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Dilemmas and Optimization of Third-Party Assessment System in Chinese Fair Competition Review
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作者 Cui Xu Mingyu Hu 《Open Journal of Applied Sciences》 2024年第8期2039-2049,共11页
The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, cha... The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, characterized by independence and specialization, is designed to mitigate these shortcomings. However, the implementation of third-party assessment faces challenges too. This paper intends to improve the third-party assessment system and to realize the legislative purpose of the system. Based on social research, discussions and exchanges with relevant parties, and the existing research results, this paper analyzes the challenges and possible optimization measures for the third-party assessment. The challenges include repulsion from policy-making bodies, insufficient independence of assessment bodies, disparity of assessment quality, and limited application of assessment outcomes. Possible optimization measures include promoting fair competition culture, increasing the acceptance of third-party assessment from policy-making bodies, enhancing the quality of third-party assessment, clarifying the relationship between policy-making bodies and assessment bodies, ensuring the independence of third-party assessments, and promoting the application of assessment results. 展开更多
关键词 Fair Competition Review Self-Review third-Party Assessment DILEMMA Optimization
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Galerkin-Bernstein Approximations for the System of Third-Order Nonlinear Boundary Value Problems
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作者 Snigdha Dhar Md. Shafiqul Islam 《Journal of Applied Mathematics and Physics》 2024年第6期2083-2101,共19页
This paper is devoted to find the numerical solutions of one dimensional general nonlinear system of third-order boundary value problems (BVPs) for the pair of functions using Galerkin weighted residual method. We der... This paper is devoted to find the numerical solutions of one dimensional general nonlinear system of third-order boundary value problems (BVPs) for the pair of functions using Galerkin weighted residual method. We derive mathematical formulations in matrix form, in detail, by exploiting Bernstein polynomials as basis functions. A reasonable accuracy is found when the proposed method is used on few examples. At the end of the study, a comparison is made between the approximate and exact solutions, and also with the solutions of the existing methods. Our results converge monotonically to the exact solutions. In addition, we show that the derived formulations may be applicable by reducing higher order complicated BVP into a lower order system of BVPs, and the performance of the numerical solutions is satisfactory. . 展开更多
关键词 System of third-Order BVP Galerkin Method Bernstein Polynomials Nonlinear BVP Higher-Order BVP
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Analysis of third and one-third harmonic generation in lossy waveguides
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作者 Jianyu Zhang Yunxu Sun Qinghai Song 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第6期209-212,共4页
A comprehensive study on the requirements for the highly efficient third harmonic generation(THG)and its inverse process,one-third harmonic generation(OTHG),in lossy waveguides is proposed.The field intensity restrict... A comprehensive study on the requirements for the highly efficient third harmonic generation(THG)and its inverse process,one-third harmonic generation(OTHG),in lossy waveguides is proposed.The field intensity restrictions for both THG and OTHG caused by loss are demonstrated.The effective relative phase ranges,supporting the positive growth of signal fields of THG and OTHG are shrunken by the loss.Furthermore,it turns out that the effective relative phase ranges depend on the intensities of the interacting fields.At last,a modified definition of coherent length in loss situation,which evaluates the phase matching degree more precisely,is proposed by incorporating the shrunken relative phase range and the nonlinear phase mismatch.These theoretical analysis are valuable for guiding the experimental designs for highly efficient THG and OTHG. 展开更多
关键词 coupled mode theory third HARMONIC GENERATION one-third HARMONIC GENERATION LOSS effects
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Research on China Third Language Learners' Metalinguistic Awareness
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作者 吕新博 石运章 《海外英语》 2018年第5期18-19,共2页
