检索结果-南通市图书馆

litterfall,litter Decomposition,and Nutrient Dynamics in Two Subtropical Bamboo Plantations of China

Pedosphere 2014年第1期24卷 84-97页

作者： tu li-hua HU Hong-ling HU Ting-Xing ZHANG Jian li Xian-Wei liU li XIAO Yin-Long CHEN Gang li Ren-Hong College of Forestry Sichuan Agricultural University Institute of Ecological Forestry College of ForestrySichuan Agricultural UniversityChengdu CampusWenjiang District Personnel Department Sichuan Agricultural University Sichuan Forestry Inventory and Plan Institute

Bamboos are one of the fast-growing and multiple use species in the world, and thus bamboo forests/plantations play an important role in C sequestration at regional and global levels. We studied aboveground litterfall, litter decomposition and nutrient dynamics for two years in two subtropical bamboo ecosystems in Southwest China so as to test the hypothesis that litter quality determine the rate and nutrient dynamics during decomposition of different litter fractions. Mean annual total aboveground litter production ranged from 494 to 434 g m-2 in two bamboo stands （P stand, dominated by Pleioblastus amarus and H stand, hybrid bamboo dominated by Bambusa pervariabilis x Dendrocalamopsis daii）. Bulk （-80%） of litter production was contributed by leaf litter in two stands followed by twigs and sheathes. Different litter fractions represented considerable variations in the rates of mass loss and nutrient release. Variation of the mass remaining after 2 years of decomposition was significantly explained by initial C/N ratio and initial P concentration. Initial concentrations of N, P, Ca, and Mg explained 57.9%, 95.0%, 99.8% and 98.1%, respectively, of the variations of these elements mass remaining after 2 years of decomposition. The patterns of nutrient dynamics and the final amount remaining were mainly determined by their initial litter substrate quality in tl^ese two subtropical bamboo plantations.

关键词： C/N ratio litter fraction litter substrate mass loss Pleioblastus amarus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Decomposition of Different litter Fractions in a Subtropical Bamboo Ecosystem as Affected by Experimental Nitrogen Deposition

引用

Pedosphere 2011年第6期21卷 685-695页

作者： tu li-hua HU Hong-ling HU Ting-Xing ZHANG Jian liU li li Ren-Hong DAI Hong-Zhong LUO Shou-hua Sichuan Provincial Key Laboratory of Forestry Ecological Engineering College of Forestry Sichuan Agricultural University Xingkang Road 46 Ya'an 625014 (China) Maize Research Institute Sichuan Agricultural University Ya'an 625014 (China) Sichuan Forestry Inventory and Plan Institute Chengdu 610081 (China)

As an important component of the global carbon （C） budget, litter decomposition in terrestrial ecosystems is greatly affected by the increasing nitrogen （N） deposition observed globally. We hypothesized that different litter fractions derived from a single tree species may respond to N deposition differently depending on the quality of the litter substrate. To test the hypothesis, a two-year field experiment was conducted using the litterbag method in a Pleioblastus amarus plantation in the rainy region of Southwest China. Four N treatment levels were applied： control （no N added）, low-N （50 kg N ha-1 year-1）, medium-N （150 kg N ha-a year-1）, and high-N （300 kg N ha-1 year-l）. We observed different patterns of mass loss for the three P. amarus litter fractions （leaves, sheaths, and twigs） of varying substrate quality in the control plots. There were two decomposition stages with different decay rates （fast rate in early stages and slow rate in the later stages） for leaves and sheaths, while we did not observe a slower phase for the decay of twigs during the 2-year study period. The annual decomposition rate （k） of twigs was significantly lower than that of leaves or sheaths. Addition of N slowed the decomposition of leaves and twigs in the later stages of decomposition by inhibiting the decay of lignin and cellulose, while addition of N did not affect the mass loss of sheaths during the study period. In the decomposition of all three litter fractions, experimental N deposition reduced the net N accumulation in the early stages and also decreased the net N release in the later stages. The results of this study suggest that litter substrate quality may be an important factor affecting litter decomposition in a bamboo ecosystem affected by N deposition.

