检索结果-南通市图书馆

Designing coal panels in the conditions of associated methane and spontaneous fire hazards

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

International Journal of Mining Science and Technology 2020年第4期30卷 525-531页

作者： Stanislaw Prusek Eugeniusz krause Jacek Skiba Central Mining Institute Katowice 40-166Poland

An increase in methane,spontaneous fire and bumping hazards in Polish hard coal mines,observed in the last two decades,led to the need to elaborate the tools allowing proper selection of a range of preventive measures to fight them at the stage of designing coal *** the production of a coal seams in the conditions of associated methane and spontaneous fires hazards in Polish hard coal mines requires elaboration of the design standards for coal panels in gassy coal *** paper presents the guidelines on how to design production in the conditions of associated methane and spontaneous fire *** tools and methodology since the very first research were many times verified by daily mining operations in the conditions of associated methane and spontaneous fire hazards,which confirms their significant contribution to the development of safe and economical mining operations.

关键词： Coal exploitation Methane Spontaneous fires Associated hazards Designing coal panels Ventilation

Low Temperature Growth of SWNTs on a Nickel Catalyst by Thermal Chemical Vapor Deposition

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

Nano Research 2011年第4期4卷 334-342页

作者： Maoshuai He Alexander I. Chernov Elena D. Obraztsova Jani Sainio Emma Rikkinen Hua Jiang Zhen Zhu Antti Kaskela Albert G. Nasibulin Esko I. Kauppinen Marita Niemela outi.krause Department of Biotechnology and Chemical Technology School of Science and Technology Aalto University P.O. Box 16100 F1-00076 Aalto Finland A.M. Prokhorov General Physics Institute RAS 38 Vavilov Street 119991 Moscow Russia Department of Applied Physics School of Science and Technology Aalto University P.O. Box 11100 FI-00076 Aalto Finland Nanomaterials Group Department of Applied Physics and Center for New Materials School of Science and Technology Aalto UniversityP.O. Box 15100 FI-00076 Aalto Finland VTT Biotechnology EO. Box 1000 FI-02044 Espoo Finland

Single-walled carbon nanotubes （SWNTs） have been grown on a silica-supported monometallic nickel （Ni） catalyst at temperatures ranging from as low as 450℃to 800℃. Different spectroscopic techniques, such as Raman, photoluminescence emission （PLE）, and ultra violet-visible-near infrared （UV-vis-NIR） absorption spectroscopy were used to evaluate file diameter and quality of the SWNTs grown over the Ni catalyst at different temperatures. The analysis revealed that high quality SWNTs with a very narrow diameter distribution were obtained at a growth temperature of 500 ℃. In the PLE and absorption spectra, differences were observed between the SWNTs grown oil Ni and those grown on cobalt （Co）. This result expands the potential of growing a specific （n, m） tube species with relatively high abundance by tuning the catalyst composition. Furthermore, the prerequisites for the low temperature growth of SWNTs over a monometallic transition metal catalyst have been elucidated.

关键词： Single-walled carbon nanotubes synthesis low temperature nickel catalyst

Frequency-selective Optimization of Periodic Gate Control Signals in DC/DC Converters for EMI-reduction

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 Journal of Electrical Engineering 2022年第4期8卷 11-18页

作者： Caroline krause Stephan Frei On-board Systems Lab TU Dortmund UniversityDortmund 44227Germany

High-frequency switching of power transistors in power electronic systems can cause electromagnetic *** approaches for reducing high-frequency disturbances,such as inserting an additional gate resistor,lead to increased power *** makes achieving both electromagnetic compatibility and power efficiency *** gate drivers help to find a trade-off between these ***,only narrow-band disturbances must be ***,a target signal with a spectrum notched at some frequencies can be *** target signal can be reached by a target-signal-oriented control of the transistor’s *** leads to steeper switching slopes,such that the power losses are less *** arbitrary target signals is *** transistor signal exhibits some physical limitations.A constraint satisfaction problem must be solved,and the gate drive signal must be optimized by applying a residual and Newton’s *** proposed optimization process in the frequency domain is based on the circuit simulation method named“harmonic balance”.Measurements on a DC/DC converter exhibit the benefits of this method.

关键词： Power electronics active gate driving electromagnetic compatibility Newton’s method

New means to monitor the effect of glucocorticoid therapy in children

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第9期16卷 1104-1109页

作者： Hanne Rintamki Harri M Salo outi Vaarala Kaija-Leena Kolho Division of Gastroenterology Hospital for Children and AdolescentsUniversity of Helsinki Immune Response Unit Department of Vaccination and Immune ProtectionNational Institute for Health and Welfare

