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Identification of reservoir types in deep carbonates based on mixedkernel machine learning using geophysical logging data
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作者 Jin-Xiong Shi Xiang-Yuan Zhao +3 位作者 Lian-Bo Zeng Yun-Zhao Zhang Zheng-Ping Zhu Shao-Qun Dong 《Petroleum Science》 SCIE EI CAS CSCD 2024年第3期1632-1648,共17页
Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analy... Identification of reservoir types in deep carbonates has always been a great challenge due to complex logging responses caused by the heterogeneous scale and distribution of storage spaces.Traditional cross-plot analysis and empirical formula methods for identifying reservoir types using geophysical logging data have high uncertainty and low efficiency,which cannot accurately reflect the nonlinear relationship between reservoir types and logging data.Recently,the kernel Fisher discriminant analysis(KFD),a kernel-based machine learning technique,attracts attention in many fields because of its strong nonlinear processing ability.However,the overall performance of KFD model may be limited as a single kernel function cannot simultaneously extrapolate and interpolate well,especially for highly complex data cases.To address this issue,in this study,a mixed kernel Fisher discriminant analysis(MKFD)model was established and applied to identify reservoir types of the deep Sinian carbonates in central Sichuan Basin,China.The MKFD model was trained and tested with 453 datasets from 7 coring wells,utilizing GR,CAL,DEN,AC,CNL and RT logs as input variables.The particle swarm optimization(PSO)was adopted for hyper-parameter optimization of MKFD model.To evaluate the model performance,prediction results of MKFD were compared with those of basic-kernel based KFD,RF and SVM models.Subsequently,the built MKFD model was applied in a blind well test,and a variable importance analysis was conducted.The comparison and blind test results demonstrated that MKFD outperformed traditional KFD,RF and SVM in the identification of reservoir types,which provided higher accuracy and stronger generalization.The MKFD can therefore be a reliable method for identifying reservoir types of deep carbonates. 展开更多
关键词 Reservoir type identification Geophysical logging data Kernel Fisher discriminantanalysis Mixedkernel function Deep carbonates
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2型糖尿病患者AST/ALT比值与动脉硬化的相关性
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作者 王慧萌 白洁 《现代诊断与治疗》 2025年第10期1429-1433,共5页
目的探讨2型糖尿病患者AST/ALT比值与动脉硬化的相关性。方法回顾性分析2021年10月至2023年10月我院收治的312例2型糖尿病患者的临床资料。根据AST/ALT比值及臂踝脉搏波传导速度(baPWV)分为两组:非动脉硬化组(baPWV<1400 cm/s,n=95)... 目的探讨2型糖尿病患者AST/ALT比值与动脉硬化的相关性。方法回顾性分析2021年10月至2023年10月我院收治的312例2型糖尿病患者的临床资料。根据AST/ALT比值及臂踝脉搏波传导速度(baPWV)分为两组:非动脉硬化组(baPWV<1400 cm/s,n=95)和动脉硬化组(baPWV≥1400 cm/s,n=217)。根据AST/ALT比值三分位分组:低组Q1(≤0.93,n=107)、中组Q2(0.93~1.19,n=102)、高组Q3(≥1.19,n=103)。收集年龄、性别比例、生化指标、AST/ALT比值、baPWV等指标进行统计学分析。结果(1)动脉硬化组AST/ALT比值比非动脉硬化组高,差异有统计学意义(P<0.05)。(2)AST/ALT比值与baPWV、年龄、病程呈正相关(r分别为0.541、0.496、0.312,P<0.01)。(3)Logistic回归分析提示,校正其他混杂因素后AST/ALT比值是T2DM患者发生动脉硬化的独立危险因素(OR值为26.866,95%CI:7.287~99.049,P<0.01)。(4)ROC曲线显示,AST/ALT比值预测T2DM患者动脉硬化的AUC为0.765(95%CI:0.712~0.819,P<0.01),约登指数为0.435,临界值为1.01,灵敏度为0.677,特异度为0.758。结论AST/ALT比值有可能是临床上预测T2DM患者动脉硬化风险的简单、实用的指标。 展开更多
关键词 2型糖尿病 谷草转氨酶/谷丙转氨酶比值 臂踝脉搏波传导速度 动脉硬化
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Dynamic interpretation of stress adjustment types in high geostress hard rock tunnels based on microseismic monitoring
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作者 Weihao Xu Chunchi Ma +4 位作者 Tianbin Li Shoudong Shi Feng Peng Ziquan Chen Hang Zhang 《International Journal of Mining Science and Technology》 2025年第5期801-816,共16页
Dynamic stress adjustment in deep-buried high geostress hard rock tunnels frequently triggers catastrophic failures such as rockbursts and collapses.While a comprehensive understanding of this process is critical for ... Dynamic stress adjustment in deep-buried high geostress hard rock tunnels frequently triggers catastrophic failures such as rockbursts and collapses.While a comprehensive understanding of this process is critical for evaluating surrounding rock stability,its dynamic evolution are often overlooked in engineering practice.This study systematically summarizes a novel classification framework for stress adjustment types—stabilizing(two-zoned),shallow failure(three-zoned),and deep failure(four-zoned)—characterized by distinct stress adjustment stages.A dynamic interpretation technology system is developed based on microseismic monitoring,integrating key microseismic