关键词： decomposition rate litter substrate N dynamics plant biomass Pleioblastus amarus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

NIR-IIb-triggered photodynamic therapy combined with chemotherapy platform based on rare-earth-doped nanoparticles

引用

Rare Metals 2024年第7期43卷 3220-3231页

作者： Zhuo tu Yong Wan Juan Ge Chen-Chen li Tao liang Zhen li Chemistry and Chemical Engineering Hubei UniversityWuhan 430062China

Photodynamic therapy(PDT),with high spatiotemporal selectivity,minimal side effects and less drug resistance,has emerged as a promising approach for the treatment of ***,inadequate penetration depth and poor efficacy seriously restrict its practical *** address these challenges,we developed a combined therapy platform(RENP@C/D-FA)based on rare-earth-doped nanoparticles(RENPs)with a structure of NaErF_(4):Tm(0.5%)@NaYF_(4),on which photosensitizer Ce6(chlorin e6)and chemo-therapeutic drug(DOX)(doxorubicin)were loaded by encapsulating with an amphiphilic polymer distearoyl phosphatidylethanolamine-polyethylene glycol-folic acid(DSPE-PEG-FA).RENPs with NaErF_(4) as the matrix possess multiple excitation/emission peaks,enabling activation of PDT under near-infrared-Ⅱb(NIR-Ⅱb,1500-1700 nm)excitation and luminescence imaging in NIR-Ⅱb region by absorbing 808 nm near-infrared ***,DOX can be selectively released in the acidic microenvironment of *** from the tumor targeting capability of folic acid,this platform can successfully ablate tumor cells and inhibit tumor growth by combining PDT and *** innovative approach holds great promise as a powerful tool for cancer treatment,showing the potential to revolutionize PDT.

关键词： Photodynamic therapy Rare-earth-doped nanoparticles NIR-IIb Chemotherapy Combined therapy

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A New Solution to Intrusion Detection Systems Based on Improved Federated-Learning Chain

引用

Computers, Materials & Continua 2024年第6期79卷 4491-4512页

作者： Chunhui li hua Jiang School of Computer and Electronic Information Guangxi UniversityNanning530000China Cyber Security and Information Center Guangxi UniversityNanning530000China

In the context of enterprise systems,intrusion detection(ID)emerges as a critical element driving the digital transformation of *** systems spanning various sectors of enterprises geographically dispersed,the necessity for seamless information exchange has surged *** existing cross-domain solutions are challenged by such issues as insufficient security,high communication overhead,and a lack of effective update mechanisms,rendering them less feasible for prolonged application on resource-limited *** study proposes a new cross-domain collaboration scheme based on federated chains to streamline the server-side *** this framework,individual nodes solely engage in training local data and subsequently amalgamate the final model employing a federated learning algorithm to uphold enterprise systems with efficiency and *** curtail the resource utilization of blockchains and deter malicious nodes,a node administration module predicated on the workload paradigm is introduced,enabling the release of surplus resources in response to variations in a node’s contribution *** encountering an intrusion,the system triggers an alert and logs the characteristics of the breach,facilitating a comprehensive global update across all nodes for collective *** results across multiple scenarios have verified the security and effectiveness of the proposed solution,with no loss of its recognition accuracy.

关键词： Cross-domain collaboration blockchain federated learning contribution value node management release slack resources

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

In situ photocatalytically enhanced thermogalvanic cells for electricity and hydrogen production

引用

Chinese Journal of Structural Chemistry 2024年第1期43卷 1-2页

作者： Tianhao li Wenguang tu Zhigang Zou School of Science and Engineering The Chinese University of Hong KongShenzhenGuangdong518172PR China

Converting low-grade thermal energy into electricity through ther-mogalvanic cells offers a promising approach to addressing environ-mental challenges[1].However,thermogalvanic cells face obstacles,due to limited thermopower,connected to differences in solvent-dependent entropy(ΔS)among redox anions and varying concentration ratios(ΔC)between hot and cold sides[2,3].A typical strategy to enhance the thermopower involves the improvement ofΔS of the redox ***-fortunately,ΔC tends to approach zero spontaneously due to the ther-modynamic instability and redox ion ***,the challenge is to maintain significantΔC for both redox ions and unravel the intricate modulation mechanisms[4].

