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Global Analysis of Cytosine Methylation and Proteome Under Cold Treatment in Brassica napus 被引量:2
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作者 WEI Fang HU Jie +3 位作者 CUI Ming-zhu ZHANG Yan-hui LI Yun-ling TIAN Bao-ming 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第10期2170-2176,共7页
Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic e... Cytosine methylation/demethylation plays pivotal roles in regulating gene expression at a genome-wide level. However, limited reports are available to reveal correlating changes of cytosine methylation and proteomic expression in Brassica napus so far. Therefore, in the present study, global cytosine methylation and proteome were analysed in B. napus after cold treatment by methylation-sensitive amplified polymorphism (MSAP) and two-dimensional protein electrophoresis technology (2-DE). The results showed that the lowered genome-wide DNA methylation status was revealed after cold treatment, and about 0.88% of discrepancy in DNA methylation was detected between the non-flowering and flowering plants after cold treatment. Moreover, the 52 significantly up-regulated proteins emerged in comparison with the 36 down-regulated proteins, as well as the 14 proteins exclusively detected in the flowering plants. Intriguingly the 8 specifically expressed proteins in the non-flowering plants disappeared in the flowering plants with cold treatment. Therefore, these present data proved that the correlating changes of cytosine methylation and proteomic expression were evidenced under cold treatment in B. napus. 展开更多
关键词 DNA methylation/demethylation MSAP 2-DE cold treatment Brassica napus
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Effect of Cold Plasma Treatment on the Mechanical Properties of RTM Composites 被引量:2
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作者 WeiQIN ZhiqianZHANG XiaohongWU 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第3期281-283,共3页
Cold plasma technology was used to treat the surface of carbon fibers braided by PET in this paper and SEM was used to analyze the fracture microstructure of composite interlaminar shear stress (ILSS). The result show... Cold plasma technology was used to treat the surface of carbon fibers braided by PET in this paper and SEM was used to analyze the fracture microstructure of composite interlaminar shear stress (ILSS). The result shows that the surface polarity of carbon fibers was modified by cold plasma treatment, which increases the impregnation of PET braided carbon fibers during the process of resin flowing, improves the interfacial properties of RTM composites, and therefore enhances the mechanical properties of the KTM composites. 展开更多
关键词 cold plasma surface treatment Carbon fibers RTM composites Mechanical properties
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Effect of Cold Plasma Treatment on Seed Germination and Growth of Wheat 被引量:13
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作者 蒋佳峰 何昕 +5 位作者 李玲 李建刚 邵汉良 徐启来 叶仁宏 董元华 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第1期54-58,共5页
This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied... This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential (6.0%) and germination rate (6.7%) compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Com- pared with the control, plant height (20.3%), root length (9.0%) and fresh weight (21.8%) were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content (9.8%), nitrogen (10.0%) and moisture content (10.0%) were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t-ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield. 展开更多
关键词 cold plasma seed treatment WHEAT seed germination plant growth increasedyield
