increasing the corrosion resistance.Additionally,the microscale electric fields between theα-Ti matrix and the Ti_(2)Cu was responsible for the enhancement of the antibacterial properties. 展开更多
关键词 selective laser melting Ti−3Cu alloy MICROSTRUCTURE corrosion resistance antibacterial properties
下载PDF
Experimental Study of Selective Batch Bio-Adsorption for the Removal of Dyes in Industrial Textile Effluents
4
作者 Zakaria Laggoun Amel Khalfaoui +3 位作者 Kerroum Derbal Amira Fadia Ghomrani Abderrezzaq Benalia Antonio Pizzi 《Journal of Renewable Materials》 2025年第1期127-146,共20页
This research aims to study the bio-adsorption process of two dyes,Cibacron Green H3G(CG-H3G)and Terasil Red(TR),in a single system and to bring them closer to the industrial textile discharge by a binary mixture of t... This research aims to study the bio-adsorption process of two dyes,Cibacron Green H3G(CG-H3G)and Terasil Red(TR),in a single system and to bring them closer to the industrial textile discharge by a binary mixture of two dyes(TR+CG-H3G).The Cockle Shell(CS)was used as a natural bio-adsorbent.The characterizations of CS were investigated by Fourier transform infrared(FTIR),X-ray diffraction(XRD),scanning electron microscopy(SEM),energy-dispersive X-ray spectroscopy(EDX)and Brunauer–Emmett–Teller(BET).The adsorption potential of Cockle Shells was tested in two cases(single and binary system)and determined by:contact time(0–60 min),bio-adsorption dose(3–15 g/L),initial concentration(10–300 mg/L),temperature(22–61°C)and pH solution(2–12).The study of bio-adsorption(equilibrium and kinetics)was conducted at 22°C.The kinetic studies demon-strated that a pseudo-second-order adsorption mechanism had a good correlation coefficient(R2≥0.999).The Langmuir isotherm modeling provided a well-defined description of TR and CG-H3G bio-adsorption on cockle shells,exhibiting maximum capacities of 29.41 and 3.69 mg/g respectively at 22°C.The thermodynamic study shows that the reaction between the TR,CG-H3G dyes molecules and the bio-adsorbent is exothermic,spontaneous in the range of 22–31°C with the aleatory character decrease at the solid-liquid interface.The study of selectivity in single and binary systems has been performed under optimal operating conditions using the industrial textile rejection pH(pH=6.04).CG-H3G dye is found to have a higher selectivity than TR in single(0–60 min)and binary systems with a range of 6–45 min,as shown by the selectivity measurement.It was discovered that CS has the capability to remove both CG-H3G and TR dyes in both simple and binary systems,making it a superior bio-adsorbent. 展开更多
关键词 Cockle shells bio-adsorption binary system dyes cibacron green terasil red selectivity
下载PDF
Genomic selection for meat quality traits based on VIS/NIR spectral information
5
作者 Xi Tang Lei Xie +8 位作者 Min Yan Longyun Li Tianxiong Yao Siyi Liu Wenwu Xu Shijun Xiao Nengshui Ding Zhiyan Zhang Lusheng Huang 《Journal of Integrative Agriculture》 2025年第1期235-245,共11页
The principle of genomic selection(GS) entails estimating breeding values(BVs) by summing all the SNP polygenic effects. The visible/near-infrared spectroscopy(VIS/NIRS) wavelength and abundance values can directly re... The principle of genomic selection(GS) entails estimating breeding values(BVs) by summing all the SNP polygenic effects. The visible/near-infrared spectroscopy(VIS/NIRS) wavelength and abundance values can directly reflect the concentrations of chemical substances, and the measurement of meat traits by VIS/NIRS is similar to the processing of genomic selection data by summing all ‘polygenic effects' associated with spectral feature peaks. Therefore, it is meaningful to investigate the incorporation of VIS/NIRS information into GS models to establish an efficient and low-cost breeding model. In this study, we measured 6 meat quality traits in 359Duroc×Landrace×Yorkshire