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谷氨酰胺、癌症及其治疗 被引量:24
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作者 V.Suzanne Klimberg John L.McClellan +1 位作者 Little Rock arkansas 《中国临床营养杂志》 1999年第2期51-57,共7页
目的回顾谷氨酰胺、癌症及其治疗方面的一些进展,主要是关于谷氨酰胺与肿瘤生长方面的体内与体外、动物和人体的研究结果。对荷瘤宿主在接受放疗和化疗时补充谷氨酰胺的某些益处进行总结。背景谷氨酰胺是体内最丰富的游离氨基酸。而肿... 目的回顾谷氨酰胺、癌症及其治疗方面的一些进展,主要是关于谷氨酰胺与肿瘤生长方面的体内与体外、动物和人体的研究结果。对荷瘤宿主在接受放疗和化疗时补充谷氨酰胺的某些益处进行总结。背景谷氨酰胺是体内最丰富的游离氨基酸。而肿瘤组织就象一个“谷氨酰胺网”消耗大量的谷氨酰胺,从而促使机体恶病质的发生。体外研究中,肿瘤细胞的生长依赖于谷氨酰胺的结果使得人们未在临床上给癌症病人补充谷氨酰胺。方法对谷氨酰胺与接受放、化疗荷瘤宿主的关系的研究结果进行归纳和总结。结果大量体内研究表明,补充谷氨酰胺不但不会使肿瘤生长,而且还会通过刺激机体的免疫系统来抑制肿瘤的生长。在机体接受放疗和化疗时,谷氨酰胺可以保护机体并增加化疗对肿瘤的选择性。结论还需要进行前瞻、随机的研究来证明在接受放疗和化疗的病人补充谷氨酰胺的安全性和有效性。 展开更多
关键词 谷氨酰胺 癌症 肿瘤生长 谷胱甘肽
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Distribution of ^3H—nicotine in Rat Tissues Under the Influence of Simulated Microgravity 被引量:6
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作者 PARIMAL CHOWDHURY MICHAEL E. SOULSBY AND JAMES N. PASLEY (Department of Physiology and Biophysics, University of arkansas for Medical Scienses, Little Rock, arkansas 72205, USA) 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1999年第2期103-109,共7页
Rat tail suspension offers a useful model to reproduce physiologic responses to weightlessness.The present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues emp... Rat tail suspension offers a useful model to reproduce physiologic responses to weightlessness.The present study was conducted in the head-down-tilt(HDT) rat model to assess changes in metabolism of body tissues employing 3H-nicotine. Twelve male rats were used in the study. Half of the rats were tail suspended at 30°for two weeks on a 12/12 light/dark cycle. During this period,body weight, food and fluid intakes were measured. At term, animals were anesthetized and injected IV withe a solution contaming 4 microuries of micotine. After 90 min the animals were sacrificed, exsanguinated and tissues (brain,blood,trachea,salivary gland,lung,heart,esophagus,spleen, kidneys and testes) were harvested. The distribution of 3H-nicotine per gram of each tissue was determinded and ealeulated as percent of total injected radioactivity. Final body weights of suspended ammals were significantly (P < 0.0 5) lower than those of eontrols(309±21 vs 350±11g). 3HNicotine waw retained in greatest amounts by the kindneys, followed inorder by salivary glands, spleen, and gastrointestinal tissues. compared to non-suspended control, the tissue retention of nicotine in suspended animals was decreased in the following tissues:esphyagus (25 %), aorta (25%). fundus (25%), trachea (22%), adrenals (18%), spleen (17 %), and pancreas (12 %). The decreased retention of mcotine in tissues from suspended animals may be indicative of the fluid shifts and changes in blood flow to those tissue beds. The lack of differnces in nicotine retention in liver and kidney between control and suspended groups may implicate a normal metabolic function of these organs even under simulated weightlessness. 展开更多
关键词 GRAVITATION Animals Male NICOTINE RATS Rats Sprague-Dawley Research Support Non-U.S. Gov't Tissue Distribution Tritium Weightlessness Simulation
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Danshao Huaxian capsule in treatment of decompensated cirrhosis resulting from chronic hepatitis B
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作者 Ming-Liang Cheng, Tong Lu, Yu-Mei Yao and Xiao-Xia Geng Department of Infectious Diseases, Affiliated Hospital of Guiyang Medical College, Guiyang 550004, China and Department of Internal Medicine, University of arkansas for Medical Sciences, Little Rock, arkansas, USA 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2006年第1期48-51,共4页
