基于目标级联技术的含风电互联电网机组组合策略

针对含风电互联电网日前安全约束机组组合的规模大、约束复杂、求解困难等问题,提出基于目标级联分析技术的分散协调优化策略。将问题分解为负责区域间边界节点电压相角协调的上层优化问题和以并行方式独立优化各区域发电计划的下层优化问题。下层优化以弃风电量期望和电量不足期望,量化各区域内风电、负荷预测误差,以及常规机组强迫停运等系统运行不确定性所带来的风险,并以罚函数的形式引入目标函数,以综合优化系统可靠性与经济性。2区域12节点系统和IEEE RTS96三区域互联系统算例仿真验证所建模型和算法的有效性。     

Multilayer assembly of ionic starches on old corrugated container recycled cellulosic fibers

In this study, old corrugated container recycled fibers were treated with polyelectrolyte multilayers consisting of biopolymer cationic starch with two degrees of substitution (DS) each in combination with one anionic starch. Pulp zeta potential, paper strength and the thin layer ellipsometry technique were applied to examine the influence of cationic starch DS on the formation of polyelectrolyte multilayers. The results indicated a significant interaction between the DS of cationic starch and the number of ionic starch layers formed. When low‐DS cationic starch was used, the pulp zeta potential and the paper strength increased significantly in assembling the first cationic layer. However, in depositing high‐DS cationic starch a greater zeta potential and a stronger influence on the paper strength were observed with a larger number of starch layers. This was confirmed by thin layer ellipsometry when a greater thickness of multilayers was achieved by employing high‐DS cationic starch to form a higher number of layers. © 2017 Society of Chemical Industry     

食用百合高效生态栽培技术

文章从食用百合的经济意义入手,分析了现阶段百合生产存在的问题,总结了食用百合高效生态栽培技术,期望为食用百合的栽培提供理论基础与实践经验。     

A Bio‐Inspired and Biomass‐Derived Healable Photochromic Material Induced by Hierarchical Structural Design

Utilization of bionics to develop stimuli responsive polymers that can heal damage with excellent restorability is particularly attractive for a sustainable society. Herein, inspired by chameleons, a hierarchical structural design strategy is proposed and illustrated to fabricate a healable photochromic material based on a self‐healable polymeric matrix and a finely dispersed photochromic spirooxazine. The self‐healable polymeric matrix is fabricated via the integration of multiple hydrogen bonds (H bonds) and covalent cross‐links into a biomass‐derived elastomer. The dynamic nature and soft characteristics enable the as‐prepared elastomer superior extensibility as well as self‐healing ability, while the covalent cross‐links can assist the reassociation of ruptured H bonds. The representative elastomer exhibits an extensibility of 2600% and toughness of 42.76 MJ m^?3. Furthermore, it shows good self‐healing ability with complete recovery of scratch as well as restoration against 1900% of elongation and 24.1 MJ m^?3 of toughness after healing at 60 °C for 24 h. This combination of moderate toughness, good self‐healing ability, and smart photochromic property in biomass‐derived materials should largely improve their applicability, reliability, and sustainability in various materials and devices.     

机械涂覆技术在光催化材料制备中的应用进展

机械球磨技术因工艺简单、成本低廉而受到广泛关注,特别在粉体材料的混合、细化及合金化等领域有着广阔的应用前景。综述了由机械球磨原理发展而成机械涂覆技术的应用现状,包括用于材料表面改性的功能涂层和光催化降解的薄膜材料制备。分析了工艺参数、涂覆材料及涂覆基底等因素对涂覆效果（厚度）的影响规律,并对该技术在薄膜制备中表现出的简便、廉价且可在球形等形状复杂基底上成膜的独特优势做了讨论。基于当前机械涂覆技术制备的薄膜形貌、厚度不可控且成膜基底材质受限等现状,指出今后应该向拓展成膜基底材料类型和加快推进光催化薄膜材料的实际应用方向发展。     

Seeing is believing? When scanning electron microscopy (SEM) meets clinical dentistry: The replica technique.

In restorative dentistry, the in situ replication of intra‐oral situations, is based on a non‐invasive and non‐destructive scanning electron microscopy (SEM) evaluation method. The technique is suitable for investigation restorative materials and dental hard‐ and soft‐tissues, and its interfaces. Surface characteristics, integrity of interfaces (margins), or fracture analysis (chipping, cracks, etc.) with reliable resolution and under high magnification (from ×50 to ×5,000). Overall the current study aims to share detailed and reproducible information about the replica technique. Specific goals are: (a) to describe detailed each step involved in producing a replica of an intra‐oral situation, (b) to validate an integrated workflow based on a rational sequence from visual examination, to macrophotography and SEM analysis using the replica technique; (c) to present three clinical cases documented using the technique. A compilation of three clinical situations/cases were analyzed here by means the replica technique showing a wide range of possibilities that can be reached and explored with the described technique. This guidance document will contribute to a more accurate use of the replica technique and help researchers and clinicians to understand and identify issues related to restorative procedures under high magnification.     

