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Anti-channeling cementing technology for long horizontal sections of shale gas wells
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作者 Zhao Changqing Hu Xiaoqiang +5 位作者 Zhang Yongqiang Liang Hong Fang Hao Zhang Lei Tang Shouyong Zeng Fankun 《Natural Gas Industry B》 2018年第3期212-218,共7页
Large-scale hydraulic fracturing combined with horizontal well drilling is the key technology in shale gas development.But poor cementing quality is a crucial bottleneck restricting well completion and reservoir stimu... Large-scale hydraulic fracturing combined with horizontal well drilling is the key technology in shale gas development.But poor cementing quality is a crucial bottleneck restricting well completion and reservoir stimulation.In this paper,the shale gas development blocks in the Sichuan Basin were taken as the examples to explore the process and support measures that can be used to keep the mechanical integrity of cement sheath under the effect of hydraulic fracturing.It is indicated that the near-bit three-centralizer drifting BHA used for casing stiffness simulation can decrease the casing running difficulty in the long horizontal section of a shale gas well and increase the time efficiency and safety of casing running;that the flushing efficiency of high-efficiency oil flushing spacer fluid system is higher than 90%from room temperature to 120℃,so it can guarantee the displacement efficiency of cement slurry to the oil-based drilling fluid and the effective cementing of borehole wall;that the performance of anti-channeling ductile cement slurry used in the cementing of long horizontal sections in this area after it is set is confirmed,with the elastic modulus of set cement being lower than 7 GPa and triaxial strength being higher than 40 MPa,so as to alleviate or avoid the damage to cement sheath in the process of fracturing;and that cementing quality is improved by applying the support technologies,e.g.drilling fluid adjustment,pre-stress cementing and ground high-pressure pumping.During 2015e2016,these cementing technologies were applied in 85 wells in the Sichuan Basin.The average well depth of these wells is 4832 m,the average length of horizontal sections is 1560 m and the quality rate of well cementing is 89.58%.During the waiting-on-cement(WOC)time after well cementing,there is no sustained casing pressure.And gas channeling in the annulus during well drilling,completion and test is improved remarkably.It is concluded that this suite of technologies can guarantee and improve the cementing quality of long horizontal sections in shale gas wells and provides good cementing conditions for shale gas development. 展开更多
关键词 Shale gas Horizontal well CEMENTING Casing running anti-channeling ductile slurry Spacer fluid Set cement Strength Elastic modulus Sichuan basin
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Research and Inspiration of Drug Traceability System in the USA
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作者 Zhang Qi Tian Lijuan 《Asian Journal of Social Pharmacy》 2025年第3期236-244,共9页
