检索结果-南通市图书馆

Estimation of carbon pools in secondary tropical deciduous forests of Odisha,India

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2021年第2期32卷 663-673页

作者： Subhashree Pattnayak M.kumar N.K.Dhal Sudam c.Sahu Department of Life Sciences Sambalpur UniversitySambalpurOdisha 768019India Environment and Sustainability Department CSIR-IMMTBhubaneswarOdisha 751013India Department of Botany North Orissa UniversityBaripadaOdisha 757003India

Secondary tropical forests sequester atmospheric cO 2 at relatively faster rates in vegetation and in soil than old-growth primary *** understanding of biomass and carbon stocks in different plant functional types of these forests is ***,diversity,composition,soil features and carbon stocks in six distinct plant functional types,namely:Moist Mixed-Deciduous Forest,Peninsular Sal Forest(PSF),Semi-Evergreen Forest(SEF),Planted teak Forest,Bamboo Brakes(BB),and Degraded thorny Shrubby Forest were quantified as secondary tropical deciduous forests of the chandaka Wildlife Sanctuary,Eastern Ghats of Odisha,***-one species≥10 cm Girth at breast height(GBH)were recorded,belonging to 38 families and 65 ***-ground biomass carbon and soil organic carbon ranged from 2.1–72.7 Mg c ha^(−1) and 20.6–67.1 Mg c ha^(−1),respectively,among all plant functional *** organic carbon and important value index were positively correlated with above-ground biomass *** carbon alloc.t.on was in SOc pool(51–91%),followed by the above-ground biomass pool(9–52%),indic.t.ng SOc is one of the major carbon sinks in secondary dry *** results highlight the importance of secondary tropical deciduous forests in biodiversity conservation and ecological importance in reducing greenhouse gases.

关键词： chandaka wildlife Sanctuary Diversity indices Soil organic carbon Above-ground biomass carbon correlation study

Dirac-like cone-based electromagnetic zero-index metamaterials

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applic.t.ons) 2021年第11期10卷 2048-2066页

作者： Yang Li c.t.chan Eric Mazur State Key Laboratory of Precision Measurement technology and Instrument Department of Precision InstrumentTsinghua UniversityBeijingChina Department of Physics Hong Kong University of Science and TechnologyKowloonHong KongChina John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMAUSA

Metamaterials with a Dirac-like cone dispersion at the center of the Brillouin zone behave like an isotropic and impedance-matched zero refractive index material at the Dirac-point *** metamaterials can be realized in the form of either bulk metamaterials with efficient coupling to free-space light or on-chip metamaterials that are efficiently coupled to integrated photonic *** materials enable the interactions of a spatially uniform electromagnetic mode with matter over a large area in arbitrary *** unique optical property paves the way for many applic.t.ons,including arbitrarily shaped high-transmission waveguides,nonlinear enhancement,and phase mismatch-free nonlinear signal generation,and collective emission of many *** review summarizes the Dirac-like cone-based zero-index metamaterials’fundamental physics,design,experimental realizations,and potential applic.t.ons.

关键词： index collective realization

An efficient synthesis of pyrazole chalcones under solvent free conditions at room temperature

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

chinese chemical Letters 2011年第1期22卷 37-40页

作者： Parvin kumar Sunil kumar Khalid Husain Ashwani kumar chemistry Department Guru Nanak Khalsa CollegeHaryana 135001India chemistry Department Government CollegeHaryana 125001India Drug Discovery and Research Laboratory Department of Pharmaceutical SciencesGuru Jambheshwar University of Science & TechnologyHaryana 125001India

An easy, safe, solvent free and effective method for the synthesis of pyrazole-substituted chalcones has been achieved by grinding pyrazole aldehydes and ac.t.phenones in the presence of activated barium hydroxide （c-200） in high yield within short span of time. All reactions were carried out just by grinding the two reactants in the presence of activated barium hydroxide （c-200）. Results are also compared with sodium hydroxide and potassium hydroxide.

关键词： Pyrazole aldehydes chalcones Activated barium hydroxide (c-200) Solvent free conditions

Synergistic effect of hybrid Himalayan Nettle/Bauhinia-vahlii fibers on physico-mechanical and sliding wear properties of epoxy composites

在线全文

学校读者我要写书评

暂无评论

Defence technology（防务技术） 2020年第4期16卷 762-776页

作者： Sandeep kumar KKSMer Brijesh Gangil Vinay kumar Patel Department of Mechanical Engineering S.O.E.T.H.N.B.Garhwal UniversitySrinagar-Garhwal246174UttarakhandIndia Department of Mechanical Engineering Govind Ballabh Pant Institute of Engineering and Technology GhurdauriPauri Garhwal246001UttarakhandIndia