关键词： redox maintain entropy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

SWG: an architecture for sparse weight gradient computation

引用

Science China(Information Sciences) 2024年第2期67卷 302-321页

作者： Weiwei WU Fengbin tu Xiangyu li Shaojun WEI Shouyi YIN School of Integrated Circuits Tsinghua University Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology

On-device training for deep neural networks(DNN) has become a trend due to various user preferences and scenarios. The DNN training process consists of three phases, feedforward(FF), backpropagation(BP), and weight gradient(WG) update. WG takes about one-third of the computation in the whole training process. Current training accelerators usually ignore the special computation property of WG and process it in a way similar to FF/BP. Besides, the extensive data sparsity existing in WG, which brings opportunities to save computation, is not well explored. Nevertheless, exploiting the optimization opportunities would meet three underutilization problems, which are caused by(1) the mismatch between WG data dimensions and hardware parallelism,(2) the full sparsity, i.e., the sparsity of feature map(Fmap),error map(Emap), and gradient, and(3) the workload imbalance resulting from irregular sparsity. In this paper, we propose a specific architecture for sparse weight gradient(SWG) computation. The architecture is designed based on hierarchical unrolling and sparsity-aware(HUSA) dataflow to exploit the optimization opportunities of the special computation property and full data sparsity. In HUSA dataflow, the data dimensions are unrolled hierarchically on the hardware architecture. A valid-data trace(VDT) mechanism is embedded in the dataflow to avoid the underutilization caused by the two-sided input sparsity. The gradient is unrolled in PE to alleviate the underutilization induced by output sparsity while maintaining the data reuse opportunities. Besides, we design an intra-and inter-column balancer(IIBLC) to dynamically tackle the workload imbalance problem resulting from the irregular sparsity. Experimental results show that with HUSA dataflow exploiting the full sparsity, SWG achieves a speedup of 12.23× over state-of-the-art gradient computation architecture, Train Ware. SWG helps to improve the energy efficiency of the state-of-the-art training accelerator LNPU from

关键词： CNN training gradient computation sparsity architecture

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Improving anammox activity and reactor start-up speed by using CO_(2)/NaHCO_(3) buffer

引用

Journal of Environmental Sciences 2024年第5期139卷 60-71页

作者： Shaoan Cheng huahua li Xinyuan He hua Chen Longxin li State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou 310027China

Anammox bacteria grow slowly and can be affected by large pH *** suitable buffers could make the start-up of anammox reactors easy and *** this study,the effects of three kinds of buffers on the nitrogen removal and growth characteristics of anammox sludge were *** with CO_(2)/NaHCO_(3)buffer solution(CCBS)performed the best in nitrogen removal,while 4-(2-hydroxyerhyl)piperazine-1-ethanesulfonic acid(HEPES)and phosphate buffer solution(PBS)inhibited the anammox *** with 50 mmol/L CCBS could start up in 20 days,showing the specific anammox activity and anammox activity of 1.01±0.10 gN/(gVSS·day)and 0.83±0.06 kgN/(m^(3)·day),*** Kuenenia was the dominant anammox bacteria,with a relative abundance of 71.8%.Notably,anammox reactors could also start quickly by using 50 mmol/L CCBS under nonstrict anaerobic *** findings are meaningful for the quick start-up of engineered anammox reactors and prompt enrichment of anammox bacteria.

