我国鲜食玉米标准体系及营养标准研究

近年来我国鲜食玉米产业发展迅猛, 但同时也暴露出诸多产业乱象。梳理现有鲜食玉米标准体系是促进产业标准化、规范化的重要举措。本文通过对我国现行鲜食玉米标准进行梳理, 总结出目前我国鲜食玉米标准体系中抽样及一般性检测标准较完善、技术规程体系成熟、标准体系框架已建立的特点; 同时提出我国鲜食玉米标准体系存在技术规程标准内容重复、品质分级标准混乱、缺乏营养评价指标相关标准、感官评价标准混乱、缺乏甜糯玉米和笋玉米的相关标准、标准体系结构不合理等的问题; 并针对上述问题提出对应应统一技术规程标准, 建立营养评价体系, 统一品质分级标准, 统一感官评价指标, 完善甜糯玉米和笋玉米相关标准的解决办法。为鲜食玉米标准体系的建设及规范化提供参考和建议。     

Multifunctional cementitious composites with integrated self-sensing and self-healing capacities using carbon black and slaked lime

This study aims to develop multifunctionality of cementitious composites with the integrated self-sensing and self-healing capacities by incorporating conductive carbon black (CB) with CB-encapsulated slaked lime (SL). The microsized SL particles were premixed with a half of designed content of nanosized CB particles. When CB agglomerations coat around the SL surfaces, SL does not hydrate until the CB coating is removed. Another half of designed weight of CB is uniformly dispersed using ultrasonication with superplasticizer and added to obtain piezoresistivity. The results show that the stress sensing capacity of CB-SL-cementitious composite performs well with the compressive stress. Autogenous healing performances presented significantly can improve the self-healing capacity with the increase of SL. Furthermore, the healing efficiency is affected by the crack width and dispersion of SL, and the smaller cracks with SL are more easily healed. The size of CB agglomerations decreases with the added SL, and the main product of self-healing is calcium carbonate.     

A three-dimensional surface measurement system implemented with Gaussian process based adaptive sampling

Self-adaptive surface measurements that can reduce data redundancy and improve time efficiency are in high demand in many fields of science and technology. For this purpose, a system implemented with Gaussian process (GP) adaptive sampling is developed. The non-parametric GP model is applied to reconstruct the topography and guide the subsequent sampling position, which is determined from the inference uncertainty estimation. A criterion is proposed to terminate the GP adaptive measurement automatically without any prior model or data of the topography. Experiments on typical surfaces validate the intelligence, adaptability, and high accuracy of the GP method along with the stabilization of the automatic iteration termination. Compared with traditional raster sampling, data redundancy is reduced and the time efficiency is improved without sacrificing the surface reconstruction accuracy. The proposed method can be implemented in other systems with similar measurement principles, thus benefitting surface characterizations.     

LWD仪器临界电压数据读取分析与解决

锂电池是LWD仪器正常工作的动力来源,是仪器的心脏。仪器出井后,需要在井口读取数据,当锂电池的电量接近耗尽时,会导致数据读取失败的问题。该问题处理不当,会造成长期占用井口,影响钻井时效,严重时还可能会因短路造成昂贵的LWD仪器损坏。锂电池的临界电压问题暴露了该仪器的设计缺陷,在此通过技术方法充分利用INSITE系统本身提供的功能,绕过其设计缺陷将问题解决。     

Black phosphorous nanosheets–gold nanoparticles–cisplatin for photothermal/photodynamic treatment of oral squamous cell carcinoma

To improve five-year survival rate of oral squamous cell carcinoma (OSCC), the development of a novel composite material of black phosphorus nanosheets (BPNSs) and gold nanoparticles (AuNPs) for tumor treatment was carried out. The purpose of this study is to evaluate the cytostatic effects of BPNSs, AuNPs loaded with cisplatin (CDDP) on human tongue squamous cell carcinoma cells lines (SCC-9), and 7,12-dimethylbenz anthracene induced cheek squamous cell carcinoma was validated in golden hamsters animal models. The results showed that BPNSs could efficiently inhibit the metastasis and growth of OSCC compared with CDDP and AuNPs. And a combination composite of AuNPs–BPNSs loaded with CDDP could more effectively inhibit the metastasis and growth of OSCC, which might be due to the high drug-loading capacity, excellent photothermal properties and the combination of photodynamic and photothermal therapy of BPNSs and AuNPs, as well as the synergistic effects of AuNPs, BPNSs and CDDP.     