parameters(energy index EI,apparent stressσa,microseismic activity S),seismic source parameter space clustering,and microseismic paths.This approach enables precise identification of evolutionary stages,stress adjustment types,and failure precursors,thereby elucidating the intrinsic linkage between geomechanical processes(stress redistribution)and failure risks.The study establishes criteria and procedures for identifying stress adjustment types and their associated failure risks,which were successfully applied in the Grand Canyon Tunnel of the E-han Highway to detect 50 instances of disaster risks.The findings offer invaluable insights into understanding the evolution process of stress adjustment and pinpointing the disaster risks linked to hard rock in comparable high geostress tunnels. 展开更多
关键词 High geostress tunnels Stress adjustment types Microseismic monitoring Dynamic interpretation Risk identification
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FVID: Fishing Vessel Type Identification Based on VMS Trajectories 被引量:10
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作者 HUANG Haiguang HONG Feng +3 位作者 LIU Jing LIU Chao FENG Yuan GUO Zhongwen 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第2期403-412,共10页
Vessel Monitoring System(VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels.... Vessel Monitoring System(VMS) provides a new opportunity for quantified fishing research. Many approaches have been proposed to recognize fishing activities with VMS trajectories based on the types of fishing vessels. However, one research problem is still calling for solutions, how to identify the fishing vessel type based on only VMS trajectories. This problem is important because it requires the fishing vessel type as a preliminary to recognize fishing activities from VMS trajectories. This paper proposes fishing vessel type identification scheme(FVID) based only on VMS trajectories. FVID exploits feature engineering and machine learning schemes of XGBoost as its two key blocks and classifies fishing vessels into nine types. The dataset contains all the fishing vessel trajectories in the East China Sea in March 2017, including 10031 pre-registered fishing vessels and 1350 unregistered vessels of unknown types. In order to verify type identification accuracy, we first conduct a 4-fold cross-validation on the trajectories of registered fishing vessels. The classification accuracy is 95.42%. We then apply FVID to the unregistered fishing vessels to identify their types. After classifying the unregistered fishing vessel types, their fishing activities are further recognized based upon their types. At last, we calculate and compare the fishing density distribution in the East China Sea before and after applying the unregistered fishing vessels, confirming the importance of type identification of unregistered fishing vessels. 展开更多
关键词 VMS VESSEL type identification FISHING DENSITY TRAJECTORY analysis classification
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The regional types of China's floating population: Identification methods and spatial patterns 被引量:9
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作者 LIU Shenghe HU Zhang +1 位作者 DENG Yu WANG Yingjie 《Journal of Geographical Sciences》 SCIE CSCD 2011年第1期35-48,共14页
With the rapid increase of the number and influence of floating population in China,it is urgently needed to understand the regional types of China's floating population and their spatial characteristics. After revie... With the rapid increase of the number and influence of floating population in China,it is urgently needed to understand the regional types of China's floating population and their spatial characteristics. After reviewing the current methods for identifying regional types of floating population,this paper puts forward a new composite-index identification method and its modification version which is consisted of two indexes of the net migration rate and gross migration rate. Then,the traditional single-index and the new composite-index identification methods are empirically tested to explore their spatial patterns and characteristics by using China's 2000 census data at county level. The results show:(1) The composite-index identification method is much better than traditional single-index method because it can measure the migration direction and scale of floating simultaneously,and in particular it can identify the unique regional types of floating population with large scale of immigration and emigration. (2) The modified composite-index identification method,by using the share of a region's certain type of floating population to the total in China as weights,can effectively correct the over-or under-estimated errors due to the rather large or small total population of a region. (3) The spatial patterns of different regional types of China's floating population are closely related to the regional differentiation of their natural environment,population density and socio-economic development level. The three active regional types of floating population are mainly located in the eastern part of China with lower elevation,more than 800 mm precipitation,rather higher population densities and economic development levels. 展开更多