pigs from Guangxi Zhuang Autonomous Region, China, and genotyped them with high-density SNP chips. According to the completeness of the information for the target population, we proposed 4breeding strategies applied to different scenarios: Ⅰ, only spectral and genotypic data exist for the target population;Ⅱ, only spectral data exist for the target population;Ⅲ, only spectral and genotypic data but with different prediction processes exist for the target population;and Ⅳ, only spectral and phenotypic data exist for the target population.The 4 scenarios were used to evaluate the genomic estimated breeding value(GEBV) accuracy by increasing the VIS/NIR spectral information. In the results of the 5-fold cross-validation, the genetic algorithm showed remarkable potential for preselection of feature wavelengths. The breeding efficiency of Strategies Ⅱ, Ⅲ, and Ⅳ was superior to that of traditional GS for most traits, and the GEBV prediction accuracy was improved by 32.2, 40.8 and 15.5%, respectively on average. Among them, the prediction accuracy of Strategy Ⅱ for fat(%) even improved by 50.7% compared to traditional GS. The GEBV prediction accuracy of Strategy Ⅰ was nearly identical to that of traditional GS, and the fluctuation range was less than 7%. Moreover, the breeding cost of the 4 strategies was lower than that of traditional GS methods, with Strategy Ⅳ being the lowest as it did not require genotyping.Our findings demonstrate that GS methods based on VIS/NIRS data have significant predictive potential and are worthy of further research to provide a valuable reference for the development of effective and affordable breeding strategies. 展开更多
关键词 VIS/NIR genomic selection GEBV machine learning PIG meat quality
下载PDF
Early and accurate diagnosis and selection of appropriate treatment plans are crucial for patients with gastrointestinal hemangiomas
6
作者 Zhou Chen Liang Wang Peng-Jie Yu 《World Journal of Gastrointestinal Surgery》 2025年第2期303-307,共5页
Gastrointestinal hemangioma(GIH)is clinically rare,accounting for 7%-10%of benign gastrointestinal tumors and 0.5%of systemic hemangiomas.GIH can occur as either solitary or multiple lesions,with gastrointestinal blee... Gastrointestinal hemangioma(GIH)is clinically rare,accounting for 7%-10%of benign gastrointestinal tumors and 0.5%of systemic hemangiomas.GIH can occur as either solitary or multiple lesions,with gastrointestinal bleeding as a significant clinical manifestation.Understanding the clinical and endoscopic features of GIH is essential for improving diagnostic accuracy,particularly through endoscopy and selective arteriography,which are highly effective in diagnosing GIH and preventing misdiagnosis and inappropriate treatment.Upon confirmed diagnosis,it is essential to thoroughly evaluate the patient's condition to determine the most suitable treatment modality—whether surgical,endoscopic,or minimally invasive intervention.The minimally invasive interventional partial embolization therapy using polyvinyl alcohol particles,proposed and implemented by Pospisilova et al,has achieved excellent clinical outcomes.This approach reduces surgical trauma and the inherent risks of traditional surgical treatments. 展开更多
关键词 HEMANGIOMA Gastrointestinal hemangioma Gastrointestinal hemorrhage Minimally invasive interventional treatment selective embolization
下载PDF
用草酸从铜冶炼稀酸中选择性沉铜除砷试验研究
7
作者 王雷 张峰 张桧楠 《湿法冶金》 北大核心 2025年第1期40-44,共5页
以铜冶炼稀酸为原料,研究了采用草酸选择性沉铜除砷,考察了草酸用量、溶液pH、搅拌速度、反应温度和时间对铜砷分离的影响。结果表明:在H_(2)C_(2)O_(4)/Cu物质的量比1.1、溶液pH=0.4、搅拌速度500 r/min、反应温度25℃、反应时间30 mi... 以铜冶炼稀酸为原料,研究了采用草酸选择性沉铜除砷,考察了草酸用量、溶液pH、搅拌速度、反应温度和时间对铜砷分离的影响。结果表明:在H_(2)C_(2)O_(4)/Cu物质的量比1.1、溶液pH=0.4、搅拌速度500 r/min、反应温度25℃、反应时间30 min条件下,铜沉淀率达98.5%以上,砷沉淀率低于0.20%,铜、砷可实现高效分离。 展开更多
关键词 稀酸 草酸 选择性 沉淀 分离
下载PDF
Short-span interleaving based selected mapping
8
作者 吴炳洋 程时昕 《Journal of Southeast University(English Edition)》 EI CAS 2005年第4期385-388,共4页