BACKGROUND: The prognosis of decompensated cirrhosis resulting from chronic hepatitis B is poor, and the benefits of treatment with interferon are ourweight serious sideeffects and the risk of fatal exacerbation of di... BACKGROUND: The prognosis of decompensated cirrhosis resulting from chronic hepatitis B is poor, and the benefits of treatment with interferon are ourweight serious sideeffects and the risk of fatal exacerbation of disease. Danshao Huaxian capsule rapidly reduces hepatitis B virus(HBV)-DNA in serum to undetectable levels. METHODS: A total of 35 patients with chronic hepatitis B and decompensated cirrhosis were treated with Danshao Huaxian 1.2g. po. tid daily. Before the treatment, HBVDNA in serum was positive in all patients. Ten patients had Child-Pugh class B and 25, class C hepatitis B. Seven patients underwent liver transplantation within 6 months of initial treatment. Of the 10 patients of class B, 5 died within 6 months, and the other 5 did not complete the treatment for some reasons; the 25 patients of class C were treated for at least 6 months (mean =19 months). RESULTS: In most of the 25 patients, liver function was improved slowly but markedly after 9 months of treatment, showing a decreased level of serum bilirubin from 67±13 to 30±4μmol/L (P<0.05, baseline vs.6 months), an increased level of serum albumin from 27±1 to 34±1 g/L(P<0.05) and a decreased level of Child-Pugh score from 10.3±0.4 to 7.5+0.5 (P<0.05). Three patients developed resistance to Danshao Huaxian because of a mutation in the YMDD motif, but liver function was not deteriorated. Inhibition of viral replication with Danshao Huaxian resulted in a significant improvement of liver function in patients with decompensated HBV cirrhosis, but the long-term results remain uncertain. CONCLUSION: Danshao Huaxian capsule is effective in inhibiting viral DNA replication in patients with decompensated cirrhosis and making clinical improvement. 展开更多
关键词 Danshao Huaxian capsule decompensated cirrhosis chronic hepatitis B PROGNOSIS
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Phosphorus availability in two soils amended with poultry litter
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作者 Han Xingguo (Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China)Duane C.Wolf (Department of Agronomy,University of arkansas,Fayetteville, AR 72701,USA) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1996年第4期483-490,共8页
Understanding P transformation in soils amended with poultry litter is important if water quality is to be protected.Our objectives were to determine the influence of method of litter application and temperature on P ... Understanding P transformation in soils amended with poultry litter is important if water quality is to be protected.Our objectives were to determine the influence of method of litter application and temperature on P availability. Poultry litter containing 20. 8g P/kg (dry weight) was either surface-applied or incorporated into Captina (fine-silty, siliceous, mesic Typic Fragiudult) and Nixa (loamy-skeletal,siliceous,Glossic Fragiudult) silt loams at rates of 0 or 10g/kg and incubated at 20℃ or 35℃ at a water potential of -40 kpa. Water soluble and available P (0.03 mol/L NH4F+0. 025mol/L HCl extraction) were determined during a 60d laboratory study. Results indicated that water soluble and available P levels in the soils initially decreased, then rapidly increased,and approached a steady state phase after approximately 20d. After 60d, water soluble P levels were significantly higher when litter was surface applied than when litter was incor porated. When the incubation was terminated, the net increase in available P in both soils was>100 mg P/kg.For efficient recycling of P and protection of water quality, application method and temperature should be considered when amending soils with poultry litter, 展开更多
关键词 nutrient cycling phosphorus availability poultry litter water quality.