the cellulosic bast fibers are recognized as a justifiable and biodegradable substitute for producing moderate strength polymer composite materials because of their characteristics of renewability,ecofriendliness,and higher specific *** the aim of this research work is to fabric.t. Himalayan bast fibers(Nettle fiber(NF)/bauhinia vahlii fiber(BF)) based mono/hybrid epoxy composites at varying weight percentage of 2-6 wt% and evaluate the physical(void fraction and water absorption),mechanical(tensile strength,flexural strength,hardness) and sliding wear properties of as-fabric.t.d *** 6 wt% NBF reinforced composites exhibited higher mechanical properties as compared to NF and BF composites with tensile strength of 34.04 MPa,flexural strength of 42.45 MPa,and hardness of 37.01 Hv *** influence of various control factors(sliding veloc.t.,NF/BF/NBF contents,normal load and sliding distance) on specific sliding wear rate of composites was evaluated by taguchi(three factors at three levels) experimental design and the percentage contribution of these selected parameters on sliding wear performance was examined by Analysis of variance(ANOVA).the sliding wear property of as-developed composites was found to be greatly influenced by sliding veloc.t. and the wear resistance was observed to be improved with the NF/BF/NBF *** wear mechanism of the as-fabric.t.d composites has been elucidated by scanning electron microscopy *** research outcomes demonstrated that the hybridization of Bauhinia vahlii fiber with Nettle fiber led to improve the mechanical and wear properties of epoxy composites.

关键词： Natural fiber Physical properties Mechanical properties Wear properties taguchi analysis

Identific.t.on and characterization of phenolics and terpenoids from ethanolic extracts of Phyllanthus species by HPLc-ESI-QtOF-MS/MS

在线全文

学校读者我要写书评

暂无评论

Journal of Pharmaceutical Analysis 2017年第4期7卷 214-222页

作者： Sunil kumar Awantika Singh Brijesh kumar Sophistic.t.d Analytical Instrument Facility CSIR-Central Drug Research InstituteLucknow 226031Uttar PradeshIndia Academy of Scientific and Innovative Research (AcSIR) New Delhi 110025India

Phyllanthus species plants are a rich source of phenolics and widely used due to their medicinal properties. A liquid chromatography–tandem mass spectrometry(Lc–MS/MS) method was developed using high-pressure liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry(HPLc-ESI-QtOFMS/MS) for the identific.t.on and characterization of querc.t.n, kaempferol, ellagic acid and their derivatives in ethanolic extracts of Phyllanthus species. the chromatographic separation was carried out on thermo Betasil c_8 column(250 mm×4.5 mm, 5 μm) using 0.1% formic acid in water and 0.1% formic acid in methanol as the mobile phase. the identific.t.on of diagnostic fragment ions and optimization of collision energies were carried out using 21 reference standards. totally 51 compounds were identified which include 21 compounds identified and characterized unambiguously by comparison with their authentic standards and the remaining 30 were tentatively identified and characterized in ethanolic extracts of P. emblica, P. fraternus, P. amarus and ***.

关键词： Phyllanthus species HPLc-ESI-QtOF-MS/MS Phenolics

Preformation probability and kinematics of cluster emission yielding Pb-daughters

在线全文

学校读者我要写书评

暂无评论

chinese Physics c 2023年第7期47卷 123-132页

作者： Joshua t.Majekodunmi M.Bhuyan K.Anwar N.Abdullah Raj kumar Institute of Engineering Mathematics Universiti Malaysia PerlisArau02600PerlisMalaysia center for theoretical and computational Physics Department of PhysicsFaculty of ScienceUniversity of MalayaKuala Lumpur 50603Malaysia School of Physics and Materials Science Thapar Institute of Engineering and TechnologyPatialaPunjab 147004India

In the present study,the newly established preformation formula is applied for the first time to study the kinematics of the cluster emission from various radioactive nuclei,especially those that decay to the double shell closure^(208)Pb nucleus and its neighbors as *** recently proposed universal cluster preformation formula has been established based on the concepts that underscore the influence of mass and charge asymmetry(η_(A)andη_(Z)),cluster mass A_(c),and the Q-value,paving the way to quantify the energy contribution during preformation as well as during the tunneling process *** cluster-daughter interaction potential is obtained by folding the relativistic mean-field(RMF)densities with the recently developed microscopic R3Y using the NL 3^(*)and the phenomenological M3Y NN potentials to compare their *** penetration probabilities are calculated from the WKB *** the inclusion of the new preformation probability P_(0),the predicted half-lives of the R3Y and M3Y interactions are in good agreement with the experimental ***,a careful inspection reflects slight differences in the decay half-lives,which arise from their respective barrier *** P_(0)for systems with double magic shell closure^(208)Pb daughter are found to be an order of≈10^(2)higher than those with neighboring Pb daughter *** exploring the contributions of the decay energy,the recoil effect of the daughter nucleus is evaluated,in contrast to several other ***,the centrality of the Q-value in the decay process is demonstrated and redefined within the preformed cluster-decay ***,we have introduced a simple and intuitive set of criteria that governs the estimation of recoil energy in the cluster radioactivity.