Objective To draw on the experience of the construction and development of drug traceability system in the USA and to provide reference for improving China’s drug traceability system.Methods Literature research and c... Objective To draw on the experience of the construction and development of drug traceability system in the USA and to provide reference for improving China’s drug traceability system.Methods Literature research and comparative study were used to sort out the background and development of drug traceability system in the USA,including drug traceability code,drug traceability model,drug traceability platform and the application of blockchain technology.On this basis,some suggestions on the construction of drug traceability system in China were put forward.Results and Conclusion The United States has a perfect system of laws and regulations on drug traceability,which encourages the construction of third-party traceability platforms to avoid the formation of monopolies.Besides,the application of blockchain technology in the construction of drug traceability system is also relatively mature.It is suggested that China strengthen the construction of drug traceability system,give play to the advantages of third-party traceability platforms,and improve the application of blockchain technology in drug traceability. 展开更多
关键词 drug traceability drug traceability code blockchain
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Metrological traceable calibration of organic carbon and elemental carbon based on laboratory-generated reference materials
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作者 Yue Liu Junjie Liu +3 位作者 Ji Xiao Jing Ye Lixu Guo Caiqing Yan 《Journal of Environmental Sciences》 2025年第3期524-534,共11页
Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce th... Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source apportionment.The accurate separation of OC and EC is controversial due to the charring of OC.Therefore,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further study.Previous RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC concentration.To develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz filters.To generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC surrogate.The RMs were analyzed using different protocols.The homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol measurement.Moreover,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers. 展开更多
关键词 Carbonaceous aerosol Split point Reference material Laboratory-generated traceability
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Genomic approaches for almond traceability from nursery and along the food chain
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作者 Alessandra Gentile Ilaria Inzirillo +5 位作者 Stefania Bennici Francesco Scollo Giuseppina Las Casas Mario Di Guardo Stefano La Malfa Gaetano Distefano 《Horticultural Plant Journal》 2025年第3期1103-1115,共13页
Almond is widely cultivated in the world thanks to the quality and healthy features of the kernel.Almond kernel is consumed fresh or employed in the food industry.Hundreds of almond cultivars were selected throughout ... Almond is widely cultivated in the world thanks to the quality and healthy features of the kernel.Almond kernel is consumed fresh or employed in the food industry.Hundreds of almond cultivars were selected throughout the long history of cultivation;in this context,an efficient method for varietal identification is essential to ensure cultivar traceability along the chain.This study surveyed the widely employed commercial kits and protocols for DNA extraction from several almond matrices including leaves,kernels(fresh and roasted)and several processed products.Commercial kits(though with minor modification)outperformed the other extraction methods for the isolation of DNA suitable for molecular analysis from all the tested matrices.In parallel,a germplasm collection composed of 140 accessions(123 Sicilian genotypes complemented with widely known national and international cultivars)was genotyped with the Axiom^(TM)60K