AIM:To study the individual effects of glucocorticoid (GC) therapy on the state ofimmune activation in patient ***:We developed a novel assay in which the effect of corticosteroid-treated patient serum on healthy donor peripheral blood mononuclear cells (target cells) was studied,with a panel of markers for effector [interferon (IFN)γ and interleukin (IL)-5] and regulatory T cells (FOXP3 and glucocorticoid-induced tumor necrosis factor receptor,GITR).The study group comprised 19 children with inflammatory bowel *** individual effect of patient serum on target cells was analyzed prior to GC therapy and 2 wk ***:The effect of GC therapy mediated by patient serum was seen as a decrease in the target cells expression of regulatory T-cell-related markers GITR (median suppression 24%,range of suppression 1%-63%,in 2 cases increase of 6% and 77%,P < 0.01 for mitogen-activated target cells) and FOXP3 (median suppression 33%,range of suppression 0%-79%,in one case an increase of 173%,P < 0.05 for resting cells),and secretion of IFNγ [from a mean of 87 700 pg/mL (SD 33 900 pg/mL) to 60 900 pg/mL (SD 44 200 pg/mL) in mitogen-activated target cells,13 of the cases showed a decrease,P < 0.01].The total or weight-related prednisolone dose did not correlate with the patient-seruminduced changes in the target cell ***:GC response could be monitored at an individual level by studying the effect of patient serum on signaling pathways of target immune cells.

关键词： Glucocorticoid-induced tumor necrosis factor receptor FOXP3 Inflammatory bowel disease Children

Diapause affects cuticular hydrocarbon composition and mating behavior of both sexes in Drosophila montana

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Insect Science 2020年第2期27卷 304-316页

作者： outi Ala-Honkola Hannele Kauranen Venera Tyukmaeva Fabian A.Boetzl Anneli Hoikkala Thomas Schmitt Department of Biological and Environmental Science University of JyvaskylaJyvaskylaFinland Department of Animal Ecology and Tropical Biology BiocenterUniversity of WurzburgWurzburgGermany

Envipnmental cues,mainly photoperiod and temperature,are known to control female adult reproductive diapause in several insect *** enhances female survival during adverse conditions and postpones progeny production to the favorable *** diapause(a reversible inability to inseminate receptive females)has been studied much less than female ***,if the males maximized their chances to fertilize females while minimizing their energy expenditure,they would be expected to be in diapause at the same time as *** investigated Drosophila montana male mating bchavior under short-day conditions that induce diapause in females and found the males to be reproductively *** also found that males reared under long-day conditions(reproducing individuals)court reproducing postdiapause fermales,but not diapausing *** diapausing fies of both sexes had more long-chain and less short-chain hydrocarbons on their cuticle than the reproducing ones,which presumably increase their survival under stressful conditions,but at the same time decrease their *** study shows that the mating behavior of females and males is well coordinated during and afier overwintering and it also gives support to the dual role of insect cuticular hydrocarbons in adaptation and mate choice.

关键词： cuticular hydrocarbon diapause Drosophila male choice male reproduction

Evaluating Local Approximations of the L^(2)-Orthogonal Projection Between Non-Nested Finite Element Spaces

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Numerical Mathematics(Theory,Methods and Applications) 2014年第3期7卷 288-316页

作者： Thomas Dickopf Rolf krause Universit`a della Svizzera italiana(USI University of Lugano)Institute of Computational ScienceVia G.Buffi 136904 LuganoSwitzerland

We present quantitative studies of transfer operators between finite element spaces associated with unrelated *** local approximations of the global L^(2)-orthogonal projection are reviewed and evaluated *** numerical studies in 3D provide the first estimates of the quantitative differences between a range of transfer operators between non-nested finite element *** consider the standard finite element interpolation,Cl´ement’s quasi-interpolation with different local polynomial degrees,the global L^(2)-orthogonal projection,a local L^(2)-quasi-projection via a discrete inner product,and a pseudo-L^(2)-projection defined by a Petrov-Galerkin variational equation with a discontinuous test *** their qualitative and quantitative behaviors in this computational way is interesting per se;it could also be relevant in the context of discretization and solution techniques which make use of different non-nested *** turns out that the pseudo-L^(2)-projection approximates the actual L^(2)-orthogonal projection *** obtained results seem to be largely independent of the underlying computational domain;this is demonstrated by four examples(ball,cylinder,half torus and Stanford Bunny).

关键词： Finite elements unstructured meshes non-nested spaces transfer operators interpolation projection

Product Variability of the ‘Cineole Cassette＇ Monoterpene Synthases of Related Nicotiana Species

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Molecular Plant 2011年第6期4卷 965-984页

作者： Anke Fahnrich Katrin krause Birgit Piechulla University of Rostock Institute for Biological Sciences Albert-Einstein-Str. 3 18059 Rostock Germany

