检索结果-南通市图书馆

Influence of distance between paralleled metal fibers on giant magnetoimpedance

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2018年第3期25卷 255-260页

作者： Shu-ling Zhang Wei-ye chen gui-hong geng Zi-qiang Han Yong-chuan Yu Bo Zhang Wen-jie Ding Xue-jun Zhu School of Mechanical Engineering Ningxia UniversityYinchuan 750021 Ningxia China School of Material of Science and Engineering North MinzuUniversity Yinchuan 750021 Ningxia China

giant magnetoimpedance （gMI） and the gMI effect of a Co-based fiber beam were investigated in the frequency range of 0.1-10 MHz, and the influence of distance between adjacent fibers on the distribution of the surface circumferential magnetic field and gMI effect was analyzed. Compared with a single fiber, the distribution of the surface magnetic field of paralleled fibers is non-uniform, induced by magnetic interaction between metal fibers. The originally uniformly dis- tributed circumferential magnetic field changes into two obvious coexisting parts： one stronger and one weaker. The results prove that the strengthened circumferential magnetic field determines the gMI effect and sensitivity. It is found that the maximum surface of the circumferential magnetic field is reinforced by 88% when the four fibers are as closely parallel as possible; the gMI effect is greatest under higher field sensitivity. At 5 MHz, the sensitivity of the four-fiber beam reaches 3090 V/T, an increase of 277% compared with a single fiber. However, the magnetic interaction fades with the increase in distance between fibers and as the distribution of the surface magnetic field becomes even. The maximum magnetic field also becomes gradually equal to the level of a single fiber. When the distance is 1 mm, the maximum surface magnetic field is increased by 3.2%, and the improvement in the gMI effect is correspondingly slight. Therefore, a strong magnetic interaction among fibers can improve the intensity of the surface circumferential magnetic field and give rise to a fine gMI effect and high field sensitivity in Co-based metal fibers.

关键词： giant magnetoimpedance-Metallic fiber Sensitivity Magnetization-Magnetic interaction Sensor

Comparative morphological study on the genus Leptura Linnaeus of China(Coleoptera: Cerambycidae: Lepturinae)

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

Zoological Systematics 2014年第3期39卷 395-410页

作者： Jie-Qun Ren gui-qiang Huang Si-Yao He Li chen Zhi-Ping Liu College of Plant Protection Southwest University Institute of Entomology

A comparative morphological research was done based on the morphological characters of 21 species from Leptura in this paper. The results indicated that 18 morphological characters, such as the ratio of the lower eye lobe to genae, the relative length of antennae segments, the shape of maxillary palpi apex, prothorax, elytra apex and elytral maculae can be used to identify species in the genus. Meanwhile, the color of elytra and the size of elytral maculae could not be used to identify species from Leptura. In addition, the shape of 7th abdominally sternal apex, the length of antennae and the ratio of the first hind tarsal segment to the second can be used to distinguish the male and the female.

关键词： Comparative morphology Cerambycidae Leptura China.

Impact of TID on response to pulsed X-ray irradiation in the bipolar operational amplifier

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2015年第2期58卷 390-396页

作者： LI Rui Bin WANg gui Zhen chen Wei MA qiang LIU Yan LIN Dong Sheng YANg ShanChao BAI XiaoYan QI Chao JIN XiaoMing State Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear Technology

groups of a typical operational amplifier-μA741 were irradiated in a cobalt unit, each group accumulating a different total ionizing dose （TID）. The results showed that the TID caused power consumption current and slew rate （SR） to degenerate in ultra-linearity, owing to a severe reduction in the current gain of the internal LPNP transistors. Pulsed X-ray irradiation experiments were carried out on the μA741 groups with different values, and the results revealed that the impact on the response to the pulsed X-ray irradiation was greater when the devices absorbed more TID. The mechanism for this is explained on the basis of the circuit construction of the μA741; the sensitive parameters of the circuit were obtained via simulation on SP1CE. The simulation results additionally showed that if the sensitive parameters were optimized, the duration of interruption caused by the pulsed X-ray irradiation would be reduced significantly. In addition, several proposals are provided for hardening the devices.

关键词： TID pulsed X-ray irradiation operational amplifier simulation

Evaluation on the anisotropic brittleness index of shale rock using geophysical logging

在线全文

学校读者我要写书评

暂无评论

Petroleum 2023年第4期9卷 545-557页

作者： Junchuan gui Jianchun guo Yu Sang Yaxi chen Tianshou Ma P.g.Ranjith Research Institute of Shale gas PetroChina Southwest Oil and Gasfield CompanyChengdu610051China State Key Laboratory of Oil and gas Reservoir geology and Exploitation Southwest Petroleum UniversityChengdu610500China Shunan gas Mine PetroChina Southwest Oil and Gas Field CompanyLuzhou646000China Downhole Service Company CNPC Chuanqing Drilling Engineering Company LimitedChengdu610501China Deep Earth Energy Laboratory Department of Civil EngineeringMonash UniversityMelbourne3800Australia