almond SNP Array enabling the detection of 6374 unique SNPs that can be readily used for varietal traceability.A subset of unique SNPs was further validated employing a high-resolution melting(HRM)assay on a discovery panel encompassing ten of the most widely cultivated accessions.The DNA extracted from leaves and kernels of five cultivars was genotyped with eight SSRs allowing the identification of the maternal origin of each kernel.The paper integrates the survey of the widely employed protocols for DNA extraction with the high-throughput genotyping of 140 almond accessions.In this context,unique SNPs validated and optimized for an HRM assay and the availability of SSR markers demonstrated their efficacy in traceability analysis along the chain. 展开更多
关键词 Prunus dulcis Unique SNP Maternal traceability Mislabeling High-resolution melting
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TRE-DSP:A traceable and revocable CP-ABE based data sharing scheme for IoV with partially hidden policy
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作者 Yousheng Zhou Rundong Peng +2 位作者 Yuanni Liu Pandi Vijayakumar Brij Gupta 《Digital Communications and Networks》 2025年第2期455-464,共10页
With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the... With the popularity of the Internet of Vehicles(IoV),a large amount of data is being generated every day.How to securely share data between the IoV operator and various value-added service providers becomes one of the critical issues.Due to its flexible and efficient fine-grained access control feature,Ciphertext-Policy Attribute-Based Encryption(CP-ABE)is suitable for data sharing in IoV.However,there are many flaws in most existing CP-ABE schemes,such as attribute privacy leakage and key misuse.This paper proposes a Traceable and Revocable CP-ABE-based Data Sharing with Partially hidden policy for IoV(TRE-DSP).A partially hidden access structure is adopted to hide sensitive user attribute values,and attribute categories are sent along with the ciphertext to effectively avoid privacy exposure.In addition,key tracking and malicious user revocation are introduced with broadcast encryption to prevent key misuse.Since the main computation task is outsourced to the cloud,the burden of the user side is relatively low.Analysis of security and performance demonstrates that TRE-DSP is more secure and practical for data sharing in IoV. 展开更多
关键词 PRIVACY-PRESERVING Attribute-based encryption Partially hidden policy traceability User revocation Internet of vehicles
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The Role of Endoscope Diagnosis and Treatment Center Traceability System in Quality Control of Endoscope Cleaning
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作者 Na Zhao Fengjuan Wang 《Journal of Clinical and Nursing Research》 2025年第9期271-275,共5页
As the cornerstone of sterile instrument maintenance in endoscopy centers,the quality of endoscope cleaning directly impacts hospital infection control effectiveness.The traceability system for endoscopy centers utili... As the cornerstone of sterile instrument maintenance in endoscopy centers,the quality of endoscope cleaning directly impacts hospital infection control effectiveness.The traceability system for endoscopy centers utilizes digital means to document the entire cleaning process,enabling real-time monitoring and precise quality control.This paper analyzes current quality control practices in endoscope cleaning and addresses existing challenges.It explores how traceability systems standardize procedures,enhance monitoring,and improve management efficiency.The study proposes optimization strategies for traceability system implementation,clarifying its core value in endoscope cleaning quality control.These findings provide theoretical foundations and practical guidance for hospitals to refine management of endoscopy centers,ensure diagnostic safety,and reduce infection risks,ultimately advancing endoscope cleaning quality control toward standardized and informatized development. 展开更多
