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随着网络传输数据流量的爆炸性增长,传统电交换由于其有限的带宽和高功耗将很难满足网络带宽发展需求。光交换能直接在光域上完成光信道间信息的交换,具有高速、宽带、透明、低功耗以及潜在的低成本等诸多优点,能满足下一代全光交换网络、数据中心和高性能计算机光互连网络建设的迫切需求。文章介绍了集成光开关的发展现状及核心技术,包括采用氧化硅、III-V族半导体材料和硅材料来制作光开关的进展以及各种技术的特点。其中硅基集成光开关具有结构紧凑、功耗小、成本低以及与互补型金属-氧化物-半导体（CMOS）工艺兼容的优势,适合大规模光开关制作和量产,具有潜在的巨大市场商用价值。文章重点介绍了实现硅基光开关的核心单元器件以及几种代表性光开关阵列,并对光开关状态监控和调节以及光电封装做了阐述。

文章基于受激布里渊散射增益补偿技术,对微波光子滤波器的波长特性进行研究,并提出了一种改进方法。若将受激布里渊散射的一个增益谱与两个损耗谱相互叠加,可实现波长选择及带宽可调。通过计算,可以使带宽从20 MHz减小到3.8 MHz,减小了81%,而选择性提高了5倍多。在一些特殊应用领域,对滤波器进行级联,可使带宽进一步减小。通过这种方法,使带宽从13 MHz减小到了2.5 MHz,减小了80.8%,选择性进一步得到提高。经过仿真及实验,证明了这种方法是切实可行的。

防屈曲钢板墙(简称BRSPSW)是一种适用于高层钢结构的新型抗侧力构件,具有塑性性能好、滞回特性稳定、可独立变化墙板承载力和刚度以及布置灵活等优点,可克服支撑框架易受建筑功能限制的缺点。以某34层钢结构住宅为背景,首先提出BRSPSW适用性布置方式,并对其进行比选分析。然后基于结构弹性层间位移角要求,通过6组算例对D形布置BRSPSW跨越门洞传力转换进行了分析,提出了有效高宽比概念与BRSPSW体系方案设计阶段参考建议。

近年来,威海一直致力于生态城市的建设。物种多样性是生态城市的重要指标,而在物种多样性中,城市鸟类多样性起着重要的作用。本文调查了冬季威海7个斑块（2个校园和5个典型生活小区）的鸟类多样性,对其物种多样性指数以及均匀度指数进行分析,得出山东大学校园和哈尔滨工业大学校园的鸟类多样性高于5个小区斑块,而且2个校园斑块的均匀度在7个斑块中也处于较高水平。另外,结合实际情况,文章从绿化面积、城市栖息地的空间异质性、生境破碎化程度以及人为干扰4个方面对城市鸟类丰富度与多样性的影响因素做出讨论,并就城市化对鸟类的影响问题做出分析,得出威海冬季鸟类的多样性从一定程度上反映了当地生态环境的多样性,建议将鸟类的多样性作为评价城市环境好坏的一种新指标。

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biotechnology Bulletin is the property of Biotechnology Bulletin Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective］ To study the effects of brackish water irrigation on soil water and salt characteristics and crop growth is helpful to guide the safe utilization of brackish water. Methods］ A pot experiment of winter wheat was carried out under the condition of rain-shielding. Deionized water was used as the control (CK). Three kinds of brackish water treatments with conductivity of 4 dS/m and different sodium-potassium ratios were set up, including sodium-potassium ratio of 1: 0 (T1), sodium-potassium ratio of 1: 1 (T2), sodium-potassium ratio of 0 5 1 (T3). The water-salt characteristics of the soil, the photosynthetic physiology, growth and development as well as yield formation of winter wheat were studied. Results］ Compared with CK, the () -- 4() cm soil moisture content under T1, T2 and T3 brackish water irrigation increased by 19%, 8% and 14% (pW().()5), respectively. Soil EC]: 5 (soil water ratio 1: 5 extract conductivity) and Na+ and K+ concentrations continued to increase with the growth period of winter wheat. The () -- 4() cm soil salinity of T1, T2 and T3 treatments increased by 252%, 223% and 234% (<().05), respectively, and most of the salt accumulated in the 1() -- 20 cm soil layer. The net photosynthetic rate of winter wheat was significantly reduced (by 16%, p〈().()5) in the T1 treatment compared to CK, while there was no significant differences (p>().()5)between the T2 and T3 treatments and CK. The T2 treatment enhanced plant height, leaf area per plant and aboveground dry matter mass of winter wheat, and increased the yield by 8. 41 % (p〈0.()5) compared to CK; while there was no significant difference in underground dry matter mass among treatments (p X).()5). Conclusion] Tn summary, irrigation using 4 dS/m brackish water changed the original water-salt characteristics of the soil, caused salts to accumulate in the soil and promoted winter wheat growth in the short term. Tn this study, the use of brackish water with a sodium-potassium ratio of 1 5 1 had a better effect on winter wheat growth and yield enhancement. The results can provide a theoretical basis for sustain able utilization of brackish water. [ABSTRACT FROM AUTHOR]

