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文章针对吉比特无源光网络（GPON）系统中具有动态带宽分配（DBA）能力的光网络单元（ONU）以太网桥接子系统,首先分析ONU板载Linux系统中网桥子系统的整体结构,然后,提出一种网桥中DBA的算法,并对此算法进行分析。实验结果表明,相比一般网桥,具有DBA的网桥能够更有效地利用GPON远端系统的PON中有限的带宽资源,提高带宽的利用率。

混合无源光网络（HPON）通过波分复用的方式提升了接入带宽,但其远端节点（RN）所采用的点到点拓扑结构不利于组播复制。针对这个特点,文章首先提出了基于HPON的组播实现方案,通过单拷贝广播（SCB）来提高组播复制效率;然后对原有的光线路终端（OLT）、RN和光网络单元（ONU）设备进行改进设计,实现对组播业务流的控制功能;最后对改进前后的系统进行组播性能对比测试。测试结果表明,该方案可以提高HPON的组播性能。

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 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 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.)

The recognition of named entities in the field of water conservancy is of great significance for the building of water conservancy knowledge graphs and intelligent question answering systems. However, in the current field of water conservancy, there are shortcomings in named entity recognition, such as a lack of annotated corpus, low recognition accuracy of traditional methods and inability to solve polysemous entities. Aiming at the characteristics of water conservancy texts, a Named Entity Recognition Model for Machine Reading Comprehension (MRC) based on data (vocabulary and entity type labels) enhancement, namely the MRC-WLE model was put forward. Mainly, the vocabulary feature information and entity type label feature information in water conservancy texts were injected into the model as "knowledge". It introduced models such as BERT-CRF, BERT-CRF-Word, BERT-BILSTM-CRF and BERT-BILSTM-CRF-Word as controls to evaluate the performance of the MRC-WLE model. The results show that compared with the BERT-CRF and other models mentioned above, the micro average F1 value of the MRC-WLE model has been improved. Compared with the MRC model, the micro average F1 value of the MRC-WLE model has been increased by 0.85%, reflecting the effectiveness of data augmentation. [ABSTRACT FROM AUTHOR]

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 Nonferrous Metals (Mineral Processing Section) is the property of Beijing Research Institute of Mining & Metallurgy Technology Group 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 Acta Agriculturae Zhejiangensis is the property of Acta Agriculturae Zhejiangensis 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.)

In order to study the mechanical properties and failure characteristics of layered shale in New Yan'an Tunnel and analyze the influence of different inclination angles of bedding plane on rock mechanical parameters. Laboratory uniaxial compression, triaxial compression and Brazil splitting tests and numerical uniaxial compression and triaxial compression tests under different bedding angles were carried out. The laboratory test analysis show that the peak intensity first decreases and then increases with the increase of inclination angle. The compressive strength shows a U-shaped trend, the elastic modulus changes in a “V” shape. And through a large number of numerical simulation tests to expand the scope of laboratory tests and the relationships between compressive strength and elastic modulus with dip angle were fitted respectively. The increase of confining pressure weakens shale anisotropy, but the degree of weakening decreases with the increasing of confining pressure. The strength of laminated shale is weakened by cohesion much more than internal friction angle. The tensile strength decreases with the increase of inclination angle. The failure modes of layered shale are different with different inclination angles, under the condition of uniaxial compression, tensile failure occurs for 0°, shear slip failure along the bedding plane controlled by the weak plane occurs at 30° ~ 60°, cleavage tensile failure occurs at 90°. Under triaxial compression, the shale specimens with different bedding plane inclinations mainly undergo shear failure. [ABSTRACT FROM AUTHOR]

Copyright of Precious Metals / Guijinshu is the property of Precious Metals 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 Science Technology & Industry / Keji he Chanye 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.)

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 Hydrometallurgy of China is the property of Hydrometallurgy of China 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.)

