检索结果-南通市图书馆

Journal of environmental Sciences 2003年第3期15卷 367-371页

作者： PeNGShao-lin ReNHai WUJian-guo LUHong-fang SouthChinaInstituteofBotany ChineseAcademyofSciencesGuangzhou510650China.E-mail:renhai@*** ArizonaStateUniversityWest PhoenixAZ85069USA

The removal of litterfall in the eucalyptus plantations in South China affected the plant biodiversity in these ecosystems was found based on the field observation and lab analysis. The protection times of species diversity of three eucalyptus communities were different (Community Ⅰ with no protection, Community Ⅱ with 7-year-protection, Community Ⅲ with 35-year-protection). The total numbers of species in these communities (from Community Ⅰ to Ⅱ to Ⅲ) are 1, 6, and 17, respectively. The results showed that the protection of litterfall from being taken out of the ecosystem is important and can increase plant species diversity. This study combined biomass data, the chemical and physical properties of the soil, and the diversity of microbes in the communities. It is concluded that the mechanism of the effects of litter removal on biodiversity includes three factors: removing the suitable habitat of microbe and animal, decreasing the soil nutrient, and changing the special habitat for the germination and growth of invading plants. These results should have important implications for managing these eucalyptus forest ecosystems in South China.

关键词： litter removal biodiversity eucalyptus plantation South China

Assessment of water pollution control strategies: a case study for the Dianchi Lake

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2002年第1期14卷 76-78页

作者： ChenJN ZhangTZ DepartmentofenvironmentalScienceandengineering TsinghuaUniversityBeijing100084China.E－mail：jchenl@*** DepartmentofenvironmentalScienceandengineering TsinghuaUniversityBeijing100084Chin

Lake eutrophication has increasingly become a major environmental issue in China. Although significant efforts have been made towards its resolution in the last decade, most of the implemented control strategies are fragmented, and the formation of policy lacks of sound scientific basis and long\|term objectives. Taking the well\|known Dianchi Lake as a case study, this paper presented a comprehensive assessment for the effectiveness of various eutrophication control strategies. It is expected that the concluding lessons would have a major implication to future eutrophication control.

关键词： pollution control eutrophication Dianchi Lake assessment

QTLs for Rice Leaf Chlorophyll Content Under Low N Stress

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2004年第2期14卷 145-150页

作者： FANGPing YUXiao-Min ZHURi-Qing WUPing CollegeofenvironmentalandResourceSciences ZhejiangUniversityHangzhou310029（China）.E-mail：pfang@*** CollegeofLifeSciences ZhejiangUniversityHangzhou310029（China）

Quantitative trait loci (QTLs) for chlorophyll content of a rice leaf weremapped on to the molecular marker linkage map of a double-haploid (DH) population derived from across between two rice varieties 'IR64' and 'Azucena' in both nutrient solutionand soil cultureexperiments to detect rice nitrogen nutrition status under low N stress A chlorophyll meter was usedto measure the soil plant analysis development (SPAD) value of the topmost fully expanded leaf asthe index of chlorophyll content thatexpressed nitrogen status in rice plants. Totally 3 QTLs forSPAD values, two on chromosome 3 located at interval RG179-CDO337 and RG348-RZ329, respectively, andone on chromosome 10 at interval RZ500-RG134, were detected under stressed conditions of low N inthe soil and/or nutrient solution culture experiments. One QTL located at interval RG179-GDO337 onchromosome 3 associated with a relative change in SPAD value from a high N level to a low N level inthe soil culture experiment was also *** on the different responses to low N stressbetween the two parents, it was supposed that the QTLs identified in this study associated withnitrogen efficiency in rice at low N levels might be useful in applying marker technology to ricebreeding programs.