In view of the absorption and diffusion characteristics of laser in the paint layer and the base layer, heat transfer model I and thermal connection boundary conditions for the paint layer and the metal base layer was established. As a comparison, corresponding heat transfer models II and III were established, with the thermal connection conditions at the interface between the paint layer and the base layer ignored. In model III, both the paint layer and the base layer were connected to the bulk heat source. A semi-analytical solution to the problem was obtained through the Laplacian transformation. Corresponding numerical solution examples were given through the Laplacian numerical inverse transformation. The results show that, model I gives continuous temperature distributions, while model II and model III give discontinuous temperature distributions, which goes against physical reality. Secondly, based on model I, the predicted time and energy density for cleaning and removing the paint layer are between those of model II and model III. The work provides a theoretical reference for improving the laser cleaning process. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Information & Control is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Donghua University (Natural Science Edition) is the property of Journal of Donghua University (Natural Science) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of High Pressure Physics is the property of Chinese Journal of High Pressure Physics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Tropical Medicine is the property of China Tropical Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Biotechnology Bulletin is the property of Biotechnology Bulletin Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Anhui Agricultural Sciences is the property of Journal of Anhui Agricultural Sciences Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Yellow River is the property of Editorial Board of Yellow River and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The sensitivity of the carbonate reservoir in the second block of the Shunbei oilfield is evaluated through rock fracture stability correction method. In the evaluation drilling fluid samples taken from operational field were used and the results of the evaluation show that the main factors causing reservoir damage are stress sensitivity and solids invasion; the damage to the reservoir caused by these two factors totals 78.07%. In laboratory study, the idea of “temporarily plugging the reservoir during drilling and the plugging agents can be removed in well completion” was adopted in drilling fluid design, and the microfractures in the reservoir rocks are intentionally protected with the plugging agents. According to the theory of bridging and plugging the microfractures, plugging agents that are highly acid soluble and fibers that are degradable are selected as the key additives working together to plugging the microfractures. Using these plugging agents, a drill-in fluid capable of plugging the microfractures in the reservoir through multiple bridging is formulated. The performance of the drill-in fluid in resisting high temperatures and salt and calcium contamination as well as the settling stability, compatibility and reservoir protection property are evaluated. The results show that the drill-in fluid works normally at temperatures up to 180 ℃, the pressure bearing capacity of the layers formed by the solids of this drill-in fluid exceeds 10 MPa, the permeability recovery after acid job is 96.86%, an increase by 16.23% over conventional drill-in fluids containing no acid soluble temporary plugging agents. This drill-in fluid has strong plugging capacity the high rate of flowback characteristics, and is expected to alleviate the formation damage in the second block in Shunbei oilfield. [ABSTRACT FROM AUTHOR]