A novel interleaving based selected mapping (SLM) scheme to depress the relatively high peak power of transmit signals in multicarrier communications is proposed. In the scheme, a group of bit-level interleavers spa... A novel interleaving based selected mapping (SLM) scheme to depress the relatively high peak power of transmit signals in multicarrier communications is proposed. In the scheme, a group of bit-level interleavers spanning only a few bits are used to produce multiple sequences representing the same information, and one of the sequences resulting in the lowest peak-to-average power ratio (PAPR) is selected for transmission. The implementation of the scheme including the structure of the short-span interleaver is illustrated. The performance of this PAPR reduction scheme is investigated by simulations. This scheme exhibits a good PAPR reduction performance, and for signals of high level modulation, such as 16QAM and 64QAM, it approaches the best performance of all SLM schemes. Compared to the conventional interleaving SLM, this short-span interleaving SLM results in a very short time delay, requires very few register units for buffering, and can be easily implemented by hardware. 展开更多
关键词 multicarrier communications peak-to-average power ratio selected mapping INTERLEAVING
下载PDF
基于SELECT理念腹腔镜下保留脾脏的胰体尾切除
9
作者 李爽 张标 +5 位作者 刘航宇 祁冰 Thomas Juby 张桂信 张庆凯 尚东 《临床外科杂志》 2024年第7期776-779,共4页
腹腔镜下胰体尾切除术目前已经成为治疗胰腺体尾部肿瘤的标准术式。而腹腔镜下保留脾脏的胰体尾切除术由于可保留脾脏功能,减少脾切除术后并发症,越来越受到重视。然而,胰腺肿瘤发病隐匿、解剖位置复杂,这些对其诊断和保留脾脏的胰体尾... 腹腔镜下胰体尾切除术目前已经成为治疗胰腺体尾部肿瘤的标准术式。而腹腔镜下保留脾脏的胰体尾切除术由于可保留脾脏功能,减少脾切除术后并发症,越来越受到重视。然而,胰腺肿瘤发病隐匿、解剖位置复杂,这些对其诊断和保留脾脏的胰体尾切除术带来了挑战。近年来,我们团队积累了丰富的胰腺肿瘤诊疗经验,创新提出“SELECT”(S-Single-Operator Cholangiopancreatoscopy,E-ERCP,L-Laparoscopy,E-Endoscopic ultrasound,C-Choledochoscopy/Confocal laser endomicroscopy,T-Traditional Chinese medicine)多镜组合中西医微创诊治理念。根据胰腺肿瘤的类型及特点,应用多种内镜和腹腔镜技术,多种不同微创诊疗方法的优选组合,围手术期采用中医药,进行中西医结合加速康复。将SELECT理念充分应用于腹腔镜下保留脾脏的胰体尾切除术,有利于术前精准诊断、术中精准切除、术后并发症预判和治疗,一站式诊治胰腺肿瘤,使病人利益最大化。 展开更多
关键词 select理念 多镜联合 胰腺肿瘤 保留脾脏 胰体尾切除术
下载PDF
生涯教育视角下普通高中选科指导实践模式的建构及检验 被引量:2
10
作者 顾雪英 陈华若 陈实 《华东师范大学学报(教育科学版)》 CSSCI 北大核心 2024年第2期63-77,共15页
新高考改革将选择权交还给学生,不仅带来选择空间的放大和决策时间的前置,而且引发高中生对未来愿景的更多期许。选科指导成为兼及学生当下选择与长远发展的重要契机和有力抓手。基于生涯教育的视角建构涵盖选科指导目标之“谐和”、内... 新高考改革将选择权交还给学生,不仅带来选择空间的放大和决策时间的前置,而且引发高中生对未来愿景的更多期许。选科指导成为兼及学生当下选择与长远发展的重要契机和有力抓手。基于生涯教育的视角建构涵盖选科指导目标之“谐和”、内容之“融和”、路径之“通和”、评价之“正和”为一体的“4和”模式,并通过实践运用检验其效用和价值,旨在回应时代关切。研究结果表明,该模式能显著降低学生选科过程中的决策困难,提升学生生涯发展的成熟度,加深其对高中学习意义的理解,促进由表层学习动机向深层学习动机的转化。实验结果一方面验证了生涯教育视角对于选科指导具有正向作用,另一方面也在操作层面检验了“4和”实践模式的可借鉴性。 展开更多
关键词 生涯教育 选科指导 实践模式 实验研究
下载PDF
Growth performance and physiological parameters of the second generation selected and control groups of Pinctada martensii 被引量:10
11
作者 DENG Yuewen YU Ziniu +2 位作者 DU Xiaodong WANG Qingheng FU Shao 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第2期120-125,共6页
In May of 2007,the second generation selected (SS) and control (SC) groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the... In May of 2007,the second generation selected (SS) and control (SC) groups of pearl oyster Pinctada martensii were established by selecting 10% breeders with the largest and mean shell length,respectively,from the first generation selected group.Growth performance of the SS and SC groups were compared on the basis of measurement data at Days 8,18,60,95,195 and 365.On Day 365,100 individuals (60.0–75.0 mm at shell length) were sampled from each group and then subjected to the experiment where physiological parameters such as filtrate rate,oxygen consumption and ammonia excretion were measured at 15,20,25 and 30°C.The results show that the SS group had significantly larger mean shell length and shell height than the SC group at Days 8,18,60,95,195 and 365 (P 0.05).The genetic gains at different ages varied from 6.0% to 17.0% for shell length and 5.7% to 14.6% for shell