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Some Practical Issues Regarding Java Programming
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作者 Ming-fang Wang Department of Computer Science, University of Central arkansasConway, arkansas 72035 wangm @ panda.cs.uca.eduWu JieShanghai Institute of Computing Tech. Shanghai, China 200040 Telephone: 62520070 《计算机工程》 CAS CSCD 北大核心 1996年第S1期106-121,共16页
Java programming language is a major . new development which involves object-oriented programming and computer networking. Here, several examples of Java programs are presented. These examples show some major features... Java programming language is a major . new development which involves object-oriented programming and computer networking. Here, several examples of Java programs are presented. These examples show some major features that Java language provides, such as multi-thread, exception handling, network application writing, and the usage of Java applets. This article also shows some ways of setting up a Java language programming environment. All these examples are correct and ready to run. 展开更多
关键词 Java programming/object- ORIENTED programming/multi - THREAD
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MULTI-DISPLACEMENT CONTINUUM MODEL WITH LOCAL RESONANCE
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作者 Aiping Liu 1 Guoliang Huang 2 Gengkai Hu 1 ( 1 School of Aerospace Engineering, Beijing Institute of Technology, 100081 Beijing, China) ( 2 Department of Systems Engineering, University of arkansas at Little Rock, Little Rock, AR, 72204, USA) 《Acta Mechanica Solida Sinica》 SCIE EI 2011年第S1期17-21,共5页
We propose a multi-displacement continuum (MDC) model to characterize the local resonance presented in a lattice system. Dispersion curves in a mass-in-mass system are studied and compared to the single-displacement m... We propose a multi-displacement continuum (MDC) model to characterize the local resonance presented in a lattice system. Dispersion curves in a mass-in-mass system are studied and compared to the single-displacement model. It is shown that the dispersive relations and the local resonant band gap structures can be adequately described. The acoustic mode can be accurately predicted, while the optical mode is correctly predicted for certain frequency range, where the wave length is large enough. The single-displacement model fails to describe the bang gap structure inherent in the system due to local resonance. 展开更多
关键词 multi-displacement continuum model wave propagation dispersion curves
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Structural and optical properties of periodically ordered ZnO nanowires
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作者 J.B.CUI Department of Physics and Astronomy, University of arkansas at Little Rock, Little Rock, AR 72204, USA 《Science China(Technological Sciences)》 SCIE EI CAS 2009年第2期313-317,共5页
