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1. chinaXiv:201707.00007 [pdf]

B tensors and tensor complementarity problems

Yisheng Song; Wei Mei
分类: 数学 >> 控制和优化

In this paper, one of our main purposes is to prove the boundedness of solution set of tensor complementarity problem with B tensor such that the specific bounds only depend on the structural properties of tensor. To achieve this purpose, firstly, we present that each B tensor is strictly semi-positive and each B$_0$ tensor is semi-positive. Subsequencely, the strictly lower and upper bounds of different operator norms are given for two positively homogeneous operators defined by B tensor. Finally, with the help of the upper bounds of different operator norms, we show the strcitly lower bound of solution set of tensor complementarity problem with B tensor. Furthermore, the upper bounds of spectral radius and $E$-spectral radius of B (B$_0$) tensor are obtained, respectively, which achieves our another objective. In particular, such the upper bounds only depend on the principal diagonal entries of tensors.

提交时间: 2017年07月25日 点击量:269, 下载量:76

2. chinaXiv:201703.01054 [pdf]

Impaired spinal glucocorticoid receptor signaling contributes to the attenuating effect of depression on mechanical allodynia and thermal hyperalgesia in rats with neuropathic pain

Wei, Xiao; Sun, Yuqi; Luo, Fei
分类: 生物学 >> 神经生物学

Although depression-induced altered pain perception has been described in several laboratory and clinical studies, its neurobiological mechanism in the central nervous system, particularly in the spinal dorsal horn remains unclear. In this study, we therefore aimed to clarify whether nociceptive sensitivity of neuropathic pain is altered in the olfactory bulbectomy (OB) model of depression and whether glucocorticoid receptor (GR), which is involved in the etio-pathologic mechanisms of both major depression and neuropathic pain, contributes to these processes in the spinal dorsal horn of male Sprague-Dawley rats. The results showed that mechanical allodynia and thermal hyperalgesia induced by spinal nerve ligation (SNL) were attenuated in OB-SNL rats with decreased spinal GR expression and nuclear translocation, while NOB (non-olfactory bulbectomy)-SNL rats showed an increased spinal GR nuclear translocation. Decreased GR nuclear translocation with normal mechanical nociception and hypoalgesia of thermal nociception were observed in OB-Sham rats, too. Intrathecal injection of GR agonist dexamethasone (4 µg / rat / day for 1 week) eliminated the attenuating effect of depression on the nociceptive hypersensitivity in OB-SNL rats and aggravated neuropathic pain in NOB-SNL rats, associating with the up-regulation of BDNF, TrkB and NR2B expression in the spinal dorsal horn. The present study shows that depression attenuates the mechanical allodynia and thermal hyperalgesia of neuropathic pain and suggests that altered spinal GR-BDNF-TrkB signaling may be one of the reasons for depression-induced hypoalgesia.

提交时间: 2017年07月24日 点击量:149, 下载量:102

3. chinaXiv:201707.00579 [pdf]

长萼兰花蕉(Orchidantha chinensis T. L. Wu var. longisepala (D. Fang) T. L. Wu)的繁育系统研究

徐凯; 崔长杰; 邹璞; 叶育石; 廖景平; 匡延凤; 刘焕芳
分类: 生物学 >> 植物学

通过野外观察、杂交指数(OCI)、花粉/胚珠比(P/O)、人工授粉、等方法,对长萼兰花蕉(Orchidantha chinensis T. L. Wu var. longisepala (D. Fang) T. L. Wu)种群的繁育系统进行了研究,并采用常规石蜡切片与扫描电子显微镜(SEM)观察了柱头与“V”形黏盘的结构与形态。结果表明:该种单花花期一般为18d,依其花部形态的变化可分为5个时期:(1)蕾期;(2)花萼未反转期;(3)花萼反转期;(4)唇瓣枯萎期;(5)花萼枯萎期。由于杂交指数(OCI)值为4,P/O值为253.89±21.09,结合人工异花授粉结实率分别为45%、75%,可以确定长萼兰花蕉属于异交,传粉过程需要传粉者;石蜡切片结果观察到长萼兰花蕉黏盘区与柱头可授区之间是光滑的表皮细胞,根据人工授粉实验与分泌物含糖量测定结果,表明长萼兰花蕉的“V”形黏盘不具有可授性,其作用可能是分泌粘液附着在传粉者背部使其便于携带花粉。长萼兰花蕉整个花期周围环境湿冷、多雨,且开花同步性较低,这些因素很可能造成了其有效传粉媒介的缺乏,影响了传粉成功,在有性繁殖受到限制时,通过根状茎进行的无性繁殖是其分布范围狭窄的主要原因。