Soil water deficit is the main obstacle factor of plant reconstruction in rocky desertification area of Southwest China. Mycorrhizal mulberry (Morus alba L.) can cope with the main ecological barriers during the seasonal drought in the rocky desertification area. However, it is unclear the water resource of mulberry. In this study, we studied the water use strategy of mulberry root in different seasons by hydrogen and oxygen stable isotope technique. The mulberry was grown in typical rocky desertification area in Qingshuipu town, Qixingguan district, Bijie city (105°35′02′′E, 27°41′19′′N) in Guizhou Province. The precipitation was mainly concentrated in June-September. The mulberry was not irrigated. The annual growth of mulberry was in 2 seasons: from April to June and from September to November. The samples of rainfall water, soil and plant branch were collected from April to November of 2014. Soil was sampled at 0-60 cm depth with 10 cm as a sampling layer. The abundance of deuterium and oxygen stable isotope were measured. The correction analysis method was used to preliminarily evaluate water sources of mulberry. The contribution rate of water at each soil layer was also calculated. The results showed that in rainfall water, the abundance of deuterium from April to November averaged -25.9‰ and the oxygen stable isotope abundance averaged -4.82‰. In spring from April to June, the abundance of deuterium and oxygen stable isotope in rainfall water averaged -0.24‰ and -1.68‰, respectively. In autumn from September to November, the abundance of deuterium and oxygen stable isotope in rainfall water averaged -60.0‰ and -8.17‰, respectively. In spring, the abundance of deuterium and oxygen stable isotope in soil water averaged -29.4‰ and -4.77‰, respectively while the abundance of deuterium and oxygen stable isotope in xylem water averaged -33.2‰ and -5.39‰, respectively. In autumn, the abundance of deuterium and oxygen stable isotope in soil water averaged -70.1‰ and -9.27‰, respectively while the abundance of deuterium and oxygen stable isotope in xylem water averaged -55.7‰ and -7.92‰, respectively. The abundance of both stable isotopes in soil water and xylem water were below that in the rainfall water and that of xylem water were between soil water and rainfall water. It indicated that the mulberry mainly used soil water. Both isotopes in rainwater were more enriched in the early stage of mulberry growth (spring, from April to June) than in the late growth stages (autumn, from September to November). With the seasonal variation of rainfall, the both isotopes of soil water showed a downward trend. According to rainfall water equations, the mulberry absorbed mainly soil water. Both isotopes had clear seasonal trend. In spring, the isotopes in soil water decreased with the increase of soil depth. In autumn, isotopes in soil water decreased then increased with soil depth. Based on the correlation method, the mulberry absorbed water from different soil depth. In spring, it absorbed water from soil below 20 cm while it absorbed water from soil 0-20 cm. In September, it also absorbed water from 50-60 cm soil layer. Based on results from the IsoSource software, in spring, mulberry mainly used soil water from soil layers of 10-30 to 50-60 cm. In autumn, it mainly used soil water from soil layers of 50-60 to 0-10 cm. In spring, the contribution rate was 69.1% by 10-30 cm in soil, 31.8% and 66% by 50-60 cm layer in May and June, 70.2% by 50-60 cm in September and 94.3% and 71.9% by 0-10 cm in October and November, respectively. The study will be helpful to mulberry manage and application in rocky desertification area. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Science & Technology (1008-0864) is the property of Journal of Agricultural 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 Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan 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 Journal of Southern Agriculture is the property of Journal of Southern Agriculture 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】 The present paper aimed to provide the theoretical basis for optimization management of mulberry field by verifying nutrients and ecological stoichiometry characteristics of soil from returning farmland to mulberry field in stony desertification region. 【Method】 The nutrients and ecological stoichiometry characteristics of soils with different soil depth of Libo mulberry field(returning farmland to forestry for one year) and Bijie mulberry field(returning farmland to forestry for ten years) in different season were studied by the space replacing time method and actual investigation. 【Result】(i) The returning farmland to mulberry field is beneficial for improvement of soil nutrients in stony desertification region. The nutrients of mulberry present the fluctuating variation trend during the year-round growth process. The C, N and P in mulberry field soils with different soil depth has a‘ surface segregation’characteristics and their content gradually reduces with increase of soil depth. The organic carbon and total Ca content in the soil of Bijie mulberry field(returning farmland to forestry for ten years)shows a decline-rise-decline trend, the total nitrogen and total phosphorus content decreases continuously and total potassium content presents a first decline and then rise trend.(ii) C/N, C/P and N/P ratio of the soil from Bijie mulberry field(returning farmland to forestry for ten years) increases but its C/K, C/Ca and N/K ratio decreases. The C/P and N/P ratio presents a rising trend with seasonal variation but a rapid decrease trend with increase of soil depth. 【Conclusion】 The phosphorus is the main limitation factor to influence soil of mulberry fields, followed by nitrogen factor. The needed nutrients for mulberry should be supplied and the variation between different soil elements should be paid attention in management of mulberry fields. The soil ecological stoichiometry ratio of the mulberry field from returning farmland to forestry is significantly related to its nutrients. The contribution of organic carbon and total nitrogen is positive to soil C/P, C/K, N/P and N/K. The contribution of total Ca is positive to soil C/K and N/K. The contribution of total phosphorus is negative to soil C/P and N/P. The contribution of total potassium is negative to soil total Ca and C/Ca. [ABSTRACT FROM AUTHOR]