Periodically ordered ZnO nanowire arrays were fabricated by a combination of soft templates created by electron beam lithography and an electrochemical process. Individual ZnO nanowires were precisely placed in desire... Periodically ordered ZnO nanowire arrays were fabricated by a combination of soft templates created by electron beam lithography and an electrochemical process. Individual ZnO nanowires were precisely placed in desired locations to form two-dimensional periodic structures with specific patterns. Scanning electron microscopy and light diffraction measurements confirmed the long-range ordered structures in the nanowire arrays. Variable temperature photoluminescence revealed both band edge and defect emissions. The obtained photonic structures may have potential applications in optical and optoelectronic devices. 展开更多
关键词 ZINC OXIDE NANOWIRES ORDERED structure optical PROPERTY
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EIGENFREQUENCIES OF THE THREE DIMENSIONAL EULER-BERNOULLI BEAM SYSTEM WITH DISSIPATIVE JOJNTS
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作者 William H. Paulsen(Department of Computer Science, Mathematics, and Physics, arkansasState Unirersity, arkansas. 72467, USA) 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1995年第8期723-746,共16页
In this paper, we will compute the transfer matrices to find the eigenfrequenciesfor the vibrations of the general non-collinear Euler-Bernoulli or Timoshenko beamstructure with dissipative joints. We will allow the s... In this paper, we will compute the transfer matrices to find the eigenfrequenciesfor the vibrations of the general non-collinear Euler-Bernoulli or Timoshenko beamstructure with dissipative joints. We will allow the structure to be three dimensional,and thus we must consider all types of vibrations simulaneously, including longitudinaland torsional vibrations. The general structure considered will consist of any number ofbeams joined end to end to form a chain. Many, different kinds of dampers areallowed, even within the same structure. We also will allow different materials withinthe structure as well as different beam widths. We then will show. that asymptotic estimates can be used to find the eigenfrequencies approximately. 展开更多
关键词 ASYMPTOTICS coupled beams EIGENFREQUENCIES Euler-Bernoulli Timoshenko linear joints
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男男性行为人群HIV暴露前预防需求与使用障碍研究 被引量:35
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作者 石安霞 Don Operario +8 位作者 张志华 赵越 朱晓芳 杨璀 Nickolas Zaller 高攀 王君 孙业桓 张洪波 《中华流行病学杂志》 CAS CSCD 北大核心 2020年第3期343-348,共6页
目的:了解MSM对HIV暴露前预防(PrEP)的实际需求及阻碍其使用的相关因素。方法:通过同性社交Blued 6.5.0软件、MSM同伴推荐等方法招募MSM为调查对象,估算样本量600人。利用"问卷星"平台,在调查员的指导下进行匿名电子问卷调查... 目的:了解MSM对HIV暴露前预防(PrEP)的实际需求及阻碍其使用的相关因素。方法:通过同性社交Blued 6.5.0软件、MSM同伴推荐等方法招募MSM为调查对象,估算样本量600人。利用"问卷星"平台,在调查员的指导下进行匿名电子问卷调查,调查内容包括一般情况、PrEP相关知识和使用意愿与顾虑、PrEP实际需求及PrEP使用自我效能等。结果:共调查622名MSM,知晓和曾使用过PrEP的比例分别为56.4%(351/622)和4.3%(27/622);67.2%(418/622)有PrEP实际需求,PrEP使用自我效能良好的为21.2%(132/622)。结构方程模型分析结果显示,PrEP相关知识和使用顾虑对PrEP使用自我效能发挥直接正向作用,效应系数分别为0.08和0.13,自我歧视是由于PrEP使用顾虑而间接影响PrEP使用自我效能,效应系数为0.035;广义线性混合模型分析结果表明,曾使用过PrEP可增加使用自我效能(OR=5.55);PrEP相关知识和使用顾虑每增加1分,PrEP使用自我效能分别增加0.14倍和0.07倍。担心药物副作用、预防效果和费用者分别占61.1%(380/622)、60.1%(374/622)和53.2%(331/622);期望获取PrEP服务途径主要为CDC(75.6%,470/622)、MSM社会组织(65.4%,407/622)和互联网(63.8%,397/622)。结论:MSM对PrEP呈现高需求与低使用的较大差距,PrEP相关知识缺乏、自我歧视、对药物预防效果、副作用及费用的顾虑是阻碍MSM使用PrEP的因素,故需要建立适合MSM特点的PrEP服务模式,以满足MSM对PrEP干预的需求。 展开更多