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Surface Treatment of Crl2MoV Steel towards Long-Life Cold-Work Dies 被引量:5
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作者 SHIWen WANGJun-Li +2 位作者 WANGZhen WANZi XULuo-Ping 《材料热处理学报》 EI CAS CSCD 北大核心 2004年第05B期837-840,共4页
With the rapid development of the automobile industry in China, there is an ever-increasing demand for long-life cold working dies used for punching automobile components. However, the full potential of such advanced ... With the rapid development of the automobile industry in China, there is an ever-increasing demand for long-life cold working dies used for punching automobile components. However, the full potential of such advanced surface engineering technologies as PVD coatings and duplex surface treatments in cold work dies has not been realized. In the present study, Crl2MoV steel has been surface engineered by single PVD Ti/TiN coating and duplex treatment combining low temperature plasma nitriding (LTPN) with PVD Ti/TiN coatings. The properties of Ti/TiN coatings in terms of surface morphology, microhardness, load bearing capacity, bonding strength and wear resistance were evaluated by microhardness, scratch and wear tests. The experimental results show that PVD Ti/TiN coatings can significantly enhance the surface load bearing capacity (especially for duplex treatments) and wear resistance of Crl2MoV steel by more than one order of magnitude. This can be mainly attributed to the hard and well-adherent PVD Ti/TiN surface coatings and strong mechanical support of the LTPN sublayer. While two-body abrasive wear prevails for uncoated Crl2MoV, the micropolishing action of the counterface dominates in surface engineered material. 展开更多
关键词 CR12MOV钢 PVD 二相处理 冷作拉模
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Microstructure, cold rolling, heat treatment, and mechanical properties of Mg-Li alloys 被引量:3
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作者 Haibin Ji Guangchun Yao Hongbin Li 《Journal of University of Science and Technology Beijing》 CSCD 2008年第4期440-443,共4页
The magnesium-lithium (Mg-Li) alloy exhibits two phase structures between 5.7wt% and 10.3wt% Li contents, consisting of the a (hcp) Mg-rich and the β (bcc) Li-rich phases, at room temperature. In the experimen... The magnesium-lithium (Mg-Li) alloy exhibits two phase structures between 5.7wt% and 10.3wt% Li contents, consisting of the a (hcp) Mg-rich and the β (bcc) Li-rich phases, at room temperature. In the experiment, Mg-5Li-2Zn, Mg-9Li-2Zn, Mg-16Li-2Zn, Mg-22Li-2Zn, Mg-5Li-2Zn-2Ca, Mg-9Li-2Zn-2Ca, Mg-16Li-2Zn-2Ca, and Mg-22Li-2Zn-2Ca (wt%) were melted. During the melting process, the flux, which was composed of lithium chloride (LiCl) and lithium fluoride (LiF) in the proportion of 3:1 (mass ratio) and argon gas were used to protect the alloys from oxidation. The microstructure, mechanical properties, and cold-rolling workability of the wrought alloys were studied. The crystal grain of the alloys (adding Ga) is fine . The hardness of the studied alloys decreases with an increase in element Li. The density of the studied alloys is in the range of 1.187 to 1.617 g/cm^3. The reduction of the Mg-16Li-2Zn and Mg-22Li-2Zn alloys can exceed 85% at room temperature. The Mg-9Li-2Zn-2Ca alloy was heat treated at 300℃ for 8, 12, 16, and 24 h, respectively. The optimum heat treatment of the Mg-9Li-2Zn-2Ca alloy is 300℃×12h by metallographic observation and by studying the mechanical properties of the alloys. 展开更多
关键词 Mg-Li alloy Mg-Li-Zn alloy cold rolling heat treatment MICROSTRUCTURE mechanical properties
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Effect of heat treatment on microstructure and properties of single crystal copper cold-welded joints 被引量:1
