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具有修正的Min(N,D)-策略和单重休假的Geo/G/1离散时间排队分析
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作者 魏瑛源 余玅妙 唐玉玲 《应用数学》 北大核心 2026年第1期108-128,共21页
本文研究服务员具有单重休假和系统采用修正的Min(N,D)-策略的离散时间Geo/G/1排队系统,运用更新过程理论、全概率分解技术和z-变换工具,从任意初始状态开始,研究队长的瞬时性态和平稳性态,得到了任意时刻n^(+)处队长瞬态分布的z-变换... 本文研究服务员具有单重休假和系统采用修正的Min(N,D)-策略的离散时间Geo/G/1排队系统,运用更新过程理论、全概率分解技术和z-变换工具,从任意初始状态开始,研究队长的瞬时性态和平稳性态,得到了任意时刻n^(+)处队长瞬态分布的z-变换表达式和稳态分布的递推表达式,同时给出了不同时刻n^(-)、n、n^(+)和外部观测点处队长稳态分布之间的重要关系.进一步借助于数值实例,讨论了系统的空闲率与稳态平均队长关于系统参数的敏感性,并且阐述了便于作数值计算的队长稳态分布的递推公式在系统容量优化设计中的重要价值.最后,运用更新报酬过程定理,建立了费用结构模型,获得了系统长期运行下单位时间内所产生的期望费用的显示表达式,并通过数值算例,寻求使期望费用最小的最优控制策略(N^(*),D^(*)). 展开更多
关键词 离散时间排队 修正的Min(N D)-策略 单重休假 队长分布 系统容量优化设计 最优控制策略
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两参数混合型S.D.E解的性质(英文)
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作者 刘平兵 向绪言 《湖南文理学院学报(自然科学版)》 CAS 2005年第3期3-6,共4页
设M={Mz,z∈R+2},A分别是两参数连续鞅和适应增过程,Y={Yz,z∈R+2}为Poisson单,Λ是Y的特征测度且N=Y-Λ.本文考虑如下混合型S.D.E:X_s=X_0+■其中z∈R+2.在方程系数fi,i=1,2,3,4满足一定假设条件下,得到了方程解的性质.
关键词 两参数鞅 Poisson单 混合型S.d.e 性质
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I.D.E.A.L技术与经胫骨隧道技术重建前交叉韧带的疗效比较研究 被引量:2
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作者 王凡 王国梁 +3 位作者 李彦林 李骅 施青吕 李黎 《中国修复重建外科杂志》 CAS CSCD 北大核心 2024年第8期987-994,共8页
目的比较I.D.E.A.L技术与经胫骨隧道(transtibial,TT)技术重建前交叉韧带(anterior cruciate ligament,ACL)的疗效。方法回顾分析2020年1月—2022年9月收治且符合选择标准的60例ACL损伤患者临床资料。患者均接受关节镜下自体肌腱重建ACL... 目的比较I.D.E.A.L技术与经胫骨隧道(transtibial,TT)技术重建前交叉韧带(anterior cruciate ligament,ACL)的疗效。方法回顾分析2020年1月—2022年9月收治且符合选择标准的60例ACL损伤患者临床资料。患者均接受关节镜下自体肌腱重建ACL,术中股骨隧道定位采用I.D.E.A.L技术30例(I.D.E.A.L组)、TT技术30例(TT组)。