关键词 China floating population regional types spatial pattern composite-index identification method
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Isolation, Identification and Pathogenicity Analysis of Streptococcus suis Type 2 被引量:4
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作者 Zicheng MA Yan LI +6 位作者 Jinyuan GU Tao PENG Zhaohu LIU Hongyu WANG Fanliang MENG Fangkun WANG Sidang LIU 《Agricultural Biotechnology》 CAS 2019年第4期64-68,共5页
[Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determinati... [Objectives]This study aimed to investigate the pathogenicity,growth characteristics and drug resistance of Streptococcus suis type 2.[Methods]Bacterial isolation and identification,biochemical experiments,determination of growth curve and correlation curve between OD 600 values and viable counts,drug susceptibility tests,pathogenicity analysis,and histopathological observations were carried out.[Results]The Streptococcus strain isolated from infected pigs was identified as Streptococcus suis type 2,which was named TA01 strain.TA01 strain reached the growth peak at 6-8 h post-incubation,and viable counts gradually declined after 8 h of incubation.The correlation equation between OD 600 values and viable counts is y=24.659 x-1.076 1,R^2=0.996 7.TA01 strain was sensitive to penicillin,erythromycin,florfenicol and oxacillin,and resistant to ciprofloxacin,polymyxin B and clindamycin.According to the results of pathogenicity analysis,all the mice in 3.6×10^9 cfu/mouse group died within 48,and these dead mice exhibited acute pyaemia septica.Based on the Reed-Muench formula,it was calculated that LD 50 of TA01 strain was 1.137×10^8 cfu/mouse.Pathological examination showed obvious blue-stained bacteria clusters,accompanied by neutrophil infiltration.[Conclusions]TA01 strain was a virulent strain of Streptococcus suis type 2.Compared with Streptococcus strains which were isolated and reported in China,TA01 strain exhibited strong virulence and rapid proliferation. 展开更多
关键词 STREPTOCOCCUS SUIS type 2 ISOLATION and identification Growth curve Drug sensitivity test PATHOGENICITY LD 50 determination
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Identification, characteristic and phylogenetic analysis of type II DNA topoisomerase gene in Giardia lamblia 被引量:1
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作者 DeHE JianFanWEN +2 位作者 WanQunCHEN SiQiLU4 DeDongXIN 《Cell Research》 SCIE CAS CSCD 2005年第6期474-482,共9页
The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino... The genes encoding type II DNA topoisomerases were investigated in Giardia lamblia genome, and a type IIA gene,GlTop 2 was identified. It is a single copy gene with a 4476 bp long ORF without intron. The deduced amino acid sequence shows strong homology to eukaryotic DNA Top 2. However, some distortions were found, such as six insertions in the ATPase domain and the central domain, a -100 aa longer central domain; a ~200 aa shorter C-terminal domain containing rich charged residues. These features revealed by comparing with Top 2 of the host, human, might be helpful in exploiting drug selectivity for antigiardial therapy. Phylogenetic analysis of eukaryotic enzymes showed that kinetoplastids, plants, fungi, and animals were monophyletic groups, and the animal and fungi lineages shared a more recent common ancestor than either did with the plant lineage; microsporidia grouped with fungi. However, unlike many previous phylogenetic analyses, the ''amitochondriate'' G. lamblia was not the earliest branch but diverged after mitochondriate kinetoplastids in our trees. Both the finding of typical eukaryotic type IIA topoisomerase and the phylogenetic analysis suggest G, lamblia is not possibly as primitive as was regarded before and might diverge after the acquisition of mitochondria. This is consistent with the recent discovery of mitochondrial remnant organelles in G. lamblia. 展开更多
关键词 evolutionary position GlTop2 gene Giardia lamblia identification phylogenetic analysis type II DNAtopoisomerase.