height,respectively.At 15,20,25 and 30 ° C,the SS groups had significantly larger filtrate rate than the SC group (P 0.05).At 15 and 25 °C,the differences in oxygen consumption rate between the SS and SC groups were not significant (P 0.05).At 20 and 30 °C,however,the oxygen consumption rate of the SS group was significantly larger than the SC group (P 0.05).At 15,20,25 and 30 °C,there were no significant differences in ammonia excretion rate between the SS and SC groups (P 0.05).The present results indicate that there existed considerable genetic variability in the base population and a further selection could be likely fruitful.Mass selection for faster growth might produce animals that had higher intake of metabolizable energy by virtue of faster filtrating behavior. 展开更多
关键词 Pinctada martensii the second generation selected group GROWTH genetic gains physiological parameters
下载PDF
The Power of Patronage Exercised in the Translation of Selected Works of Deng Xiaoping
12
作者 韩媛媛 赵伟兴 《科技信息》 2010年第4期17-18,共2页
By referring to Lefevere’s theory of patronage, this paper examines the issue of patronage in the translation of Selected Works of Deng Xiaoping, a remarkable political work of our country. It addresses the questions... By referring to Lefevere’s theory of patronage, this paper examines the issue of patronage in the translation of Selected Works of Deng Xiaoping, a remarkable political work of our country. It addresses the questions like"Who are the patrons?","What is the structure of patronage?", and "How does patronage work in the translation?"Through investigating these issues, the paper concludes that if it had not been for the powerful manipulation by patronage, there could not have been the high-quality translation of such voluminous works. The power of patronage made undeniable contribution to the translation of Selected Works of Deng Xiaoping. 展开更多
关键词 英语学习 学习方法 英语翻译 语言学
下载PDF
Accuracy analysis of the part made by selected laser sintering 被引量:3
13
作者 Zitian FAN Naiyu HUANG +1 位作者 Yuejia XIAO Ming HAN 《China Foundry》 SCIE CAS 2004年第1期49-52,共4页
The effects of different factors, including the precision of selected laser sintering (SLS) equipment, sintering temperature, sintered thickness of individual layer and laser scanning route, on the SLS part accuracy h... The effects of different factors, including the precision of selected laser sintering (SLS) equipment, sintering temperature, sintered thickness of individual layer and laser scanning route, on the SLS part accuracy have been analyzed and studied. Some measures are suggested in order to improve the part accuracy made by SLS. 展开更多
关键词 rapid PROTOTYPING selected LASER SINTERING LASER SCANNING part accuracy
下载PDF
Evaluation of age, weaning weight, body condition score, and reproductive tract score in pre-selected beef heifers relative to reproductive potential 被引量:2
14
作者 Sarah E.Dickinson Michelle F.Elmore +5 位作者 Lisa Kriese-ANDerson Joshua B.Elmore Bailey N.Walker Paul W.Dyce Soren P.Rodning Fernando H.Biase 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2019年第2期307-313,共7页
Background: Artificial insemination is a preferred breeding method for beef heifers as it advances the genetic background, produces a predictive and profitable calving season, and extends the heifer’s reproductive li... Background: Artificial insemination is a preferred breeding method for beef heifers as it advances the genetic background, produces a predictive and profitable calving season, and extends the heifer’s reproductive life span.As reproductive efficiency in heifers is key for the success of beef cattle production systems, following artificial insemination, heifers are exposed to a bull for the remainder of the breeding season. Altogether, up to 95% of heifers might become pregnant in their first breeding season. Heifers that do not become pregnant at the end of the breeding