两组患者年龄、性别、身体质量指数、致伤原因、损伤侧别、受伤至手术时间、合并软骨及半月板损伤构成比以及术前Lysholm评分、国际膝关节文献委员会(IKDC)评分、疼痛视觉模拟评分(VAS)、胫骨前移差值、Blumensaat角等基线资料比较,差异均无统计学意义(P>0.05)。记录住院时间、术后早/远期并发症发生情况,采用Lysholm评分、IKDC评分及VAS评分评价膝关节功能及疼痛程度,测量胫骨前移差值;MRI复查观察移植物愈合情况,并测量移植物股骨端、中段、胫骨端信噪比(signal to noise quotien,SNQ)值,以及膝关节Blumensaat角。计算胫骨前移差值以及Blumensaat角的手术前后差值(变化值)进行组间比较。结果术后两组切口均Ⅰ期愈合,住院时间组间差异无统计学意义(P>0.05)。患者均获随访,随访时间12~18个月,平均14.9个月。术后两组膝关节Lysholm评分、IKDC评分均较术前增加,VAS评分降低,其中TT组术后1周VAS评分与术前差异无统计学意义(P>0.05),其余评分两组组内与术前差异均有统计学意义(P<0.05)。术后随时间延长,两组上述评分均呈进一步改善趋势;Lysholm评分、VAS评分术后1周及1、3、6、12个月间差异均有统计学意义(P<0.05),IKDC评分仅术后1个月与术后1周差异有统计学意义(P<0.05)。术后1周I.D.E.A.L组膝关节Lysholm评分、IKDC评分高于TT组、VAS评分更低,差异均有统计学意义(P<0.05);1、3、6、12个月两组间差异均无统计学意义(P>0.05)。术后12个月,两组胫骨前移差值均较术前降低(P<0.05);且I.D.E.A.L组变化值高于TT组,差异有统计学意义(P<0.05)。I.D.E.A.L组术后早、远期并发症发生率均低于TT组(P<0.05)。术后12个月MRI检查示两组膝关节移植物均生存良好,Blumensaat角均较术前降低(P<0.05),且I.D.E.A.L组Blumensaat角变化值以及移植物股骨端、中段、胫骨端SNQ值均高于TT组(P<0.05)。结论采用I.D.E.A.L技术重建ACL术后早期疗效更好,膝关节稳定性更高,术后并发症率更低;但采用TT技术重建术后移植物成熟度更高。 展开更多
关键词 关节镜 前交叉韧带重建 I.d.e.A.L技术 经胫骨隧道技术 移植物
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后软骨缘顶点辅助定位器进行前交叉韧带I.D.E.A.L股骨骨道定位 被引量:3
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作者 史尉利 马勇 +4 位作者 孟庆阳 杨渝平 刘平 龚熹 敖英芳 《中国运动医学杂志》 CAS CSCD 北大核心 2021年第8期595-600,共6页
目的:探索一种可以在前交叉韧带(ACL)股骨残端不清晰的病例中简单有效定位I.D.E.A.L骨道位置的方法。方法:回顾性分析2019年1月至2020年10月ACL单束重建的46例患者。其中残端较为完整的23例纳入对照组;无残端的23例纳入观察组。对照组男... 目的:探索一种可以在前交叉韧带(ACL)股骨残端不清晰的病例中简单有效定位I.D.E.A.L骨道位置的方法。方法:回顾性分析2019年1月至2020年10月ACL单束重建的46例患者。其中残端较为完整的23例纳入对照组;无残端的23例纳入观察组。对照组男性20例,女性3例;16例为右腿,7例为左腿;年龄30.57±6.39岁;身高173.91±7.08 cm;BMI 24.91±3.82 kg/m^(2)。观察组男性19例,女性4例;15例为右腿,8例为左腿;年龄29.48±9.97岁;身高175.30±7.03 cm;BMI 24.70±3.77 kg/m^(2)。对照组I.D.E.A.L股骨骨道的制备依靠术中直视下用射频在残端区域做标记,并观察将定位器卡在髁间窝外侧壁后软骨缘顶点(ADC)上时定位器与外侧胫骨平台的关系。