提交时间: 2017年07月20日 点击量:45, 下载量:25

4. chinaXiv:201707.00514 [pdf]

Transcriptome analysis of Hamelia patens (Rubiaceae) anthers reveals candidate genes for tapetum and pollen wall development

Yue, Lin; Twell, David; Kuang, Yanfeng; Liao, Jingping; Zhou, Xianqiang
分类: 生物学 >> 植物学

Studies of the anther transcriptome on non-model plants without a known genome are surprisingly scarce. RNA-Seq and digital gene expression (DGE) profiling provides a comprehensive approach to identify candidate genes contributing to developmental processes in non-model species. Here we built a transcriptome library of developing anthers of Hamelia patens and analysed DGE profiles from each stage to identify genes that regulate tapetum and pollen development. In total 7,720 putative differentially expressed genes across four anther stages were identified. The number of putative stage-specific genes was: 776 at microspore mother cell stage (MMC), 807 at tetrad stage (TET), 322 at uninucleate microspore stage (UNM) and the highest number (1,864) at bicellular pollen stage (BCP). GO enrichment analysis revealed 243 differentially expressed and 108 stage-specific genes that are potentially related to tapetum development, sporopollenin synthesis and pollen wall. The number of expressed genes, their function and expression profiles were all significantly correlated with anther developmental processes. Overall comparisons of anther and pollen transcriptomes with those of rice and Arabidopsis together with the expression profiles of homologs of known anther-expressed genes, revealed conserved patterns and also divergence. The divergence may reflect taxon-specific differences in gene expression, the use RNA-seq as a more sensitive methodology, variation in tissue composition and sampling strategies. Given the lack of genomic sequence, this study succeeded in assigning putative identity to a significant proportion of anther-expressed genes and genes relevant to tapetum and pollen development in H. patens. The anther transcriptome revealed a molecular distinction between developmental stages, serving as a resource to unravel the functions of genes involved in anther development in H. patens and informing the analysis of other members of the Rubiaceae.

提交时间: 2017年07月18日 点击量:132, 下载量:55

5. chinaXiv:201707.00510 [pdf]

Soil wetting decreases the level of apparent activation energy for microbial respiration in subtropical forest ecosystems

Hao, Guangcun; Zhao, Weiping; Zhuang, Qianlai; Wei, Hui; Zhu, Qing; Liu, Yaling; Shen, Weijun
分类: 生物学 >> 生态学

Apparent activation energy (Ea) is one of the most important and sensitive parameters that control soil organic C (SOC) decomposition in prevailing earth system models (ESMs). The variation of apparent Ea is affected by multiple soil environmental factors, among which soil moisture exerts a strong effect. Aiming to better inform temperature sensitivity parameterization in ESMs, here we examined the relationship between apparent Ea and soil moisture with both incubation experiment and field measurement in subtropical forests. We found that apparent Ea declined as soil moisture increased, consistently in both incubation and field experiments. We speculated that this phenomenon was due to altered microbial community composition from changing soil moisture. Our results suggest that future warming and changing precipitation would significantly affect the decomposition of recalcitrant carbon pools in subtropical forests. Lacking representation of the impact of soil moisture on SOC decomposition temperature sensitivity in current ESMs might have biased climate projection.