关键词 Endoscopic diagnosis and treatment center traceability system Endoscope cleaning Quality control Hospital infection prevention and control
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诺丁斯关怀理论下溯源预控护理对脑卒中患者高危风险事件的影响
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作者 雷丽君 王宏茹 +1 位作者 徐美琪 蒋孟珠 《临床心身疾病杂志》 2026年第1期145-149,共5页
目的探讨诺丁斯关怀理论下溯源预控护理对脑卒中患者高危风险事件的影响。方法选取194例脑卒中患者为研究对象,按照随机数字表法分组为对照组和研究组,每组97例。对照组患者进行常规护理,研究组患者在对照组基础上进行诺丁斯关怀理论下... 目的探讨诺丁斯关怀理论下溯源预控护理对脑卒中患者高危风险事件的影响。方法选取194例脑卒中患者为研究对象,按照随机数字表法分组为对照组和研究组,每组97例。对照组患者进行常规护理,研究组患者在对照组基础上进行诺丁斯关怀理论下的溯源预控护理。护理前后,评估两组患者的心理状态[焦虑自评量表(SAS)、抑郁自评量表(SDS)评分]、家庭功能[家庭关怀度指数问卷(Family APGAR)评分]、自我管理行为[脑卒中自我管理行为评定量表(SSMS)评分]。比较护理期间两组患者的高危风险事件发生情况。结果护理后,两组患者SAS、SDS评分较护理前降低,且研究组低于对照组(P<0.01);两组患者Family APGAR总分及各维度评分、SSMS总分及各维度评分较护理前升高,且研究组高于对照组(P<0.05或0.01);研究组患者高危风险事件发生率为6.19%,低于对照组的16.49%(P<0.05)。结论诺丁斯关怀理论下的溯源预控护理能够有效改善脑卒中患者的心理状态和家庭功能,提升其自我管理行为,降低高危风险事件发生率,值得临床推广应用。 展开更多
关键词 诺丁斯关怀理论 溯源预控护理 脑卒中 应用效果
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Design and Implementation of Traceability Management System of Agricultural Products Quality and Safety Based on Domestic Basic Software of China 被引量:1
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作者 徐杰 张俊 +2 位作者 王秀徽 周正 杨宝祝 《Agricultural Science & Technology》 CAS 2012年第8期1811-1816,共6页
[Objective] To establish the traceability mechanism of agricultural products safety, and the application of promote domestic based software in the supervision area of agricultural products quality and safety. [Method]... [Objective] To establish the traceability mechanism of agricultural products safety, and the application of promote domestic based software in the supervision area of agricultural products quality and safety. [Method] Through the analysis on the circulation characteristics of agricultural products, like fruits, vegetables, livestock and poultry, the agricultural products quality safety management and traceability query business component libraries were designed. Based on the run-time-supporting environment provided by domestic based software, traceability management system of agricultural products quality and safety was constructed. [Result] The traceability management system provided the information interaction and comprehensive management platform of agricultural product quality and safety based on domestic based software for the government, enterprises and consumers. [Conclusion] Through the application demonstration, the quality control and information traceability of full circulation of agricultural products was achieved effective and reliably, and the management level of agricultural products quality and safety was improved. 展开更多
关键词 Domestic based software Quality and safety of agricultural products traceability management SOA framework Component library
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生鲜牛肉生产过程中沙门氏菌的流行情况、分布及多样性
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作者 张皓琪 崔中磊 +5 位作者 毛衍伟 董鹏程 周广晖 韩广星 肖阳 张一敏 《肉类研究》 北大核心 2026年第1期58-66,共9页