观察组I.D.E.A.L股骨骨道的制备依靠定位器与外侧胫骨平台成平行关系来定位骨道中心。术后通过三维CT测量ADC至前骨缘的水平距离(L)和ADC至骨道中心的水平距离(l),通过l/L计算骨道前后位置R;在二维横断面上测量骨道中心到下骨缘的距离(D)。将对照组数据定义为l1、L1、R1和D1;观察组数据定义为l2、L2、R2和D2。利用独立样本t检验比较两组之间的R和D值,从而判断该定位方法的稳定性和可重复性。结果:两组之间入组病例数相同,年龄、性别、身高、BMI和侧别上无统计学差异,具有可比性。两组患者术后CT测量发现,对照组骨道中心的前后位置R1为38.69%±4.82%;观察组骨道中心的前后位置R2为38.27%±4.60%。对照组骨道中心距离下骨缘距离D1为9.12±0.74 mm;观察组骨道中心距离下骨缘距离D2为8.52±1.62 mm。两组骨道位置之间无统计学差异。结论:在前交叉韧带重建术中,以髁间窝外侧壁后软骨缘顶点(ADC)为标志,4字位放置膝关节,在屈膝120°时使用off center股骨定位器,当定位器与外侧胫骨平台平行时可以有效地定位到I.D.E.A.L股骨骨道的中心;该方法可重复性好。 展开更多
关键词 前交叉韧带(ACL)重建 髁间窝外侧壁后软骨缘顶点(ADC) I.d.e.A.L股骨骨道 CT重建
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I.D.E.A.L技术在前交叉韧带单束重建中股骨端定位的应用 被引量:3
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作者 邹文 周明 +2 位作者 范少勇 侯慧铭 龚礼 《江西医药》 CAS 2022年第11期1802-1804,共3页
目的 探讨I.D.E.A.L技术在前交叉韧带(ACL)单束重建中股骨端定位的应用价值。方法 选择2017年1月至2019年1月南昌市洪都中医院收治的60例ACL损伤患者,按随机数字表法分为观察组(30例)和对照组(30例)。观察组用I.D.E.A.L技术定位股骨端,... 目的 探讨I.D.E.A.L技术在前交叉韧带(ACL)单束重建中股骨端定位的应用价值。方法 选择2017年1月至2019年1月南昌市洪都中医院收治的60例ACL损伤患者,按随机数字表法分为观察组(30例)和对照组(30例)。观察组用I.D.E.A.L技术定位股骨端,对照组行解剖中心定位股骨端。比较两组术前、术后12个月关节活动度、膝关节功能。结果 术后12个月两组关节活动度均明显高于术前,观察组关节活动度高于对照组[(126.13±11.32)°vs(119.85±10.31)°],差异有统计学意义(P<0.05);术后12个月两组IKDC评分、Lysholm评分均明显高于术前,观察组IKDC评分、Lysholm评分高于对照组[(92.13±7.21)分vs(86.69±6.09)分、(95.07±4.69)分vs(91.33±7.71)分],差异有统计学意义(P<0.05)。结论 在前交叉韧带单束重建中采取I.D.E.A.L技术定位股骨端,有利于术后关节活动度及膝关节功能恢复,值得临床推广。 展开更多
关键词 前交叉韧带损伤 I.d.e.A.L技术 股骨端定位 关节镜下ACL损伤单束重建 膝关节功能
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D.E石墨的形成机理和防止E型石墨产生的措施 被引量:8
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作者 邱复兴 《铸造》 CAS CSCD 北大核心 1989年第3期24-25,23,共3页
应用了缺陷生长、成分过冷、晶核脱落与增殖等概念,从生产出发,分析了D型和E型石墨形成的原因,认为奥氏体晶核工业的先析出及奥氏体枝晶的特征是决定因素.提出了D型石墨生成,防止E型石墨产生的工艺措施.