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作者 黄勇 冉小龙 +1 位作者 严晓娟 郭廷彪 《China Welding》 EI CAS 2019年第2期1-9,共9页
With the means of electron backscattered diffraction(EBSD),mechanical properties test and digital eddy current metal conductivity,the single crystal copper cold-welded joint was tested and analyzed,the structure chang... With the means of electron backscattered diffraction(EBSD),mechanical properties test and digital eddy current metal conductivity,the single crystal copper cold-welded joint was tested and analyzed,the structure change of cold-welded joint and the effect of heat treating on the structure and property of cold-welded joint were discussed.The results show that:The deformation area of the single crystal copper cold welded joint is broken,the crystalline grain at the interface of the joint is refined,and the single crystal structure is still maintained in the base metal area.The hardness of the deformation area increases greatly,the conductivity of the joint does not change much,and the tensile strength of the joint reaches about 70%of that of the base metal.At the interface of the heat treating joint,the single crystal structure of the deformation area and the base metal area are destroyed,and the grains grow up at the interface and the orientation is different.The hardness of the joint interface is much lower than that of the non-heat treating joint,the electrical conductivity of the joint is good,and the tensile strength of the joint is higher than that of the base metal. 展开更多
关键词 single crystal copper cold pressure WELDING heat treatment CONDUCTIVITY
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Influence of TiCl_4 treatment on performance of dye-sensitized solar cell assembled with nano-TiO_2 coating deposited by vacuum cold spraying 被引量:3
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作者 FAN Shengqiang LI Changjiu YANG Guanjun ZHANG Lingzi 《Rare Metals》 SCIE EI CAS CSCD 2006年第z1期163-168,共6页
Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crysta... Titanium tetrachloride (TiCl4) treatment was employed to TiO2 coating deposited on fluoride-doped tin oxide (FTO) conducting glass and indium oxide doped tin oxide (ITO) conducting glass, respectively. The nano-crystalline TiO2 coating was deposited using a composite powder composed of polyethylene glycol (PEG) and 25 nm TiO2 particles by vacuum cold spraying (VCS) process. A commercial N-719 dye was used to adsorb on the surface of TiO2 coating to prepare TiO2 electrode, which was applied to assemble dye-sensitized solar cell (DSC). The cell performance was measured under simulated solar light at an intensity of 100 mW·cm-2. Results show that with an FTO substrate the DSC composed of a VCS TiO2 electrode untreated by TiCl4 gives a short-circuit current density of 13.1 mA·cm-2 and an open circuit voltage of 0.60 V corresponding to an overall conversion efficiency of 4.4%. It is found that after TiCl4 treatment to the VCS TiO2 electrode with an FTO substrate, the short circuit current density of the cell increases by 31%, the open-circuit voltage increases by 60 mV and a higher conversion yield of 6.5% was obtained. However, when an ITO substrate is used to deposit TiO2 coating by VCS, after TiCl4 treatment, the conversion efficiency of the assembled cell reduces slightly due to corrosion of the conducting layer on the ITO glass by TiCl4. 展开更多
关键词 titanium TETRACHLORIDE treatment VACUUM cold spraying DYE-SENSITIZED solar cell NANO-CRYSTALLINE TiO2 COATING
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Effect of vacuum heat treatment on microstructure and microhardness of cold sprayed Cu-4Cr-2Nb alloy coating 被引量:2
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作者 李文亚 郭学平 +2 位作者 L.DEMBINSKI 廖汉林 C.CODDET 《中国有色金属学会会刊:英文版》 CSCD 2006年第B01期203-208,共6页
