检索结果-南通市图书馆

Impact of Carbon Chain Structures in the Backbone on the Flexibility of Modified Polyarylene Sulfide Resins: Molecular Dynamics Simulations and Mesoscopic Analysis

引用

Chinese Journal of Polymer Science 2024年第4期42卷 544-557页

作者： Chi Zhang Rong Liu Jing-Yuan Liu wen-wei jiang Key Laboratory of Fine Chemical Engineering and Functional Materials School of Chemical EngineeringSichuan UniversityChengdu610065China

In the domain of high-performance engineering polymers, the enhancement of mechanical flexibility in poly(phenylene sulfide) (PPS) resins has long posed a significant challenge. A novel molecular structure, designated as PP-He-IS, wherein imide rings and an aliphatic hexylene chain are covalently incorporated into the PPS backbone to enhance its flexibility, is introduced in this study. Molecular dynamics (MD) simulations are employed to systematically explore the effects of diversifying the backbone chain structures by substituting phenyl units with alkyl chains of varying lengths, referred to as PP-A-IS where “A” signifies the distinct intermediary alkyl chain configurations. Computational analyses reveal a discernable decrement in the glass transition temperature (Tg) and elastic modulus, counterbalanced by an increment in yield strength as the alkyl chain length is extended. Notably, the PP-He-IS variant is shown to exhibit superior yield strength while simultaneously maintaining reduced elastic modulus and Tg values, positioning it as an advantageous candidate for flexible PPS applications. Mesoscopic analyses further indicate that structures such as PP-He-IS, PP-Pe-IS, and PP-Bu-IS manifest remarkable flexibility, attributable to the presence of freely rotatable carbon-carbon single bonds. Experimental validation confirms that a melting temperature of 504 K which is lower than that of conventional PPS, and lower crystallinity are exhibited by PP-He-IS, thereby affording enhanced processability without compromising inherent thermal stability. Novel insights into the strategic modification of PPS for mechanical flexibility are thus furnished by this study, which also accentuates the pivotal role played by molecular dynamics simulations in spearheading high-throughput investigations in polymer material modifications.

关键词： Molecular dynamics simulations Polyarylene Sulfide Main-chain modifications Flexibility Aliphatic hexylene chain

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Fano Effect in T-Shaped Double Quantum Dot Structure with Decoherence Effect

引用

Communications in Theoretical Physics 2008年第3期49卷 771-776页

作者： GAO wen-Zhu GONG wei-jiang ZHENG Yi-Song LIU Yu LU Tian-Quan Department of Physics Jilin University Changchun 130023 China

By introducing a floating lead to mimic the decoherence mechanism, the Fano effect in the linear conductance spectrum of a T-shaped double quantum dot structure is studied. We find that even in the case that the self-energy arising from the decoherence mechanism is much smaller than the coupling strength between the connected quantum dot and the conducting lead, the Fano lineshape can be largely destroyed. In addition, the decoherence renders the high-order electron transmission paths unimportant to contributing to the Fano lineshape.

关键词： quantum dot conductance Pkno effect

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of chip rate on the ranging accuracy in a regenerative pseudo-noise ranging system

引用

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第2期12卷 132-139页

作者： Jian-wen jiang wei-jun YANG Chao-jie ZHANG Xiao-jun JIN Zhong-he JIN Department of Information Science and Electronic Engineering Zhejiang University Hangzhou 310027 China

The ranging accuracy of a pseudo-noise ranging system is mainly decided by range jitter and time delay discrimination. Many factors can affect the ranging accuracy, one of which is the chip rate. In digital signal processing, the time delay discrimination and autocorrelation function of sampled ranging sequences of different chip rates are very different. An approximation simulation model is established according to an in-phase quadrature (I/Q) correlator which is used to evaluate the time delay. Simulation results of the range jitter and time delay discrimination show that the chip rate which provides a non-integer sample-to-chip rate ratio can achieve a higher ranging accuracy, and some test results validate the simulation model. In some design missions, the simulation results may help to select an optimum sample-to-chip rate ratio to satisfy the design requirement on the ranging accuracy.

关键词： Ranging accuracy Range jitter Time delay discrimination Sample-to-chip rate ratio Integration time Autocorrelation function Fractional chip period delay

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Molecular markers of oral cancer and chemopreventive effects of traditional Chinese medicine

引用

中国口腔颌面外科杂志 2008年第B5期6卷 49-50页

作者： wei wen jiang Zeng Tong Zhou Department of Oral Mucosal Disease Ninth People's Hospital School of Medicine Shanghai Jiao Tong University Shanghai 200011China

With the arriving of post-transcriptional time, people recognize that cancer is result from genetics and epigenetics. Besides coding genetic information, there is a lot genetic information hiding out of DNA sequence.

