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Vibration Superposition in Tunnel Blasting with Millisecond Delay

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Journal of Southwest Jiaotong University(English Edition) 2009年第1期17卷 42-46页

作者：郑俊杰楼晓明罗德丕 Institute of Geotechnical and Underground Engineering Huazhong University of Science and Technology

According to explosion dynamics and elastic wave theory, the models of particle vibration velocity for simultaneous blasting and milliseeond blasting are built. In the models, influential factors such as delay interval and charge quantity, are considered. The calculated vibration velocity is compared with the field test results, which shows that the theoretical values are close to the experimental ones. Meanwhile, the particle vibration velocity decreases quickly with time due to the damping of rock mass and has a harmonic motion, and the particle vibration velocity of millisecond blasting has short interval. The superposition of particle vibration velocities may reduce vibration because of wave interference, or magnify the surrounding rock response to the blastinginduced vibration.

关键词： Tunnel blasting Millisecond blasting Vibration velocity Superposition

Enhancing the Crystallization Performance of Poly(L-lactide) by Intramolecular Hybridizing with Tunable Self-assembly-type Oxalamide Segments

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Chinese Journal of Polymer Science 2021年第1期39卷 122-132,I0008页

作者： Man-Man Yu Wei-Jun Yang De-Yu Niu xiao-Xia Cai Yun-Xuan Weng Wei-Fu Dong ming-Qing Chen Peng-Wu Xu Yang Wang Hong Chu pi-ming Ma The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics Beijing Technology and Business UniversityBeijing 100048China

In this work, hydroxyl-terminated oxalamide compounds N^(1),N^(2)-bis(2-hydroxyethyl)oxalamide(OXA1) and N^(1),N^(1)′-(ethane-1,2-diyl)bis(N^(2)-(2-hydroxyethyl)oxalamide(OXA2) were synthesized to initiate the ring-opening polymerization of L-lactide for preparation of oxalamide-hybridized poly(L-lactide)(PLA_(OXA)), i.e., PLA_(OXA1) and PLA_(OXA2). The crystallization properties of PLA were improved by the self-assembly of the oxalamide segments in PLA_(OXA) which served as the initial heterogeneous nuclei. The crystal growth kinetics was studied by HoffmanLauritzen theory and it revealed that the nucleation energy barrier of PLA_(OXA1) and PLA_(OXA2) was lower than that of PLA. Consequently, PLA_(OXA) could crystallize much faster than PLA, accompanied with a decrease in spherulite size and half-life crystallization time by 74.8% and 86.5%(T=125 ℃), respectively. In addition, the final crystallinity of PLA_(OXA1) and PLA_(OXA2) was 6 and 8 times higher, respectively, in comparison with that of neat PLA under a controlled cooling rate of 10 ℃/min. The results demonstrate that the hybridization of oxalamide segments in PLA backbone will serve as the self-heteronucleation for promoting the crystallization rate. The higher the content of oxalamide segments(PLA_(OXA2) compared with PLA_(OXA1)) is, the stronger the promotion effect will be. Therefore, this study may provide a universal approach by hybridizing macromolecular structure to facilitate the crystallization of semi-crystalline polymer materials.

关键词： Poly(L-lactide) Oxalamide compounds Self-heteronucleation Crystallization kinetics

Rietveld quantification of γ-C_2S conversion rate supported by synchrotron X-ray diffraction images

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第11期14卷 815-821页

作者： pi-qi ZHAO Xian-ping LIU Jian-guo WU Pei-ming WANG School of Materials Science and Engineering Tongji University Key Laboratory of Advanced Civil Engineering Materials (Tongji University) Ministry of Education

The pure γ-Ca2SiO4 （]t-C2S） phase was prepared at 1623 K of calcining temperature, 10 h of holding time and furnace cooling. The 13-C2S phase was obtained through γ-C2S conversion with the following calcination system which was adopted at 1473 K of calcining temperature, 1 h of holding time and then water-cooling. The conversion rate of γ-C2S was studied by the Rietveld quantitative laboratory X-ray powder diffraction supported by synchrotron X-ray diffraction images. The refinement results show that the final conversion rate of γ-C2S is higher than 92%. The absolute error of the γ-C2S conversion rate between two Rietveld refinements （sample with or without α-Al2O3） is 3.6%, which shows that the Rietveld quantitative X-ray diffraction analysis is an appropriate and accurate method to quantify the γ-C2S conversion rate.