The effect of vacuum heat treatment on the microstructure and microhardness of cold-sprayed Cu-4%Cr-2%Nb alloy coating was investigated. The heat treatment was conducted under the temperatures from 250 ℃ to 950 ℃ wi... The effect of vacuum heat treatment on the microstructure and microhardness of cold-sprayed Cu-4%Cr-2%Nb alloy coating was investigated. The heat treatment was conducted under the temperatures from 250 ℃ to 950 ℃ with a step of 100 ℃ for 2 h. It was found that a dense thick Cu-4Cr-2Nb coating could be formed by cold spraying. After heat treatment, a Cr2Nb phase was uniformly distributed in the matrix, which was transferred from the gas-atomized feedstock. A little grain growth of Cr2Nb phase was observed accompanying with the healing-up of the incomplete interfaces between the deposited particles at the elevated temperatures. The coating microhardness increases a little with increasing the temperature to 350 ℃, and then decreases with further increasing temperature up to 950 ℃. This fact can be attributed to the microstructure evolution during the heat treatment. 展开更多
关键词 Cu-4Cr-2Nb合金涂层 冷喷涂 真空热处理 显微结构 显微硬度
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Numerical Analysis of Doublet Wells for Cold Energy Storage on Heat Damage Treatment in Deep Mines 被引量:11
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作者 HE Man-chao ZHANG Yi +1 位作者 GUO Dong-ming QIAN Zeng-zhen 《Journal of China University of Mining and Technology》 EI 2006年第3期278-282,共5页
Deep mining is an inevitable tendency in the development of coal industry. There are many heat damage problems with the increase of mining depth. The technology of using doublet wells, together with Heat Exchange Mach... Deep mining is an inevitable tendency in the development of coal industry. There are many heat damage problems with the increase of mining depth. The technology of using doublet wells, together with Heat Exchange Machine Systems (HEMSs), to store cold energy is a key to solve the heat damage problems in deep mines. Based on the geological conditions, thermodynamic and hydraulic parameters of Jiahe Mine, the isotherms in the period of cold energy storage and refrigeration and the volumes of cold water within different temperature ranges of the cold energy storage well were numerically analyzed. The results show that 1) with the same pumped and injected water volumes, the lower the temperature of injected water is, the larger the volume of cold water in the cold energy storage well is. With the larger volume, the effect of cold energy storage is better. 2) the larger the volumes of pumped and reinjected water are, the larger the volume of cold water from the cold energy storage well is. With the larger volume, the effect of refrigeration is better. And 3) without disturbance, the volume and temperature of cold water in the cold energy storage well can keep unchanged or have only a little change for a long time. Therefore the technology of doublet wells for cold energy storage is feasible and the cold energy storage aquifers can meet the requirement of the technology. 展开更多
关键词 深井 数值分析 热爆处理 蓄水层 蓄冷
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The effect of annealing treatment on the microstructures and mechanical properties of cold-sprayed nickel coating 被引量:1
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作者 ZHANG Huabing ZHANG Junbao +1 位作者 LIANG Yongli SONG Hongwei 《Baosteel Technical Research》 CAS 2009年第2期46-51,共6页