关键词 D型石墨 E型石墨 形成机理 石墨
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Synthesis of modified D401 chelating resin and its adsorption properties for Pb^(2+) 被引量:2
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作者 王菲 王连军 +2 位作者 李健生 孙秀云 张亮 《Journal of Central South University》 SCIE EI CAS 2009年第4期575-580,共6页
A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating r... A novel chelating resin with sulfonic group was synthesized by chemical modification of D401 resin with sulphonation reaction and characterized by FT-IR spectrometry. The adsorption properties of the novel chelating resin for Pb2+ were studied by batch adsorption, and the adsorption process was analyzed from thermodynamics and kinetics aspects. The adsorption mechanism of Pb2+ on the modified D401 chelating resin was discussed by FT-IR spectrometry. Experimental results show that in the Pb2+ concentration range of 200-400 mg/L, the adsorption capacities of the modified D401 chelating resin for Pb2+ increase by 77%-129%, and Langmuir isothermal adsorption model is more suitable for the equilibrium adsorption data. Adsorption is an endothermic process that runs spontaneously. Kinetic analysis shows that the adsorption rate is mainly governed by liquid film diffusion. The best pH value under adsorption condition is 4-5. The saturated resin can be regenerated by 3 mol/L nitric acid, and the adsorption capacity remains stable after five consecutive adsorption-desorption cycles. The maximal static saturated adsorption capacity of the resin is 206 mg/g at 333 K in the Pb2+ concentration range of 200-400 mg/L. The modified D401 chelating resin is an efficient adsorbent for the removal of Pb2+ from its single-metal ion solution. 展开更多
关键词 modified D401 chelating resin pb^2+ SYNTHESIS ADSORPTION DESORPTION
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Satisfactory surgical outcome of T2 gastric cancer after modified D2 lymphadenectomy 被引量:1
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作者 Shupeng Zhang Liangliang WU +2 位作者 Xiaona Wang Xuewei Ding Han Liang 《Chinese Journal of Cancer Research》 SCIE CAS CSCD 2017年第2期100-108,共9页
Objective: Though D2 lymphadenectomy has been increasingly regarded as standard surgical procedure for advanced gastric cancer (GC), the modified D2 (D 1+7, 8a and 9) lymphadenectomy may be more suitable than D2... Objective: Though D2 lymphadenectomy has been increasingly regarded as standard surgical procedure for advanced gastric cancer (GC), the modified D2 (D 1+7, 8a and 9) lymphadenectomy may be more suitable than D2 dissection for T2 stage GC. The purpose of this study is to elucidate whether the surgical outcome of modified D2 lymphadenectomy was comparable to that of standard D2 dissection in T2 stage GC patients. Methods: A retrospective cohort study with 77 cases and 77 controls matched for baseline characteristics was conducted. Patients were categorized into two groups according to the extent of lymphadenectomy: the modified D2 group (roD2) and the standard D2 group (D2). Surgical outcome and recurrence date were compared between the two groups. Results: The 5-year overall survival (OS) rate was 71.4% for patients accepted mD2 lymphadenectomy and 70.1% for those accepted standard D2, respectively, and the difference was not statistically significant. Multivariate survival analysis revealed that curability, tumor size, TNM stage and postoperative complications were independently prognostic factors for T2 stage GC patients. Patients in the mD2 group tended to have less intraoperative blood loss (P=0.001) and shorter operation time (P〈0.001) than those in the D2 group. While there were no significant differences in recurrence rate and types, especially lymph node recurrence, between the two groups. Conclusions: The surgical outcome of mD2 lymphadenectomy was equal to that of standard D2, and the use of mD2 instead of standard D2 can be a better option for T2 stage GC. 展开更多
关键词 Gastric carcinoma T2 modified D2 lymphadenectomy prognosis COMPLICATION
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A modified Gillespie algorithm for E.coli gene regulation systems