关键词： relativistic mean field cluster radioactivity preformation probability decay width and half life recoil energy Q-value of the decay

Influences of residual stress and micro-deformation on microstructures and mechanical properties for ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy produced by laser powder bed fusion

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & technology 2021年第16期75卷 174-183页

作者： c.c.Zhang H.L.Wei t.t.Liu L.Y.Jiang t.Yang W.H.Liao National Joint Engineering Research center of Nc Forming technology and Equipment School of Mechanical EngineeringNanjing University of Science and TechnologyNanjing 210094China

Laser powder bed fusion(LPBF)yields unique advantages during the fabric.t.on of titanium *** the present work,ti-6.5 Al-3.5 Mo-1.5 Zr-0.3 Si alloy specimens with excellent mechanical performances were fabric.t.d by *** as-built specimens displayed relatively high strength and ductility under modest volume energy densities(VEDs),whereas they manifested high strength with low ductility under high *** investigate the key reason of this phenomenon,the specimens were designed with two VEDs ranges of 60 J/mm^(3) and 85 J/mm^(3).Special attention was paid to the influences of residual stress and micro-deformation on microstructures and mechanical properties for the first *** results indic.t.d that the residual stresses and relative density of the 60 J/mm^(3) range specimens were higher than that of the 85 J/mm3 range *** multiplic.t.on and disloc.t.on movement promoted by the residual stress were hindered by the initialα’phase grain boundary(prior-α’GB),leading to the formation ofα’metastable *** mean tensile strength and elongation of the 60 J/mm^(3) range specimens were 1248.1 MPa and 12.3%,respectively,whereas the corresponding values for the 85 J/mm^(3) range specimens were 1405.3 MPa,5.0%,*** deformation,the strength and ductility of the specimens were first improved by lamellar structures generated from prior-α’phases,and then effectively enhanced by the interaction between the{10–12}twins and ***,pores significantly reduced the ductility;hence,high VED specimens with large twins and numerous large pores increased the strength and reduce the ductility.

关键词： Laser powder bed fusion ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy Residual stress twin Mechanical properties

A correlation between pulse diagnosis of human body and health monitoring of structures

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering and Engineering Vibration 2004年第1期3卷 117-125页

作者： c.c.chang Henry t.Y.Yang Department of civil Engineering Hong Kong University of Science and TechnologyHong Kong Department of Mechanical and Environmental EngineeringUniversity of California Department of Mechanical and Environmental Engineering University of California

the concept of health monitoring is a key aspect of the field of medicine that has been practiced for a long time. A commonly used diagnostic and health monitoring practice is pulse diagnosis, which can be traced back approximately five thousand years in the recorded history of china. With advances in the development of modern technology, the concept of health monitoring of a variety of engineering structures in several applic.t.ons has begun to attract widespread attention. Of particular interest in this study is the health monitoring of civil structures. It seem natural, and even beneficial, that these two health-monitoring methods, one as applies to the human body and the other to civil structures, should be analyzed and compared. In this paper, the basic concepts and theories of the two monitoring methods are first discussed. Similarities are then summarized and commented upon. It is hoped that this correlation analysis may help provide structural engineers with some insights into the intrinsic concept of using pulse diagnosis in human health monitoring, which may of be some benefit in the development of modern structural health monitoring methods.

关键词： human health monitoring pulse diagnosis structural health monitoring vibration-based techniques local detection techniques

Surgical management of polycystic liver disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2007年第38期13卷 5052-5059页

作者： Robert t Russell c Wright Pinson Vanderbilt University Medical center Department of Hepatobiliary Surgery and Liver Transplantation 1301 22nd Avenue South Nashville TN 37232-5545 United States

Adult polycystic liver disease (PcLD) is an autosomal dominant condition commonly associated with autosomal dominant polycystic kidney disease (ADPKD). However in the last decade, it has been recognized that there is a distinct form of autosomal dominant PcLD that arises without concomitant ADPKD. Early knowledge of the pathogenesis was gained from the study of hepatic cysts in patients with ADPKD. Bile duct overgrowth after embryogenesis results in cystic hepatic dilatations that are known as biliary microhamartomas or von Meyenburg complexes. Further dilatation arises from cellular proliferation and fluid secretion into these cysts. there is a variable, broad spectrum of manifestations of PcLD. Although PcLD is most often asymptomatic, massive hepatomegaly can lead to disabling symptoms of abdominal pain, early satiety, persistent nausea, dyspnea, asc.t.s, biliary obstruction, and lower body edema. complic.t.ons of PcLD include cyst rupture and cyst infection. Also, there are associated medical problems, especially intracranial aneurysms and valvular heart disease, which clinicians need to be aware of and evaluate in patients with PcLD. In asymptomatic patients, no treatment is indic.t.d for PcLD. In the symptomatic patient, surgical therapy is the mainstay of treatment tailored to the extent of disease for each patient. Management options include cyst aspiration and sclerosis, open or laparoscopic fenestration, liver resection with fenestration, and liver transplantation. the surgical literature discussing treatment of PcLD, including techniques, outcomes, and complic.t.on rates, are summarized in this review.

关键词： Polycystic liver disease Fenestration Laparoscopy Liver resection Liver transplantation