The effect of annealing treatment on the microstructures and mechanical properties of cold-sprayed Ni coating was investigated by conducting micro-hardness and tensile tests and using a normal optical microscope (OM... The effect of annealing treatment on the microstructures and mechanical properties of cold-sprayed Ni coating was investigated by conducting micro-hardness and tensile tests and using a normal optical microscope (OM) ,a scanning electron microscope ( SEM), a transmission electron microscope (TEM) and an electron probe X-ray microanalyzer (EPMA). The results show that following the increase of the annealing temperature ,the micro-hardness of cold-sprayed Ni coating decreases and the elongation after fracture increases, while the tensile strength increases before decreasing. The tensile deformation and fracture behavior change from a typical brittle fracture to a hybrid brittle and ductile fracture, then to a typical ductile failure. It is found that when annealed at an elevated temperature ( e. g. 900℃ ) ,the grains tend to grow abnormally with the oxides spheroidizing and the defects agglomerating at the interfaces, causing the tensile strength reduction of the cold-sprayed nickel coating. It is also pointed out that the tensile strength of the cold-sprayed Ni coating can be significantly improved by the appropriate annealing procedures, but the elongation after fracture cannot be clearly increased because it is difficult to eliminate the main defects in the coating by the following heat treatments. 展开更多
关键词 cold spray Ni coating annealing treatment microstructure and mechanical property
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Efficacy of a Novel Antibody TLR3 Modulator in the Self-Treatment of Common Cold: The ESTUAR Trial
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作者 Andrey Martyushev-Poklad Jacques Bruhwyler +1 位作者 Stéphane Heijmans Michel Thiry 《Advances in Infectious Diseases》 2015年第4期204-217,共14页
Context: Since the discovery of toll-like receptor 3 (TLR3), no specific tools have been developed to modulate its activity in upper respiratory tract viral infections (URTIs). ContafluTM (antibodies to TLR3 cytoplasm... Context: Since the discovery of toll-like receptor 3 (TLR3), no specific tools have been developed to modulate its activity in upper respiratory tract viral infections (URTIs). ContafluTM (antibodies to TLR3 cytoplasmic fragment) is the first specific TLR3 modulator that showed efficacy in a mouse model of influenza. Objective: To evaluate the efficacy of Contaflu in URTI. Methods: A double-blind randomized placebo-controlled trial in adults with self-reported URTI (the ESTUAR trial) was conducted in 2012/2013 in Belgium. Adult outpatients started a 7-day treatment course with oral tablets of Contaflu or placebo within 36 h after onset of at least one of 4 typical symptoms of URTI. Patients were examined twice by their general practitioners, on days 2-3 and 10-14 after start of treatment. The primary endpoint was the overall severity of URTI calculated as the sum of Wisconsin Upper Respiratory Symptom Survey (WURSS-21) scores over the follow-up. Independent Student’s t test was used to compare the disease severity between groups. Results: A total of 243 patients were enrolled by 32 investigators (121 Contaflu, 122 placebo);92% of cases matched ICD codes J00 or J06. Most patients had very mild (41.8%) or mild (18.2%) URTI symptoms. In the ITT cohort, neither primary nor secondary outcome measures (duration of URTI, day-to-day and overall functional impairments) showed statistically significant differences between groups. The rate of adverse events was similar in both groups. In patients with moderate to severe URTI symptoms, Contaflu tended to reduce the overall disease severity, daily symptoms, and to improve the functional state. Due to the small size of the corresponding subgroups, Contaflu efficacy on daily scores was statistically significant (p < 0.05) only 1, 2, and 5 days after start of treatment. Conclusion: Contaflu was ineffective in mild URTI and showed efficacy in moderate to severe URTI cases. 展开更多