关键词 艾滋病病毒 男男性行为人群 暴露前预防 需求
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SiC、Si、混合功率模块封装对比评估与失效分析 被引量:16
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作者 李晓玲 曾正 +3 位作者 陈昊 邵伟华 胡博容 冉立 《中国电机工程学报》 EI CSCD 北大核心 2018年第16期4823-4835,共13页
随着SiC器件在新能源发电、电动汽车等领域的快速发展,对定制化、高可靠SiC功率模块的需求日益迫切。然而,现有SiC功率模块大多沿用Si模块的封装技术,存在寄生电感大等问题,无法适应SiC器件的高速开关能力,难以充分发挥SiC器件的优越性... 随着SiC器件在新能源发电、电动汽车等领域的快速发展,对定制化、高可靠SiC功率模块的需求日益迫切。然而,现有SiC功率模块大多沿用Si模块的封装技术,存在寄生电感大等问题,无法适应SiC器件的高速开关能力,难以充分发挥SiC器件的优越性能。该文梳理了功率模块的材料选型准则,以及封装工艺方法,给出了自主封装功率模块的测试流程。针对全Si、混合、全SiC功率模块,基于相同的封装技术和测试方法,对比研究了3种功率模块的动态性能和温敏特性,为不同应用需求下的器件选型提供参考。针对全SiC半桥功率模块,提出了开关损耗的数学模型,并利用实验结果验证了其有效性。此外,结合功率模块的大量故障案例建立了数学模型,分析封装失效的机理,为下一代SiC功率模块的封装集成研究提供了有益的经验和思路。 展开更多
关键词 SiC功率模块 Si功率模块 混合功率模块 封装集成方法 失效模式分析
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基于上下文感知和个性化度量嵌入的下一个兴趣点推荐 被引量:11
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作者 鲜学丰 陈晓杰 +2 位作者 赵朋朋 杨元峰 Victor S.Sheng 《计算机工程与科学》 CSCD 北大核心 2018年第4期616-625,共10页
随着基于位置的社交网络推荐系统的逐步发展,兴趣点推荐成为了研究热门。兴趣点推荐的研究旨在为用户推荐兴趣点,并且为商家提供广告投放和潜在客户发掘等服务。由于用户签到行为的数据具有高稀疏性,为兴趣点推荐带来很大的挑战。许多... 随着基于位置的社交网络推荐系统的逐步发展,兴趣点推荐成为了研究热门。兴趣点推荐的研究旨在为用户推荐兴趣点,并且为商家提供广告投放和潜在客户发掘等服务。由于用户签到行为的数据具有高稀疏性,为兴趣点推荐带来很大的挑战。许多研究工作结合地理影响、时间效应、社会相关性等方面的因素来提高兴趣点推荐的性能。然而,在大多数兴趣点推荐的工作中,用户访问的周期性习惯和伴随用户偏好的上下文情境信息没有被深度地挖掘。而且,下一个兴趣点推荐中一直存在着数据的高稀疏度。基于以上考虑,针对用户签到的数据稀疏性问题,将用户周期性行为模式归结为上下文情境信息,提出了一种基于上下文感知的个性化度量嵌入推荐算法,同时将用户签到的上下文情境信息考虑进来,从而丰富有效数据,缓解数据稀疏性问题,提高推荐的准确率,并且进一步优化算法,降低时间复杂度。在两个真实数据集上的实验分析表明,本文提出的算法具有更好的推荐效果。 展开更多
关键词 基于位置的社交网络 下一个兴趣点推荐 推荐系统 上下文感知 度量嵌入
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大数据时代首席数据官的角色与职责 被引量:11
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作者 聂钰 肖忠东 +1 位作者 冯泰文 John R.Talburt 《中国科技论坛》 CSSCI 北大核心 2019年第7期157-164,共8页
随着大数据时代的到来,首席数据官(CDO)承担起了管理各类数据的工作,但作为一个新兴的职位,CDO在组织中扮演的角色和承担的职责尚不完全清晰。本文运用两阶段调研法,以美国多家企业的CDO为主要调研对象,结合他们的实际工作,梳理CDO承担... 随着大数据时代的到来,首席数据官(CDO)承担起了管理各类数据的工作,但作为一个新兴的职位,CDO在组织中扮演的角色和承担的职责尚不完全清晰。本文运用两阶段调研法,以美国多家企业的CDO为主要调研对象,结合他们的实际工作,梳理CDO承担的主要工作职责,归纳其在企业运行中扮演的角色,建立CDO角色和职责的层次结构。研究表明,CDO在企业中主要承担最大化商业价值、挖掘新的商业机会、数据质量管理等28项工作职责;主要扮演5种角色:数据管理者、商业价值挖掘者、决策制定者、协调者、数据概念及技能推广者。通过角色和职责权重分析得出,CDO最重要的角色是数据管理者和商业价值挖掘者,最重要的职责是最大化数据价值和挖掘新的商业机会。 展开更多
关键词 大数据 首席数据官 角色 职责 商业价值
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膜分离技术在大型养殖场沼液处理中的应用与展望 被引量:10
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作者 尹福斌 詹源航 +3 位作者 岳彩德 胡旭朝 朱志平 董红敏 《农业环境科学学报》 CAS CSCD 北大核心 2021年第11期2335-2341,共7页
大型养殖场沼液具有产生量大且集中、养分含量低、可能含有抗生素残留等特点,若处理不当易对环境造成污染。膜分离技术可对污染物进行高效分离去除且操作简单,因此受到了广泛关注。本文总结分析了应用于大型养殖场沼液的膜分离技术工艺... 大型养殖场沼液具有产生量大且集中、养分含量低、可能含有抗生素残留等特点,若处理不当易对环境造成污染。膜分离技术可对污染物进行高效分离去除且操作简单,因此受到了广泛关注。本文总结分析了应用于大型养殖场沼液的膜分离技术工艺,通过比较分析不同膜分离工艺对养殖场沼液中碳、氮、磷和抗生素等污染物的去除效果,对膜分离技术在养殖场粪污处理方面的未来发展趋势和重点进行了展望,为膜分离技术在养殖粪污处理利用领域的广范应用提供科技支撑。 展开更多
关键词 膜分离 养殖场沼液 污染物 抗生素
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次氯酸钠对肉鸡屠宰预冷清洗中沙门氏菌交叉污染的控制效果 被引量:9