The brittleness index plays a significant role in the hydraulic fracturing design and wellbore stability analysis of shale *** brittleness indices have been proposed to characterize the brittleness of shale rocks,but almost all of them ignored the anisotropy of the brittleness ***,uniaxial compression testing integrated with geophysical logging was used to provide insights into the anisotropy of the brittleness index for Longmaxi shale,the presented method was utilized to assess brittleness index of Longmaxi shale formation for the interval of 3155e3175 m in CW-1 *** results indicated that the brittleness index of Longmaxi shale showed a distinct anisotropy,and it achieved the minimum value at β=45°-60°.As the bedding angle increased,the observed brittleness index(BI_(2_β))decreased firstly and increased then,it achieved the lowest value at β=40°-60°,and it is consistent with the uniaxial compression testing *** to the isotropic brittleness index(β=0°),the deviation of the anisotropic brittleness index ranged from 10%to 66.7%,in other words,the anisotropy of brittleness index cannot be ignored for Longmaxi *** matter content is one of the main intrinsic causes of shale anisotropy,and the anisotropy degree of the brittleness index generally increases with the increase in organic matter *** present work is valuable for the assessment of anisotropic brittleness for hydraulic fracturing design and wellbore stability analysis.

关键词： Shale rock Brittleness Brittleness index Anisotropy Transverse isotropy geophysical logging

Improvement of in situ LA-ICP-MS U-Pb dating method for carbonate minerals and its application in petroleum geology

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第12期66卷 2914-2929页

作者： Xuesong Lu Lili gui Weiyan chen Shaobo LIU Shitou WU Junjia FAN qiang LIU Jing SUN Liangliang ZHANg Yang XIAO Wenxia YANg Rizhou CAO Research Institute of Petroleum Exploration and Development Beijing 100083China Key Laboratory of Basin Structure and Hydrocarbon Accumulation CNPCBeijing 100083China Institute of geology and geophysics Chinese Academy of SciencesBeijing 100029China School of geosciences China University of Petroleum(Beijing)Beijing 102249China Institute of Earth Sciences China University of Geosciences(Beijing)Beijing 100083China Sichuan Chuangyuan Weipu Analytical Technology Co. Ltd.Chengdu 610059China School of geosciences Changjiang UniversityWuhan 430100China Research Institute of Exploration and Development Daqing Oilfield CoLtd.Daqing 163712China

In situ carbonate U-Pb dating is gaining popularity,and it has great potential for application in petroleum ***,the low U content(<10μg/g)and high common Pb content of carbonate minerals,along with the uneven distrib... 详细信息

In situ carbonate U-Pb dating is gaining popularity,and it has great potential for application in petroleum ***,the low U content(g/g)and high common Pb content of carbonate minerals,along with the uneven distribution of U and Pb and the lack of matrix-matched reference material make carbonate U-Pb dating inaccurate and less successful,which limits the widespread application in *** study evaluated the limitations of in situ carbonate U-Pb dating and proposed a method to rationally determine the laser ablation parameters of samples by improving the experimental approach based on the laser ablation sector field inductively coupled plasma mass spectrometry(LA-SF-ICP-MS).By setting a different spot size and laser frequency for the reference material and unknown samples in the same session based on the U content of the sample,the ablation craters of the reference material and unknown samples were given the same depth/width ratio,avoiding systematic offset caused by differences in down-hole element fractionation and reducing the consume of reference *** on the heterogeneous distribution of U and Pb contents in carbonate minerals,the method of grid screening and setting ablation spots during screening were used to quickly select domains with high U and low common Pb,which improves the efficiency of setting laser spots and the success rate of dating,as well as reduces the experimental time and economic *** accuracy and success rate of carbonate U-Pb dating were effectively improved by improving the experimental method,and the technique was applied to two carbonate samples with low U and high common Pb contents that were difficult to date by traditional *** two samples are the saddle dolomite in the central Sichuan Basin and the calcite cement in the sandstone reservoir of the Cretaceous Qingshuihe Formation in the South Junggar *** robust ages have been obtained,which constrains the timing of the diagenetic and

关键词： Carbonate U-Pb dating LA-SF-ICP-MS Ablation craters Fractionation effects Systematic offset Critical time limitation

Development of Biomimetic Synthesis of Propindilactone g

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2020年第11期38卷 1339-1352页

作者： Yu Wang Bo chen Xubiao He Jinghan gui CAS Key Laboratory of Synthetic Chemistry of Natural Substances Center for Excellence in Molecular SynthesisShanghai Institute of Organic ChemistryUniversity of Chinese Academy of SciencesChinese Academy of SciencesShanghai 200032China

of main observation and conclusion The natural product propindilactone g is a complex Schisandra nortriterpenoid with a unique 5/5/7/6/5 pentacyclic *** full paper describes the development of concise biomimetic synthesis of propindilactone g from a known steroid *** key C19-OH intermediate was synthesized via Breslow and Suarez radical remote C—H ***-Meerwein rearrangement was subsequently utilized for the expansion of the B *** invert the configuration of the C1O tertiary alcohol,an intramolecular peroxide cyclization catalyzed by BF3-Et2O was *** 5/5 fused lactone system was then assembled in a biomimetic transesterification/oxa-Michael addition *** work should provide experimental support for the proposed biosynthetic pathway and facilitate investigation of the biological activities of pro pindilactone g.

