Review and Analysis of Key Techniques in Marine Sediment Sampling

Deep-sea sediment is extremely important in marine scientific research,such as that concerning marine geology and microbial communities.The research findings are closely related to the in-situ information of the sediment.One prerequisite for investigations of deep-sea sediment is providing sampling techniques capable of preventing distortion during recovery.As the fruit of such sampling techniques,samplers designed for obtaining sediment have become indispensable equipment,owing to their low cost,light weight,compactness,easy operation,and high adaptability to sea conditions.This paper introduces the research and application of typical deep-sea sediment samplers.Then,a representative sampler recently developed in China is analyzed.On this basis,a review and analysis is conducted regarding the key techniques of various deep-sea sediment samplers,including sealing,pressure and temperature retaining,low-disturbance sampling,and no-pressure drop transfer.Then,the shortcomings in the key techniques for deep-sea sediment sampling are identified.Finally,prospects for the future development of key techniques for deep-sea sediment sampling are proposed,from the perspectives of structural diversification,functional integration,intelligent operation,and high-fidelity samples.This paper summarizes the existing samplers in the context of the key techniques mentioned above,and can provide reference for the optimized design of samplers and development of key sampling techniques.

A Novel Sample Introduction Technique for the Simultaneous Determination of As,Se,Ge and Hg in Chinese Medicinal Material

A novel technique of Moveable Reduction Bed Hydride Generator（MRBHG）was applied tohe hydride generation or cold vapor generation of As，Se，Ge，and Hg existing In TraditionalChinese Medicinal Material（TCM）．The simultaneous determination of the multi－elements wasperformed with ICP－MS．A solid reduction system involving the use of potassiumtetraborohydride and tartaric acid was applied to generating metal hydride or cold vaporefficiently．The factors affecting the metal cold vapor generation were studied．The mainadvantage of the technique is that only a 4μL volume of sample was required for the cold vapor

H_∞ Design for Sampled-Data Systems via Lifting Technique: Conditions and Limitation

The initial motivation of the lifting technique is to solve the H∞control problems. However, the conventional weighted H∞design does not meet the conditions required by lifting, so the result often leads to a misjudgement of the design. Two conditions required by using the lifting technique are presented based on the basic formulae of the lifting. It is pointed out that only the H∞disturbance attenuation problem with no weighting functions can meet these conditions, hence, the application of the lifting technique is quite limited.

Rapid Sample Product Trial Manufacture Technique for Developing Water Meter New Products

This paper advances the viewpoints and methods of the rapid sample product trial manufacture technique for developing water meter new products by CAD and simulation, computer virtual assembling and optimizing, rapid machining process and measurement etc. as the design and sample product trial manufacture process of water meter new products are long in product development period, and low in product development efficiency in the present time.

Accumulator-Based Deep-Sea Microbe Gastight Sampling Technique

The accumulator is used as a pressure compensation device to realize deep-sea microbe gastight sampling. Four key states of the accumulator are proposed to describe the pressure compensation process and a corresponding mathematical model is established to investigate the relationship between the results of pressure compensation and the parameters of the accumulator. Simulation results show that during the falling process of the sampler, the accumulator＇ s real opening pressure is greater than its precharge pressure; when the sampling depth is 6000 m and the accumulator＇ s precharge pressure is less than 30 MPa, to increase the accumulator＇ s precharge pressure can improve pressure compensation results obviously. Laboratory experiments at 60 MPa show that the acctunulator is an effective and reliable pressure compensation device for deep-sea microbe samplers, The success in sea trial at a depth of 2000 m in the South China Sea shows that the mathematical model and laboratory experiment results are reliable.

Research Progress on Analysis and Detection Techniques of Veterinary Drug Residues in Animal Foods

As an important guarantee for the prevention and control of animal diseases,veterinary drugs have important functions in improving animal production performance and product quality and maintaining ecological balance.They are an important guarantee for the healthy development of animal husbandry,food safety and public health.However,the irrational use and abuse of veterinary drugs and feed pharmaceutical additives are widespread,causing harmful substances in animal foods and damage to human health,and threatening the sustainable development of the environment and animal husbandry as well.In order to ensure human health,it is urgent to develop a simple,rapid,high-sensitivity,high-throughput and low-cost veterinary drug residue detection technology.In this paper,the sample pretreatment methods and detection techniques for the analysis of veterinary drug residues in animal foods were reviewed.