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作者 肖兴宁 汪雯 +4 位作者 张巧艳 张建民 廖明 杨华 李延斌 《食品工业科技》 CAS 北大核心 2019年第12期206-210,217,共6页
为探究肉鸡屠宰预冷清洗环节添加次氯酸钠(NaClO)对沙门氏菌交叉污染的控制作用,模拟不同NaClO浓度(0~70 mg/L)和初始污染率(25%~100%)条件下3批次鸡肉预冷清洗过程,计算每批次鸡肉清洗后的沙门氏菌污染率及3批次鸡肉全部清洗后的总体... 为探究肉鸡屠宰预冷清洗环节添加次氯酸钠(NaClO)对沙门氏菌交叉污染的控制作用,模拟不同NaClO浓度(0~70 mg/L)和初始污染率(25%~100%)条件下3批次鸡肉预冷清洗过程,计算每批次鸡肉清洗后的沙门氏菌污染率及3批次鸡肉全部清洗后的总体污染率。结果显示,当预冷水中添加0,20,50和70 mg/L的NaClO时,3批次鸡肉全部清洗后沙门氏菌污染率分别为88.9%,38.9%,36.1%和36.1%,NaClO可有效控制交叉污染(p<0.05);NaClO浓度(50 mg/L时,清洗后的预冷水未有沙门氏菌检出,可减小交叉污染风险。色差分析未发现20~70 mg/L的NaClO清洗对鸡肉色泽的显著影响(p>0.05)。本研究可用于肉鸡屠宰预冷清洗环节沙门氏菌污染率控制,为微生物定量风险评估提供重要信息。 展开更多
关键词 次氯酸钠 肉鸡 交叉污染 沙门氏菌 污染率 预冷清洗
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治理态理论视域下的风险社会治理 被引量:6
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作者 白锐 苏琳 Nicholas S.Brasovan 《上海大学学报(社会科学版)》 CSSCI 北大核心 2021年第5期123-130,共8页
风险社会治理研究需要从基础理论上加以把握。可借鉴福柯治理态理论,分析基于现代性的风险社会特征,以新的角度对国家治理作宏观与动态理解,从而寻求达成风险社会治理的一般性理论。治理态理论主张现代国家治理是基于国家理性且根本目... 风险社会治理研究需要从基础理论上加以把握。可借鉴福柯治理态理论,分析基于现代性的风险社会特征,以新的角度对国家治理作宏观与动态理解,从而寻求达成风险社会治理的一般性理论。治理态理论主张现代国家治理是基于国家理性且根本目标在于规避不确定性的专业化管理领域,而作为“第二现代性”典型体现的风险社会的最根本特征是其系统性、不确定性以及实践与知识的专门化。因此,治理态理论为风险社会治理的一般理论提供了根本性概念架构。同时我们特别需要警惕,制度僵化和过度治理由于制度、文化及技术原因正成为当代社会治理的潜在陷阱。 展开更多
关键词 风险社会 治理态 过度治理
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Game Theory Optimization via Diverse Genetic Crossover Intelligence
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作者 David Webb Eric Sandgren 《Journal of Applied Mathematics and Physics》 2024年第10期3315-3327,共13页
Game theory is explored via a maze application where combinatorial optimization occurs with the objective of traversing through a defined maze with an aim to enhance decision support and locate the optimal travel sequ... Game theory is explored via a maze application where combinatorial optimization occurs with the objective of traversing through a defined maze with an aim to enhance decision support and locate the optimal travel sequence while minimizing computation time. This combinatorial optimization approach is initially demonstrated by utilizing a traditional genetic algorithm (GA), followed by the incorporation of artificial intelligence utilizing embedded rules based on domain-specific knowledge. The aim of this initiative is to compare the results of the traditional and rule-based optimization approaches with results acquired through an intelligent crossover methodology. The intelligent crossover approach encompasses a two-dimensional GA encoding where a second chromosome string is introduced within the GA, offering a sophisticated means for chromosome crossover amongst selected parents. Additionally, parent selection intelligence is incorporated where the best-traversed paths or population members are retained and utilized as potential parents to mate with parents selected within a traditional GA methodology. A further enhancement regarding the utilization of saved optimal population members as potential parents is mathematically explored within this literature. 展开更多
关键词 Crossover Intelligence Game Theory Maze Navigation Genetic Optimization