This study investigated the general situation of metalinguistic awareness of third language learners in Chinese universities.Data analyses showed that the level of metalinguistic awareness in those learners was signif... This study investigated the general situation of metalinguistic awareness of third language learners in Chinese universities.Data analyses showed that the level of metalinguistic awareness in those learners was significantly higher than that of second language learners.And learning a third language can improve metalinguistic awareness. 展开更多
关键词 metalinguistic awareness third language learners second language learners
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A review of third generation SiC fibers and SiC_f/SiC composites 被引量:47
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作者 Pengren Wang Fengqi Liu +2 位作者 Hao Wang Hao Li Yanzi Gou 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2019年第12期2743-2750,共8页
Compared with the first and second generations SiC fibers, the third generation SiC fibers have obvious improvement in heat-resistance, oxidation-resistance and creep-resistance, which promote the development of SiCf/... Compared with the first and second generations SiC fibers, the third generation SiC fibers have obvious improvement in heat-resistance, oxidation-resistance and creep-resistance, which promote the development of SiCf/SiC composite materials. Therefore, the third generation SiC fibers have more advantages and broader prospects in engineering applications. In this paper, the fabrication and properties of the third generation SiC fibers are compared and discussed. The preparation processes of the third generation SiC fibers reinforced SiC matrix composites and their application in aeroengine and nuclear energy fields are summarized, while their future development is prospected as well. 展开更多
关键词 SiC fiber third generation COMPOSITE
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Prognostic factors of refractory NSCLC patients receiving anlotinib hydrochloride as the third-or further-line treatment 被引量:54
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作者 Jing Wang Yizhuo Zhao +18 位作者 Qiming Wang Li Zhang Jianhua Shi Zhehai Wang Ying Cheng Jianxing He Yuankai Shi Hao Yu Yang Zhao Weiqiang Chen Yi Luo Xiuwen Wang Kejun Nan Faguang Jin Jian Dong Baolan Li Zhujun Liu Baohui Han Kai Li 《Cancer Biology & Medicine》 SCIE CAS CSCD 2018年第4期443-451,共9页
Objective:Anlotinib hydrochloride is a multitarget tyrosine kinase inhibitor that targets vascular endothelial growth factor receptor,fibroblast growth factor receptor,platelet-derived growth factor receptor,c-Kit,and... Objective:Anlotinib hydrochloride is a multitarget tyrosine kinase inhibitor that targets vascular endothelial growth factor receptor,fibroblast growth factor receptor,platelet-derived growth factor receptor,c-Kit,and c-MET;therefore,it exhibits both antitumor and anti-angiogenetic activities.A phase III trial has shown that anlotinib improved progression-free survival(PFS)and overall survival(OS)in patients with advanced non-small cell lung cancer(NSCLC),who presented with progressive disease or intolerance after standard chemotherapy.This study aimed to analyze the characteristics of patients receiving anlotinib treatment to determine the dominant populations who are fit for the treatment.Methods:Data were collected from March 2015 to January 2017 from a randomized,double-blind,placebo-controlled,multicenter,phase III trial of anlotinib(ALTER0303).A total of 437 patients were enrolled and randomly allocated(2:1)to the anlotinib and placebo groups.Kaplan–Meier analysis and log-rank test were performed to compare PFS and OS.Cox proportional hazards model was adopted for multivariate prognostic analysis.Results:Multivariate analysis indicated that high post-therapeutic peripheral blood granulocyte/lymphocyte ratio and elevated alkaline phosphatase levels were independent risk factors for PFS.Meanwhile,elevated thyroid-stimulating hormone,blood glucose,and triglyceride levels;hypertension;and hand–foot syndrome were independent protective factors of PFS.High posttherapeutic peripheral blood granulocyte/lymphocyte ratio,an Eastern Cooperative Oncology Group(ECOG)score≥2,and the sum of the maximal target lesion length at baseline were independent risk factors of OS,and hypertriglyceridemia was an independent protective factor of OS.Conclusions:This study preliminarily explored the possible factors that affected PFS and OS after anlotinib treatment in patients with advanced refractory NSCLC,and the baseline characteristics of the therapeutically dominant populations were then identified. 展开更多
关键词 NON-SMALL cell lung cancer anlotinib third- or further-line therapy PROGNOSTIC factor analysis