关键词： chlorophyll meter nitrogen efficiency QTLs rice (Oryza sativa L.) SPADvalue

A Non-Blocking Locking Method and Performance evaluation on Network of Workstations

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2001年第1期16卷 25-38页

作者：于戈王国仁郑怀远金泰勇 Department of Computer Science Northeastern University Shenyang 110006 P.R. China E-mail: {yuge wanggr zhenghy}@*** Kunihiko Kaneko and Akifumi Makinouchi Department of Intelligent Systems Kyushu University Fukuoka Japan E-mail: {jty kaneko akifumi}@db.is.kyushu-u.ac.jp

network of workstation (NOW) can act as a single and scalable powerful computer by building a parallel and distributed computing platformon top of it. WAKASHI is such a platform system that supports persistent objectmanagement and makes full use of resources of NOW for high performance transaction processing. One of the main difficulties to overcome is the bottleneck causedby concurrency control mechanism. Therefore, a non-blocking locking method isdesigned, by adopting several novel techniques to make it outperform the other typical locking methods such as 2PL: 1) an SDG (Semantic Dependency Graph) basednon-blocking locking protocol for fast transaction scheduling; 2) a massively virtualmemory based backup-page undo algorithm for fast restart; and 3) a multi-processorand multi-thread based transaction manager for fast execution. The new mechanismshave been implemented in WAKASHI and the performance comparison experimentswith 2PL and DWDL have been done. The results show that the new method canoutperform 2PL and DWDL under certain conditions. This is meaningful for Choosing effective concurrency control mechanisms for improving transaction- processingperformance in NOW environments.

关键词： distributed and parallel database concurrency control transaction

Numerical Simulation of Sub-cooled Cavitating Flow by Using Bubble Size Distribution

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal Science 2003年第4期12卷 350-356页

作者： Yutaka ITO es.titech.ac.jp Hideki WAKAMATSU es.titech.ac.jp Takao NAGASAKI es.titech.ac.jp Department of energy Sciences Tokyo Institute of Technology 4259 Nagatsuta-cho Midori-ku Yokohama 226-8502 Japan E-mail: itoDepartment of Energy Sciences Tokyo Institute of Technology 4259 Nagatsuta-cho Midori-ku Yokohama 226-8502 Japan E-mail: itoDepartment of Energy Sciences Tokyo Institute of Technology 4259 Nagatsuta-cho Midori-ku Yokohama 226-8502 Japan E-mail: ito

A new cavitating model by using bubble size distribution based on mass of bubbles is proposed. Liquid phase is treated with eulerian framework as a mixture containing minute cavitating bubbles. Vapor phase consists of various sizes of minute vapor bubbles, which is distributed to classes based on their mass. The change of bubble number density for each class was solved by considering the change of bubble mass due to phase change as well as generation of new bubbles due to heterogeneous nucleation. In this method the mass of bubbles is treated as an independent variable, in other word, a new coordinate, and dependant variables are solved in eulerian framework for spatial coordinates and bubble-mass coordinate. The present method is applied to a cavitating flow in a convergent-divergent nozzle, and the two-phase flow with bubble size distribution and phase change was successfully predicted.

关键词： cavitation numerical simulation liquid nitrogen bubble size distribution.

Hydrothermal Synthesis and Structure of a Novel Binuclear Molybdenum Complex with Oxalate Ligand, (enH_2){NH_4[Co(en)_3][Mo_2O_7(C_2O_4)] }_2·2H_2O

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2004年第1期23卷 57-61页

作者： LIUPei-De PeIXiao-Ke LINBi-Zhou InstituteofMaterialsPhysicalChemistry HuaqiaoUniversityQuanzhouFujian362011China. InstituteofMaterialsPhysicalChemistry HuaqiaoUniversityQuanzhouFujian362011ChinaTel：0595-2691569E-mail：bzlin@hqu.e***