season represent an irreparable economical loss. Additionally, heifers conceiving late in the breeding season to natural service, although acceptable, poses serious losses to producers. To minimize losses due to reproductive failure, different phenotypic parameters can be assessed and utilized as selection tools. Here, we tested the hypothesis that in a group of pre-selected heifers, records of weaning weight, age at weaning, age at artificial insemination, and age of dam differ among heifers of varied reproductive outcomes during the first breeding season.Results: None of the parameters tested presented predictive ability to discriminate the heifers based on the response variable(‘pregnant to artificial insemination’, ‘pregnant to natural service’, ‘not pregnant’). Heifers categorized with body condition score = 6 and reproductive tract score ≥ 4 had the greatest proportion of pregnancy to artificial insemination(49% and 44%, respectively). Furthermore, it was notable that heifers presenting body condition score = 6 and reproductive tract score = 5 presented the greatest pregnancy rate at end of the breeding season(89%). Heifers younger than 368 d at the start of the breeding season did not become pregnant to artificial insemination. Those young heifers had 12.5% chance to become pregnant in their first breeding season,compared to 87.5% if the heifers were older than 368 days.Conclusion: Our results suggest that beef heifers with body condition score = 6 and reproductive tract score ≥ 4 are more likely to become pregnant to artificial insemination. Careful assessment should be undertaken when developing replacement heifers that will not reach 12 months of age by the beginning of the breeding season. 展开更多
关键词 FERTILITY PHENOTYPIC selection PREGNANCY OUTCOME Replacement HEIFER
下载PDF
Investigating on casting mold (or core) making with coated sand by the selected laser sintering 被引量:6
15
作者 Zitian FAN Naiyu HUANG +1 位作者 Yan LI Zhili LIU 《China Foundry》 SCIE CAS 2004年第2期122-126,共5页
Using a special coated sand as the material of the selected laser sintering (SLS), the authors test and investigate the strength change of the test samples in terms of different sintering parameters (scanning speed, l... Using a special coated sand as the material of the selected laser sintering (SLS), the authors test and investigate the strength change of the test samples in terms of different sintering parameters (scanning speed, laser power, sintering thickness, and so on). The characteristics of coated sand hardening by laser beam are analyzed. The sintered mold (or core) for given casting is poured with molten metal. 展开更多
关键词 rapid prototyping selected laser sintering(SLS) laser scanning casting mold(core) technological parameters
下载PDF
Pyramiding Breeding by Marker-Assisted Recurrent Selection in Upland Cotton: Selected Effects on Resistance to Helicoverpa armigera 被引量:1
16
作者 YICheng-xin GUOWang-zhen ZHUXie-fei MINLiu-fang ZHANGTian-zhen 《Agricultural Sciences in China》 CAS CSCD 2004年第5期330-339,共10页
The coincidence rates were more than 96% among the instar-weighted average of bioassaysin the lab, the percentage of resistance to Km in the field and the percentage of plantscontaining Bt gene. So, the performance of... The coincidence rates were more than 96% among the instar-weighted average of bioassaysin the lab, the percentage of resistance to Km in the field and the percentage of plantscontaining Bt gene. So, the performance of resistance to Km in the field can be used torepresent the transgenic Bt gene for selecting the resistance to bollworm. The instar-weighted averages were 30.585, 24.182, 16.615, 10.601, 10.123, 7.440 and 7.215 for theC0, P1, M1, M2, MP1, P2 and MP2 populations, respectively. The variance analysisindicated that the instar-weighted average in C0 was greatly significantly higher thanthat in all other populations, i.e., the