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The third-party regulation on food safety in China:A review 被引量:12
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作者 ZHANG Man QIAO Hui +3 位作者 WANG Xu PU Ming-zhe YU Zhi-jun ZHENG Feng-tian 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2015年第11期2176-2188,共13页
Stakeholders in the field of food safety management in China can be classified into three categories, government, food producers (farmers and enterprises), and the third-party regulatory bodies. The third-party regu... Stakeholders in the field of food safety management in China can be classified into three categories, government, food producers (farmers and enterprises), and the third-party regulatory bodies. The third-party regulation has experienced rapid development in past twenty years, and recently received considerable attention from consumers and the central government. This paper provides a review about the development, problems and future trend of the third-party regulation on food safety in China. To be specific, five forms of the third-party regulation are assessed, including media exposure, the third-party certification, regulation by consumer associations, social movements promoted by non-governmental organiza- tions (NGOs), and regulation by industry associations. The study concludes that media and consumer associations are the major players in the third-party regulation and are highly repudiated among customers. The food certification industry has developed rapidly, but is now facing crises of confidence among consumers because of its lack of self-regulation. NGOs and industry associations still remain in the early development stages of food safety management, and therefore, are of little importance in current regulatory bodies. 展开更多
关键词 food safety China the third-party regulation MEDIA CERTIFICATION
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MULTIPLE POSITIVE SOLUTIONS OF SINGULAR THIRD-ORDER PERIODIC BOUNDARY VALUE PROBLEM 被引量:21
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作者 孙经先 刘衍胜 《Acta Mathematica Scientia》 SCIE CSCD 2005年第1期81-88,共8页
This paper deals with the singular nonlinear third-order periodic boundary value problem u'' + p(3)u = f (t, u), 0 less than or equal to t less than or equal to 2pi, with u((i)) (0) = u((i)) (2pi), i = 0, 1, 2... This paper deals with the singular nonlinear third-order periodic boundary value problem u'' + p(3)u = f (t, u), 0 less than or equal to t less than or equal to 2pi, with u((i)) (0) = u((i)) (2pi), i = 0, 1, 2, where p is an element of (Graphics) and f is singular at t = 0, t = 1 and u = 0. Under suitable weaker conditions than those of [1], it is proved by constructing a special cone in C[0, 2pi] and employing the fixed point index theory that the problem has at least one or at least two positive solutions. 展开更多
关键词 singular boundary value problem third-order differential system positive solution
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Clinicopathological characteristics of clinical early gastric cancer in the upper-third stomach 被引量:6
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作者 Daisuke Ichikawa Shuhei Komatsu +5 位作者 Toshiyuki Kosuga Hirotaka Konishi Kazuma Okamoto Atsushi Shiozaki Hitoshi Fujiwara Eigo Otsuji 《World Journal of Gastroenterology》 SCIE CAS 2015年第45期12851-12856,共6页
AIM: To elucidate the clinicopathological characteristics of clinically early gastric cancer in the upper-third stomach and to clarify treatment precautions.METHODS: A total of 683 patients with clinical early gastric... AIM: To elucidate the clinicopathological characteristics of clinically early gastric cancer in the upper-third stomach and to clarify treatment precautions.METHODS: A total of 683 patients with clinical early gastric cancer were enrolled in this retrospective study, 128 of whom had gastric cancer in the upper-third stomach(U group). All patients underwent a double contrast barium examination, endoscopy, and computed tomography(CT), and were diagnosed preoperatively based on the findings obtained. The clinicopathological features of these patients were compared with those of patients with gastric cancer in the middle- and lower-third stomach(ML group). We also compared clinicopathological factors between accurate-diagnosis and under-diagnosis groups in order to identify factors affecting the accuracy of a preoperative diagnosis of tumor depth.RESULTS: Patients in the U group were older(P = 0.029), had a higher ratio of males to females(P = 0.015), and had more histologically differentiated tumors(P = 0.007) than patients in the ML group. A clinical under-diagnosis occurred in 57 out of 683 patients(8.3%), and was more frequent in the U group than in the ML group(16.4% vs 