关键词： β-C28 γ-C28 Rietveld quantification Synchrotron X-ray diffraction image

Stereocompfexed Poiy(iactide) Composites toward Engineering Plastics with Superior Toughness, Heat Resistance and Anti-hydrolysis

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Chinese Journal of Polymer Science 2020年第10期38卷 1107-1116,I0006页

作者： Bao-Gou Wu WeiJun Yang De-Yu Niu WeiFu Pong ming-Qing Chen Tian-Xi Liu ming-Liang Du pi-ming Ma The Key Laboratoryof Synthetic and Biogial Colloids Ministyof Educationliangnan UniversityWuxi214122 China

Polyl(lactide),PLA,suffers from bitleness and low heat deflection temperature(HDT),which limits its application as an engineering *** this work,poly(L-lactide)/poly(D-lactide)/ethylene-vinyl acetate glycidyl methacrylate random copolymer(PLLA/PDL A/EVM-GMA=1/1/x)composites were prepared by melt blending,and the in situ formed EVM-g PLA copolymers improved the compatibility between PLA and ***,the blends were subjected to a two-step annealing process during compression molding,*** annealing at 120℃ to rapidly form a certain amount of stereocomplex(sc)crystallites as nucleation sites,and then annealing at 200℃ to guide the formation of new *** differential scanning calorimetry(DSC)and wide angle X-ray dffrction(WAXD)measurements confirmed the formation of highly stereocomplexed PLA *** results showed that the PLLA/PDLA blend with 20 wt%of EVM-GMA had a notched impact strength up to 65 kJ/m2 and an elongation at break of 48%,while maintaining a tensile strength of 40 ***,dynamic mechanical analysis(DMA)and heat deflection tests showed that the PLA composite had an HDT up to 142℃ which is 90℃ higher than that of normal PLA *** electron microscopy(SEM)confirmed the fine dispersion of EVM-GMA particles,which facilitated to understand the toughening ***,the highly stereocomplexed PLA composites simultaneously exhibited excellent chemical and hydrolysis ***,these fascinating properties may extend the application range of sc PLA material as an engineering bioplastic.

关键词： PLA composites Stereocomplexation Annealing Heat resistance Toughness

Relationship of calcitonin gene-related peptide with disease progression and prognosis of patients with severe traumatic brain injury

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Neural Regeneration Research 2018年第10期13卷 1782-1786页

作者： Li-Xiong Chen Wei-Feng Zhang ming Wang pi-Feng Jia Department of Critical Care Medicine North Hospital of Ruijin Hospital Department of Neurosurgery North Hospital of Ruijin Hospital

Calcitonin gene-related peptide（CGRP） has been implicated in multiple functions across many bioprocesses; however, whether CGRP is associated with severe traumatic brain injury（TBI） remains poorly understood. In this study, 96 adult patients with TBI（enrolled from September 2015 to December 2016） were divided into a mild/moderate TBI group（36 males and 25 females, aged 38 ± 13 years） and severe TBI group（22 males and 13 females, aged 38 ± 11 years） according to Glasgow Coma Scale scores. In addition, 25 healthy individuals were selected as controls（15 males and 10 females, aged 39 ± 13 years）. Radioimmunoassay was used to detect serum levels of CGRP and endothelin-1 at admission and at 12, 24, 48, 72 hours, and 7 days after admission. CGRP levels were remarkably lower, but endothelin-1 levels were obviously higher in the severe TBI group compared with mild/moderate TBI and control groups. Levels of CGRP were remarkably lower, but endothelin-1 levels were obviously higher in deceased patients compared with patients who survived. Survival analysis and logistic regression showed that both CGRP and endothelin-1 levels were associated with patient mortality, with each serving as an independent risk factor for 6-month mortality of severe TBI patients. Moreover, TBI patients with lower serum CGRP levels had a higher risk of death. Thus, our retrospective analysis demonstrates the potential utility of CGRP as a new biomarker, monitoring method, and therapeutic target for TBI.

关键词： nerve regeneration calcitonin gene-related peptide severe traumatic brain injury prognosis biomarkers endothelin-1 mortality dynamic serum levels critical care medicine neural regeneration

Endoscopic-ultrasound-guided biliary drainage with placement of electrocautery-enhanced lumen-apposing metal stent for palliation of malignant biliary obstruction:Updated meta-analysis

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World Journal of Gastrointestinal Surgery 2024年第3期16卷 907-920页

作者： Zu-Xiang Peng Fang-Fang Chen Wen Tang Xu Zeng Hong-Juan Du Ru-Xian pi Hong-ming Liu xiao-xiao Lu Department of Hepatobiliary Surgery Daping HospitalArmy Medical UniversityChongqing 400042China Department of Oncology Chongqing General HospitalChongqing UniversityChongqing 401147China Department of Gastroenterology and Hepatobiliary Surgery People’s Hospital of Fenggang CountyGuizhou 564200Guizhou ProvinceChina Hepatobiliary and Pancreatic Tumor Center Chongqing University Cancer HospitalChongqing 400030China