微型土压平衡盾构机液压系统故障分析

以微型土压平衡(Earth Pressure Balance,EPB)盾构机推进液压系统作为研究对象,介绍了推进系统的工作原理,对混入空气后的油液黏度和有效体积弹性模量进行分析,建立了推进系统数学模型,并对混入不同百分比空气的系统进行仿真运算,得到了液压缸位移响应和速度响应随系统含气量变化的关系。研究表明:随着液压系统空气含量的增加,液压缸位移响应发生迟滞,速度响应变慢,液压缸在运动时产生振动。结合各液压元件工作原理,依次对实际盾构机推进系统元件进行排气,最终排除了液压系统中混入的空气,为实现盾构机平稳推进提供了理论依据。     

基于Matlab的量子激光雷达稳频通信模拟系统设计

传统通信模拟系统设计较为复杂,导致模拟过程消耗能量较大,不能准确模拟稳频通信质量。因此,提出基于Matlab的量子激光雷达稳频通信模拟系统。由于振荡器是雷达形成初始信号源的基础,通过分析振荡电路与相位噪声,获得相位噪声函数与通信频率存在的关系;为确保通信过程的稳定,将准确性与稳定性作为信号质量的评价指标,并采用锁频环稳频技术计算频率偏移程度,根据PID控制算法控制频率,量子激光雷达稳频通信;利用Matlab确定激光器、探测器等硬件组成结构,通过时序与数字阵列的设置完成模拟系统设计。仿真结果表明所提系统结构简便、性能稳定,能够真实模拟出稳频通信的信号质量。     

对大中型钢结构企业生产管理体系的研究分析

以某大型钢结构制造企业为例,通过对产量分布、质量控制、劳动效率等基本数据的分析,研判外协生产管理体系方面存在的问题,从组织形态、管理模式、职能管理等多个维度提出了可行性建议,可为同类型钢结构制造企业提供经验借鉴。     

马尔可夫跳变线性系统最优控制的研究现状与进展

马尔可夫跳变线性系统（MJLS）是一种具有多个模态的随机系统，系统在各个模态之间的跳变转移由一组马尔可夫链来决定。MJLS模型因其在表示过程中可以产生突变而更能精确的描述实际工程应用中的系统。近年来，MJLS的最优控制问题成为了研究的热点，动态规划、极大值原理以及线性矩阵不等式等成为了解决此类问题的主流方法。本文对MJLS最优控制领域的研究现状进行了综述。分别对一般情况下、带有噪声的情况下、带有时滞的情况下以及某些特定情况下的MLJS最优控制问题的国内外研究现状进行论述。最后进行了总结并提出MJLS最优控制领域未来值得关注的研究方向。     

Evaluation and Characterization of Mechanical, Electrical, and Thermal Properties of Polymer Nanocomposites Reinforced with Different Allotropes of Carbon

The present work aims to present the results based on the processing of nanocomposites, which consist of matrix materials like epoxy and filler materials such as conjugated nanomaterials/allotropes of carbon, namely, carbon black, graphite, and multiwalled carbon nanotube (MWCNT) used for targeted applications. To improve the physical and chemical properties and to facilitate a better interfacial interface between the polymer and nanotube, functional MWCNT is used during the preparation of the composite. The prime objective of the study is to establish the thermal, mechanical, and electrical properties of nanocomposites using experimental methods. It has been observed from the experimental results that carbon nanotube (CNT) based composite exhibits higher mechanical (tensile and hardness) and thermal properties as compared with the others. The electrical properties are found to be better in a graphite-based composite. Although CNT has superior mechanical and thermal properties, the exorbitant price limits its use. Hence, the allotropes of carbon may be used judiciously considering both the cost and property requirements of the targeted application. The work also studies the dispersion state of nanofibers through scanning electron microscopy (SEM).