关键词：口腔癌治疗方法疗效分子技术传统中医

来源：

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

Pancreatic tumor:DSA diagnosis and treatment

引用

World Journal of Gastroenterology 1998年第1期4卷 85-86页

作者： XU HongBing1, ZHANG YiJun2, wei wenjiang3, LI weiMin1 and TU XiangQun1

IM To study the clinical significance of the diagnosis and catheterized interventional treatment of digital subtraction angiography (DSA) for pancreatic tumors.METHODS Ninetytwo patients with pancreatic tumor, 69 males and 23 females, aged from 41 to 70 years (mean 571 years) were diagnosed with DSA. Sixtyone patients with pancreatic cancer were treated with transcatheter celiac and superior mesenteric arterial anticancer agents (MMC 20mg, EADM 40mg and 5FU 20g) infusion (TCSAI).RESULTS The DSA diagnoses were confirmed by operations and pathological examinations, with a coincidence 826% rate of, and a therapeutic effective rate of 426%.CONCLUSION DSA is of diagnostic value for pancreatic tumors, and helpful in understanding the course of the disease, judging the prognosis and selecting the therapeutic regimen, and could improve the chemotherapeutic effect as well..

关键词： ancreatic neoplasms/diagnosis pancreatic neoplasms/therapy angiography, digital subtraction

来源：

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

AAS法测定出口氟石粉中锰的研究

引用

光谱学与光谱分析 2006年第1期26卷 144-146页

作者：陈宗宏温伟江蒋海宁上海出入境检验检疫局上海200135

基于出口矿产品氟石粉需要测定锰而建立该方法。该方法是将氟石样品经过氢氟酸去除硅,高氯酸冒烟,冷却后再用盐酸、硼酸加热溶解等处理过程,标准溶液中需加入与样品相匹配的钙基体进行测定。锰的线性范围为0.09～2.5μg·mL-1,测量下限... 详细信息

基于出口矿产品氟石粉需要测定锰而建立该方法。该方法是将氟石样品经过氢氟酸去除硅,高氯酸冒烟,冷却后再用盐酸、硼酸加热溶解等处理过程,标准溶液中需加入与样品相匹配的钙基体进行测定。锰的线性范围为0.09～2.5μg·mL-1,测量下限为0.001%。用不同含量水平的实际样品所测定的结果与用ISO高碘酸钠光度法测定的结果一致。该方法的特点是准确可靠、简便可行、易于推广。

关键词：氟石原子吸收分光光度法锰

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

中国特色社会主义政治经济学研究方法辨析

引用

上海经济研究 2018年第8期30卷 23-29,83页

作者：魏文江韩保江中共中央党校研究生院 100091 中共中央党校经济学部 100091

经济学是一门研究人类经济行为的社会科学,数学的应用极大地促进了学科的发展。然而,长期以来,对于数学在经济学中的应用却争论不休,褒贬不一。在经济研究中,我们应该合理利用数学方法,同时也要辩证地看待数学的应用,避免过度数学化或... 详细信息

经济学是一门研究人类经济行为的社会科学,数学的应用极大地促进了学科的发展。然而,长期以来,对于数学在经济学中的应用却争论不休,褒贬不一。在经济研究中,我们应该合理利用数学方法,同时也要辩证地看待数学的应用,避免过度数学化或＂数学滥用＂。该文运用马克思主义政治经济学研究的基本方法——辩证分析法,梳理了经济学和数学关系的动态发展过程,分析相关争论背后的原因,总结出二者关系的正确认识以及合理使用数学的范围和一般原则。

关键词：经济学方法论经济学数学化 “数学滥用” 经济学发展辩证分析

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Antibiotic prophylaxis in third molar surgery:a systematic review and meta-analysis

Antibiotic prophylaxis in third molar surgery:a systematic r...

引用

中华口腔医学会第14次全国口腔医学学术会议（2012年会）

作者： College of Stomatology,Shanghai Jiao Tong University(Shanghai 200011,China) wen Xiao,wei-wen jiang

Background:The use of antibiotic prophylaxis in third molar surgery is still under *** aim of this meta-analysis was to assess the effect of antibiotic prophylaxis in patients undergoing third molar extraction with respect to incidence of postoperative infection. Methods:A literature search was conducted in databases of MEDLINE,EMBASE, and Cochrane Central Register of Controlled *** selection,data extraction, quality assessment,and meta-analysis were conducted according to the recommendations by Cochrane collaboration. Results:Ten randomized controlled trials were *** infection occurred in 108/1,402(7.7%)patients in the treatment group and in 155/991(15.6%) patients in the control *** antibiotic therapy was effective in reducing the risk of postoperative infection(odds ratio,0.29;95%confidence interval,0.21-0.41;P<0.001). Conclusions:Antibiotics prophylaxis reduced the risk of postoperative *** patients with the systemic disease were recommended to have evaluation of basic health status before third molar surgery.

