福建光泽毛竹林冻灾恢复措施与建议

为恢复竹林优势,把灾害造成的损失降到最小限度,光泽县在灾情调查基础上,通过留笋养竹、竹林施肥、竹山水利设施建设等措施,探索科学方法,不断总结经验,为灾后竹林生产提供参考。     

利用遥感和地理信息系统技术通过分析土壤性质预测洪水灾害: 以泰国Chiang Mai省Mae Rim分水岭为例

Physiography and soil in Mae Rim watershed,Chiang Mai Province,Thailand were investigated by using aerial photographs and satellite image in conjunction with field work,and soil infiltration rate and soil shear resistance were measured in field. Many factors affecting runoff were analyzed usig the Integrated Land and Water Informaiton System(ILWIS).As a result,a model determining flood hazar was set up.Three mps including runoff curve number map,runoff coefficent map,and flood inumdation map were created,In addition,the time of concentration was predicted.     

HACCP在双孢菇速冻保鲜加工中的应用

双孢菇速冻保鲜产品在加工和冷藏过程中容易出现霉变和褐变等现象,或存在重金属或有害化学物质超标等问题,不仅危害消费者健康,同时阻碍我国双孢菇产业的健康可持续发展。为保证双孢菇速冻保鲜产品的质量安全,将HACCP应用于双孢菇速冻保鲜生产。分析了生产过程中各环节的潜在危害,确定了影响产品质量安全的关键控制点,并针对每个关键控制点,制定了相应的预防措施、关键限值,以及工作计划表和纠偏措施,将生产过程中的潜在危害降到最低,保证了产品质量安全。     

加强农业气象灾情防控 确保粮食和生态环境安全——基于中国农业科学院专家科技帮扶黄淮海涝区“三秋”抢收抢种实践

近些年,随着全球气候变暖,暴雨、飓风、冰雹、干旱等极端气象灾害频发,为农业生产带来了诸多不利因素和困难,甚至严重威胁国家粮食安全。2021年夏秋之际,河南、山西、山东、河北、陕西等5省遭遇持续降雨,给农业生产,特别是秋收、秋种、秋管工作造成了巨大困难。文章基于中国农业科学院专家在5省洪涝灾区开展科技帮扶“三秋”抢收抢种技术指导服务实践,着重分析了部分粮食产区应对极端天气存在的主要问题并提出了相应对策建议。     

高粱育种田除草剂的筛选

旨在更加科学地筛选高粱育种田除草剂种类及使用时间,为高粱育种田的管理提供理论依据.以6种高粱种质和3种除草剂为试验材料,用方差分析法测得适合夏播高粱育种田使用的除草剂及其使用时间.结果 表明:T3对出苗率影响较小,各种质平均出苗率为94.32％.处理间药害分析,T6最重,平均达3.87％,与其他比较,差异均达极显著水平...     

泉州海岸带灾害系统及防灾减灾措施

在系统分析泉州海岸带灾害系统的孕灾环境、孕灾因子、承灾体的基础上,结合泉州海岸带的实际情况,提出了相应的防灾减灾措施,以期对泉州海岸带的防灾减灾工作有一定的借鉴和参考价值。     

生食牡蛎HACCP计划的语义建模及可视化应用

为有效保障危害分析及关键控制点(HACCP)计划国家标准的可执行性,以国标中的生食牡蛎加工HACCP计划的语义表达为研究对象,提出生食牡蛎HACCP计划的知识可视化应用模型(HVEM),对HACPP计划进行结构和数据两方面的语义理解,从动态和静态两个角度进行知识提取,实现活牡蛎接收、干法冷藏、牡蛎肉储存等关键控制点(CCP)、监控以及验证、纠偏的实体、联系知识表达,构建HACCP计划知识体系,结合图数据库实现知识储存、可视化,并给出一个基于HVEM模型的HACCP质量溯源应用测试。结果表明,HACCP计划的知识可视化应用模型能较为系统地实现生食牡蛎HACCP计划的知识理解、知识表达、知识存储和可视化应用。     

亚表层土壤修饰改性对镉离子的吸附影响

采用室内试验方法,研究了不同比例CTMAB单一修饰和CTMAB+SDS混合修饰的亚表层对金属镉离子的吸附影响。结果表明,吸附量顺序为CK>50%CTMAB>100%CTMAB≥120%CS,最佳吸附等温线模型可以用BET模型描述。热力学参数的研究表明,吸附自发性与吸附量具有相同的变化规律,反应的熵变对于反应的自发性具有决定作用。土样修饰改性后镉离子吸附的自发性减小,活性增加,淋溶性及对地下水的危害性增大。     

Bayesian inference in a piecewise Weibull proportional hazards model with unknown change points

The main difference between parametric and non-parametric survival analyses relies on model flexibility. Parametric models have been suggested as preferable because of their lower programming needs although they generally suffer from a reduced flexibility to fit field data. In this sense, parametric survival functions can be redefined as piecewise survival functions whose slopes change at given points. It substantially increases the flexibility of the parametric survival model. Unfortunately, we lack accurate methods to establish a required number of change points and their position within the time space. In this study, a Weibull survival model with a piecewise baseline hazard function was developed, with change points included as unknown parameters in the model. Concretely, a Weibull log-normal animal frailty model was assumed, and it was solved with a Bayesian approach. The required fully conditional posterior distributions were derived. During the sampling process, all the parameters in the model were updated using a Metropolis-Hastings step, with the exception of the genetic variance that was updated with a standard Gibbs sampler. This methodology was tested with simulated data sets, each one analysed through several models with different number of change points. The models were compared with the Deviance Information Criterion, with appealing results. Simulation results showed that the estimated marginal posterior distributions covered well and placed high density to the true parameter values used in the simulation data. Moreover, results showed that the piecewise baseline hazard function could appropriately fit survival data, as well as other smooth distributions, with a reduced number of change points.     

Cytotoxic Drug Residues in Urine of Dogs Receiving Anticancer Chemotherapy

The presence of cytotoxic drug residues in urine of dogs may represent an exposure risk for pet owners and other people as well as a potential environmental contaminant. However, studies on cytotoxic drug residues in excretions of clinical patients are lacking in veterinary oncology. Hypothesis: Variable concentrations of cytotoxic residues are present in urine samples, depending on sampling time and substance. Animals: Client‐owned dogs with lymphoma or mast cell tumors treated with standard chemotherapy protocols. Methods: Urine samples were collected before, directly after, and on days after administration of chemotherapy. Measurement of vincristine, vinblastine, cyclophosphamide, and doxorubicin residues in canine urine was performed by a quantitative liquid chromatography tandem mass spectrometry (LC/MS/MS) method. Results: Median cyclophosphamide residue concentration was 398.2 μg/L directly after treatment (d0) and was below the level of detection on days 1–3 (d1, d2, d3). Median vincristine residue concentration was 53.8 μg/L directly after treatment and was 20.2, 11.4, and 6.6 μg/L on days 1, 2, and 3. Median vinblastine residues were 144.9 (d0), 70.8 (d1), 35.6 (d2), and 18.7 μg/L (d3) with low concentrations detectable for 7 days after treatment. Median urine doxorubicin concentrations were 354.0 (d0), 165.6 (d1), 156.9 (d2), and 158.2 μg/L (d3). Low concentrations of doxorubicin were measurable up to 21 days after administration. Conclusions and Clinical Importance: Variable concentrations of chemotherapeutics were measured in urine samples, depending on sampling time point and drug. Findings may inform current chemoprotection guidelines and help minimize exposure risks.