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基于Span-ASTE的可解释性政府多对象态度识别模型研究 被引量:1
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作者 曾江峰 程征 +1 位作者 黄泳潼 段尧清 《情报理论与实践》 CSSCI 北大核心 2024年第5期175-182,共8页
[目的/意义]在政府态度识别研究中,针对没有考虑到新闻文本中可能存在多个评价对象、政府态度识别结果可解释性不强等问题,基于Span-ASTE构建政府态度识别模型,提升态度识别效果。[方法/过程]首先,采用BERT提取词级别特征,基于跨度转化... [目的/意义]在政府态度识别研究中,针对没有考虑到新闻文本中可能存在多个评价对象、政府态度识别结果可解释性不强等问题,基于Span-ASTE构建政府态度识别模型,提升态度识别效果。[方法/过程]首先,采用BERT提取词级别特征,基于跨度转化为跨度特征表示;然后,联合方面术语和观点术语提取任务提取评价对象和态度描述语,利用双通道跨度剪枝策略筛选得到对象和态度描述语候选池;最后,结合候选池中的对象和态度描述语计算得到态度极性结果。[结果/结论]以美国国务院新闻文本为实验数据进行实验验证。实验结果表明:Span-ASTE在进行政府态度识别时具有一定优越性。相比于效果较好的对比模型,其精确率、召回率和F1值分别提升了约15.68%、19.37%和17.48%;在进行多对象态度识别时同样具有良好的性能表现;态度描述语可为态度极性的判断提供解释依据。[局限]政府态度识别效果还有待进一步提升,且数据规模较为有限,未来可尝试对数据集进行扩充。 展开更多
关键词 Span-astE 政府态度 态度识别 多对象 可解释性
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Isolation and Identification of Different Sources of Salmonella and Comparisons on the Drug Resistance Spectrum Types
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作者 CHEN Chao-xi XI Ge-ji TANG Cheng 《Animal Husbandry and Feed Science》 CAS 2013年第2期65-67,72,共4页
[ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar S... [ Objective] In order to make out differences between drug resistance spectrum types of different animal sources of Salmonella. [ Meth- otis] Selenite cystine broth, Salmonella- Shigella genus agar medium, CHROMagar Salmonella chromogenic culture, Reveal Salmonella detection kit and molecular biology methods were used for isolation and identification of Salmonella from different animal feces samples. Antibacterialantimi- crobial susceptibility tests of 17 kinds of drugs such as enrofloxacin, apramycin and florfenicol were done on isolated strains with broth microdilution method, and test data was analysed with WHOnet 5.4 software. [ Results ] 699 feces samples from different animals were separated, and 53 strains of Salmonella were achieved with separation rate of 7.58%, among which those of yak, poultry, and pet sources were respectively 4.33%, 9.06% and 8.37%. [ Condusions] Separation rates and drug resistance spectrum types of different animal origin Salmonella varied greatly, among which separation rates and drug resistance spectrum types of yak source Salmonella were the lowest, there was little difference between separation rates of poultry and dog source Salmonella, however there were large differences on drug resistance spectrum types. 展开更多
关键词 SALMONELLA Isolation and identification Drug resistance spectrum type
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Identification of Lubricating Oil Additives Using XGBoost and Ant Colony Optimization Algorithms 被引量:1
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作者 Xia Yanqiu Cui Jinwei +2 位作者 Xie Peiyuan Zou Shaode Feng Xin 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS CSCD 2024年第2期158-167,共10页