关键词 Common cold treatment TOLL-LIKE Receptor 3 TLR3 Modulation RANDOMIZED Clinical TRIAL
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Application of Cold Plasma Technology in Sludge Treatment
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作者 Hu Yanyan Xu Fuyin +1 位作者 Chen Xiang Bao Bing 《Meteorological and Environmental Research》 CAS 2019年第1期49-51,共3页
Cold plasma technology was used to treat sludge,and the effects of various discharge times on the p H,EC,content of available nutrients( available nitrogen,available phosphorus and available potassium),value of fecal ... Cold plasma technology was used to treat sludge,and the effects of various discharge times on the p H,EC,content of available nutrients( available nitrogen,available phosphorus and available potassium),value of fecal coliforms,and mortality of Ascaris lumbricoides eggs of sludge were studied. The results showed that after the treatment of sludge by cold plasma technology,it had certain effects on the p H,EC,available nitrogen and available phosphorus content of the sludge,and had no significant effect on available potassium content. Within certain discharge times,sludge p H increased,while EC,available nitrogen and available phosphorus content decreased,and there was no significant change in available potassium content. The plasma generated by discharge could effectively kill microorganisms under normal atmospheric pressure,so that the value of fecal coliforms and mortality of Ascaris lumbricoides eggs of the treated sludge could meet the requirements of the relevant standard. 展开更多
关键词 cold PLASMA SLUDGE treatment PHYSICAL and CHEMICAL properties Hygienic INDICATORS
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EMF CHANGES MADE BY COLD DRAWING AND HEATING TREATMENT IN TYPE K HEAVY-GAUGE SHEATHED THERMOCOUPLE CABLES
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作者 ZHAO Rong-bin(赵容斌) +2 位作者 LI Guan-jun (李冠军) 《Journal of Shanghai Jiaotong university(Science)》 EI 2002年第1期80-83,共4页
The electromotive force (EMF) changes in type K heavy gauge sheathed thermocouple cables was investigated. To cope with this discrepancy owing to EMF steep reduction and understand the difference between type K heavy ... The electromotive force (EMF) changes in type K heavy gauge sheathed thermocouple cables was investigated. To cope with this discrepancy owing to EMF steep reduction and understand the difference between type K heavy gauge sheathed thermocouple cables and small ones, the affects of EMF from sheath pipe, drawing times, annealing temperature, annealing time and annealing way were mainly studied and appropriately analyzed. The results show the change in the thermal EMF is related with the residual stress and crystal defects, which are imparted by cold work during manufacture. The affects of cold work can be removed by annealing. Finally, a feasible way of fabricating heavy gauge sheathed thermocouples was suggested according to practical situation. 展开更多
关键词 EMF CHANGES cold drawing HEATING treatment TYPE K heavy-gauge THERMOCOUPLE
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Pilot study on microbial treatment of high concentration chromium wastewater from cold rolling mills
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作者 Yu Yongmei Zhou Yusheng 《Baosteel Technical Research》 CAS 2008年第1期46-50,共5页