沙门氏菌(Salmonella)是世界范围内引发人类疾病的食源性致病菌,而食用其污染的肉制品是引发沙门氏菌病的重要原因。调查2家肉牛屠宰企业9个采样点沙门氏菌的流行率、污染分布、毒力基因、抗生素耐药性和溯源分析。共收集435份样品,沙... 沙门氏菌(Salmonella)是世界范围内引发人类疾病的食源性致病菌,而食用其污染的肉制品是引发沙门氏菌病的重要原因。调查2家肉牛屠宰企业9个采样点沙门氏菌的流行率、污染分布、毒力基因、抗生素耐药性和溯源分析。共收集435份样品,沙门氏菌流行率为4.1%(18/435)。皮毛中的流行率最高(9.1%;5/55),其次为粪便(7.3%;4/55)。从18份沙门氏菌阳性样品中共收集到47个沙门氏菌分离株,共检测到2种血清型,分别为鼠伤寒沙门氏菌(53.2%;25/47)和乙型副伤寒沙门氏菌(46.8%;22/47)。菌株对大部分抗生素具有耐药性,多重耐药率为80.85%(38/47)。多位点序列分型显示,47株沙门氏菌共产生2种序列型,生产链之间具有很高的交叉污染可能性。本研究揭示了肉牛屠宰加工全链条中沙门氏菌的关键污染环节及传播路径,为制定精准防控措施提供了科学依据。 展开更多
关键词 牛肉屠宰加工 沙门氏菌 流行率 抗生素耐药性 生物学特性 溯源分析
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Study on Pork Quality and Safety Traceability System and Relevant Management Systems
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作者 林凌 刘华楠 《Animal Husbandry and Feed Science》 CAS 2009年第1期40-46,共7页
It is the key to construct the traceability mechanism of quality responsibility for ensuring the quality and safety of animal products. In this study, after defining the concept of traceability system and analyzing it... It is the key to construct the traceability mechanism of quality responsibility for ensuring the quality and safety of animal products. In this study, after defining the concept of traceability system and analyzing its function mechanism, the design ideas of pork quality and safety traceability system based on bar code and Internet were put forward, including network structure, system process, business process and information identifica- tion. Then the relevant management systems were proposed. 展开更多
关键词 PORK QUALITY Safety traceability INTERNET Management system
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Antenna Design of Traceability System in Pig Breeding Stage
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作者 赵金燕 曹志勇 +2 位作者 陶琳丽 吴兴纯 张曦 《Agricultural Science & Technology》 CAS 2011年第3期409-412,共4页
[Objective] In response to pig breeding stage characteristics,the research aimed to design the traceability system to realize the pig product marking which based on RFID technology. [Method] The antenna's design meth... [Objective] In response to pig breeding stage characteristics,the research aimed to design the traceability system to realize the pig product marking which based on RFID technology. [Method] The antenna's design method of electronic tag and reader antenna were expounded and different antennas were used for testing communication test of RFID system. [Result] When the parameter setup such as data transportation ratio was same,the communication distance of external antenna was farther than RCB antenna; compare with three external antennas,the communication distance of coaxial antenna and wall-hanged antenna were farther. In 500 kbps transfer rate,communication distance was within 28 meters,and in 250 kbps transfer rate,communication distance was within 40 meters. Considered the cost of hardware,the price of wall-hanged antenna was higher than coaxial antenna,so in the same communication distance request,system selected coaxial antenna. [Conclusion] During the pig breeding stage,by dint of electronic tag and reader designed by the research could improve the safety of the pork and fully realize the track of source of food and provide technology support for the transparent management of food safety. 展开更多
关键词 PIG traceability System ANTENNA Communication distance
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基于嵌入式药品追溯码识别的扫码设备的开发与应用
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作者 姜伟 梁皓楠 +3 位作者 常德玉 李文学 符梦茹 李祥鹏 《医药导报》 北大核心 2026年第1期138-141,共4页