To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant co... To address the problem of identifying multiple types of additives in lubricating oil,a method based on midinfrared spectral band selection using the eXtreme Gradient Boosting(XGBoost)algorithm combined with the ant colony optimization(ACO)algorithm is proposed.The XGBoost algorithm was used to train and test three additives,T534(alkyl diphenylamine),T308(isooctyl acid thiophospholipid octadecylamine),and T306(trimethylphenol phosphate),separately,in order to screen for the optimal combination of spectral bands for each additive.The ACO algorithm was used to optimize the parameters of the XGBoost algorithm to improve the identification accuracy.During this process,the support vector machine(SVM)and hybrid bat algorithms(HBA)were included as a comparison,generating four models:ACO-XGBoost,ACO-SVM,HBA-XGboost,and HBA-SVM.The results showed that all four models could identify the three additives efficiently,with the ACO-XGBoost model achieving 100%recognition of all three additives.In addition,the generalizability of the ACO-XGBoost model was further demonstrated by predicting a lubricating oil containing the three additives prepared in our laboratory and a collected sample of commercial oil currently in use。 展开更多
关键词 lubricant oil additives fourier transform infrared spectroscopy type identification ACO-XGBoost combinatorial algorithm
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Isolation and Identification of Porcine Circovirus Type 2 in Taizhou
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作者 Guangfu GUO Aiping ZHU +3 位作者 Junping CAO Cailian JIN Lihong DAI Hongwei TAO 《Agricultural Biotechnology》 CAS 2018年第4期108-109,249,共3页
In September 2011, an infectious disease suspected to be postweaning multisystemic wasting syndrome (PMWS) broke out in some pig farm in Taizhou. The inguinal lymph node, liver and lung tissues were collected and gr... In September 2011, an infectious disease suspected to be postweaning multisystemic wasting syndrome (PMWS) broke out in some pig farm in Taizhou. The inguinal lymph node, liver and lung tissues were collected and grinded into tissue suspension. The suspension was subjected to PCR detection, and the positive product was sequenced. The suspension of positive samples was filtered with 0.22 μm filter membrane, and the filtrate was inoculated onto PK15 cells. After five generations of blind passages, the cell viral liquid was collected and extracted for DNA, which was subjected to PCR detection and indirect immunofluorescence. The results showed that the isolate was porcine circovirus type 2 (PCV2) and designated as TAIZ110926. The target sequence was committed to NCBI with a serial number: KF039888. 展开更多
关键词 Porcine circovirus type 2 ISOLATION identification Target sequence
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Newly-generated Seismic Rupture Zone:Identification,Type Division and Seismogeological Significance
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作者 Xiang Hongfa, Zhang Wanxia, Guo Shunmin and Xu XiweiInstitute of Geology, China Seismological Bureau, Beijing 100029, China 《Earthquake Research in China》 2000年第1期66-78,共13页