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作者 罗若愚 《生物物理学报》 CAS CSCD 北大核心 2009年第S1期10-10,共1页
The dynamics of complex gene regulation systems can be simulated by the Gillespie algorithm. The classic Gillespie algorithm is appropriate to simulate a stochastic
关键词 COLI A modified Gillespie algorithm for E.coli gene regulation systems GENE
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RELATION BETWEEN DYNAMIC LOSS MODULUS AND DIFFUSION COEFFICIENT IN A MODIFIED PET FIBER
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作者 于建明 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 1994年第4期366-371,共6页
The mobility of polymer chain segments is shown to play a major role in the diffusion ofdisperse dyes in a copolymerization modified PET system, monoepoxy compoundCH_3 (CH_3),OCH_2CH--CH_2 modified PET. The rate of dy... The mobility of polymer chain segments is shown to play a major role in the diffusion ofdisperse dyes in a copolymerization modified PET system, monoepoxy compoundCH_3 (CH_3),OCH_2CH--CH_2 modified PET. The rate of dye diffusion (diffusion coefficient D) hasbeen related to the time-dependent mechanical property, dynamic loss modulus E', which iscontrolled by the mobility of chain segments. In this modified copolyester system, the variance ofamount of modifier in the copolyester fibers causes the change in disperse dye diffusion coefficientto fiber, and in the dynamic loss modulus of the fibers, but the relationship between the diffusionand the dynamic loss modulus is in agreement with the theoretical relation derived by Bell andDumbleton. The relation obtained in this paper is:Ln D=-2. 28Ln E'+26. 81 展开更多
关键词 Dynamic loss modulus E″ Dyeing diffusion coefficient D modified PET fiber
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双中点法评估前交叉韧带重建股骨隧道I.D.E.A.L点
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作者 李腾云 付昌马 《皖南医学院学报》 CAS 2024年第5期422-425,共4页
目的:建立一种简单有效的以双中点为参考的股骨隧道位置评估方法。方法:选取2021年8月~2022年12月运用自体肌腱类等长重建前交叉韧带(ACL)损伤患者13例,采用双中点法制备股骨隧道I.D.E.A.L点。纳入患者术前物理查体及磁共振检查均提示AC... 目的:建立一种简单有效的以双中点为参考的股骨隧道位置评估方法。方法:选取2021年8月~2022年12月运用自体肌腱类等长重建前交叉韧带(ACL)损伤患者13例,采用双中点法制备股骨隧道I.D.E.A.L点。纳入患者术前物理查体及磁共振检查均提示ACL断裂。比较手术前后国际膝关节文献委员会(IKDC)评分、Lysholm评分、视觉模拟量表(VAS)评分;同时双中点制备股骨隧道的x/t(%)和y/h(%)数值与术后Bernard网格象限的理想位置x/t(%)和y/h(%)数值进行比较。结果:随访3个月,术后第3个月IKDC、Lyshlom评分均较术前上升(P<0.05),而VAS评分较术前下降(P<0.05)。术后膝关节侧位Bernard网格象限x/t(%)和y/h(%)与理想化位置x/t(%)和y/h(%)数值比较差异无统计学意义(P>0.05)。结论:双中点法是ACL重建评估股骨隧道位置的良好方法,术中关节镜测量与术后Bernard网格象限测量具有良好的一致性。 展开更多
关键词 前交叉韧带 单束重建 股骨隧道 I.d.e.A.L点 双中点 评估
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A Multi-stage Heuristic Algorithm for Matching Problem in the Modified Miniload Automated Storage and Retrieval System of E-commerce 被引量:2
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作者 WANG Wenrui WU Yaohua WU Yingying 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2016年第3期641-648,共8页
E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking d... E-commerce, as an emerging marketing mode, has attracted more and more attention and gradually changed the way of our life. However, the existing layout of distribution centers can't fulfill the storage and picking demands of e-commerce sufficiently. In this paper, a modified miniload automated storage/retrieval system is designed to fit these new characteristics of e-commerce in logistics. Meanwhile, a matching problem, concerning with the improvement of picking efficiency in new system, is studied in this paper. The problem is how to reduce the travelling distance of totes between aisles and picking stations. A multi-stage heuristic algorithm is proposed based on statement and model of this problem. The main idea of this algorithm is, with some heuristic strategies based on similarity coefficients, minimizing the transportations of items which can not arrive in the destination picking stations just through direct conveyors. The experimental results based on the cases generated by computers show that the average reduced rate of indirect transport times can reach 14.36% with the application of multi-stage heuristic algorithm. For the cases from a real e-commerce distribution center, the order processing time can be reduced from 11.20 h to 10.06 h with the help of the modified system and the proposed algorithm. In summary, this research proposed a modified system and a multi-stage heuristic algorithm that can reduce the travelling distance of totes effectively and improve the whole performance of e-commerce distribution center. 展开更多