Sleep Disorders Reduce Health-Related Quality of Life in Multiple Sclerosis (Nottingham Health Profile Data in Patients with Multiple Sclerosis)

Quality of Life (QoL) is decreased in multiple sclerosis (MS), but studies about the impact of sleep disorders (SD) on health-related quality of Life (HRQoL) are lacking. From our original cohort, a cross-sectional polysomnographic (PSG) study in consecutive MS patients, we retrospectively analysed the previously unpublished data of the Nottingham Health Profile (NHP). Those MS patients suffering from sleep disorders (n = 49) showed significantly lower HRQoL compared to MS patients without sleep disorders (n = 17). Subsequently, we classified the patients into four subgroups: insomnia (n = 17), restless-legs syndrome, periodic limb movement disorder and SD due to leg pain (n = 24), obstructive sleep apnea (n = 8) and patients without sleep disorder (n = 17). OSA and insomnia patients showed significantly higher NHP values and decreased HRQoL not only for the sleep subscale but also for the “energy” and “emotional” area of the NHP. In addition, OSA patients also showed increased NHP values in the “physical abilities” area. Interestingly, we did not find a correlation between the objective PSG parameters and the subjective sleep items of the NHP. However, this study demonstrates that sleep disorders can reduce HRQoL in MS patients and should be considered as an important confounder in all studies investigating HRQoL in MS.     

Electrodeposited and characterization of Ag–Sn–S semiconductor thin films

Thin film of silver tin sulfides (Ag–Sn–S) has been deposited on indium tin oxide coated glass (ITO) substrates using potentiostatic cathodic electrodeposition technique. New procedure for the growth of Ag–Sn–S film is presented. An electrolyte solution containing Silver Nitrate (AgNO₃), Tin(II) Chloride (SnCl₂) and Sodium Thiosulfate (Na₂S₂O₃)in acidic solution (pH ~2) and at temperature of the bath 55 °C were used for the growth of Ag–Sn–S thin film. Prior to the deposition, a cyclic voltammetry technique was performed in binary (Ag–S, Sn–S) and ternary (Ag–Sn–S) systems. This study was carried out to examine the behavior of electroactive species at the electrode surface. Based on these results, the cathodic applied potential was fixed at −1000 mV versus Ag/AgCl to obtain a uniform and good adhesion of ternary thin film. After that, structural, morphological and optical performances of films have been investigated. The X-ray diffraction patterns of the samples demonstrate the presence of the orthorhombic phase of Ag₈SnS₆ at applied potential of −1000 mV versus Ag/AgCl. Based on the scanning electron microscopy (SEM), it was found that the surface morphology and grain size were strongly influenced by the presence of Sn and/or Ag in the electrolyte bath. The band gaps of binaries and ternary compound are evaluated from optical absorption measurements. Band gap of Ag₈SnS₆ determined from transmittance spectra is in the range 1.56 eV. Flat-band potential and free carrier concentration have been determined from Mott–Schottky plot and are estimated to be around 0.18 V and 2.21×10¹⁴ cm⁻³ respectively. The photoelectrochemical test of Ag₈SnS₆ was studied and the experimental observations are discussed in detail.     

复频电导技术在隧洞超前探水中的应用

围岩富水带是隧道超前预报最关注的问题，目前，多使用电磁方法来预报围岩的含水性，但受到场地条件限制，面临掌子面条件、金属机具干扰、三维波场定位等诸多困难，特别是掌子面前方100 m范围内围岩的含水性预报，在国内外都是一个新的高难课题。在研究了岩体电导率与电容率复频特性的基础上，结合巴基斯坦NJ-TBM引水隧洞工程，开发了复频电导探水(CFC)技术。该技术基于电磁波反射与相干原理，选用100 kHz～10 MHz频率范围，采用电偶极子发射与阵列接收方式和偏移成像技术，突破了隧道内场地条件的限制。依据1/4相干波长确定含水体的位置，相干能量确定含水量的大小。在巴基斯坦NJ-TBM隧洞超前探水的应用，证明了该方法的可行性与有效性。      

Efficient framework for mobile walkthrough application

The past few years have witnessed a dramatic growth in the number and variety of graphics intensive mobile applications, which allow users to interact and navigate through large scenes such as historical sites, museums and virtual cities. These applications support many clients and impose a heavy requirement on network resources and computational resources. One key issue in the design of cost efficient mobile walkthrough applications is the data transmission between servers and mobile client devices. In this paper, we propose an effective progressive mesh transmission framework that stores and divide scene objects into different resolutions. In this approach, each mobile device progressively receives and processes only the object’s details matching its display resolution which improves the overall system’s response time and the user’s perception. A fine grained cache mechanism is used to keep the most frequently requested objects’ details in the device memory and consequently reduce the network traffic. Experiments, in simulated and real world environment, are used to illustrate the effectiveness of the proposed framework under various settings of the virtual scene and mobile device configuration. Experimental results show that the proposed framework can improve the walkthrough system performance in mobile devices, with a relatively small overhead.