Copyright of Practical Pharmacy & Clinical Remedies is the property of Editorial Department of Practical Pharmacy & Clinical Remedies 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 Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research 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 spatial and temporal variation characteristics of hydrogen and oxygen stable isotope in soil water of mulberry field at 0 - 50 cm soil depth in stony desertification area was analyzed to reveal the soil water dynamics mechanism of mulberry fields in stony desertification area and provide the basis for formulating water utilization strategy of mulberry field. Results: There is a good linear relation between hydrogen and oxygen isotope in soil water of mulberry field (δD = 8.39，δ18O = 13.76 and R2 = 0.98). The hydrogen and oxygen stable isotope composition is of obvious seasonal variation characteristics. The average δD and δ18O value in soil water of mulberry field is -33. 9 ± 18.5 and - 5. 8 ± 2. 0 in Spring〉-41.4%c±8.8%c and - 6. 4 ± 1.2 in Summer > - 87. 0 ± 6.8 and - 11.9 ± 1.2 % in Autumn. There is no obvious difference in δD and δ18O content in soil water among different sample plots. The hydrogen and oxygen stable isotope in soil water presents a gradient distribution with increase of soil depth. The δD and δ18O value in soil water decreases with increase of soil depth in April，increases with increase of soil depth in July and presents a declining-rising-declining trend in October. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southern Agriculture is the property of Journal of Southern Agriculture 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.)

To screen pepper varieties of Cd low concentration to apply in the production, pot experiments were conducted to study the transport and enrichment characteristics of Cd in typical Guizhou soil-pepper system by setting different Cd concentration. Results:( i) After harvest of pepper, Cd content was 6.11%-11.84% lower in yellow soil than in calcareous soil. When Cd content ranged from 0mg/kg to5 mg/kg, increasing trends of Cd content of pepper root and overground part were 4.1 and 1.4 times faster under the planting condition of yellow soil than calcareous soil condition respectively.( ii) In yellow soil-pepper and calcareous soil-pepper system, Cd transfer coefficients were respectively 0.04-0.25 and 0.21-0.50 from pepper root to pepper fruit. And the transfer speed was 3 times faster under the planting condition of calcareous soil than yellow soil condition. In addition, Cd enrichment characteristics were respectively 0.93-1.65 and 1.02-3.04, and the characteristics were 1.84-1.10 times higher under the planting condition of calcareous soil than yellow soil condition. In short, the transfer speed and enrichment capacity of Cd from pepper root to pepper fruit in calcareous soil was quicker than in yellow soil. Moreover, the used pepper breed initially belong to the enrichment of Cd varieties. [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.)