目的设计一种经济实惠、轻巧多用的扫码设备,以适配在多场景下快速识别药品追溯码,提高医疗机构的扫码率,从而加快建设药品信息化追溯体系。方法通过ESP32单片机与电脑服务端的网络通信,将ESP32获取的图像发送给电脑服务端,使用opencv... 目的设计一种经济实惠、轻巧多用的扫码设备,以适配在多场景下快速识别药品追溯码,提高医疗机构的扫码率,从而加快建设药品信息化追溯体系。方法通过ESP32单片机与电脑服务端的网络通信,将ESP32获取的图像发送给电脑服务端,使用opencv图像处理库预处理图像,将图像转换为灰度图,再由pyzbar条码识别库对图像进行识别,从而获取药品追溯码信息。结果通过该扫码设备,用户可以成功获取药品追溯码。实际测试表明,该扫码设备的条码识别率较高,识别速度绝大多数响应在10 ms以下。结论采用ESP32单片机与电脑服务端协同工作的方法,成功实现了药品追溯码的扫码识别,可为药品信息化追溯体系的建设提供参考。 展开更多
关键词 药品追溯码 扫码设备 嵌入式
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皂河表层水体中抗生素分布特征、来源及生态风险评估
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作者 王子龙 边重千 +3 位作者 王济佳 荀昭博 富弋洋 吴朗 《环境科学》 北大核心 2026年第1期269-277,共9页
为确定典型城市河流西安皂河水体中抗生素的污染现状,采用高效液相色谱-串联质谱技术(HPLC-MS/MS)对表层水样品中的15种抗生素浓度进行检测分析,通过主成分分析-多元线性回归方法(PCA-MLR)对抗生素来源进行源解析,并采用风险商法(RQ)对... 为确定典型城市河流西安皂河水体中抗生素的污染现状,采用高效液相色谱-串联质谱技术(HPLC-MS/MS)对表层水样品中的15种抗生素浓度进行检测分析,通过主成分分析-多元线性回归方法(PCA-MLR)对抗生素来源进行源解析,并采用风险商法(RQ)对其生态风险进行评估.结果表明,6个采样点共检测出四大类8种抗生素,检出浓度为1.08~71.27 ng·L^(-1),检出率为16.67%~100%.环丙沙星(CIP)、罗红霉素(ROX)和氧氟沙星(OFX)检出率均为100%,CIP检出浓度最高,ROX次之.丰水期皂河水体中抗生素以大环内酯类为主,枯水期则以喹诺酮类为主,且枯水期抗生素浓度普遍高于丰水期. PCA-MLR分析表明,皂河水体中抗生素主要来源于医院、污水处理厂、饲料厂、畜禽和水产养殖厂的废水或废弃物排放.冗余分析显示,ROX与pH值呈显著负相关关系,诺氟沙星(NOR)和环丙沙星与电导率(EC)和总氮(TN)呈显著正相关关系,与水温呈显著负相关关系.生态风险评估结果表明,罗红霉素和环丙沙星对藻类具有高生态风险,诺氟沙星、氧氟沙星和金霉素(CTC)对藻类具有中生态风险,四环素(TC)和土霉素(OTC)对藻类具有低生态风险;CIP、NOR、TC、OTC和磺胺甲噁唑(SMX)对水溞具有低生态风险;所有抗生素对鱼类均无明显生态风险.在健康风险方面,皂河水体中抗生素对人类暂无健康风险;在抗性风险方面,ROX、CIP和NOR具有低抗性风险.研究结果可为西安皂河抗生素污染防控提供科学依据. 展开更多
关键词 抗生素 皂河 生态风险评估 污染特征 污染溯源
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基于激光干涉仪的摄影测量标尺校准方法研究
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作者 孙彦锋 张坤 +3 位作者 余庆滨 牛鹏磊 何海坚 赫明钊 《计量与测试技术》 2026年第1期48-51,共4页
为解决大型构件测量中摄影测量标尺的长度溯源难题,突破传统校准方法的精度瓶颈与系统偏差,本文提出一种以激光干涉仪位移为长度标准,采用多参考点位移的平均值为传递载体的高精度标尺校准方法。试验表明,该方法扩展不确定度U=14μm(k=... 为解决大型构件测量中摄影测量标尺的长度溯源难题,突破传统校准方法的精度瓶颈与系统偏差,本文提出一种以激光干涉仪位移为长度标准,采用多参考点位移的平均值为传递载体的高精度标尺校准方法。试验表明,该方法扩展不确定度U=14μm(k=2),与灰度重心法的归一化偏差E_(n)值均小于0.8,具有一致性,且精度和效率较高、工程适用性较强,可为摄影测量标尺提供一种高效实用的校准方案。 展开更多
关键词 摄影测量 标尺校准 激光干涉仪 长度溯源 多点平均法
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基于Handle标识的机采棉质量追溯系统研究
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作者 郎双曼 孙文磊 +3 位作者 王丽雯 吴雪 杨敏 宋世杰 《农机化研究》 北大核心 2026年第4期86-94,共9页
针对机采棉供应链数据不透明、难以追溯的问题,提出了一种基于Handle标识技术的机采棉质量追溯系统的设计方案,以解决供应链各环节信息流转不透明的问题,提升机采棉质量信息的可追溯性。首先,对机采棉的样本数据进行了分析,并通过多重... 针对机采棉供应链数据不透明、难以追溯的问题,提出了一种基于Handle标识技术的机采棉质量追溯系统的设计方案,以解决供应链各环节信息流转不透明的问题,提升机采棉质量信息的可追溯性。首先,对机采棉的样本数据进行了分析,并通过多重插补法和过采样法解决了样本数据的缺失和不平衡问题;其次,采用模糊层次分析法(Fuzzy Analytic Hierarchy Process,FAHP)计算各供应链环节的权重值,以评估其对机采棉质量的影响程度,并基于危害分析和关键控制点(Hazard Analysis Critical Control Point,HACCP)体系筛选出对质量影响最大环节的追溯信息;再次,以二维码作为标识载体,结合Handle标识编码技术,设计了机采棉质量追溯的标识编码方案;随后,设计并搭建了机采棉质量追溯系统,实现了对机采棉产品从采收到销售全过程的质量信息追溯;最后,借助性能测试工具对该追溯系统进行了测试。结果显示:系统每秒点击量保持在40000~60000之间,查询事务的响应时间维持在3~4 s之间,系统能够满足对机采棉质量信息追溯的需求,可为机采棉质量信息的追溯提供参考。 展开更多
关键词 机采棉 质量追溯 Handle编码 标识解析 模糊层次分析法 供应链
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基于多元稳定同位素的喀斯特高原水库不同年份硫酸盐来源定性与定量解析
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作者 孔杰 周忠发 +7 位作者 王艳碧 李锐 李梨 张心乐 丁彩霞 解茹凯 孙耀鹏 曹卫堂 《湖泊科学》 北大核心 2026年第1期237-249,共13页
水体接纳较多硫酸盐(SO_(4)^(2-))会导致水环境质量恶化。采集2019-2023年西南喀斯特地区平寨水库流域水体样品、降水样品和污水样品等,分析监测期间水体理化指标和硫酸盐硫氧同位素(δ^(34)S SO_(4)和δ^(18)O SO_(4))、水氢氧同位素(... 水体接纳较多硫酸盐(SO_(4)^(2-))会导致水环境质量恶化。采集2019-2023年西南喀斯特地区平寨水库流域水体样品、降水样品和污水样品等,分析监测期间水体理化指标和硫酸盐硫氧同位素(δ^(34)S SO_(4)和δ^(18)O SO_(4))、水氢氧同位素(δD H_(2)O和δ^(18)O H_(2)O)、溶解无机碳同位素(δ^(13)C DIC)特征,对水体SO_(4)^(2-)来源进行定性和定量研究。流域水化学类型以Ca-HCO_(3)型和Ca-HCO_(3)-SO_(4)型为主,水化学特征受碳酸盐岩溶蚀的影响。同位素特征揭示了平寨水库流域SO_(4)^(2-)的生物地球化学过程以氧化作用为主(硫化物氧化时,平均61%的氧来自周围水体),监测期间流域SO_(4)^(2-)来源以硫化物氧化、土壤有机硫和农业硫肥为主。定量计算结果表明,硫化物氧化平均贡献率最高(72.9%),其次为土壤有机硫(14.1%)和农业硫肥(12.9%)。不确定性分析结果表明农业硫肥的贡献率最稳定,硫化物氧化的贡献率表现出较大的不确定性。研究结果可为平寨水库及类似喀斯特地区水环境质量保护提供数据参考和科学依据。 展开更多
关键词 硫氧同位素 贝叶斯稳定同位素混合模型 地球化学过程 硫酸盐溯源 喀斯特高原水库
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考虑信息方向的时变网络结构中溯源方法研究