The title complex (enH2){NH4[Co(en)3][Mo2O7(C2O4)]}22H2O (C18H70Co2Mo4- N16O24, Mr = 1396.52) was obtained under hydrothermal conditions and its crystal structure has been determined by single-crystal X-ray diffraction. It crystallizes in the monoclinic system, space group P21/c with a = 17.8023(8), b = 7.7527(4), c = 16.9781(4) ? b = 103.878(7), V = 2274.8(2) 3, Dc = 2.039 g/cm3, Z = 2, m(MoKa) = 1.878 mm-1 and F(000) = 1408. The final R = 0.0410 and wR = 0.1070 for 4065 observed reflections with I≥2s(I). The crystal structure is composed of bi- nuclear [Mo2O7(C2O4)]4- anions, complex [Co(en)3]2+ cations, protonated ethylenediamine cations, ammonium cations and crystal water molecules, which are held together into a three-dimensional network via hydrogen-bonding interactions. The binuclear structure of [Mo2O7(C2O4)]4- consist of one MoO4 and one MoO6 octahedra through sharing a bridging oxygen atom, where the oxalate ligand acts as a bidentate ligand coordinating to the octahedral molybdenum atom though two deprotonated corboxylate groups.

关键词： hydrothermal synthesis crystal structure molybdenum complexes cobalt complexes oxalate complexes

High efficiency DNA delivery into swine oocytes and embryos by electronic pulse delivery (ePD)

在线全文

学校读者我要写书评

暂无评论

Cell Research 1997年第1期7卷 39-49页

作者： YANG YANG SHAO HUA HUANG XI ZHAO(InCell, Inc. 2310 welsh Avenue, Santa Clara, California 95051, USA.) Present address: Department of Medicine Division of Immunology and Rheumatology Stanford University School of Medicine Stanford CA 94305 Phone: (415) 723-7949 E-mail: yyang@leland stanford. edu

The production of transgenic swine for xenotransplantation has been proposed as an optimal option to overcome the chronic shortage of human organ donors. Generation of genetically engineered swine has been elusive due to the difficulties in gene transfer. In order to achieve effective gene delivery, a key step for the genetic modification, we applied electronic pulse delivery (ePD) technology to introduce HZKb-DC DNA construct into swine eggs. Using the developed ePD ProtocolsTM, we have achieved good viability of the ePD treated oocytes, satisfactory embryonic development of the ePD treated embryos, and stable DNA transfer into the swine embryos with high efficiency. Thus, application of the ePD technology promises to effectively facilitate the generation of large trangenic mammals.

关键词： Xenotransplantation transgenic pig electronic pulse delivery (ePD) swine embryos DNA transfer

Species clarification of the prize medicinal Ganoderma mushroom“Lingzhi”

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Fungal Diversity 2012年第5期56卷 49-62页

作者： Yun Cao Sheng-Hua Wu Yu-Cheng Dai State Key Laboratory of Forest and Soil ecology Institute of Applied EcologyChinese Academy of SciencesShenyang 110164China Graduate University of the Chinese Academy of Sciences Beijing 100049China Department of Botany National Museum of Natural ScienceTaichung 404Taiwan Department of Plant Pathology National Chunghsing UniversityTaichung 402Taiwan e-mail:shwu@mail.nmns.edu.tw Institute of Microbiology Beijing Forestry UniversityBeijing 100083China e-mail:yuchengd@***

“Lingzhi”is a mushroom that has been renowned in China for more than 2,000 years because of its claimed medicinal properties plus its symbolic fortune.“Lingzhi”has high economic value mostly as a dietary supplement in the modern market especially in east Asia,and its medicinal functions have become a hot study *** over a century,the highly prized medicinal fungus,known as“Lingzhi”in east Asia,has been assigned to Ganoderma lucidum,a species originally described from *** studies in recent years have revealed that the commercially cultivated‘***’(“Lingzhi”)in east Asia is a different species from the true *** present study aims to clarify the species identity of“Lingzhi”based on morphological studies and analysis of rDNA nuc-ITS sequences,and additional gene fragments of mt-SSU,RPB1,RPB2,and TeF1-αof“Lingzhi”were *** Ganoderma species that mostly resemble“Lingzhi”in phylogeny and/or morphology were included for *** propose a new species *** for“Lingzhi”,which has an east Asia *** most striking characteristics which differentiate *** from *** are the presence of melanoid bands in the context,a yellow pore surface and thick dissepiments(80–120μm)at *** is most closely related to *** in phylogeny and is from North *** flexipes,***,***,*** and‘***’,are also closely related with *** and are reported from *** species are compared and discussed.‘Ganoderma tsuage’reported from China is determined as conspecific with ***,hence the distribution of *** extends from europe to northeastern China.