The microbial treatment of wastewater containing a high concentration of chromium from cold rolling mills was carried out as a pilot study. The pilot-scale equipment, technological process and results are described in... The microbial treatment of wastewater containing a high concentration of chromium from cold rolling mills was carried out as a pilot study. The pilot-scale equipment, technological process and results are described in this paper. Two kinds of wastewater with a high concentration of chromium were tested : one from a color coating line ; the other from a silicon steel line. The removal effect of Cr^6+ , T-Cr and chemical oxygen demand (COD) in wastewater was studied. The results showed that this microbial treatment technology could be used to treat the above two kinds of chromium-containing wastewater. The average concentrations of Cr^6+ in the color coating line effluent and the silicon steel line effluent were 0.02 mg/L and 0.04 mg/L respectively, and the average concentrations of T-Cr in the effluents were 0.71 mg/L and 0.74 mg/L respectively. Both were lower than the Sewage Discharge Standard (Cr^6+ 〈 0.5 mg/L,T-Cr 〈 1.5 mg/L). Furthermore, up to 60% of the COD was removed from chromate wastewater containing a high concentration COD ( 〉 3 g/L). The removal rate of COD was lower than 25% for chromate wastewater containing a low concentration COD ( 〈 3 g/L). Adding a flocculating agent was one of the effective ways of improving the COD removal rate from chromium-containing wastewater. 展开更多
关键词 chromium-containing wastewater cold rolling hexavalent chromium microbial treatment
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Identification and Treatment of Swine Influenza and Common Cold in Veterinary Clinic
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作者 Yi Pingchang Li Lili Li Guoping 《Animal Husbandry and Feed Science》 CAS 2018年第5期297-299,共3页
[Objective] The paper was to investigate the differentiation and treatment of swine influenza and common cold in veterinary clinic.[Method] The clinical data of diseased pigs from May 2017 to May 2018 were analyzed re... [Objective] The paper was to investigate the differentiation and treatment of swine influenza and common cold in veterinary clinic.[Method] The clinical data of diseased pigs from May 2017 to May 2018 were analyzed retrospectively to explore the clinical treatment methods for swine influenza and common cold, and the effectiveness and accuracy of clinical diagnosis was further improved. [Result] Through in-depth analysis of test results, we obtained a comprehensive understanding of the main causes of swine influenza and common cold, and found that the causes in-cluded improper breeding management of pigs, nutrition of pigs and lack of immunity of newborn pigs. [Conclusion] Analysis of the causes of swine influenza and common cold and suggestion of targeted clinical treatment measures will reduce the incidence of swine disease, and promote the vet-erinary clinical treatment effect of swine influenza and common cold. 展开更多
关键词 IDENTIFICATION treatment VETERINARIAN SWINE INFLUENZA Common cold
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冷水鱼养殖尾水治理技术试验
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作者 闫立君 王圆圆 +4 位作者 朱静 孟秋冬 赵强 方会卿 尹超 《河北渔业》 2024年第1期12-16,共5页
为保护水域生态环境,实施环保养殖,加强养殖业自身环保建设,采用固液分离、沉淀吸收、氧化降解、微生物降解过滤净化和植物吸收等生态处理技术,开展冷流水养殖尾水综合处理技术研究,在处理系统为养殖面积40%的情况下,能有效降低尾水中的... 为保护水域生态环境,实施环保养殖,加强养殖业自身环保建设,采用固液分离、沉淀吸收、氧化降解、微生物降解过滤净化和植物吸收等生态处理技术,开展冷流水养殖尾水综合处理技术研究,在处理系统为养殖面积40%的情况下,能有效降低尾水中的COD和氮磷,处理效果分别达到了100%、87.13%、75.56%。 展开更多
关键词 冷水鱼 养殖 尾水 治理
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Stochastic Model of a Cold-Stand by System with Waiting for Arrival &Treatment of Server
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作者 Rohtash K. Bhardwaj Ravinder Singh 《American Journal of Operations Research》 2016年第4期334-342,共9页