关键词： Anammox bacteria Buffer solution CO_(2)/NaHCO_(3) Physiological characteristics Microbial community shift

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Electrochemical filtration for drinking water purification:A review on membrane materials,mechanisms and roles

引用

Journal of Environmental Sciences 2024年第7期141卷 102-128页

作者： Yuying Qi Donghao li Shixuan Zhang Fengxiang li Tao hua College of Environmental Science and Engineering Nankai UniversityTianjin 300350China Key Laboratory of Pollution Process and Environmental Criteria Ministry of EducationTianjin 300350China Tianjin Engineering Center of Environmental Diagnosis and Contamination Remediation Tianjin 300350China

Electrochemical filtration can not only enrich low concentrations of pollutants but also produce reactive oxygen species to interact with toxic pollutants with the assistance of a power supply,making it an effective strategy for drinking water *** addition,the application of electrochemical filtration facilitates the reduction of pretreatment procedures and the use of chemicals,which has outstanding potential for maximizing process simplicity and reducing operating costs,enabling the production of safe drinking water in smaller *** recent years,the research on electrochemical filtration has gradually increased,but there has been a lack of attention on its application in the removal of low concentrations of pollutants from low conductivity *** this review,membrane substrates and electrocatalysts used to improve the performance of electrochemical membranes are briefly ***,the application prospects of emerging single-atom catalysts in electrochemical filtration are also ***,several electrochemical advanced oxidation processes coupled with membrane filtration are described,and the related working mechanisms and their advantages and shortcomings used in drinking water purification are ***,the roles of electrochemical filtration in drinking water purification are presented,and the main problems and future perspectives of electrochemical filtration in the removal of low concentration pollutants are discussed.

关键词： Electrochemical filtration Drinking water Conductive membrane Low concentration Electrocatalyst

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Tianmouc vision chip designed for open-world sensing

引用

Science China Materials 2024年第9期67卷 3046-3048页

作者： Haotian li Qilin hua Guozhen Shen School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing100081China Institute of Flexible Electronics Beijing Institute of TechnologyBeijing102488China

Driven by the forward development of highly interactive applications like autonomous robots and artificial intelligence[1,2],image sensors are continuously demanded to improve in terms of high speed,high resolution,wide dynamic range,and high precision[3].However,due to inherent limitations in power and bandwidth,significant enhancements in one aspect often necessitates compromises in others[4].

关键词： artificial interactive autonomous

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Insulation Design Rule for a Spacer in SF_(6)/N_(2)-filled DC Gas Insulated Apparatus

引用

CSEE Journal of Power and Energy Systems 2024年第2期10卷 727-735页

作者： Hongyang Zhou Guoming Ma Meng Zhang Cong Wang Youping tu Chengrong li State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources and the Beijing Key Laboratory of High Voltage and EMC North China Electric Power UniversityBeijing 102206China

A recurring challenge of a DC SF_(6)/N_(2)-filled GIS/GIL apparatus is the charge accumulation at DC *** conventional design rules and knowledge of AC spacers may not be applicable for this new type of apparatus.A novel design rule is proposed considering the effect of accumulated charge on the threshold of electric field strength being resistant to the superposed voltage.A surface charge accumulation simulation model is introduced,and the key parameters in the simulation model are *** addition,an experimental platform for a 100 kV spacer flashover test is *** flashover tests under superimposed voltage with opposing polarities are carried out,and the withstanding voltage of the spacer is ***,based on the proposed model,the threshold of the surface electric field strength(tangential component)on the DC spacer in SF_(6)/N_(2) mixed gases is *** a reliable insulation design of a DC GIS/GIL apparatus filled with 0.7 MPa SF_(6)/N_(2),the threshold of surface electric field strength on the DC spacer is 12 kV/*** insulation design rule can be referenced in the design of a high-voltage DC SF_(6)/N_(2)-filled GIS/GIL apparatus.

关键词： Charge accumulation DC spacer flashover voltage SF_(6)/N_(2) threshold of surface electric field strength

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：