提交时间: 2017年07月18日 点击量:124, 下载量:40

6. chinaXiv:201707.00502 [pdf]

长期生态学研究引领中国沙区的生态重建与恢复

李新荣,张志山,刘玉冰,王新平,刘立超,陈国雄
分类: 其他 >> 综合

长期生态学研究揭示了干旱沙区土壤水循环的植被调控机理,解决了降水小于200 mm沙区植被建设的关键技术,提出了生态恢复的技术体系及其应用模式;引领了荒漠生物土壤结皮的研究,探明了人工植被稳定性维持的机理,拓展了荒漠系统生态恢复的生态水文学理论基础,推动了干旱逆境生理生态学的研究,在国内外产生了重要影响,为我国风沙危害治理和沙区生态重建与恢复提供了基础理论和技术支撑。

提交时间: 2017年07月17日 来自合作期刊:《中国科学院院刊》 点击量:69, 下载量:34

7. chinaXiv:201707.00498 [pdf]

当代遥感科技发展的现状与未来展望

张兵
分类: 其他 >> 综合

现代遥感技术是利用航天或航空平台对地物进行特定电磁波谱段的数字化成像观测,业已成为人类开展地球系统科学研究和多领域空间信息应用的核心技术手段。文章概述了当今主要遥感技术的基本原理、应用和发展历程,着重介绍了21世纪遥感科技的高空间、高光谱、高时间分辨率的“三高”时代发展特征及其他重要技术突破,介绍了遥感科技在国民经济、生态保护和国防安全等多领域应用情况,讨论了未来遥感科技发展的几个主要方向和趋势。

提交时间: 2017年07月17日 来自合作期刊:《中国科学院院刊》 点击量:77, 下载量:38

8. chinaXiv:201707.00497 [pdf]

建设“国家生态再开发实验区”的科学构想与政策建议——以山西省为例

张义丰; 张吉福; 马彦平; 张伟; 马安全; 赵晓宁; 穆松林
分类: 其他 >> 综合

文章提出了区域生态再开发的理念,并以典型区域山西省为例,分析了生态再开发理念在绿色发展过程中的战略意义,提出了在山西省建设“国家生态再开发实验区”的科学构想,确定了山西省国家生态再开发实验区的战略定位,并从国家层面、省级层面和地方层面3个角度出发,提出了“国家生态再开发实验区”建设的相关政策建议,以期为山西省及类似区域的生态再开发提供科学依据和参考。

提交时间: 2017年07月17日 来自合作期刊:《中国科学院院刊》 点击量:73, 下载量:42

9. chinaXiv:201707.00496 [pdf]

重构自然资源管理制度体系

马永欢; 吴初国; 苏利阳; 林 慧
分类: 其他 >> 综合

自然资源管理制度是生态文明制度体系的重要组成部分,也是基础性制度。文章立足问题和目标导向的研究方法,以国际经验为借鉴,针对当前我国自然资源管理存在的理念落后、管理制度不完善、管理体制不健全等问题,提出要牢固树立生态文明的理念,坚持开发与保护相统一的发展观和系统观,构建由“两大基础、三大过程和四大保障”组成的系统完整的自然资源制度体系。顺应自然资源资产管理体制和自然资源监管体制改革的要求,设计了资产管理和资源监管体制改革路径,以实现自然资源管理的顺畅。

提交时间: 2017年07月17日 来自合作期刊:《中国科学院院刊》 点击量:63, 下载量:35

10. chinaXiv:201707.00495 [pdf]

历史建筑的材料病理诊断、修复与监测前沿技术

戴仕炳,钟燕
分类: 其他 >> 综合

20世纪中期,历史建筑保护发展成为一门独立的学科,现代的科学保护观念随之普及开来。对于历史建筑保护,应遵循由历史建筑保护相关国际宪章衍生而来的规范化流程:现场病害勘察与诊断基础上的方案设计,实验评估后的保护修复与实施,修复后的持续监测、评估与维护。近年来,为打造国家文化软实力,传承和保护民族传统,我国政府投入了大量人力物力资源在历史文物的保护和修缮工程中,取得了一定的成效。文章就我国在历史建筑的材料病理诊断、修复与监测方面所取得的进展进行回顾总结,并探讨在科学保护与修复历史建筑的实际操作中所遇到的困难与矛盾,希望通过对历史建筑的科学保护,为传承我国的千年古文明作出贡献。

提交时间: 2017年07月17日 来自合作期刊:《中国科学院院刊》 点击量:64, 下载量:27

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