The results of geological research show that those phenomena such as surface geology,geomorphology,deep geophysical field,and time-space distribution of seismicities can be usedas the main seismogeological indicators ... The results of geological research show that those phenomena such as surface geology,geomorphology,deep geophysical field,and time-space distribution of seismicities can be usedas the main seismogeological indicators to identify the newly-generated seismic rupture zone(NSRZ).According to their formation and evolution process,the NSRZs can be divided intothree types:pre-rupture-isolated,quasi-rupture-discontinuous and major-rupture-connected.In a pre-rupture-isolated NSRZ,the seismicity is dominated by medium-small earthquakes.In a quasi-rupture-discontinuous NSRZ,the frequency and intensity of strong earthquakesincrease and there may even be the largest earthquake to occur.A major-rupture-connectedNSRZ is the segment where rupture has entered the mature stage;in such a zone,theintensity and duration of seismic activity depend on the constitutive condition and regionalstress field in the zone. 展开更多
关键词 Newly-generated SEISMIC RUPTURE ZONE (NSRZ) identification type DIVISION Seismogeological SIGNIFICANCE
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Quantitative identification of coal-type gas and oil-type gas in source-mixed gas at the northern margin of Qaidam Basin 被引量:1
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作者 Bao Yuan Wei Chongtao +2 位作者 Peng Dehua Jiang Bo Wang Chaoyong 《International Journal of Mining Science and Technology》 SCIE EI 2013年第3期435-439,共5页
The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing rati... The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing ratio of source-mixed gas. Besides, this research quantitatively investigated the natural gas generated by different types of organic matter. The results show that different ratios of source-mixed gas exist in the 6 oil-gas fields at the northern margin of Qaidam Basin. Among them, Mabei has the highest mixing ratio of coal-type gas, followed by Nanbaxian, Mahai, Lenghu-4, Lenghu-3 and Lenghu-5, with the ratios of coal-type gas 91%, 87%, 83%, 66%, 55% and 36%, respectively. Lenghu-3 and Lenghu-4 oil-gas fields were mainly filled by coal-type gas earlier. For Lenghu-3, the gas was mainly generated from low matured source rocks in lower Jurassic Series of Lengxi sub-sag. For Lenghu-4, the gas was mainly generated from humus-mature source rocks in lower Jurassic Series of the northern slope of Kunteyi sub-sag. Gas in Lenghu-5 was mainly later filled oil-type gas, which was generated from high matured sapropelics in lower Jurassic Series of Kunteyi sub-sag. Earlier filled coal-type gas was the main part of Mahai, Nanbaxian and Mabei oil-gas fields. Gas source of Mahai was mainly generated from high mature humics in lower Jurassic Series of Yibei sub-sag; for Nanbaxian, the gas was mainly generated from high matured humics in middle-lower Jurassic Series of Saishiteng sub-sag; for Mabei, the gas was mainly generated from humus-mature source rocks in middle Jurassic Series of Yuqia sub-sag. 展开更多