Nicotiana species of the section Alatae characteristically emit the floral scent compounds of the ＇cineole cassette＇ comprising 1,8-cineole, limonene, myrcene, α-pinene, β-pinene, sabinene, and α-terpineol. We successfully isolated genes of Nicotiana alata and Nicotiana langsdorfii that encoded enzymes, which produced the characteristic monoter- penes of this ＇cineole cassette＇ with α-terpineol being most abundant in the volatile spectra. The amino acid sequences of both terpineol synthases were 99% identical. The enzymes cluster in a monophyletic branch together with the closely related cineole synthase of Nicotiana suaveolens and monoterpene synthase 1 of Solanum lycopersicum. The cyclization reactions （α-terpineol to 1,8-cineole） of the terpineol synthases of N. alata and N. langsdorfii were less efficient compared to the ＇cineole cassette＇ monoterpene synthases of Arabidopsis thaliana, N. suaveolens, Salvia fruticosa, Salvia officinalis, and Citrus unshiu. The terpineol synthases of IV. alata and N. langsdorfii were localized in pistils and in the adaxial and abaxial epidermis of the petals. The enzyme activities reached their maxima at the second day after anthesis when flowers were fully opened and the enzyme activity in N. alata was highest at the transition from day to night （diurnal rhythm）.

关键词： Nicotiana alata Nicotiana langsdorfii cineole cassette terpineol synthase multiproduct enzyme monoterpene synthase 1,8-cineole, α-terpineol.

Serum immune-activation potency and response to anti-TNF-α therapy in Crohn's disease

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2010年第46期16卷 5845-5851页

作者： Hanne Rintamki Taina Sipponen Harri M Salo outi Vaarala Kaija-Leena Kolho Division of Gastroenterology Hospital for Children and Adolescents and Helsinki University Central HospitalUniversity of Helsinki Department of Medicine Division of GastroenterologyHelsinki University Central HospitalUniversity of Helsinki Immune Response Unit Department of Vaccination and Immune ProtectionNational Institute for Health and Welfare

AIM:To study whether immune-activation stage in serum of adult Crohn's disease (CD) patients correlates with disease activity and with treatment response to antitumor necrosis factor-α (TNF-α) ***:Serum samples were obtained from 15 adult CD patients introduced to anti-TNF-α *** individual stage of immune activation was studied applying our new in vitro assay,in which target cells (donor derived peripheral blood mononuclear cells) were cultured with patient serum and the T-cell activation induced by the patient serum was studied using a panel of markers for effector [interferon γ (IFNγ),interleukin (IL)-5] and regulatory T-cells [forkhead transcription factor 3 (FOXP3) and glucocorticoid-induced tumour necrosis factor receptor (GITR)].The endoscopic disease activity was assessed with the Crohn's disease endoscopic index of severity (CDEIS) before and 3 mo after therapy with an anti-TNF-α ***:Low induction of FOXP3 and GITR in target cells cultured in the presence of patient serum was associated with high disease activity *** assessed before therapy (r=-0.621,P=0.013 and r=-0.625,P=0.013,respectively).FOXP3 expression correlated inversely with pre-treatment erythrocyte sedimentation rate (r=-0.548,P=0.034).Low serum induced FOXP3 (r=-0.600,P=0.018) and GITR (r=-0.589,P=0.021) expression and low IFNγ secretion from target cells (r =-0.538,P=0.039) associated with treatment response detected as a decrease in ***:The immune-activation potency in the patient serum prior to anti-TNF-α therapy reflected intestinal inflammation and the therapeutic response.

关键词： Crohn’s disease endoscopic index of severity Forkhead transcription factor 3 Glucocorticoid-induced tumour necrosis factor receptor Infliximab Inflammatory bowel disease

Effect of HTS Superconductors on Homogeneity of Measurement Field in Low Field Nuclear Magnetic Resonance Detection

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 Physics Letters 2010年第8期27卷 250-252页

作者：董慧张懿 krause Hans-Joachim 谢晓明 State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai 200050 Institute of Bio- and Nanosystems Forschungszentrum Jiilich. D-52425 Jiilieh Germany Graduate University of the Chinese Academy of Sciences Beijing 100049

In recent years, superconducting quantum interference devices （SQUIDs） have been demonstrated to be useful in the low field nuclear magnetic resonance （NMR） measurements. The high temperature superconducting （HTS） SQUID used in our experiments has a frequency-independent sensitivity of 40-50fT/Hz^1/2. When a liquid nitrogen cooled LC circuit is employed to form a tuned circuit with the SQUID, the sensitivity of the system can be further enhanced. The LC circuit consists of a capacitor and a coil made of copper wire or HTS tape, which is inductively coupled to the SQUID. However, the homogeneity of the measurement field deteriorates because of the HTS tape coil in the proximity of the sample. In contrast, the thin film SQUID with a washer area of 1 cm^2 has no effect on the NMR signal. Therefore, the impairment of the measurement field homogeneity in the case of different superconducting elements nearby is discussed by examining the free induction decay signals at 9 kHz. It is found that a square superconducting film with an area of i cm^2 may compensate for the inhomogeneity of the measurement field after the adjustment of its position.

关键词： HIGH temperature superconductors NUCLEAR magnetic resonance SUPERCONDUCTING quantum interference devices PHYSICS experiments LIQUID nitrogen SENSITIVITY analysis