关键词： Ganodermataceae Ganoderma lingzhi G lucidum Medicinal fungus Phylogeny Taxonomy

On the minimum cost of an evolutionary strategy response to environment stress

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

Journal of environmental Sciences 2002年第3期14卷 333-338页

作者： LinZS LiBL DepartmentofGeography NanjinNormalUniversityNanjing210097China.E－mail：zslin@*** DepartmentofBiology theUniversityofNewMexicoAlbuquerqueNM87131－1091USA

Two revised drafts about a simple evolution trade off function studied by Mitchell(Mitchell, 2000) were put up first. Considering the complex of the environment, or the nonlinear interaction of the environment and species, we put up two new cost functions:c(u,z)=c 0+c 1u+k(z+az 2)u,u>0;c(u,z)=c 0+c 1u+kz du,u>0,d>0. In the first case, if the environment is adverse to species ( a >0), the region of low stress which is more suitable for the intolerant species is very small, and at the same environment stress z , the tolerant species will pay the more cost than it will paid in the normal environment. However the tolerant species will pay more cost but low strategies in the environment of a e environment of a =0 or a >0. In the second case, the results showed that the greater the stress of the environment is, or the more complex the environment is, the lower cost the intolerant species will pay in the region of z er to exist or to evolve from an environment of high stress, the organisms must possess a higher u , or a better means of mitigating of the stress of environment. Meanwhile in the region d >1, when d decrease, the intolerant species will pays more lower cost of exploiting a habitat in the low stress environment while the tolerant one will pays more lower cost in the high stress environment. This means that scale d describes the selection character of the species system in the evolution process, the smaller the d(d e better the selection or the mitigation the system will possesses.

关键词： evolutionary strategy response environment stress

Quantum dots enhance Cu^(2+)-induced hepatic L02 cells toxicity

在线全文

学校读者我要写书评

暂无评论

Journal of environmental Sciences 2010年第12期22卷 1987-1992页

作者： Yuxia Zhao,Kuangfei Lin,Wei Zhang,Lili Liu State environmental Protection Key Laboratory of environmental Risk Assessment and Control on Chemical Process,Shanghai 200237,China [a] State environmental Protection Key Laboratory of environmental Risk Assessment Control on Chemical Process Shanghai 200237 China. E-mail: maryzyx@***

As a new class of xenogenous nanoparticle, quantum dots （QDs） possess the potential to co-exist with Cu^2＋ in human liver. The combined toxicity is thus concerned. Considering QDs and Cu^2＋ are known ROS （reactive oxygen species） inducer, we investigated the combined oxidative stress and corresponding protective strategy using human hepatic L02 cells. The results demonstrated that the presence of a small amount of MPA-CdTe QDs （2 μg/mL） in a Cu^2＋ solution （2.5-20 μg/mL） resulted in a higher toxicity with up to 8-fold cell viability decrease, which was accompanied by cell morphology changes. The combined toxicity was then confirmed as ROS associated oxidative stress with up to 300% and 35% increase of the intracellular ROS level and glutathione S-transferase （GST） activity, respectively. N-acetylcysteine （NAC） can also provide almost complete protection against the induced toxicity. Therefore, the ROS associated oxidant injury might be responsible for the QDs-Cu^2＋/Cu^2＋ induced toxicity and could be balanced through cytoprotective antioxidant enzyme GST.

关键词： quantum dots hepatic L02 cell reactive oxygen species glutathione S-transferase