关键词 e-commerce modified miniload automated storage/retrieval system matching problem multi-stage heuristic algorithm
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Electrochemical Behavior of Eu^(3+) on Eastman AQ-29D Chemically Modified Electrode
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作者 叶宪曾 卜一工 李南强 《Journal of Rare Earths》 SCIE EI CAS CSCD 1994年第1期48-51,共4页
The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0... The electrochemical behaviors of Eu3+ on Eastman AQ-29D/glassy carbon(GC) chemically modified electrode(CME) were studied. It was found that the reduction-oxidation process of Eu3+ is in a semi-infinite condition in 0.1 mol/L NaCIO4 supporting electrolyte(pH 4.4). The calibration curve was linear over the range 1.0×10-7 to 1.0×105 mol/L of Eu3+.The charge transport apparent diffusion coefficient of Eu3+ in the polymer film was determined to be(3.2±1.1)×10-11cm2/s by chronocoulometry. 展开更多
关键词 EUROPIUM Chemically modified electrode(CME) Eastman AQ-29D CHRONOCOULOMETRY
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Modified Liangfu granule exhibits anti-cancer effects in gastric cancer by regulating apoptosis-related proteins and genes
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作者 Ya Li Lingqun Zhu +5 位作者 Fengqin Shi Ruibai Li Xinyi Chen Zhi Zheng Bin Qiu Li Hou 《Journal of Traditional Chinese Medical Sciences》 2019年第4期325-330,共6页
Objective:To investigate the anti-cancer effects and mechanism of modified Liangfu granule(MLFG)in BGC-823 gastric cancer cells.Methods:The drug serum was extracted from abdominal aorta of Wistar rats treated by cyclo... Objective:To investigate the anti-cancer effects and mechanism of modified Liangfu granule(MLFG)in BGC-823 gastric cancer cells.Methods:The drug serum was extracted from abdominal aorta of Wistar rats treated by cyclophosphamide,dioscin,MLFG(high-,medium-,and low-dose),respectively.MTS assay was performed to detect the effect of different concentrations of MLFG and dioscin on cell growth.The effect of MLFG on cellular apoptosis was detected by flow cytometry.Western blot was used to examine Bcl-2 and Akt in BGC-823 cells treated with MLFG.Quantitative real-time polymerase chain reaction assay was performed to determine the expression level of caspase-3,E2F1 and E2F3 genes in cells treated by MLFG-and dioscin-containing serum.Results:MLFG-and dioscin-containing serum inhibited the cell proliferation of BGC-823 cells.MLFG induced gastric carcinoma cell apoptosis and inhibited the expression of Bcl-2 and Akt in a dosedependent manner.MLFG also significantly induced the gene expression of caspase-3 and downregulated E2F1 and E2F3 gene expression.Conclusion:The effect of MLFG and dioscin on inhibiting cell proliferation and induction of apoptosis of gastric cancer cells might be related to the regulation of Bcl-2 and Akt proteins and the expression of caspase-3,E2F1 and E2F3 genes. 展开更多
关键词 modified Liangfu granule Gastric cancer Caspase-3 E2F1 E2F3
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Analyzing the influences of two types of El Nino on Tropical Cyclone Genesis with a modified genesis potential index
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作者 王法明 杨宇星 杨磊 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第2期452-465,共14页
To understand the impacts of large-scale circulation during the evolution of E1 Nifio cycle on tropical cyclones (TC) is important and useful for TC forecast. Based on best-track data from the Joint Typhoon Warning ... To understand the impacts of large-scale circulation during the evolution of E1 Nifio cycle on tropical cyclones (TC) is important and useful for TC forecast. Based on best-track data from the Joint Typhoon Warning Center and reanalysis data from National Centers for Environmental Prediction for the period 1975- 2014, we investigated the influences of two types of E1 Nifio, the eastern Pacific E1 Nifio (EP-E1 