检索结果-南通市图书馆

Ideal class groups and their subgroups of real quadratic fields

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 1997年第9期40卷 909-916页

作者：张贤科 Lawrence c.washington Department of Mathematics Tsinghua UniversityBeijing 100084China Department of Mathematics University of MarylandCollege ParkMD 20742USA

A necessary and sufficient condition is given for the ideal class group H( m } of a real quadratic field Q (m)to contain a cyclic subgroup of order *** criteria satisfying the condition are also *** eight types of such fields are proved to have this property,*** with m=(zn+t+12)+4t(with t|zn-1),which contains the well-known fields with m=4zn+1 and m=z2n+4 as special cases.

关键词： real quadratic field ideal class group class number.

Modification of cohen-Lenstra heuristics for ideal class groups and numbers of certain real quadratic fields

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 1997年第23期42卷 1959-1962页

作者： L.c.washington Department of Mathematics University of Maryland College Park MD20742 USA

THE famous cohen-Lenstra heuristics aroused wide insterest and research. Here for a certaintype of real quadratic fields with elements P of potential order p in their ideal classes, modifi-cations of the cohen-Lenstra heuristics for the probability that the class number h is a multipleof p, and the probability that P is of order p, are presented. Via a quite large amount ofcomputations, it was found that both of these probability predictions agree fairly well with thenumerical data.

关键词： real quadratic field class group class number heuristics.

Exposure of juvenile chinook salmon to effluent from a large urban wastewater treatment *** *** profiling

在线全文

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2024年第3期9卷 367-377页

作者： James P.Meador Suzanne c.Ball c.Andrew James Jenifer K.McIntyre Dept.of Environmental and Occupational Health Sciences School of Public Health4225 Roosevelt Way NESuite 100SeattleWA98105-6099USA washington State University School of the EnvironmentPuyallup Research and Extension Center2606 W Pioneer AvePuyallupWA98371USA University of washington Tacoma Center for Urban Waters326 East D StreetTacomaWA98421-1801USA

Targeted metabolomic analysis was conducted on juvenile chinook salmon exposed for 10 days to wastewater effluent(WWE)from a large urban treatment *** included five dilutions of WWE(20%,5.3%,1.4%,0.4%,and 0.1%)and a control with 7 replicates per *** was extracted from fish and analyzed via liquid chromatography–mass spectrometry(Lc-MS)for 361 endogenous metabolites,of which 185 were ***-versus-treatment comparisons identified several metabolites that were associated with altered biochemical pathways observed for all treatments,including several that are important for energy generation and *** altered pathways are crucial for fish health and may be an early indicator of potential adverse effects on growth,reproduction,behavior,and immune *** ocean-type chinook salmon spend several days to weeks in the nearshore estuary where they may encounter high concentrations of WWE *** are exposed to a wide range of potent pharmaceuticals,personal care products,and industrial compounds from WWE that have the potential to affect physiological homeostasis and disrupt their normal life cycle.

关键词： Wastewater effluent Metabolomics Physiology chinook salmon Pharmaceuticals Metabolic pathways Estuary

Exposure of juvenile chinook salmon to effluent from a large urban wastewater treatment *** *** responses

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Aquaculture and Fisheries 2024年第3期9卷 355-366页

作者： Suzanne c.Ball James P.Meador c.Andrew James Jenifer K.McIntyre washington State University School of the EnvironmentPuyallup Research and Extension Center2606 W Pioneer AvePuyallupWA98371USA Dept.of Environmental and Occupational Health Sciences School of Public Health4225 Roosevelt Way NESuite 100SeattleWA98105-6099USA University of washington Tacoma Center for Urban Waters326 East D StreetTacomaWA98421-1801USA

Wastewater treatment plants release complex mixtures of chemicals into the aquatic environment as wastewater effluent(WWE);however,the effects of these mixtures are still poorly *** salmon(Oncorhynchus tshawytscha)are a culturally important species in the Pacific Northwest and are a vital food resource for southern resident killer whales(Orcinus orca)that are listed as‘critically endangered’under the *** Species Act(ESA).chinook populations have declined drastically in this region and have failed to show significant recovery despite regional-to-federal efforts,resulting in many populations being listed as threatened under the *** source of stress to juvenile chinook is chemical pollution from WWE during their outmigration along river corridors and residency in *** this study,we investigated effects of WWE on juvenile chinook health in a ten-day exposure to dilutions of WWE from 0.1%to 20%.At the end of the exposure,we measured endpoints associated with endocrine disruption,brain function,osmoregulation,stress,and *** to WWE significantly(α=0.1 for all analyses)induced vitellogenesis,indicating endocrine system *** saw significant reductions in plasma glucose,an indication of stress,and brain Na+/K+-ATPase(NKA)activity,an enzyme essential for neuronal ***,metabolism was affected as evidenced by altered total protein,cholesterol,and albumin in plasma,a drastic decrease in whole body lipid content,and a significant increase in visible liver *** compared contaminant concentrations in exposure water with effects concentrations from the literature for chemicals known to induce vitellogenin or inhibit brain *** most contaminants,concentrations in exposure waters were several orders of magnitude below effects concentrations in the *** exception was estrogenic hormones,which were detected at similar concentrations in this study compared to concentrations in other studies tha

关键词： Wastewater effluent chinook salmon Toxicity Sodium potassium ATPase Vitellogenin Physiology Metabolism Glucose

What Do Educators Need to Teach for Prospective Knowledge Engineers?