BACKGROUND Endoscopic ultrasound-guided biliary drainage using electrocautery-enhanced(ECE)delivery of lumen-apposing metal stent(LAMS)is gradually being re-cognized as a viable palliative technique for malignant biliary obstruction after endoscopic retrograde cholangiopancreatography(ERCP)***,most of the studies that have assessed its efficacy and safety were small and *** meta-analyses of six or fewer studies that were published 2 years ago were therefore underpowered to yield convincing *** To update the efficacy and safety of ECE-LAMS for treatment of biliary ob-struction after ERCP *** We searched PubMed,EMBASE,and Scopus databases from the inception of the ECE technique to May 13,*** outcome measure was pooled technical success rate,and secondary outcomes were pooled rates of clinical success,re-intervention,and adverse ***-analysis was performed using a random-effects model following Freeman-Tukey double-arcsine transformation in R soft-ware(version 4.1.3).RESULTS Fourteen eligible studies involving 620 participants were ultimately *** pooled rate of technical success was 96.7%,and clinical success was 91.0%.Adverse events were reported in 17.5%of *** reinter-vention rate was 7.3%.Subgroup analyses showed results were generally *** ECE-LAMS has favorable success with acceptable adverse events in relieving biliary obstruction when ERCP is *** consistency of results across most subgroups suggested that this is a generalizable approach.

关键词： Biliary obstruction Biliary drainage Electrocautery-enhanced lumen-apposing metal stents Endoscopic ultrasound Endoscopic retrograde cholangiopancreatography failure

Quassinoids from the Root Barks of Ailanthus altissima:Isolation,Configurational Assignment,and Cytotoxic Activities

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Chinese Journal of Chemistry 2021年第4期39卷 879-886页

作者： Ye-Qing Du ming Bai xiao-Qi Yu Tian-ming Lv Bin Lin xiao-xiao Huang Shao-Jiang Song Key Laboratory of Computational Chemistry-Based Natural Antitumor Drug Research&Development Liaoning ProvinceSchool of Traditional Chinese Materia MedicaShenyang Pharmaceutical UniversityShenyangLiaoning 110016China School of Pharmaceutical Engineering Shenyang Pharmaceutical UniversityShenyangLiaoning 110016China

Main observation and conclusion Quassinoids,a class of highly oxygenated triterpenes,have been isolated as bitter principles from the plants of Simaroubaceae *** new quassinoids,chouchunlactone A-E(1-5),and two known ones were identified from the root barks of Ailanthus altissima Swingle(Simaroubaceae).The chemical structures of the new compounds were deduced by spectroscopic data analyses,NMR calculations and DP4+probability *** absolute configurations were defined by comparison of their experimental and calculated electronic circular dichroism(ECD)spectra data,and compounds 1-2 were further confirmed by single-crystal X-ray ***,compound 5 showed potencies equivalent to sorafenib(IC50 value,9.70μmol·L–1)against HepG2 *** Hoechst 33342 staining,JC-1 fluorescent dye and Annexin V/pi analysis studies demonstrated that 5 can induce apoptosis and attenuate mitochondrial membrane potential(MMP)in HepG2 cells.

关键词： Ailanthus altissima Simaroubaceae Quassinoids Cytotoxicity Apoptosis

Effect of compound rhodiola sachalinensis A Bor on CCI4-induced liver fibrosis in rats and its probable molecular mechanisms

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World Journal of Gastroenterology 2003年第7期9卷 1559-1562页

作者： Chun-TaoLei ming-DeJiang xiao-BinChen YongZhang HuiXu ZhaoWang xiao-LingWU Wei-ZhengZeng pi-LongWang DepartmentofGastroenterology FirstAffiliatedHospitalChongqingUniversityofMedicalSciencesChongqing400016China DepartmentofDigestion GeneralHospitalofChengduMilitaryCommandChengdu610083SichuanProvinceChina