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作者 林志琪 胡兆龙 +1 位作者 朱响斌 李明禄 《浙江师范大学学报(自然科学版)》 2026年第1期45-54,共10页
尽管信息传播溯源受到广泛关注,但研究主要集中于静态网络结构.针对时变网络结构的溯源研究虽也有一定进展,但尚未考虑信息传播的方向性.针对时变网络结构,基于观察节点的感染方向进行网络重构,并采用标签反向传播算法推测传播源.首先,... 尽管信息传播溯源受到广泛关注,但研究主要集中于静态网络结构.针对时变网络结构的溯源研究虽也有一定进展,但尚未考虑信息传播的方向性.针对时变网络结构,基于观察节点的感染方向进行网络重构,并采用标签反向传播算法推测传播源.首先,根据最后一个时刻的快照,为不同状态的节点赋予相应的标签值.其次,获得时变网络聚合图TAG(time aggregated graph)后,依据观察节点信息对TAG进行重构,得到重构聚合图RAG(reverse aggregation graph).最后,在RAG中采用标签反向传播算法进行溯源.大量合成时变网络和真实社会网络的仿真结果表明:RAG中溯源准确度普遍提高;此外,还发现节点间频繁交互会导致溯源结果下降;观察节点的位置和选择策略对溯源结果的影响较小,这与静态网络结构的研究结论截然不同.考虑信息方向的时变网络结构中的溯源方法有助于在时变网络中精确定位信息传播的源头. 展开更多
关键词 复杂网络 时变网络 信息传播 溯源 标签传播
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三种典型白酒环境微生物群落结构解析、酿造微生物溯源及功能特性
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作者 唐家环 岳松 +1 位作者 张庆 潘强林 《中国酿造》 北大核心 2026年第1期13-20,共8页
浓香型、酱香型、大曲清香型作为3种典型白酒,均以粮谷为原料,大曲为糖化发酵剂在开放的环境中进行生产而成的蒸馏酒。开放式的生产模式使得3种典型白酒受环境微生物的影响不容忽视,随着扩增子测序、宏基因组学等技术的发展,环境微生物... 浓香型、酱香型、大曲清香型作为3种典型白酒,均以粮谷为原料,大曲为糖化发酵剂在开放的环境中进行生产而成的蒸馏酒。开放式的生产模式使得3种典型白酒受环境微生物的影响不容忽视,随着扩增子测序、宏基因组学等技术的发展,环境微生物对白酒酿造微生态的影响逐渐被深入探究。该文综述了3种典型白酒环境微生物群落分析方法、群落结构解析及其影响因素,对白酒酿造微生物进行溯源分析,并概述了酿造微生物的功能特性,旨在为解析发酵环境微生物种群结构,探讨环境微生物对白酒发酵过程的影响及塑造有利于白酒发酵的环境微生态提供参考。 展开更多
关键词 白酒 发酵 微生态 环境微生物 酿造微生物 溯源分析 功能特性
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基于组合LCA的高速公路全生命周期碳排放分析
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作者 龙祖惠 吴佳润 +1 位作者 何彬 高文慧 《科学技术创新》 2026年第2期185-188,共4页
为实现对高速公路工程全生命周期碳排放的计算与分析,提出组合LCA模型与碳排放特性分析理论。将高速公路三个阶段碳排放项目分为可溯源和不可溯源两个部分,通过PA-LCA对可溯源的材料生产、机械施工、交通运输的碳排放量进行精确计算,通... 为实现对高速公路工程全生命周期碳排放的计算与分析,提出组合LCA模型与碳排放特性分析理论。将高速公路三个阶段碳排放项目分为可溯源和不可溯源两个部分,通过PA-LCA对可溯源的材料生产、机械施工、交通运输的碳排放量进行精确计算,通过EIO-LCA估算不可溯源部分对应的剩余投资的碳排放。组合LCA模型在简化计算工作的同时使计算结果尽可能地接近真实值,更加适应目前高速公路的碳排放量的评估。 展开更多
关键词 高速公路 碳排放 组合LCA 溯源
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Studies on GIS Based Tracing and Traceability of Safe Crop Product in China 被引量:29
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作者 QU Xiao-hui ZHUANG Da-fang QIU Dong-sheng 《Agricultural Sciences in China》 CAS CSCD 2007年第6期724-731,共8页
The safety of safe crop products (SCP) is critical to maintain people's health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish cor... The safety of safe crop products (SCP) is critical to maintain people's health and living standard. With the global efforts on the improvement of the traceability of food products, it is inevitable to establish corresponding traceability systems to monitor the safety of crop products in China. In this article, the supply chain pattern of SCP in China has been analyzed and its spatial characters have been described in detail. The study deals with on how to relate traceability technology with GIS, and on how to trace and retrace the safety of SCP using the function of excellent spatial representation, spatial locating, and spatial analysis provided in GIS, which has been discussed from several aspects, such as coding technique of traceability information, transferring technique of traceability information, spatialization of traceability information, and application integration of traceability system. A pilot study was carried out to present the basic functions of the system, which provided an efficient and credible way to trace and retrace the safety of SCP in a real supply chain. An innovative idea has been brought forward for how to establish an efficient, credible, applied traceability system of SCP. 展开更多
关键词 safe crop products (SCP) tracing and traceability GIS traceability code information transformation
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