Study on Sampling Technique of Atmospheric Radionuclide

Atmospheric radionuclide monitoring usually includes two sampling techniques, namely ultra-high volume aerosol samplers to collect at- mospheric particles by using filter media, and radioactive noble gas samplers to collect atmospheric noble gas based on adsorption method. Atmos- pheric sampling techniques have been researched in Northwest Institute of Nuclear Technology since the Comprehensive Nuclear-Test-Ban Treaty （CTBT） was signed in 1996. Several ultra-high volume aerosol samplers and some types of radioactive xenon isotopes samplers had been devel- oped. For the aerosol sampler, the sampling flow is between 450 and 800 m3/h, with the minimum detectable concentration （MDC） of 131I less than 5 pBq/m3. For the xenon sampler, the sampling capacity of xenon is more than 4 ml per day, with MDC of l=Xe less than 0.25 mBq/m3. After the nuclear accident of Fukushima in 2011, monitoring of the atmospheric radionuclide was carried out for 3 months at Xi＇an, and part of radionuclide was detected with concentrations hiaher than their backorounds in the period, includina 131I.134Cs. 137Cs and 133Xe.

Standardization of Leaf Sampling Technique in Jackfruit Nutrient Status Diagnosis

In China, little information is known about the nutrient requirements of jackfruits and the traditional nutrient management usually depends on the experience. Therefore, in this study, an attempt was made to standardize the leaf sampling technique and the suitable range of leaf nutrient concentrations for jackfruit (Artocarpus heterophyllus Lam.) nutrient status diagnosis. The sampling result was affected by canopy height, leaf age and time of sampling. Therefore, the three factors were studied. The results illustrated that the stability in level of nutrient concentrations was in 3 - 6 month-old leaves from the central part of the canopy. The most stable period was from April to May for leaf sampling. It was recommended that the stable intracanopy and stable period of nutrient concentrations could be used as the standards of leaf sampling technique. Based on the leaf sampling technique, the standard of leaf nutrient concentrations was summarized, and could be used as the standard of nutrient suitability evaluation.

General limited information diffusion method of small-sample information analysis in insurance

When analyzing and evaluating risks in insurance, people are often confronted with the situation of incomplete information and insufficient data, which is known as a small-sample problem. In this paper, a one-dimensional small-sample problem in insurance was investigated using the kernel density estimation method （KerM） and general limited information diffusion method （GIDM）. In particular, MacCormack technique was applied to get the solutions of GIDM equations and then the optimal diffusion solution was acquired based on the two optimization principles. Finally, the analysis introduced in this paper was verified by treating some examples and satisfying results were obtained.

A New Approach to Robust Stability Analysis of Sampled-data Control Systems

The lifting technique is now the most popular tool for dealing with sampled-data controlsystems. However, for the robust stability problem the system norm is not preserved by the liftingas expected. And the result is generally conservative under the small gain condition. The reason forthe norm di?erence by the lifting is that the state transition operator in the lifted system is zero inthis case. A new approach to the robust stability analysis is proposed. It is to use an equivalentdiscrete-time uncertainty to replace the continuous-time uncertainty. Then the general discretizedmethod can be used for the robust stability problem, and it is not conservative. Examples are givenin the paper.

Bias Correction Technique for Estimating Quantiles of Finite Populations under Simple Random Sampling without Replacement

In this paper, the problem of nonparametric estimation of finite population quantile function using multiplicative bias correction technique is considered. A robust estimator of the finite population quantile function based on multiplicative bias correction is derived with the aid of a super population model. Most studies have concentrated on kernel smoothers in the estimation of regression functions. This technique has also been applied to various methods of non-parametric estimation of the finite population quantile already under review. A major problem with the use of nonparametric kernel-based regression over a finite interval, such as the estimation of finite population quantities, is bias at boundary points. By correcting the boundary problems associated with previous model-based estimators, the multiplicative bias corrected estimator produced better results in estimating the finite population quantile function. Furthermore, the asymptotic behavior of the proposed estimators is presented. It is observed that the estimator is asymptotically unbiased and statistically consistent when certain conditions are satisfied. The simulation results show that the suggested estimator is quite well in terms of relative bias, mean squared error, and relative root mean error. As a result, the multiplicative bias corrected estimator is strongly suggested for survey sampling estimation of the finite population quantile function.

Upgraded Analytical Protocols in Bauxite Refining Industry Using Composite Sampling Approach to Minimize Laboratory Analysis Load