Nifio) and central Pacific E1 Nifio (CP-E1 Nifio), on global TC genesis. We also examined how various environmental factors contribute to these influences using a modified genesis potential index (MGPI). The composites reproduced for two types of E1 Nifio, from their developing to decaying phases, were able to qualitatively replicate observed cyclogenesis in several basins except for the Arabian Sea. Certain factors of MGPI with more influence than others in various regions are identified. Over the western North Pacific, five variables were all important in the two E1Nifio types during developing summer (July-August-September) and fall (October- November-December), and decaying spring (April-May-June) and summer. In the eastern Pacific, vertical shear and relative vorticity are the crucial factors for the two types of El Nifio during developing and decaying summers. In the Atlantic, vertical shear, potential intensity and relative humidity are important for the opposite variation of EP- and CP-EI Nifios during decaying summers. In the Southern Hemisphere, the five variables have varying contributions to TC genesis variation during peak season (January-February-March) for the two types of E1 Nifio. In the Bay of Bengal, relative vorticity, humidity and omega may be responsible for clearly reduced TC genesis during developing fall for the two types and slightly suppressed TC cyclogenesis during EP-E1 Nifio decaying spring. In the Arabian Sea, the EP-E1 Nifio generates a slightly positive anomaly of TC genesis during developing falls and decaying springs, but the MGPI failed to capture this variation. 展开更多
关键词 two types of E1 Nifio tropical cyclone (TC) modified genesis potential index
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Numerical Study on Hydraulic Characteristics and Discharge Capacity of Modified Piano Key Weir with Various Inlet/Outlet Width Ratio
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作者 Ilan Ich Genguang Zhang +2 位作者 Anbin Li Vinhteang Kaing Ty Sok 《World Journal of Engineering and Technology》 2023年第1期113-135,共23页
A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/... A modified piano key weir with a rounded nose and a parapet wall (MPKW) can improve the discharge capacity significantly compared to a standard piano key weir. However, the optimum of the inlet/outlet width ratio (Wi/Wo) on the discharge efficiency of MPKW is still not investigated numerically. The present work utilized the numerical modeling to investigate and analyze the effects of the inlet/outlet key width ratios on the hydraulic characteristics and discharge capacity of the MPKW. To validate the numerical model with the experimental data, the results indicate that the average relative error is 2.96%, which confirms that the numerical model is fairly well to predictthe specifications of flow over on the MPKW. Numerical simulation results indicated that the discharge capacity of the MPKW can be improved up to 8.5% by optimizing the Wi/Wo ratio ranging from 1.53 to 1.67 even if the other parameters of the MPKW keep unchanged. A big Wi/Wo ratio generally leads to an increase in discharge capacity at low heads and a little effect on the discharge efficiency at high heads. The discharge efficiency of the inlet and outlet crests increases up to 9.6% for high heads, while discharge efficiency of the lateral crest decreases up to 23.5% compared with the reference model. The findings of the study revealed that the intrinsic influencing mechanism of the Wi/Wo ratio on the discharge performance of MPKWs. 展开更多
关键词 Discharge Capacity FLOW-3D Hydraulic Characteristics Numerical Simulation modified Piano Key Weir Parameter Optimization
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Scattering states of modified PSschl-Teller potential in D-dimension
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《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期38-44,共7页