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超声协同SDS-Na_(2)CO_(3)提取丝素蛋白及高强韧纳米纤维膜的制备与细胞相容性研究
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作者 牛佳杰 寿万 刘雍 《东华大学学报(自然科学版)》 CAS 北大核心 2024年第4期148-155,共8页
为解决提取过程中丝素蛋白极易受损的问题,提出以Na_(2)CO_(3)和表面活性剂SDS(十二烷基磺酸钠)的复合体系为脱胶剂,再结合超声处理的一体化天然蚕丝脱胶方案。采用该方案所得丝素蛋白纤维表面更加光洁平整,纤维损伤显著减少;相比传统的... 为解决提取过程中丝素蛋白极易受损的问题,提出以Na_(2)CO_(3)和表面活性剂SDS(十二烷基磺酸钠)的复合体系为脱胶剂,再结合超声处理的一体化天然蚕丝脱胶方案。采用该方案所得丝素蛋白纤维表面更加光洁平整,纤维损伤显著减少;相比传统的100℃碱液脱胶(30min完全脱胶),该方案在75℃下仅用10min即完成脱胶。以该方案所得脱胶纤维为原料,通过静电纺丝技术制备丝素蛋白纳米纤维膜,所得纤维膜经乙醇处理后,β折叠链片晶含量增至49.58%,展现出高达5.27MPa的断裂应力和123.49%的断裂应变。在5d的细胞培养试验中,丝素蛋白纳米纤维膜支持细胞的黏附、铺展和增殖,表现出良好的细胞相容性。这些研究成果将为制备高性能丝素蛋白纳米纤维膜提供解决方案,并有望推动丝素蛋白材料在生物医用领域的进一步应用和发展。 展开更多
关键词 丝素蛋白 脱胶 静电纺丝 细胞相容性
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Genetic Optimization via Diverse Crossover Intelligence
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作者 David Webb Eric Sandgren 《Journal of Applied Mathematics and Physics》 2024年第8期2885-2903,共19页
An intelligent crossover methodology within the genetic algorithm (GA) is explored within both mathematical and finite element arenas improving both design and solution convergence time. This improved intelligent cros... An intelligent crossover methodology within the genetic algorithm (GA) is explored within both mathematical and finite element arenas improving both design and solution convergence time. This improved intelligent crossover outperforms the traditional genetic algorithm combined with a rule-based approach utilizing domain specific knowledge developed by Webb, et al. [1]. The encoding of the improved crossover consists of two chromosome strings within the genetic algorithm where the first string represents the design or solution string, and the second string represents chromosome crossover string intelligence. This improved crossover methodology saves the best population members or designs evaluated from each generation and applies crossover chromosome intelligence to the best saved population members paired with globally selected parents. Enhanced features of this crossover methodology employ the random selection of the best designs from the prior generation as a potential parent coupled with alternating intelligence pairing methods. In addition to this approach, two globally selected parents possess the ability to mate utilizing crossover chromosome string intelligence maintaining the integrity of a global GA search. Overall, the final population following crossover employs both global and best generation design chromosome strings to maximize creativity while enhancing the solution search. This is a modification to a conventional GA that can be translated into GA encoding. This technique is explored initially through a Base 10 mathematical application followed by the examination of plate structural optimization considering stress and displacement constraints. Results from crossover intelligence are compared with the conventional genetic algorithm and from Webb, et al. [1] which illustrates the outcome of a two phase genetic optimization algorithm. 展开更多