The laboratories in the bauxite processing industry are always under a heavy workload of sample collection, analysis, and compilation of the results. After size reduction from grinding mills, the samples of bauxite are collected after intervals of 3 to 4 hours. Large bauxite processing industries producing 1 million tons of pure aluminium can have three grinding mills. Thus, the total number of samples to be tested in one day reaches a figure of 18 to 24. The sample of bauxite ore coming from the grinding mill is tested for its particle size and composition. For testing the composition, the bauxite ore sample is first prepared by fusing it with X-ray flux. Then the sample is sent for X-ray fluorescence analysis. Afterwards, the crucibles are washed in ultrasonic baths to be used for the next testing. The whole procedure takes about 2 - 3 hours. With a large number of samples reaching the laboratory, the chances of error in composition analysis increase. In this study, we have used a composite sampling methodology to reduce the number of samples reaching the laboratory without compromising their validity. The results of the average composition of fifteen samples were measured against composite samples. The mean of difference was calculated. The standard deviation and paired t-test values were evaluated against predetermined critical values obtained using a two-tailed test. It was found from the results that paired test-t values were much lower than the critical values thus validating the composition attained through composite sampling. The composite sampling approach not only reduced the number of samples but also the chemicals used in the laboratory. The objective of improved analytical protocol to reduce the number of samples reaching the laboratory was successfully achieved without compromising the quality of analytical results.

基于自动重要抽样方法的减方差技巧体系构建与验证

屏蔽计算问题根据求解目标不同一般可分为源-探测器问题、区域问题和全局问题。MCShield研究团队针对3类问题中存在的深穿透问题提出了相应的减方差技巧,本文以此为基础构建了基于自动重要抽样(AIS)方法的减方差技巧体系,并开展了验证工作。针对源-探测器问题,采用NUREG/CR-6115 PWR压力容器计算基准题对小探测器自动重要抽样(SDAIS)方法进行验证。结果表明,SDAIS方法的计算效率约为AIS方法的7倍。此外还提出并验证了基于AIS伴随蒙特卡罗的耦合减方差(AIS-CADIS)方法,将AIS方法引入到蒙特卡罗伴随计算中,取得了良好的效果。针对全局问题,提出网格化-AIS方法并使用简化反应堆屏蔽计算算例进行验证,结果表明,网格化-AIS方法的计算效率是AIS方法的12倍左右,是直接蒙特卡罗方法的290倍左右。

基于CD-BSMOTE的D-S证据融合变压器故障诊断

针对变压器油中溶解气体数据集不均衡特性对故障诊断结果的影响,提出一种基于清除临界点改进的边界合成少数类过采样算法均衡数据集和Pearson冲突距离改进D-S证据融合的变压器故障诊断模型。首先,对少数类样本进行均衡化处理,根据K-means聚类结果清除处于临界位置的样本;其次,搭建梯度提升树、随机森林、BP神经网络的故障诊断模型,实现变压器故障初步诊断;接着引入Pearson冲突距离改进D-S证据融合模型,实现诊断结果的融合决策;最后,经实际算例分析,诊断精确率达到92.65%。结果表明,所建模型能有效解决数据不平衡对诊断结果的影响,提高故障诊断精度。

基于SMOTE-IKPCA-SeNet深度迁移学习的小批量生产质量预测研究

随着智能制造技术的发展和客户个性化需求的增加,多品种小批量生产方式逐渐成为制造业的主流。面向大批量生产、以统计过程控制为核心的质量管理方式并不适用于小批量生产。针对复杂生产过程存在参数多、非线性和交互作用的问题,提出利用深度迁移学习的方式将历史生产数据作为源域迁移至小样本目标产品数据进行质量预测。首先,通过合成少数类过采样技术(synthetic minority over-sampling technique,SMOTE)和改进的核主成分分析(improved kernel principal component analysis,IKPCA)算法筛选源域和目标域的可迁移特征,这不仅兼顾了特征重要性和可迁移性,还减少了“负迁移”,提高了模型泛化能力;然后,采用结合通道注意力机制的卷积神经网络SeNet构建基于深度迁移学习的质量预测模型。仿真结果表明,随着目标域样本的增加,所提方法的预测准确性明显优于广泛采用的支持向量机建模方法。同时,所提可迁移特征筛选方法显著提高了深度迁移学习的质量预测效果,为复杂的小批量生产过程质量保证提供了新方法。

青海云杉一种重要害虫烟翅腮扁蜂越冬幼虫的空间分布型与抽样技术

为研究烟翅腮扁蜂(Cephalcia infumata)越冬幼虫在地下的空间分布,采用聚集度指标法、Taylor幂法则和Iwao回归法对烟翅腮扁蜂越冬幼虫的空间分布型进行分析。基于Iwao回归模型确定烟翅腮扁蜂越冬幼虫的理论数,通过序贯抽样技术得到不同允许误差(D=0.1、0.2、0.3)和经济阈值(m_0=3、5、10头/株)下的最大理论抽样数。结果表明,在宁夏罗山国家级自然保护区内,烟翅腮扁蜂1年发生1代,越冬幼虫主要分布在0~10 cm土壤中,在阳坡发生量大,呈聚集分布,符合负二项分布,种群聚集均数与种群平均密度呈线性关系,聚集程度随种群密度增大而增强。基于I_(wao)回归模型,在t=1.96时,当m_0=3头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为596、149、66株;当m_0=5头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为477、119、53株;当m_0=10头/株,D=0.1、0.2、0.3时,最大理论抽样数分别为388、97、43株。烟翅腮扁蜂的种群空间分布型为聚集分布,主要发生在林缘。基于序贯抽样确定的最大抽样数可用于指导烟翅腮扁蜂的监测和防治。