关键词 Source-mixed gas Quantitative identification Coal-type gas Oil-type gas Northern margin of Qaidam Basin
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1株羊源D型产气荚膜梭菌的分离鉴定及耐药性分析 被引量:3
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作者 李娜 刘重阳 +4 位作者 张靖靖 玛丽雅其其格 珠娜 陆斌 海鹰 《中国畜牧兽医》 北大核心 2025年第3期1352-1359,共8页
【目的】D型产气荚膜梭菌是一种革兰阳性厌氧菌,可引起山羊、绵羊和牛等动物发生肠毒血症,对反刍动物的健康造成巨大的影响。本研究旨在了解内蒙古乌审旗地区D型产气荚膜梭菌耐药情况,为该地区由D型产气荚膜梭菌引起的疾病的治疗提供科... 【目的】D型产气荚膜梭菌是一种革兰阳性厌氧菌,可引起山羊、绵羊和牛等动物发生肠毒血症,对反刍动物的健康造成巨大的影响。本研究旨在了解内蒙古乌审旗地区D型产气荚膜梭菌耐药情况,为该地区由D型产气荚膜梭菌引起的疾病的治疗提供科学依据。【方法】通过培养特性及革兰染色镜检对分离菌进行初步鉴定,通过16S rRNA基因序列比对和毒素基因PCR扩增对可疑菌株进一步鉴定,并采用K-B纸片法进行药敏试验,PCR检测分离菌耐药基因。【结果】分离菌在TSC培养基中长出黑色的圆形菌落,革兰染色镜检可见菌体粗短,成单个或双个排列的革兰阳性直杆菌,形态学及镜检结果符合产气荚膜梭菌特点。16S rRNA基因序列比对结果显示,分离菌与NCBI数据库中已公布的产气荚膜梭菌16S rRNA基因序列相似性均>99%,鉴定该菌株为产气荚膜梭菌。毒素基因PCR检测扩增出cpa和etx基因,表明该菌株为D型产气荚膜梭菌。药敏试验结果显示,分离菌对头孢曲松、头孢呋新、庆大霉素等16种抗菌药耐药。耐药基因检测结果显示,分离菌检出bla CTX-M、bla SHV、qnrA和aac(6′)-Ⅰb-cr 4种耐药基因,未检出bla TEM和qnrS 2种耐药基因。【结论】本试验成功从绵羊体内分离出1株D型产气荚膜梭菌,该菌株存在多重耐药,该研究结果为D型产气荚膜梭菌感染绵羊的诊断、流行病学调查和治疗提供了参考依据。 展开更多
关键词 绵羊 D型产气荚膜梭菌 分离鉴定 耐药性
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基于低场核磁共振技术和傅里叶变换红外光谱的植物油种类判别可行性分析 被引量:2
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作者 向燕 陆佳怡 +2 位作者 何强 邓莎 董怡 《中国调味品》 北大核心 2025年第7期191-197,共7页
植物油掺伪现象频发,故使用无损、高效的方法鉴别植物油种类是油脂行业技术发展的重要方向。文章以5种植物油(橄榄油、花生油、玉米油、葵花籽油、混合油)为研究对象,分析采用低场核磁共振(LF-NMR)技术和傅里叶变换红外光谱(FTIR)判别... 植物油掺伪现象频发,故使用无损、高效的方法鉴别植物油种类是油脂行业技术发展的重要方向。文章以5种植物油(橄榄油、花生油、玉米油、葵花籽油、混合油)为研究对象,分析采用低场核磁共振(LF-NMR)技术和傅里叶变换红外光谱(FTIR)判别植物油种类的可行性。对脂肪酸成分进行系统聚类分析(HCA),结果表明5种植物油可分为3组,分别为玉米油和葵花籽油、花生油和混合油、橄榄油。LF-NMR结合主成分分析(PCA)可较好地鉴别出亚油酸型植物油(葵花籽油和玉米油)和油酸型植物油(橄榄油和花生油)。FTIR结合PCA能进一步鉴别出亚油酸型植物油的种类。综上,采用LF-NMR与FTIR鉴别植物油的种类具有可行性,且两种方法联用的效果互补。该研究可为快速鉴别食用油掺伪奠定基础。 展开更多
关键词 植物油 无损 种类判别 低场核磁共振 傅里叶变换红外光谱 主成分分析
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旅游型传统村落记忆场所的类型识别与景观修复研究——以湖南省勾蓝瑶寨为例
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作者 窦银娣 刘章云 李伯华 《贵州师范大学学报(自然科学版)》 北大核心 2025年第4期84-96,共13页
伴随着乡村旅游的迅速发展,传统村落的原生态环境和文化生活气息开始退变,集体记忆逐渐缺失,使传统村落记忆场所受到巨大挑战,保护维系“乡愁”情感的记忆场所已成为亟待解决的问题。以勾蓝瑶寨为例,初步探索了基于微博图片、文本数据... 伴随着乡村旅游的迅速发展,传统村落的原生态环境和文化生活气息开始退变,集体记忆逐渐缺失,使传统村落记忆场所受到巨大挑战,保护维系“乡愁”情感的记忆场所已成为亟待解决的问题。以勾蓝瑶寨为例,初步探索了基于微博图片、文本数据进行记忆场所研究的方法和技术,采取景观基因理论从微观视角识别记忆场所。研究发现:1)景观基因理论与记忆场所在内涵结构上有着密切联系,景观基因作为记忆场所形成的物质基础与文化支撑,强化了场所的识别度与感知度。显性基因为记忆场所提供直观的视觉符号,而隐性基因更深刻地影响了人们的集体记忆。2)游客感知强度和记忆场所特征强度,对记忆场所的类型识别发挥着重要作用。从微博数据的游客感知强度和记忆场所类型识别指标体系的记忆场所特征强度,发现游客感知强度与记忆场所特征强度两者认知存在差异,两种数据叠置分析把传统村落记忆场所分为四种类型。3)景观修复尝试从功能分区、瑶族文化、建筑特征、事件记忆方面,深入挖掘记忆场所的丰厚价值,重塑承载集体记忆的物质载体,为构建和美乡村、留住美丽“乡愁”提供重要支撑。因此促进传统村落旅游可持续发展,更要实现记忆场所保护与旅游发展的结合。 展开更多
关键词 传统村落 记忆场所 类型识别 景观修复
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DHAV-3弱毒活疫苗株(HB80株)与野毒株鉴别检测的RT-PCR-RFLP方法的建立
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作者 傅秋玲 万春和 +13 位作者 焦文龙 韩相敏 程龙飞 陈珍 赖志 陈红梅 梁齐章 江南松 刘荣昌 施少华 陈翠腾 苏敬良 黄瑜 傅光华 《中国预防兽医学报》 北大核心 2025年第7期691-696,共6页