关键词： antibiotic prophylaxis third molar surgery meta-analysis

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Design and Application of Turbine Cascade Partitioned Endwall Profiling

引用

Journal of Thermal Science 2025年第1期34卷 110-128页

作者： ZENG Fei jiang Ruiqi XUE Xingxu DU wei LUO Lei ZHOU Xun AECC Hunan Aviation Powerplant Research Institute School of Energy Science and Technology Harbin Institute of Technology Science and Technology on Diesel Engine Turbocharging Laboratory China North Engine Research Institute

The influence of partitioned profiling design based on a large-pitch highly loaded cascade is studied by numerical *** partitioned profile is mainly composed of a pressure-side convex structure near the leading edge and a suction-side convex structure at the midstream and downstream sides of the *** influence of the change in the vertex axial position and peak value of the B-line on the secondary flow control is *** this paper,air(ideal gas) is selected as the flow *** average static pressure at the outlet and the average total temperature at the inlet are kept *** γ-θ is used as the turbulence *** results show that the pressure-side convex structure suppresses the spanwise and pitchwise migration of the inlet flow by adjusting the static pressure distribution of the flow field,so the development of the pressure-side leg of the horseshoe vortex is effectively *** suction-side convex structure adjusts the static pressure distribution of the flow field and increases the included angle between the cross-flow and suction surface,so the accumulation of low-momentum fluid,the development of a corner vortex and the flow separation at the trailing edge of the suction-side surface are all suppressed near the endwall-suction ***,the energy loss coefficient of the large-pitch highly loaded cascade is decreased from 0.0564 to 0.0485,representing a 25% reduction in secondary flow losses.

关键词： Vortex flow

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

建立椎动脉急性血栓栓塞犬模型:微球囊导管临时隔截取栓

引用

中国组织工程研究 2015年第18期19卷 2849-2855页

作者：韦文姜肖承江李立恒江桂华广东省第二人民医院介入科广东省广州市510317 广东省第二人民医院影像科广东省广州市510317

背景:为了避免机械取栓术中血栓脱落造成远端栓塞,作者以期运用微球囊临时隔截的方法来建立防止血栓脱落的保护装置。目的:探讨采用微球囊临时阻断动脉血流并隔截栓塞段保护下行机械碎栓、吸栓联合溶栓治疗超急性脑梗死的安全性和可行... 详细信息

背景:为了避免机械取栓术中血栓脱落造成远端栓塞,作者以期运用微球囊临时隔截的方法来建立防止血栓脱落的保护装置。目的:探讨采用微球囊临时阻断动脉血流并隔截栓塞段保护下行机械碎栓、吸栓联合溶栓治疗超急性脑梗死的安全性和可行性。方法:Beagle犬10只在全身麻醉下经股动脉插管将微球囊导管送至优势侧椎动脉内并充盈球囊临时阻断血流,经微导管注入自体血栓建立椎动脉血栓栓塞模型,按治疗方法均分为2组,对照组采用单纯支架取栓,实验组采用微球囊导管临时阻断血流并隔截靶动脉后行机械碎栓吸栓联合药物溶栓。两组治疗后均行数字减影血管造影复查栓塞椎动脉再通状况;采用血栓性脑缺血血流分级进行血流动力学评估。造模前及取栓后12 h行磁共振弥散加权成像。建模后12 h行核磁共振成像检查后处死动物行病理检查,统计两组血管再通成功率及并发症。结果与结论:10只beagle犬的优势侧椎动脉均成功出现血栓栓塞。对照组中2只犬椎动脉完全再通,3只犬椎动脉部分再通,其中1只犬椎-基底动脉与颅内动脉中可见多处小点状充盈缺损,颅内动脉显影差,对比剂返流,建模后12 h磁共振弥散加权成像示左侧颞顶叶稍高信号影,病理检查示左侧大脑颞叶动脉腔内见血栓形成。实验组中5只犬椎动脉均完全再通,未见脑梗死。实验组血管再通率高于对照组(P<0.05)。结果证实,在急性脑动脉栓塞血管再通中采用微球囊导管临时阻断血流并隔截靶动脉保护下机械碎栓、吸栓联合尿激酶溶栓,可有效防止小栓子脱落栓塞远端动脉,安全有效。

关键词：实验动物脑及脊髓损伤模型球囊导管犬椎动脉模型磁共振数字减影血管造影血栓脑动脉栓塞机械碎栓支架取栓

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：