南疆苹果园绣线菊蚜种群时空动态与调查抽样技术

绣线菊蚜Aphis spiraecola是新疆南疆地区苹果园的一种重要害虫,本文在阿克苏地区调查了绣线菊蚜在苹果园的种群消长动态,并分析其种群在果园的空间分布格局、理论抽样数及序贯抽样方法。结果表明,5月至8月苹果园中绣线菊蚜的种群动态曲线呈现出明显单峰,6月为种群发生的高峰期。在发生高峰期,绣线菊蚜在果园呈聚集型分布,种群密度在苹果树不同方位间没有显著差异。该时期苹果园绣线菊蚜的最适理论抽样模型为N=t^(2)/D^(2)(163.90/m+0.16),当防治阈值为1500头/12枝条时,序贯抽样模型公式为T_(n)=1500 n±1534√n。本研究结果为南疆苹果园绣线菊蚜种群调查与测报提供了重要科学依据。

瓶内处理技术结合快速LC-MS提高利培酮血药浓度测定效率

目的 评估“瓶内处理”(Bottle-in)技术结合快速LC-MS的方法学特性,并验证其对治疗药物监测技术自动化和标准化的促进作用。方法 选择利培酮及其主要代谢物9-羟利培酮作为研究对象,针对两种血样前处理技术——Bottle-in技术与实验室现行的常规处理(RP)技术,建立并验证相应的LC-MS检测方法。实验设计遵循CLSI EP9-A3指南,对60例服用利培酮的患者血液样本应用两种方法进行利培酮和9-羟利培酮浓度的测定,并记录样本的报告时间。采用Spearman相关性分析、Passing-Bablok回归分析、Bland-Altman一致性检验以及医学决定水平(MDL)预期偏倚分析,对两种方法的检测结果进行相关性和差异性评价。结果 两种前处理技术下的LC-MS方法在测定利培酮和9-羟利培酮血药浓度时,均满足方法学验证的标准。在60例患者的样本中,两组结果均未出现异常值,显示出强烈的相关性(P<0.01)。Passing-Bablok回归模型显示了良好的线性关系。Bland-Altman一致性检验结果表明,两者具有高度一致性。MDL预期偏倚分析进一步证实,两种检测方法的结果未出现显著性偏倚,预期偏倚值(Bc)均在可接受的偏倚限值范围内。Bottle-in技术较RP技术在前处理时间上可节约66.67%,结合快速LC-MS技术对12例患者样本进行检测,全流程检出时间上Bottle-in组较RP组能缩短12.50%的时长。结论 Bottle-in技术凭借其高效的前处理方式,提高了药物监测技术自动化和标准化,可作为替代RP技术的一种有效方法,成为现代临床药学监测中的一项重要进展。

基于双采样随机森林的临滑阶段的预测算法:以湖北黄石5号铁矿石治理地块为例

针对碎石土边坡监测过程中滑坡稳定变形期与临滑阶段监测数据量严重不匹配,导致临滑阶段数据量偏小,从而产生的非平衡数据集造成预判不准确的问题,提出了一种基于DST随机森林的碎石土边坡临滑阶段地表位移的预测算法。首先,采用过采样和欠采样相结合的双采样技术(double sampling technique,DST)对地表位移中的非平衡数据集进行采集,然后,通过随机森林预测算法有放回的随机抽样进行预测,最后,通过实验得出预测结果。结果表明:DST随机森林预测算法相比于普通随机森林预测算法预测误差率降低到3.39%,证明双采样技术(DST)采集临滑阶段非平衡数据集的必要性。

恒湿环境下不同含水饱和度砂岩制备方法及压缩试验

针对目前制备不同含水饱和度岩石试样存在的精度低和试样内部含水分布不均匀等问题,基于渗透技术和化学热力学原理,设计了一种恒湿环境下不同含水饱和度岩石试样制备装置,并通过核磁共振成像实验验证了该装置精确制备水分均匀分布岩石试样的合理性。同时,利用该装置开展了不同含水饱和度条件下砂岩常应变率压缩试验。结果表明:砂岩的单轴抗压强度和弹性模量均随着含水饱和度的增加而降低,随着围压的增大,试样砂岩压密阶段减弱,试样的变形经历弹脆性—弹塑性—应变硬化的过程。研究结果为不同含水饱和度岩石试样的精确制备提供了新的方法和思路。