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| 1 | A review of selective laser melting of aluminum alloys: Processing,microstructure, property and developing trends显示文摘Selective laser melting(SLM) is an attractive rapid prototyping technology for the fabrication of metallic components with complex structure and high performance. Aluminum alloy, one of the most pervasive structural materials, is well known for high specific strength and good corrosion resistance. But the poor laser formability of aluminum alloy restricts its application. There are problems such as limited processable materials, immature process conditions and metallurgical defects on SLM processing aluminum alloys. Some efforts have been made to solve the above problems. This paper discusses the current research status both related to the scientific understanding and technology applications. The paper begins with a brief introduction of basic concepts of aluminum alloys and technology characterization of laser selective melting. In addition, solidification theory of SLM process and formation mechanism of metallurgical defects are discussed. Then, the current research status of microstructure, properties and heat treatment of SLM processing aluminum alloys is systematically reviewed respectively. Lastly, a future outlook is given at the end of this review paper. | Jinliang Zhang Bo Song Qingsong Wei Dave Bourell Yusheng Shi | 2019 | Journal of Materials Science & Technology2019,35,2: | 77 |
| 2 | A promising new class of irradiation tolerant materials:Ti_2ZrHfV_(0.5)Mo_(0.2) high-entropy alloy显示文摘Recently, high-entropy alloys(HEAs) or multi-principal-element alloys with unprecedented physical,chemical, and mechanical properties, have been considered as candidate materials used in advanced reactors due to their promising irradiation resistant behavior. Here, we report a new single-phase bodycentered cubic(BCC) structured Ti_2 ZrHfV_(0.5)Mo_(0.2) HEA possessing excellent irradiation resistance, i.e.,scarcely irradiation hardening and abnormal lattice constant reduction after helium-ion irradiation,which is completely different from conventional alloys. This is the first time to report the abnormal XRD phenomenon of metallic alloys and almost no hardening after irradiation. These excellent properties make it to be a potential candidate material used as core components in next-generation nuclear reactors. The particular irradiation tolerance derives from high density lattice vacancies/defects. | Yiping Lu Hefei Huang Xuzhou Gao Cuilan Ren Jie Gao Huanzhi Zhang Shijian Zheng Qianqian Jin Yonghao Zhao Chenyang Lu Tongmin Wang Tingju Li | 2019 | Journal of Materials Science & Technology2019,35,3: | 23 |
| 3 | Recognition of wood surface defects with near infrared spectroscopy and machine vision显示文摘To improve the accuracy in recognizing defects on wood surfaces,a method fusing near infrared spectroscopy(NIR)and machine vision was examined.Larix gmelinii was selected as the raw material,and the experiments focused on the ability of the model to sort defects into four types:live knots,dead knots,pinholes,and cracks.Sample images were taken using an industrial camera,and a morphological algorithm was applied to locate the position of the defects.A portable near infrared spectrometer(900–1800 nm)collected the spectra of these positions.In addition,principal component analysis was utilized on these variables from spectral information and principal component vectors were extracted as the inputs of the model.The results show that a back propagation neural network model exhibited better discrimination accuracy of 92.7%for the training set and 92.0%for the test set.The research reveals that the NIR fusing machine vision is a feasible tool for detecting defects on board surfaces. | Huiling Yu Yuliang Liang Hao Liang Yizhuo Zhang | 2019 | Journal of Forestry Research2019,30,6: | 16 |
| 4 | Effect of processing parameters on the densification of an additively manufactured 2024 Al alloy显示文摘Understanding the densification behaviours and formation mechanisms of defects are essential to fabricate high quality and high strength aluminium components using selective laser melting(SLM) technology. In this work, the effects of laser power and scanning speed on the densification, defects evolution and their formation mechanisms in a SLMed 2024 aluminium(Al) alloy were investigated in consideration of the corresponding laser energy input, melting mode transition and microstructural evolution. The results showed that optimizing the processing parameters effectively reduced the porosity level below1% by avoiding the lack of fusion and keyhole melting mode, and minimizing the gas pores. However,optimization of the processing parameters could not eliminate the columnar structure associated with the SLMed 2024 Al alloy, which contributed to the hot-tearing cracks in the SLMed parts. It was found that the dependence of porosity formation on SLM processing parameters was contrary to the crack density. Hence, to further improve the SLM-processability of the 2024 Al alloy it is necessary to develop SLM methods in order avoid the hot-cracking within the optimized processing parameter window associated with the minimum porosity formation. | Qiyang Tan Yingang Liu Zhiqi Fan Jingqi Zhang Yu Yin Ming-Xing Zhang | 2020 | Journal of Materials Science & Technology2020,58,23: | 13 |
| 5 | Studies on the effect of weld defect on the fatigue behavior of welded structures显示文摘Structural integrity isstated as the science and technology of margin between safety and disaster. Systematic prediction of structural integrity of critical structures such ascombustion chambers,pressure vessels,nuclear reactor components,boilers etc.,ensures the human safety,environmental protection,and the economical considerations.The present work aims at prediction of fatigue behaviour of symmetric structures like pressure vessels in the presence of common welding defects such as lack of fusion( LOF),lack of penetration( LOP) and porosity.A ring type specimen which replicates the stress pattern in thepressure vessel is considered for the study of severity of weld imperfections. Initial dimensions of weld defects are arrived by performing NDT inspection.Crack growth analysis is carried out to determine the remaining life of the welded joint with defects. | Ramu Murugan Prabhu Raja Venugobal Thyla Pudukkarai Ramaswami Sathiskumar Jothi Somu Chinnusamy | 2018 | China Welding2018,27,1: | 12 |