6.3%, P < 0.0001). Therefore, the rates of lymph node metastasis and lymphatic invasion were slightly higher in the U group than in the ML group(P = 0.071 and 0.082, respectively). An under-diagnosis was more frequent in histologically undifferentiated tumors(P = 0.094) and in those larger than 4 cm(P = 0.024). The medianfollow-up period after surgery was 56 mo(range, 1-186 mo). Overall, survival and disease-specific survival rates were significantly lower in the U group than in the ML group(P = 0.016 and 0.020, respectively). However, limited operation-related cancer recurrence was not detected in the U group in the present study.CONCLUSION: Clinical early gastric cancer in the upper-third stomach has distinguishable characteristics that increase the risk of a clinical under-diagnosis, especially in patients with larger or undifferentiated tumors. 展开更多
关键词 Upper-third STOMACH Diagnosis GASTRIC CANCER
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THE SHARP ESTIMATE OF THE THIRD HOMOGENEOUS EXPANSION FOR A CLASS OF STARLIKE MAPPINGS OF ORDER α ON THE UNIT POLYDISK IN C^n 被引量:14
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作者 刘小松 刘太顺 《Acta Mathematica Scientia》 SCIE CSCD 2012年第2期752-764,共13页
In this article, first, a sufficient condition for a starlike mapping of order a f(x) defined on the unit ball in a complex Banach space is given. Second, the sharp estimate of the third homogeneous expansion for f ... In this article, first, a sufficient condition for a starlike mapping of order a f(x) defined on the unit ball in a complex Banach space is given. Second, the sharp estimate of the third homogeneous expansion for f is established as well, where f(z) = (f1(z), f2(z),..., fn(z))' is a starlike mapping of order a or a normalized biholomorphic starlike mapping defined on the unit polydisk in Cn, and D2fk(0)(z2) /2i= zk(∑l=1^b akzzl), k = 2t l=1 k = 1, 2,..., n. Our result states that the Bieberbaeh conjecture in several complex variables (the case of the third homogeneous expansion for starlike mappings of order α and biholomorphic starlike mappings) is partly proved. 展开更多
关键词 Estimate of the third homogeneous expansion starlike mapping of order a biholomorphic starlike mapping
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Impacted Lower Third Molar Fused with a Supernumerary Tooth—Diagnosis and Treatment Planning Using Cone-Beam Computed Tomography 被引量:11
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作者 Osny Ferreira-Junior Luciana Dorigatti de .&.Aila +3 位作者 Marcelo Bonifacio da Silva Sampieri Eduardo Dias- Ribeiro Wei-liang Chen Song Fan 《International Journal of Oral Science》 SCIE CAS CSCD 2009年第4期224-228,共5页
This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radio... This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography--which provides precise three- dimensional information--was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomo- graphy. 展开更多
关键词 third molar supernumerary tooth oral surgery cone-beam computed tomography
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Role of third molars in orthodontics 被引量:5
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作者 Konstantinia Almpani Olga-Elpis Kolokitha 《World Journal of Clinical Cases》 SCIE 2015年第2期132-140,共9页
The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not be... The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too. 展开更多
关键词 CROWDING Extraction ERUPTION third MOLAR ORTHODONTICS IMPACTION
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Bacterial Diversity in Alpine Lakes: A Review from the Third Pole Region 被引量:4
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作者 Namita Paudel Adhikari Subash Adhikari +2 位作者 Xiaobo Liu Liang Shen Zhengquan Gu 《Journal of Earth Science》 SCIE CAS CSCD 2019年第2期387-396,共10页
Microorganisms are unique among all of the living organisms because of their high population size, advanced genetic diversity, short generation time, and quick response to the small change in environmental conditions.... Microorganisms are unique among all of the living organisms because of their high population size, advanced genetic diversity, short generation time, and quick response to the small change in environmental conditions. Remote alpine lakes of the Third Pole region provide the unique habitat for microorganisms acting as a natural laboratory and offering the information about the ecological roles of microorganisms. Many researchers focused on microbial communities as well as the impact of physicochemical, biological and hydrological parameters in lakes of this region since decades but the comprehensive review focusing on bacterial diversity and the role of environmental parameters still lacks. Here we reviewed