performance of resistance to bollworm in C0 washighly significantly lower than all other populations. And the resistance in P1 wasgreatly lower than that of M1, M2, MP1, P2 and MP2, and M1 greatly lower than that of M2,MP1, P2 and MP2. There were no significant differences among M2, MP1, P2 and MP2. Withinthe populations of the first cycle selection, MP1 and M1 were greatly significantlyhigher than P1, and MP1 significantly higher than M1. The populations of the second cycleselection were significantly higher than their initial population M1, but no significantdifference among them. The boll size, seed index, the percent of the first harvest yield,fiber length, strength and elongation of the resistant plants to bollworm were significantlylower than that of sensitive plants to bollworm. And the yield of seed and lint cottonof the resistant plant to bollworm were lower than that of the sensitive to bollworm, butno significant difference between them. The boll numbers per plant, lint percent andmicronaire of the resistant plants to bollworm were significantly higher than that of thesensitive plant to bollworm. 展开更多
关键词 Upland cotton Molecular marker-assisted selection Recurrent selection Pyramiding breeding Resistance to Helicoverpa armigera
下载PDF
国家集中带量采购中选药品的供应短缺问题研究 被引量:1
17
作者 王彪 廖鹏 +2 位作者 唐啸宇 贾韵 罗力 《卫生经济研究》 北大核心 2024年第2期40-43,共4页
目的:分析我国集中带量采购中选药品的供应短缺现状,提出相关建议。方法:收集全国前5批集采药品的采购和供应数据,对药品供应短缺情况进行分析。结果:集采药品在中选后一年内出现供应短缺的占比达82%,东部和中部地区、临床用量大和价格... 目的:分析我国集中带量采购中选药品的供应短缺现状,提出相关建议。方法:收集全国前5批集采药品的采购和供应数据,对药品供应短缺情况进行分析。结果:集采药品在中选后一年内出现供应短缺的占比达82%,东部和中部地区、临床用量大和价格低的集采药品供应短缺情况更为严重。结论:加强中选企业行为的履约监管,建立参与主体的信用评价制度,综合考虑地区、药理类型和价格因素,优化集采招标规则,提升集采中选药品生产供应保障能力。 展开更多
关键词 药品集中带量采购 中选药品 供应短缺
下载PDF
An Improved DV-Hop Localization Algorithm Based on Selected Anchors 被引量:5
18
作者 Jing Wang Anqi Hou +1 位作者 Yuanfei Tu Hong Yu 《Computers, Materials & Continua》 SCIE EI 2020年第10期977-991,共15页
Wireless Sensor Network(WSN)based applications has been extraordinarily helpful in monitoring interested area.Only information of surrounding environment with meaningful geometric information is useful.How to design t... Wireless Sensor Network(WSN)based applications has been extraordinarily helpful in monitoring interested area.Only information of surrounding environment with meaningful geometric information is useful.How to design the localization algorithm that can effectively extract unknown node position has been a challenge in WSN.Among all localization technologies,the Distance Vector-Hop(DV-Hop)algorithm has been most popular because it simply utilizes the hop counts as connectivity measurements.This paper proposes an improved DV-Hop based algorithm,a centroid DV-hop localization with selected anchors and inverse distance weighting schemes(SIC-DV-Hop).We adopt an inverse distance weighting method for average distance amelioration to improve accuracy.Also in this paper,we propose an inclusive checking rule to select proper anchors to avoid the inconsistency existing in centroid localization schemes.Finally,an improved multilateration centroid method is presented for the localization.Simulations are conducted on two different network topologies and experiments results show that compared with existing DV-Hop based algorithms,our algorithm can significantly improve the performance meanwhile cost less network resource. 展开更多
关键词 DV-HOP selective mechanism centroid estimation
下载PDF
Morphological comparison between a selected fast-growing strain and the common cultured strain of turbot Scophthalmus maximus 被引量:4
19
作者 梁兴明 马爱军 +3 位作者 王新安 李娟 黄智慧 商晓梅 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2012年第4期563-568,共6页