为建立一种能快速、简便、准确鉴别检测我国鸭3型甲肝病毒(DHAV-3)野毒株与弱毒活疫苗HB80株的方法,本研究根据DHAV-3野毒株及HB80株的2A基因序列差异片段设计并合成一对特异性引物,经反应条件的优化,初步建立了鉴别检测我国DHAV-3野毒... 为建立一种能快速、简便、准确鉴别检测我国鸭3型甲肝病毒(DHAV-3)野毒株与弱毒活疫苗HB80株的方法,本研究根据DHAV-3野毒株及HB80株的2A基因序列差异片段设计并合成一对特异性引物,经反应条件的优化,初步建立了鉴别检测我国DHAV-3野毒株与HB80株的反转录聚合酶链式反应-限制性片段长度多态性(RTPCR-RFLP)方法。利用该方法检测DHAV-3野毒株和疫苗株,以及DHAV-1、鸭3型星状病毒、H9亚型禽流感病毒、禽坦布苏病毒、鸭瘟病毒、鸭3型腺病毒、鸭呼肠孤病毒和番鸭细小病毒,结果显示该方法仅能特异性扩增DHAV-3(包括野毒株和疫苗株)的682 bp片段,且仅DHAV-3野毒株的RT-PCR产物(682 bp片段)能够被Apa I酶切为444 bp和238 bp两个片段。将DHAV-3的RNA 10倍倍比稀释(1.7×10^(6)拷贝/μL~1.7×10^(1)拷贝/μL)后作为模板,利用该方法检测,结果显示该方法能够检出DHAV-3 RNA的最低浓度为170拷贝/μL。重复性结果显示,该方法对3个不同浓度DHAV-3野毒株和HB80株RNA的检测结果均一致。利用该方法和常规RT-PCR方法同时对疑似临床鸭肝炎组织、实验感染DHAV-3野毒株(HB株)和免疫DHAV-3活疫苗株鸭组织等10^(1)份样品检测,结果显示两者检测结果的符合率为100%。本研究首次建立了能特异性鉴别检测DHAV-3野毒株与我国弱毒活疫苗株的RT-PCR-RFLP方法,为我国鸭DHAV-3感染的防控提供了技术支撑。 展开更多
关键词 鸭3型甲肝病毒 野毒株 弱毒疫苗株 聚合酶链式反应-限制性片段长度多态性方法 鉴别
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数字经济背景下江苏农村电商产业集群高质量发展策略 被引量:1
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作者 梁榕 吴生生 《江苏经贸职业技术学院学报》 2025年第3期14-17,22,共5页
江苏农村电商产业集群在规模、效益和创新能力等方面存在差异。政策环境、市场环境、资源禀赋、技术创新等因素对农村电商产业集群发展的作用机制不同。为了促进江苏农村电商产业集群高质量发展,建议采取以下措施:科学规划集群空间布局... 江苏农村电商产业集群在规模、效益和创新能力等方面存在差异。政策环境、市场环境、资源禀赋、技术创新等因素对农村电商产业集群发展的作用机制不同。为了促进江苏农村电商产业集群高质量发展,建议采取以下措施:科学规划集群空间布局,突出地域特色;强化政策支持与导向作用,激发市场活力;加速技术创新与产业融合,提升核心竞争力;深化人才培养与高端引进,构建人才高地;推动区域协同与一体化发展,实现资源共享。 展开更多
关键词 农村电商产业集群 类型识别 差异 策略
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500 kV输电线路雷击故障仿真分析及类型识别方法
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作者 刘家军 李晨婧 +2 位作者 侯涛 徐浩焜 王波 《高压电器》 北大核心 2025年第7期222-233,共12页
超高压输电线路架线位置高、架设回数多及输送距离远,其运行中容易受到雷电袭扰,从而威胁系统稳定性和可靠性,不同雷击类型会对线路不同部位产生损伤。针对雷击类型的准确识别问题,提出一种超高压线路雷击类型识别方法。以500 kV同塔双... 超高压输电线路架线位置高、架设回数多及输送距离远,其运行中容易受到雷电袭扰,从而威胁系统稳定性和可靠性,不同雷击类型会对线路不同部位产生损伤。针对雷击类型的准确识别问题,提出一种超高压线路雷击类型识别方法。以500 kV同塔双回路鼓型杆塔为例,在ATP-EMTP平台中建立了考虑多因素的仿真模型,分析不同故障工况下雷电绕击、反击的特征,以雷击线路后故障信号通过杆塔入地的暂态信号作为研究对象,提出一种基于改进希尔伯特黄变换的雷击类型识别方法,利用故障信号的固有模态函数(IMF)在方差贡献率的不同分布趋势构造判据。通过不同参数验证分布规律的稳定性,发现分布趋势基本不受雷电流幅值大小及接地电阻的影响,且具有稳定清晰的界限,可准确识别雷电故障类型。对及时发现线路绝缘薄弱点以及制定更有针对性的防雷措施都具有十分重要的意义。 展开更多
关键词 雷击跳闸 故障类型识别 绕击 反击
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基于虚拟现实技术的城市公园运动共享型空间优化研究
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作者 侯韫婧 王雨萌 +1 位作者 吴雨馨 许大为 《中国园林》 北大核心 2025年第5期68-75,共8页
作为健康干预的重要空间载体,高密度地区城市公园面临着增量困难与居民多样化运动需求的显著矛盾。城市公园运动共享型空间通过提高场地使用率、周转率及活动兼容性,能够有效提升公园的运动供给能力。以哈尔滨丁香公园和群力公园为例,利... 作为健康干预的重要空间载体,高密度地区城市公园面临着增量困难与居民多样化运动需求的显著矛盾。城市公园运动共享型空间通过提高场地使用率、周转率及活动兼容性,能够有效提升公园的运动供给能力。以哈尔滨丁香公园和群力公园为例,利用Kano模型提取不同运动类型的关键环境要素,并基于虚拟现实技术和使用人群特点,自由组合关键环境要素,建构3类运动共享型空间——放松+舒缓、社交+爱好、社交+放松;最终通过模拟预测,明确运动共享型空间的必备环境要素,提出模块化共享空间优化的设计策略。结果表明:1)不同运动类型人群对活动空间的必备需求存在差异,如高强度运动人群重视场地设施,而低强度运动人群认为植物特征是提升其运动意愿的关键;2)“高围合+多色植物+趣味设施”的空间能吸引进行放松和舒缓类活动的人群共同开展体力活动,“大尺度+特色水景+休憩设施”的空间能吸引进行社交和爱好类活动的人群共同开展体力活动,“便捷出口+多样植物+健身设施”的空间能吸引进行社交和放松类活动的人群共同开展体力活动。研究结果为存量阶段城市公园的优化更新提供了新路径,有助于提高全民健康水平。 展开更多
关键词 风景园林 城市公园 虚拟现实技术 运动共享型空间 环境要素识别
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