bacterial diversity in lakes of the Third Pole region by analyzing 16 S rRNA clone libraries accessed from previous research findings. A total of 5 388 bacterial 16 S rRNA gene sequences were analyzed and classified into different phylogenetic groups. The average relative abundance of dominant taxa includes Betaproteobacteria(19%), Bacteroidetes(18%), Gammaproteobacteria(16%), Actinobacteria(15%), Alphaproteobacteria(14%), Cyanobacteria(7%), and Firmicutes(5%). Several adaptational strategies were adopted by these dominant bacterial groups in order to accommodate in the respective habitat. Nevertheless, lake water properties like temperature, pH, salinity, incident UV radiation, turbidity, and nutrients also played role in bacterial diversity. 展开更多
关键词 BACTERIAL diversity ALPINE LAKES 16S RRNA third Pole region
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Influences of solid particles on the formation of the third phase crud during solvent extraction 被引量:6
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作者 ZHENG Qi RUAN Renman WEN Jiankang SONG Yongsheng DONG Qinghai WU Minglin YAO Guocheng 《Rare Metals》 SCIE EI CAS CSCD 2007年第1期89-96,共8页
The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study... The influences of solid particles in leach solution on the formation of the third phase crud during solvent extraction of copper were studied. Analyzed from the point of view of pH value and surface tension, the study results showed that the solid particle is one of the most important contributors for the formation of the third phase crud. During solvent extraction, if the pH value was greater than 2.30, the number of solid particles in the mother solution increased, in which case the possibility of forming the third phase crud could also increase, and the interface tension value might grow in pace with the quantity of the third phase crud. 展开更多
关键词 solvent extraction solid particle the third phase crud surface tension
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Third-Molar Development in Relation to Chronologic Age in Young Adults of Central China 被引量:7
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作者 白宇明 毛靖 +1 位作者 朱声荣 魏蔚 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2008年第4期487-490,共4页
The estimation of chronologic age based on the stages of third-molar development was evaluated by using the eight stages (A–H) method of Demirjian and the third-molar development was compared, in terms of sex and a... The estimation of chronologic age based on the stages of third-molar development was evaluated by using the eight stages (A–H) method of Demirjian and the third-molar development was compared, in terms of sex and age, with results of previous studies. The samples consisted of 291 orthopantomograms from young Chinese subjects of known chronologic age and sex (including 139 males with a mean age of 14.67±3.62 y and 152 females with a mean age of 14.85±3.70 y). Statistical analysis was performed by employing the Mann-Whitney U-test and the t-test. Regression analysis was conducted to obtain regression formulas for calculating dental age from the chronologic age. Our results showed statistically significant differences (P〈0.05) in third-molar development between males and females, at the calcification stages D, E and H. And a strong correlation was found between age and third-molar development in both males (r2=0.65) and females (r2=0.61). New equations (Age=8.76+1.32 Development stage) for estimating chronologic age were derived. It is concluded that third-molar genesis took place earlier in males than in females. The use of third molars as a developmental marker is appropriate in young adults of Central China. The formula obtained in the present study can be used as a guide for estimation of dental maturity and a standard for age estimation for young adults of Central China. 展开更多
关键词 third molar chronological age age estimation
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Caudate lobectomy by the third porta hepatis anatomical method: a study of 16 cases 被引量:4
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作者 Huai-Quan Zuo, Lu-Nan Yan, Yong Zeng, Jia-Ying Yang, Hong-Zhi Luo, Jiang-Wen Liu, Li-Xin Zhou and Qiang Jin Department of General Surgery, West China Hospital, Sichuan University, Chengdu 610041, China 《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2006年第3期387-390,共4页