To evaluate the effect of genetic improvement of the turbot Scophthalmus maximus, we analyzed morphological differences between a fast-growing strain obtained by family selection and the common cultured strain, by pri... To evaluate the effect of genetic improvement of the turbot Scophthalmus maximus, we analyzed morphological differences between a fast-growing strain obtained by family selection and the common cultured strain, by principal component analysis, stepwise discriminant analysis, and t-tests. Although they clearly differed morphologically, plots of the principal components of the two strains partially overlapped. However, the difference between the strains was supported with very high precision by discriminant analysis. The t-tests revealed that 4 of the 13 morphological traits analyzed were highly significantly different (P<0.01), 4 traits also differed significantly (P<0.05), and the remainder did not differ significantly. The coefficients of difference of the 13 traits were all lower than the threshold value between subspecies (1.28). Together, the results indicate that a trend for segregation of characters from the common cultured strain have already appeared in the selected fast-growing strain but the degree of segregation have not risen to subspecies level. 展开更多
关键词 Scophthalmus maximus divergence by selection quantitative trait analysis
下载PDF
Selective footprints and genes relevant to cold adaptation and other phenotypic traits are unscrambled in the genomes of divergently selected chicken breeds 被引量:2
20
作者 Michael N.Romanov Alexandra S.Abdelmanova +11 位作者 Vladimir I.Fisinin Elena A.Gladyr Natalia A.Volkova Olga A.Koshkina Andrey N.Rodionov Anastasia N.Vetokh Igor V.Gusev Dmitry V.Anshakov Olga I.Stanishevskaya Arsen V.Dotsev Darren K.Griffin Natalia A.Zinovieva 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2023年第3期887-907,共21页
Background The genomes of worldwide poultry breeds divergently selected for performance and other phenotypic traits may also be affected by,and formed due to,past and current admixture events.Adaptation to diverse env... Background The genomes of worldwide poultry breeds divergently selected for performance and other phenotypic traits may also be affected by,and formed due to,past and current admixture events.Adaptation to diverse environments,including acclimation to harsh climatic conditions,has also left selection footprints in breed genomes.Results Using the Chicken 50K_CobbCons SNP chip,we genotyped four divergently selected breeds:two aboriginal,cold tolerant Ushanka and Orloff Mille Fleur,one egg-type Russian White subjected to artificial selection for cold tolerance,and one meat-type White Cornish.Signals of selective sweeps were determined in the studied breeds using three methods:(1)assessment of runs of homozygosity islands,(2)F_(ST) based population differential analysis,and(3)haplotype differentiation analysis.Genomic regions of true selection signatures were identified by two or more methods or in two or more breeds.In these regions,we detected 540 prioritized candidate genes supplemented them with those that occurred in one breed using one statistic and were suggested in other studies.Amongst them,SOX5,ME3,ZNF536,WWP1,RIPK2,OSGIN2,DECR1,TPO,PPARGC1A,BDNF,MSTN,and beta-keratin genes can be especially mentioned as candidates for cold adaptation.Epigenetic factors may be involved in regulating some of these important genes(e.g.,TPO and BDNF).Conclusion Based on a genome-wide scan,our findings can help dissect the genetic architecture underlying various phenotypic traits in chicken breeds.These include genes representing the sine qua non for adaptation to harsh environments.Cold tolerance in acclimated chicken breeds may be developed following one of few specific gene expression mechanisms or more than one overlapping response known in cold-exposed individuals,and this warrants further investigation. 展开更多
关键词 ACCLIMATION Adaptation Chicken breeds Cold tolerance Divergent selection Genetic diversity Genomewide scan Phenotypic traits selective sweeps
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部