The service facility or server is the key constituent to keep a system operational for desired period of time. As any eventuality with the system necessitates immediate presence of it (server) so the time point of arr... The service facility or server is the key constituent to keep a system operational for desired period of time. As any eventuality with the system necessitates immediate presence of it (server) so the time point of arrival and treatment of server significantly affects the system performance. This paper works out the steady state behavior of a cold standby system equipped with two similar units and a server with elapsed arrival and treatment times following general probability distributions. It practices the theory of semi-Markov processes, regenerative point technique and Laplace transforms to derive the expressions for state transition probabilities, mean sojourn times, mean time to system failure, system availability, server busy period and expected frequencies of repairs and treatments. The profit function is also developed taking different costs and revenue in to account. For tracing wider applicability of the model for different reliability and cost-effective systems, a particular case study is also presented as an illustration. 展开更多
关键词 Stochastic Model cold-Standby System Server Failure Regenerative Point Arrival and treatment Times
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突尼斯软籽石榴防寒越冬措施的防护效果
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作者 黄梦真 关思慧 +5 位作者 柴亚倩 许静 杨元玲 刘慧英 杨磊 刁明 《果树学报》 CAS CSCD 北大核心 2024年第5期929-940,共12页
【目的】通过调查分析大田及冷棚突尼斯软籽石榴冬季不同防寒越冬措施的防护效果,筛选出适宜的防寒越冬措施,为突尼斯软籽石榴的安全过冬提供理论依据与技术支撑。【方法】以1年生突尼斯软籽石榴为试材,在12连设置露地3种覆土厚度下的7... 【目的】通过调查分析大田及冷棚突尼斯软籽石榴冬季不同防寒越冬措施的防护效果,筛选出适宜的防寒越冬措施,为突尼斯软籽石榴的安全过冬提供理论依据与技术支撑。【方法】以1年生突尼斯软籽石榴为试材,在12连设置露地3种覆土厚度下的7种物理保护措施共21个处理,测定不同物理防寒措施下,石榴树体周围的温湿度变化情况,并调查分析翌年春季突尼斯软籽石榴的冻害情况;以3年生突尼斯软籽石榴为试材,在20连设置5种和19连设置2种防寒保护措施,调查分析翌年春季石榴的冻害情况,以筛选适宜的冬季防寒越冬措施。【结果】草帘+钢筋+覆土以及草帘+塑料膜+覆土的防寒措施对软籽石榴安全越冬效果较好,均可有效提高石榴树体微环境的湿度、日平均温度及日最低温度,且草帘+塑料膜+覆土15 cm防寒措施下的突尼斯软籽石榴整体冻害最轻(冻害指数8.3%)。冷棚内不同覆盖方式中最好的物理保护措施是草帘+拱棚,突尼斯软籽石榴苗均未遭受冻害,保护效果较好的物理保护措施为毛毡和覆土。【结论】新疆冬季气候寒冷,在传统埋土防寒措施下,突尼斯软籽石榴仍发生严重冻害,需采取其他物理保护措施与覆土相结合的方式,才能有效地避免突尼斯软籽石榴遭受冻害。草帘+塑料膜+覆土15 cm防寒措施下的突尼斯软籽石榴整体冻害最轻,可以在生产中推广应用。单纯的冷棚设施栽培并不能对突尼斯软籽石榴起到良好的防冻效果,在冷棚内搭建小拱棚并在其上覆盖草帘能够保证软籽石榴安全越冬。 展开更多
关键词 突尼斯软籽石榴 防寒措施 冻害
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高海拔严寒地区隧道冻害研究现状及展望
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作者 乔雄 杨小龙 冯勇 《隧道建设(中英文)》 CSCD 北大核心 2024年第2期233-256,I0033-I0056,共48页
针对高海拔严寒地区隧道冻害问题,结合隧道冻害的相关研究,从冻害类型及原因分析、冻害机制、温度场、处置措施等4个方面的现状进行阐述和分析,对当前研究存在的不足和未来的发展方向进行探讨。主要成果为:1)通过对高海拔严寒地区隧道... 针对高海拔严寒地区隧道冻害问题,结合隧道冻害的相关研究,从冻害类型及原因分析、冻害机制、温度场、处置措施等4个方面的现状进行阐述和分析,对当前研究存在的不足和未来的发展方向进行探讨。主要成果为:1)通过对高海拔严寒地区隧道工程实例进行分析,总结4种冻害类型及4种冻害原因;2)基于含水风化层冻胀理论、整体性围岩冻胀理论、衬砌背后积水冻胀理论、裂隙水冻胀理论等4种冻胀理论,建立多年冻土区以整体性围岩冻胀理论为主、季冻区以裂隙水冻胀理论为主的多理论联合分析的方法;3)温度场研究方法分为现场监测、理论解析、模型试验、数值模拟等4种,其中现场监测是对洞内外温度进行监测,而理论分析、模型试验、数值模拟则是对监测结果进行验证分析;4)冻害处置措施有防排水措施、保温防寒措施、抗冻措施等3种,防冻的关键是将三者相结合进行综合治理;5)指出冻害机制适用性、温度场研究方法现状、处置措施适用性等方面的不足,未来应在高海拔严寒地区建立多种冻胀理论、多种研究方法综合应用的研究体系,并在隧道防排水、保温防寒、抗冻等方面给出处置措施。 展开更多
关键词 隧道工程 高海拔严寒地区 冻害机制 温度场 处置措施
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外源甜菜碱与褪黑素复合处理对龙眼果实贮藏性能的影响
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作者 张瑞敏 胡凯雪 +2 位作者 邱秋萍 刘顺枝 胡位荣 《包装工程》 CAS 北大核心 2024年第5期38-45,共8页
目的研究不同浓度甜菜碱与褪黑素复合处理对采后龙眼果实冷藏的保鲜效果,以期为龙眼贮藏保鲜新技术提供理论参考。方法以‘储良’龙眼为实验材料,分别采用0、5、10、15 mmol/L的甜菜碱与300 mmol/L的褪黑素复配制成保鲜剂处理果实。在... 目的研究不同浓度甜菜碱与褪黑素复合处理对采后龙眼果实冷藏的保鲜效果,以期为龙眼贮藏保鲜新技术提供理论参考。方法以‘储良’龙眼为实验材料,分别采用0、5、10、15 mmol/L的甜菜碱与300 mmol/L的褪黑素复配制成保鲜剂处理果实。在温度为4℃、相对湿度为85%条件下贮藏,研究其冷藏期间质量损失率及可溶性固形物(TSS)、可滴定酸(TA)、抗坏血酸(VC)、丙二醛(MDA)、游离脯氨酸含量和过氧化氢酶(CAT)、过氧化物酶(POD)、超氧化物歧化酶(SOD)活性的变化。结果与300 mmol/L褪黑素对照组相比,复合保鲜剂能有效减少龙眼果实水分、TSS、TA、VC和游离脯氨酸含量的损失,使龙眼果肉保持较高的SOD、CAT活性(P<0.05),而POD活性和MDA含量维持在较低水平。结论300mmol/L褪黑素+10 mmol/L甜菜碱处理对龙眼的冷藏保鲜效果最佳。 展开更多
关键词 龙眼 甜菜碱 褪黑素 复合处理 冷藏
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