BACKGROUND: The treatment for primary tumor in the caudate lobe of the liver is difficult because of its unique anatomical location. This study was undertaken to improve operative techniques and results by a new anato... BACKGROUND: The treatment for primary tumor in the caudate lobe of the liver is difficult because of its unique anatomical location. This study was undertaken to improve operative techniques and results by a new anatomical method of caudate lobectomy. METHODS: Clinical data of 16 patients who had had caudate lobectomy for the liver from January 1996 to November 2004 were retrospectively analyzed. The third porta hepatis anatomical method was performed in all 16 patients. Operative time, intraoperative blood loss, postoperative complications were recorded. The 1-, 3-, and 5-year survival rates of 13 patients with caudate lobe carcinoma were followed up. Anatomical status, operative routes, operative procedures, liver blood supply were evaluated. RESULTS: The operation was successful in the 16 patients. The operative time was 255±70 minutes and blood loss 740±402 ml. None of the patients died from massive bleeding during the operation, nor did complications such as biliary fistula and liver failure occurred. In 13 patients with malignant tumor, 7 died from recurrence and metastasis of the tumor and the other 6 are still alive at the end of follow-up. One patient has survived for 6 years. The 1-, 3-, and 5-year survival rates in the 13 patients were 83.9%, 58.7% and 39.2%, respectively. CONCLUSION: Caudate lobectomy by the third porta hepatis anatomical method can improve operative effect and increase the resection probability for solitary tumor in the caudate lobe. 展开更多
关键词 caudate lobectomy the third porta hepatis ANATOMY titanium clip
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Preparation of TeO_x-SiO_2 film with excellent third-order nonlinear optical properties by electrochemically induced sol-gel method 被引量:6
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作者 Qiang Li Min Gu 《Chinese Chemical Letters》 SCIE CAS CSCD 2011年第11期1359-1362,共4页
TeOx-SiO2 composite films having third-order nonlinearities were prepared by electrochemically induced sol-gel deposition method on ITO substrate.The third-order optical nonlinearities of the films were measured by Z-... TeOx-SiO2 composite films having third-order nonlinearities were prepared by electrochemically induced sol-gel deposition method on ITO substrate.The third-order optical nonlinearities of the films were measured by Z-scan technique.The third-order nonlinear susceptibilities(χ^((3))) of the as-prepared films are 5.9×10^(-7) to 4.29×10^(-6)esu.The surface morphology and composition of the films were characterized by SEM/EDX,which identified that Te metallic particles well dispersed in TeO_x-SiO_2 gel films. 展开更多
关键词 TeOx-SiO2 composite Electrochemically induced sol-gel method third-order nonlinearities Z-SCAN
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Accuracy of the half-power bandwidth method with a third-order correction for estimating damping in multi-DOF systems 被引量:5
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作者 Wang Jinting Lü Dandan +1 位作者 Jin Feng Zhang Chuhan 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第1期33-38,共6页
A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth m... A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth method with the third-order correction in damping estimation for multi-DOF linear systems.Damping ratios in a two-DOF linear system are estimated using its displacement and acceleration frequency response curves,respectively.A wide range of important parameters that characterize the shape of these response curves are taken into account.Results show that the third-order correction may greatly improve the accuracy of the half-power bandwidth method in estimating damping in a two-DOF system.In spite of this,the half-power bandwidth method may significantly overestimate the damping ratios of two-DOF systems in some cases. 展开更多
关键词 half-power bandwidth method third-order correction damping ratio estimation error two-DOF system
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Recent progress in third-generation low alloy steels developed under M^3 microstructure control 被引量:8
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作者 Zhen-jia Xie Cheng-jia Shang +3 位作者 Xue-lin Wang Xue-min Wang Gang Han Raja-devesh-kumar Misra 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第1期1-9,共9页