We present a new approximation scheme for the centrifugal term, and apply this new approach to the SchrSdinger equation with the modified P5schl Teller potential in the -dimension for arbitrary angular momentum state... We present a new approximation scheme for the centrifugal term, and apply this new approach to the SchrSdinger equation with the modified P5schl Teller potential in the -dimension for arbitrary angular momentum states. The approximate analytical solutions of the scattering states are derived. The normalized wave functions expressed in terms of the hypergeometric functions of the scattering states on the 2 scale and the calculation formula of the phase shifts are given. The numerical results show that our results are in good agreement with those obtained by using the amplitude-phase method (APM). 展开更多
关键词 modified Poschl Teller potential in D-dimension SchrSdinger equation scattering states
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Scattering states of modified Pschl-Teller potential in D-dimension
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作者 陈昌远 陆法林 尤源 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第3期38-44,共页
We present a new approximation scheme for the centrifugal term,and apply this new approach to the Schrdinger equation with the modified Pschl-Teller potential in the D-dimension for arbitrary angular momentum states.T... We present a new approximation scheme for the centrifugal term,and apply this new approach to the Schrdinger equation with the modified Pschl-Teller potential in the D-dimension for arbitrary angular momentum states.The approximate analytical solutions of the scattering states are derived.The normalized wave functions expressed in terms of the hypergeometric functions of the scattering states on the k/2π scale and the calculation formula of the phase shifts are given.The numerical results show that our results are in good agreement with those obtained by using the amplitude-phase method(APM). 展开更多
关键词 modified Pschl-Teller potential in D-dimension Schrdinger equation scattering states
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Role of Ischemia Modified Albumin in Diagnosis of Pulmonary Embolism
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作者 Ashraf Abd El Halim Adel Attia +3 位作者 Saad Samra Tayseer Zytoun Hosam Eldeen Salah Manal Al-Anazi 《Open Journal of Respiratory Diseases》 2014年第1期22-26,共5页
Pulmonary embolism is a common and potentially lethal condition. Clinical signs and symptoms for pulmonary embolism are nonspecific. New and simple tests are therefore needed in order to help in early diagnosis of pul... Pulmonary embolism is a common and potentially lethal condition. Clinical signs and symptoms for pulmonary embolism are nonspecific. New and simple tests are therefore needed in order to help in early diagnosis of pulmonary embolism. The aim of this work is to elucidate the role of IMA in the diagnosis of pulmonary embolism. Subjects and Methods: 75 patients with suspected pulmonary embolism and 20 control healthy subjects were included in this study. Measurement of IMA was done in all subjects. Results: The mean values of IMA were statistically significantly higher among the PE patient group (0.43 ± 0.104 ABSU) in comparison with non PE patient group (0.27 ± 0.053 ABSU) and healthy control subjects (0.21 ± 0.080 ABSU). At cut-off value of 0.305 ABSU, IMA had 97.5% sensitivity and 71.42% specificity. The area under the curve was 0.952. The positive predictive value of this cut-off value was 79.59% while the negative predictive value was 96.15%. Conclusions: IMA is a good alternative to D-dimer in the diagnosis and exclusion of PE. Larger studies are needed to augment our results. 展开更多
关键词 ISCHEMIA modified ALBUMIN D-DIMER PULMONARY EMBOLISM
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城市电商化转型与企业可持续发展能力 被引量:2
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作者 李雪欣 《企业经济》 北大核心 2025年第8期5-15,共11页
探讨城市电商化转型过程中企业的可持续发展问题对于促进电子商务健康快速发展和推进现代市场体系建设具有重要意义。基于我国电子商务示范试点的实施,采用多期双重差分实证方法检验发现:城市电商化转型有助于企业可持续发展能力的提升... 探讨城市电商化转型过程中企业的可持续发展问题对于促进电子商务健康快速发展和推进现代市场体系建设具有重要意义。基于我国电子商务示范试点的实施,采用多期双重差分实证方法检验发现:城市电商化转型有助于企业可持续发展能力的提升,其中企业研发强度和投融资期限错配起到了差异化的中介作用;进一步研究表明,城市电商化转型对企业可持续发展能力的积极影响存在地区异质性,对东部和中部企业发挥作用更为显著,但该影响趋势不会因企业产权性质不同而产生显著变化。鉴于此,企业在应对电商化转型带来的变化时,应积极培育企业核心竞争优势,建立标准化研发体系,拓展融资渠道,赋能企业可持续发展。 展开更多
关键词 城市电商化转型 可持续发展能力 研发强度 投融资期限错配 资源编排理论
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