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 Systems Engineering and Electronics 1995年第3期6卷 1-6页

作者： Jay Liebowitz(Dept. of Management Science, George washington University, washington, D. c. 20052) Dept. of Management Science Georg washington University Washington D. C. 20052

As expert systems technology has matured and migrated into mainstream computing, there arestill areas which are overlooked in education prospective knowledge engineers. This paper addresses this issue, and provides a message to educators that expert and knowledge-based systems should be an importantstrategic science and technology for many organizations.

关键词： Knowledge engineers Expert systems Intelligent systems Knowledge engineering

在线全文

学校读者我要写书评

暂无评论

乳液生产新技术

日用化学品科学 1988年第4期 40-43页

作者： c.washington 赵章楣

乳化产品广泛地用于制药工业(用于制皮肤抗感染药、口服药和静脉注射药物);最近的生产工艺特别要求严格控制产品质量。典型的例子是静脉注射乳液(如内酯类物),以及全氟化碳乳液、血液代用品。许多单位正在研究胶体物质(如乳液、微粒)的... 详细信息

乳化产品广泛地用于制药工业(用于制皮肤抗感染药、口服药和静脉注射药物);最近的生产工艺特别要求严格控制产品质量。典型的例子是静脉注射乳液(如内酯类物),以及全氟化碳乳液、血液代用品。许多单位正在研究胶体物质(如乳液、微粒)的应用。当然,脂质体(作为药物基剂)和几种产品在这一领域已处于发展的领先阶段。因此,生产乳液的新方法必将引起很大的兴趣,这并不引人惊奇。在此考虑对于注入静脉的微粒或乳液产品的要求是实用的。静脉注射乳液药物最好用粒度在200～300nm的液滴,由肺的毛细管

关键词：乳液液滴静脉注射颗粒流化器超声波探头

Allophane as a Nanotechnological Additive in Masonry Materials to Increase Resistance and Waterproofing

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Materials Physics and chemistry 2024年第8期14卷 196-212页

作者： Edward H. Jiménez Joao Rivera Juan H. Villalba Paola E. Vera Marlon cuenca Belén Granja Javier Fuentes Sandra Gavilanes Daniel Hidalgo Fernando Garcia Jose Bermudez washington Ruiz Alexis Martial Debut Facultad de Ingeniera Qumica Universidad Central del Ecuador Quito Ecuador Facultad de Arquitectura y Urbanismo Universidad Central del Ecuador Quito Ecuador Nanomaterials characterization Laboratory Universidad de las Fuerzas Armadas ESPE Sangolqu Ecuador

The constant need for high-strength materials in the construction industry promotes the research of additives that improve the properties of masonry materials. The use of allophane as an additive in concrete and mortar mixtures was implemented to improve their strength and waterproofing, respectively, using compression and water absorption tests according to their corresponding standards (ASTM c1231, ASTM D2938, and ASTM c1585). The samples were evaluated at different concentrations and curing ages. In addition, different sand/cement ratios were considered for the mortar. The results revealed that there was a 9.4% increase in compressive strength in concrete and a 23.7% reduction in water absorption in mortar for the 5:1 ratio. These changes would be the result of the interaction of the nanoporous additive in the atomic crystal structure of the material demonstrating the nanotechnological nature of allophane.

关键词： Allophane Nano Additive Strength Impermeability concrete Mortar

Designated critical habitats for *** species are not protected from climate and land-use change

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geography and Sustainability 2024年第3期5卷 482-490页

作者： Aimee Delach Laura A.Nunes Alex Borowicz Theodore c.Weber center for conservation Innovation Defenders of Wildlife113017th Street NWWashingtonD.C.20036United States

Designation of critical habitat is an important conservation tool for species listed as threatened or endangered under the United States(U.S.)Endangered Species Act(ESA).While this is an important protective mechanism,lands designated as critical habitat could still be subject to degradation and fragmentation if they are not also in a protected status that prioritizes biodiversity ***,most designations of critical habitat do not explicitly take climate change into *** objective of our study was to determine whether and to what extent critical habitats for species listed under the ESA are located within protected areas and areas previously identified as climate refugia or climate corridors,to inform management strategies to better conserve and recover these *** mapped the designated critical habitats of 153 ESA-listed species and measured their overlap with previously-identified areas of climate refugia and corridors(cRc),and also with lands designated as nature-protected by *** Survey’s Gap Analysis Project(GAP Status 1 or 2)and working lands with wildlife habitat potential(GAP Status 3).Only 18%of all designated critical habitat is located on lands that are both in cRc and nature-protected,and only 9%of species had over half of their designated critical habitats in such lands.84%of species hadcritical habitats with these *** habitats may therefore not fulfill their essential role of helping imperiled species persist and recover.

关键词： Endangered Species Act critical habitat climate refugia climate corridors Protected areas Biodiversity conservation

Non-linear dynamic state-space network modeling for decoding neurodegeneration

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第9期19卷 1879-1880页

作者： Venkata c.chirumamilla chi Wang Ip Martin Reich Robert Peach Jens Volkmann Bahman Nasseroleslami Muthuraman Muthuraman Prenatal Pediatrics Institute Children’s National HospitalWashingtonDCUSA Neural Engineering with Signal Analytics and Artificial Intelligence Department of NeurologyUniversity of WürzburgWürzburgGermany Academic Unit of Neurology Trinity Biomedical Sciences InstituteTrinity College DublinUniversity of DublinDublinIreland

Neurodegenerative disorders represent a pervasive global health challenge,yet therapeutic options remain conspicuously *** disorders are inherently dynamic processes within the central nervous system,unfolding across distinct sub-stages:initial structural neuronal alterations(sub-stage 1),functional impairment(sub-stage 2),and culminating in neuronal death(sub-stage 3).

关键词： alterations impairment dynamic