During the past thirty years, two generations of low alloy steels(ferrite/pearlite followed by bainite/martensite) have been developed and widely used in structural applications. The third-generation of low alloy stee... During the past thirty years, two generations of low alloy steels(ferrite/pearlite followed by bainite/martensite) have been developed and widely used in structural applications. The third-generation of low alloy steels is expected to achieve high strength and improved ductility and toughness, while satisfying the new demands for weight reduction, greenness, and safety. This paper reviews recent progress in the development of third-generation low alloy steels with an M^3 microstructure, namely, microstructures with multi-phase, meta-stable austenite, and multi-scale precipitates. The review summarizes the alloy designs and processing routes of microstructure control, and the mechanical properties of the alloys.The stabilization of retained austenite in low alloy steels is especially emphasized. Multi-scale nano-precipitates, including carbides of microalloying elements and Cu-rich precipitates obtained in third-generation low alloy steels, are then introduced. The structure–property relationships of third-generation alloys are also discussed. Finally, the promises and challenges to future applications are explored. 展开更多
关键词 third-generation low alloy steels multi-phase microstructure meta-stable retained austenite multi-scale precipitates
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The coupling of dynamics and permeability in the hydrocarbon accumulation period controls the oil-bearing potential of low permeability reservoirs:a case study of the low permeability turbidite reservoirs in the middle part of the third member of Shahejie 被引量:11
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作者 Tian Yang Ying-Chang Cao +4 位作者 Yan-Zhong Wang Henrik Friis Beyene Girma Haile Ke-Lai Xi Hui-Na Zhang 《Petroleum Science》 SCIE CAS CSCD 2016年第2期204-224,共21页
The relationships between permeability and dynamics in hydrocarbon accumulation determine oil- bearing potential (the potential oil charge) of low perme- ability reservoirs. The evolution of porosity and permeabilit... The relationships between permeability and dynamics in hydrocarbon accumulation determine oil- bearing potential (the potential oil charge) of low perme- ability reservoirs. The evolution of porosity and permeability of low permeability turbidite reservoirs of the middle part of the third member of the Shahejie Formation in the Dongying Sag has been investigated by detailed core descriptions, thin section analyses, fluid inclusion analyses, carbon and oxygen isotope analyses, mercury injection, porosity and permeability testing, and basin modeling. The cutoff values for the permeability of the reservoirs in the accumulation period were calculated after detailing the accumulation dynamics and reservoir pore structures, then the distribution pattern of the oil-bearing potential of reservoirs controlled by the matching relationship between dynamics and permeability during the accumulation period were summarized. On the basis of the observed diagenetic features and with regard to the paragenetic sequences, the reservoirs can be subdivided into four types of diagenetic facies. The reservoirs experienced two periods of hydro- carbon accumulation. In the early accumulation period, the reservoirs except for diagenetic facies A had middle to high permeability ranging from 10 × 10-3 gm2 to 4207 × 10-3 lain2. In the later accumulation period, the reservoirs except for diagenetic facies C had low permeability ranging from 0.015 × 10-3 gm2 to 62× 10-3 -3m2. In the early accumulation period, the fluid pressure increased by the hydrocarbon generation was 1.4-11.3 MPa with an average value of 5.1 MPa, and a surplus pressure of 1.8-12.6 MPa with an average value of 6.3 MPa. In the later accumulation period, the fluid pressure increased by the hydrocarbon generation process was 0.7-12.7 MPa with an average value of 5.36 MPa and a surplus pressure of 1.3-16.2 MPa with an average value of 6.5 MPa. Even though different types of reservoirs exist, all can form hydrocarbon accumulations in the early accumulation per- iod. Such types of reservoirs can form hydrocarbon accumulation with high accumulation dynamics; however, reservoirs with diagenetic facies A and diagenetic facies B do not develop accumulation conditions with low accumu- lation dynamics in the late accumulation period for very low permeability. At more than 3000 m burial depth, a larger proportion of turbidite reservoirs are oil charged due to the proximity to the source rock, Also at these depths, lenticular sand bodies can accumulate hydrocarbons. At shallower depths, only the reservoirs with oil-source fault development can accumulate hydrocarbons. For flat surfaces, hydrocarbons have always been accumulated in the reservoirs around the oil-source faults and areas near the center of subsags with high accumulation dynamics. 展开更多
关键词 Reservoir porosity and permeabilityevolution Accumulation dynamics Cutoff-values ofpermeability in the accumulation period Oil-bearingpotential Low permeability reservoir The third memberof the Shahejie Formation Dongying Sag
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