AIM: To explore the anti-fibrotic effect of a traditional Chinese medicine, compound rhodiola sachalinensis A Bor on CCl4-induced liver fibrosis in rats and its probable molecular mechanisms. METHODS: Ninety healthy male SD rats were randomly divided into three groups: normal group (n=-10), treatment group of compound rhodiola sachalinensis A Bor (n=-40) and CCl4-induced model group (n=40). The liver fibrosis was induced by CCl4 subcutaneous injection. Treatment group was administered with compound rhodiola sachalinensis A Bor (0.5 g/kg) once a day at the same time. Then the activities of several serum fibrosis-associated enzymes: alanine aminotransferase (ALT), aspartate aminotransferase (AST), N-acetyl-beta-D-glucosaminidase (β-NAG) and the levels ofserum procollagen Ⅲ (PCⅢ), collagen Ⅳ (CⅣ), hyaluronic acid （HA） were assayed. The histooathol(mical chanaes were observed with HE, VG and Masson stain. The expression of TGF-β1 mRNA,αl (I) mRNA and Na+/Ca2+ exchanger (NCX ) mRNA was detected by reverse transcription polymerase chain reaction (RT-PCR) in ***: Compound rhodiola sachalinensis A Bor significantly reduced serum activities of ALT, AST, β-NAG and decreased the levels of PCⅢ, CⅣ, HA, improved the liver histopathological changes, inhibited the expression of TGF-β1 mRNA, α(1) mRNA and Na+/Ca2+ exchanger mRNA in rats. CONCLUSION: Compound rhodiola sachalinensis A Bor can intervene in CCI4-induced liver fibrosis in rats, in which potential mechanisms may be decreasing the production of TGF-β1, reducing the production of collagen, preventing the activation of hepatic stellate cell (HSC) and inhibiting theexpression of TGF-β1 mRNA, αl(I) mRNA and Na+/Ca2+ exchanger mRNA.

关键词：肝纤维化中医药疗法 rhodiola-sachalinensis-A-Bor CCI4 肝星状细胞转化生长因子

基于中药超分子探究甘草配伍石膏与CaSO_(4)·2H_(2)O的汤剂相态、物质形态和晶型状态差异

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中国中药杂志 2025年第2期50卷 412-420页

作者：张瑶芝皮雯敏谭心如徐冉王旭许明阳黄雪梅王鹏龙北京中医药大学中药学院北京102488

以甘草-石膏药对为研究对象,运用中药超分子化学研究矿物药石膏与其主要成分CaSO_(4)·2H_(2)O分别配伍植物药甘草的差异性,以初步探讨临床配伍应用石膏的科学内涵。采用马尔文粒度仪、扫描电子显微镜、电导率仪观察并测定石膏、CaSO_(4... 详细信息

以甘草-石膏药对为研究对象,运用中药超分子化学研究矿物药石膏与其主要成分CaSO_(4)·2H_(2)O分别配伍植物药甘草的差异性,以初步探讨临床配伍应用石膏的科学内涵。采用马尔文粒度仪、扫描电子显微镜、电导率仪观察并测定石膏、CaSO_(4)·2H_(2)O及二者分别与甘草共煎后水煎液的微观形貌、粒径、电导率等物理指标;运用电感耦合等离子体发射光谱仪检测甘草-石膏、甘草-CaSO_(4)·2H_(2)O中的无机金属元素,采用等温滴定量热仪量化石膏、CaSO_(4)·2H_(2)O与甘草间的相互作用,利用傅里叶变换红外光谱仪分析甘草-石膏、甘草-CaSO_(4)·2H_(2)O的特征吸收峰变化,结合X-射线衍射仪测定2种配伍组合的晶体结构、物相组成;进一步以甘草酸代替甘草,分别与石膏、CaSO_(4)·2H_(2)O的药材/水煎液冻干粉进行共煎,以XRD结果进行验证分析。结果表明CaSO_(4)·2H_(2)O虽为石膏主要成分,但二者单煎液以及与甘草的共煎液存在明显不同,具体表现在:①CaSO_(4)·2H_(2)O与石膏药材的微观形貌均为无定形纤维状,但二者单煎液的粒径、电导率差异明显;②电镜下,甘草-CaSO_(4)·2H_(2)O的形貌不规则,甘草-石膏的形貌呈均匀纳米级颗粒;③甘草-CaSO_(4)·2H_(2)O、甘草-石膏的粒径和电导率等结果差别较大,且较单煎结果趋势不一致;④甘草-石膏较甘草-CaSO_(4)·2H_(2)O间的分子结合能力、官能团结构变化程度更强;⑤CaSO_(4)·2H_(2)O与石膏单煎液冻干粉的晶型差别明显,且二者与甘草共煎液的冻干粉晶型也明显不同。引起上述差异的原因是石膏具有较CaSO_(4)·2H_(2)O更丰富的微量元素,甘草酸代替甘草分别与石膏和CaSO_(4)·2H_(2)O的共煎物XRD结果进一步证明了石膏中微量元素对中药超分子形成的重要性,该研究初步揭示配伍矿物药石膏与CaSO_(4)·2H_(2)O对汤剂相态、物质形态和晶型状态的影响,为中医临床合理使用石膏提供依据。

关键词：矿物药石膏甘草 CaSO_(4)·2H_(2)O 微量元素中药超分子