Copyright of Southwest China Journal of Agricultural Sciences is the property of Editorial Department of Southwest China Journal of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Automation Equipment / Dianli Zidonghua Shebei is the property of Electric Power Automation Equipment Press and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Remote Sensing is the property of Editorial Office of Journal of Remote Sensing & Science Publishing Co. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy & Electric Power Technology & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Severe acute pancreatitis (SAP) is a common disease that seriously threatens human life and health, characterized by rapid progression, complexity and variability, and multiple complications. SAP can lead to intestinal microbiota imbalance and intestinal mucosal barrier dysfunction in the early stages. Traditional Chinese medicine has shown unique advantages in regulating gut microbiota and has become a potential method for treating intestinal microbiota imbalance in SAP. The article reviews the research progress of traditional Chinese medicine in treating SAP from the perspective of gut microbiota. [ABSTRACT FROM AUTHOR]

The path planning algorithm was proposed for multiple unmanned aerial vehicles in the petrochemical industry, aiming to find the shortest smooth inspection path. The problem was modeled as a multiple traveling salesman problem based on Dubins curve. It was achieved by using Dubins curve and the rolling branch-and-bound algorithm. To achieve the optimal inspection path planning, the rolling branch-and-bound algorithm was proposed to update the path length constantly, and the optimal path was sought by continuous iterative optimization of the upper and lower bounds. Besides, the algorithm combined the minimum insertion algorithm with the greedy algorithm to obtain better candidate solutions to prune more branches and optimize the inspection path. And then, the smooth Dubins path was planned by discretizing the heading angle of each grid cell and using the sliding window. Simulation results demonstrate that the proposed algorithm has better performance in terms of exploration time compared to other existing inspection path planning algorithms. [ABSTRACT FROM AUTHOR]

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Flying-wing unmanned aerial vehicles can use active flow control technology to replace traditional control surfaces, avoiding radar echoes generated by control surface deflection, and can achieve better stealth performance. This article proposes a joint optimization method for high aspect ratio flying-wing unmanned aerial vehicles loaded with circulation controllers, which considers both aerodynamic and stealth performance. A joint optimization framework based on surrogate model is established for the two-dimensional airfoil containing circulation control (CC) mechanism, and the Pareto frontier solution set is obtained through optimization solution. The aerodynamic and stealth performance of the two-dimensional airfoil corresponding to three points in the Pareto front is evaluated, and the numerical results confirm the feasibility of the joint optimization method proposed in this paper. [ABSTRACT FROM AUTHOR]

[Objective]The aims of this study are to understand the soil microbial communities in different protection forests in coastal sand dune ecosystem, and to provide theoretical basis for sustainable management of the protection forests. [Methods]A study was conducted to compare the effects of different forests on soil microbial composition and the relationship between soil microorganism and environmental factors by phospholipid fatty acid method(PLFA)in 5 forests including secondary forest, and plantations of Casuarina equisetifolia, Pinus elliottii, Acacia crassicarpa and Eucalyptus urophylla × E. grandis. [Results](1)18 kinds of PLFA biomarkers were detected in the soils of different protection forests in coastal sand dune ecosystem, which were most in Eucalyptus urophylla × E. grandis plantation and secondary forest, and least in Pinus elliottii and Acacia crassicarpa plantations. (2)The contents of total PLFA, gram-positive bacteria and gram-negative bacteria were all higher in Eucalyptus urophylla × E. grandis plantation and secondary forest, and lower in Acacia crassicarpa and Casuarina equisetifolia plantations. In addition, the fungi content was significantly higher in Eucalyptus urophylla ×E. grandis plantation than in other forest types, the content of soil fungi in Eucalyptus urophylla × E. grandis plantation was the highest, and that of arbuscular mycorrhizal in secondary forest was the highest, no significant difference was found among other protection forests. (3)The soil microbial diversity and evenness of the secondary forest were higher than those of the four plantations. (4)The soil pH, fine root carbon and nitrogen contents had the greatest impact on soil microbial community, followed by soil total nitrogen and nitrate nitrogen contents, litter lignin/nitrogen and fine root carbon nitrogen ratio. [Conclusion]The effects of protection forests on soil microbial community are significantly different. The introduction of Eucalyptus urophylla XE. grandis and native trees in the coastal Casuarina equisetifolia protection forest can increase soil microbial diversity and improve forest ecological functions [ABSTRACT FROM AUTHOR]

Copyright of Tianjin Medical Journal is the property of Tianjin Medical Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Management & Systems is the property of Business Administration Association of R.O.C. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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