关键词： lactone utilized rearrangement

Experimental study on geochemical characteristic of methane hydrate formed in porous media

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 Natural gas Chemistry 2009年第2期18卷 217-221页

作者： Qiang.chen Changling Liu Yuguang Ye Qingdao Institute of Marine geology the Ministry of Land and Resources Qingdao 266071 Shandong China The key Laboratory of Marine Hydrocarbon Resources and Environment Resources the Ministry of Land and Resources Qingdao 266071 Shangdong China

The natural occurrence of methane hydrates in marine sediments has been intensively studied over the past decades, and geochemical charac-teristic of hydrate is one of the most attractive research fields. In this paper, we discussed the geochemical anomaly during hydrate formation in porous media. By doing so, we also investigated the temperature influence on hydrate formation under isobaric condition. It turns out that sub-cooling is an important factor to dominate hydrate formation. Larger subcooling provides more powerful driving force for hydrate formation. During the geochemical anomaly research, six kinds of ions and the total dissolved salt （TDS） were measured before and after the experiment in different porous media. The result is that all kinds of ionic concentration increased after hydrate formation which can be defined as salting out effect mainly affected by gas consumption. But the variation ratio of different ions is not equal. Ca^2＋ seems to be the most significantly influenced one, and its variation ratio is up to 80%. Finally, we theoretically made a model to calculate the TDS variation, the result is in good accordance with measured one, especially when gas consumption is large.

关键词： hydrate formation porous media subcooling salting out effect geochemical anomaly

The Prokaryotic Expression and Bioactivity of the Recombinant Red Fire Ant Venom Allergen Sol i 4

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2009年第2期8卷 182-187页

作者： HAN Xue-qing LIN Xiang-mei chen Hong-jun ZHANg Yong-guo YE gui-sheng WU Shao-qiang LI Jian chen Nai-zhong.chen Yan ZHU Shui-fang Chinese Academy of Inspection and Quarantine Beijing 100029 P.R.China

The sting of red imported fire ant （RIFA） could cause serious allergic response in fraction of people. These allergic reactions are mainly caused by its venom, especially venom allergen Sol i 1-4. To produce large amount of RIFA venom allergen Sol i 4 for diagnosis of RIFA allergy and allergen-specific immunotherapy, the gene encoding this protein was amplified and cloned into the prokaryotic expression vector pET43, la. The recombinant plasmid was used to transform competent cells and the recombinant proteins were expressed in E. coll. SDS-PAgE and Western blotting analysis indicated that high-level expression of Sol i 4 protein was successfully achieved. Allergenic activity analysis of the recombinant allergen Sol i 4 was then performed on rabbit. The result showed that the recombinant protein obtained had significant allergenic activity. It indicated that the recombinant allergen Sol i 4 of RIFA venom was successfully expressed in E. coli, which provided foundation for further developing therapeutic and diagnosis reagents of RIFA allergy.

关键词： red imported fire ant recombinant allergen Sol i 4 expression activity

Rare earth element geochemistry of groundwater from a deep seated sandstone aquifer,northern Anhui province,China

在线全文

学校读者我要写书评

暂无评论

Mining Science and Technology 2011年第4期21卷 477-482页

作者： gui Herong Sun Linhua chen Luwang.chen Song School of Earth Sciences and Engineering Suzhou Universing Suzhou 234000 China School of Resources and Environmental Engineering Hefei University of Technology Hefei 230009 China

Deep coal mines in northern Anhui province, China, provide opportunities for tracing the distribution and fractionation of rare earth elements CREEs） in deep seated environments. Major ions, as well as REE concentrations were measured in groundwater from a sandstone aquifer located between -400 and -280 m. Our results indicate that this groundwater consists of ***-Na or ***3-Na water types with warm temperature （30.1-31.4~C）, circumneutral pH （7.27-8.61） and high levels of total dissolved solids （TDS ~ 1306--2165 mg/L）. Concentrations of REEs in groundwater are high as expressed by their Nd con- centrations （0.0086-0.018μg/L）. Except for weak heavy REEs （HREE） enrichment relative to light REEs （LREE）, the similarity of REE distribution patterns between groundwater and aquifer rock indicate that enrichment of REEs is considered to be controlled by aquifer rock, as well as by their minerals, whereas the fractionation of REEs is controlled by HREE enriched minerals and, to a lesser extent, by inorganic REE complexes. Ce anomalies normalized to Post Archean Average Shale （PAAS） and aquifer rock are weak, which probably reflect the contribution of reduced conditions in combination with pH, rather than a sig- nature of aouifer rock.

关键词： Rare earth elements Water-rock interaction Sandstone aquifer groundwater