关键词 CROSSOVER Topological Design Structural Optimization Genetic Optimization Variable Material Design
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电子政务作为反腐败工具:跨国面板数据分析 被引量:7
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作者 朴准宪 金国旻 +1 位作者 邵彤(译) 王伊(审校) 《国际行政科学评论(中文版)》 2020年第4期103-120,共18页
在过去的20年里,世界上许多国家的政府都将电子政务作为一种反腐工具。然而,电子政务对腐败的影响缺乏实证证据。因此,本文旨在通过实证检验电子政务是否减少了各国的腐败。为此,我们收集了2003—2016年214个国家的纵向数据,并基于固定... 在过去的20年里,世界上许多国家的政府都将电子政务作为一种反腐工具。然而,电子政务对腐败的影响缺乏实证证据。因此,本文旨在通过实证检验电子政务是否减少了各国的腐败。为此,我们收集了2003—2016年214个国家的纵向数据,并基于固定效应模型进行面板数据分析。分析结果表明,电子政务整体上对腐败的抑制作用显著,而政务公开作为电子政务的一种形式,其作用尚不明确。然而,法治则调节了政务公开与腐败之间的关系。也就是说,比起法律制度发挥作用较低的国家,在法律制度更有效的国家,政务公开更有可能减少腐败。 展开更多
关键词 反腐败 腐败 电子政务 政务公开
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Corn and Soybean Growth as Affected by Wastewater-Derived Struvite-Phosphorus Sources and Irrigation Water Types
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作者 Machaela Morrison Kristofor R. Brye +2 位作者 Gerson Drescher Jennie Popp Lisa S. Wood 《Agricultural Sciences》 2024年第4期472-504,共33页
Struvite (MgNH<sub>4</sub>PO<sub>4</sub>·6H<sub>2</sub>O) produced synthetically from a stock solution of known phosphorus (P) and nitrogen (N) concentrations has been shown to... Struvite (MgNH<sub>4</sub>PO<sub>4</sub>·6H<sub>2</sub>O) produced synthetically from a stock solution of known phosphorus (P) and nitrogen (N) concentrations has been shown to be an effective, alternative fertilizer-P source for various crops, but little is known about the potential agronomic effectiveness of struvite created from an actual municipal wastewater source. The objective of this study was to evaluate the effects of soil [i.e., Creldon silt loam (Oxyaquic Fragiudalf) and Calloway silt loam (Aquic Fraglossudalf) series], fertilizer-P source [i.e., synthetically produced electrochemically precipitated struvite (ECSTsyn), real-wastewater-derived ECST (ECSTreal), chemically precipitated struvite (CPST), monoammonium phosphate (MAP), and an unamended control (UC)], and irrigation water type (i.e., tapwater and struvite-removed wastewater) on corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] growth and N, P, and magnesium (Mg) uptake in a 60-day, greenhouse potted-plant study. Crop growth and N, P, and Mg uptakes for the struvite treatments (i.e., CPST, ECSTsyn, and ECSTreal) were generally similar to or at least 1.2 times greater than MAP. The ECSTsyn material commonly had up to five times greater N, P, and Mg uptake in corn and soybean than any other fertilizer-P source. Struvite-removed wastewater resulted in at least 1.3 times lower dry matter and N, P, and Mg uptake than tapwater. Similar corn and soybean results from the struvite fertilizers among the various soil-water type combinations compared to MAP suggest that struvite generates similar crop responses as at least one widely used, commercially available, multi-nutrient fertilizer-P source. 展开更多
关键词 ARKANSAS Corn Production Soybean Production STRUVITE Recovered Nutrients
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