| 6 | Prevention of neural tube defects with folic acid: The Chinese experience显示文摘Neural tube defects(NTDs) are a group of congenital malformations of the central nervous system that are caused by the closure failure of the embryonic neural tube by the 28 th day of conception. Anencephaly and spina bifida are the two major subtypes. Fetuses with anencephaly are often stillborn or electively aborted due to prenatal diagnosis, or they die shortly after birth. Most infants with spina bifida are live-born and, with proper surgical treatment, can survive into adulthood. However, these children often have life-long physical disabilities. China has one of the highest prevalence of NTDs in the world. Inadequate dietary folate intake is believed to be the main cause of the cluster. Unlike many other countries that use staple fortification with folic acid as the public health strategy to prevent NTDs, the Chinese government provides all women who have a rural household registration and who plan to become pregnant with folic acid supplements, free of charge, through a nation-wide program started in 2009. Two to three years after the initiation of the program, the folic acid supplementation rate increased to 85% in the areas of the highest NTD prevalence. The mean plasma folate level of women during early and mid-pregnancy doubled the level before the program was introduced. However, most women began taking folic acid supplements when they knew that they were pregnant. This is too late for the protection of the embryonic neural tube. In a postprogram survey of the women who reported folic acid supplementation, less than a quarter of the women began taking supplements prior to pregnancy, indicating that the remaining three quarters of the fetuses remained unprotected during the time of neural tube formation. Therefore, staple food fortification with folic acid should be considered as a priority in the prevention of NTDs. | Ai-Guo Ren | 2015 | World Journal of Clinical Pediatrics2015,4,3: | 12 |
| 7 | Advancement and prospect of short-term numerical climate prediction显示文摘The defects of present methods of short-term numerical climate prediction are discussed in this paper, and four challenging problems are put forward. Considering our under developed computer conditions, we should innovate in the approcuch of numerical climate prediction on the basis of our own achievements and experiences in the field of short-term numerical climate prediction. It is possibly an effective way to settle the present defects of short-term numerical climate prediction. | CHOU Jifan & XU Ming1. Department of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China 2. Training Center of Chinese Meteorological Administration, Beijing 100081, China | 2001 | Chinese Science Bulletin2001,46,18: | 11 |
| 8 | Birth defects in pregestational diabetes:Defect range,glycemic threshold and pathogenesis显示文摘Currently,60 million women of reproductive age(18-44 years old) worldwide,and approximately 3 million American women have diabetes mellitus,and it has been estimated that this number will double by 2030.Pregestational diabetes mellitus(PGD) is a significant public health problem that increases the risk for structural birth defects affecting both maternal and neonatal pregnancy outcome.The most common types of human structural birth defects associated with PGD are congenital heart defects and central nervous system defects.However,diabetes can induce birth defects in any other fetal organ.In general,the rate of birth defects increases linearly with the degree of maternal hyperglycemia,which is the major factor that mediates teratogenicity of PGD.Stringent prenatal care and glycemic control are effective means to reduce birth defects in PGD pregnancies,but cannot reduce the incidence of birth defects to the rate of that is seen in the nondiabetic population.Studies in animal models have revealed that PGD induces oxidative stress,which activates cellular stress signalling leading to dysregulation of gene expression and excess apoptosis in the target organs,including the neural tube and embryonic heart.Activation of the apoptosis signalregulating kinase 1(ASK1)-forkhead transcription factor 3a(Fox O3a)-caspase 8 pathway causes apoptosis in the developing neural tube leading to neural tube defects(NTDs).ASK1 activates the c-Jun-N-Terminal kinase 1/2(JNK1/2),which leads to activation of the unfolded protein response and endoplasmic reticulum(ER) stress.Deletion of the ASK1 gene,the JNK1 gene,or the JNK2 gene,or inhibition of ER stress by 4-Phenylbutyric acid abrogates diabetes-induced apoptosis and reduces the formation of NTDs.Antioxidants,such as thioredoxin,which inhibits the ASK1-Fox O3a-caspase 8 pathway or ER stress inhibitors,may prevent PGD-induced birth defects. | Rinat Gabbay-Benziv E Albert Reece Fang Wang Peixin Yang | 2015 | World Journal of Diabetes2015,6,3: | 10 |
| 9 | Study of Sr–Ca–Si-based scaffolds for bone regeneration in osteoporotic models显示文摘Bone tissue engineering has emerged as a promising alternative therapy for patients who suffer bone fractures or defects caused by trauma,congenital diseases or tumours.However,the reconstruction of bone defects combined with osteoporosis remains a great challenge for clinicians and researchers.Based on our previous study,Ca–Si-based bioceramics(MSCs)showed enhanced bone formation capabilities under normal conditions,and strontium was demonstrated to be therapeutic in promoting bone quality in osteoporosis patients.Therefore,in the present study,we attempted to enlarge the application range of MSCs with Sr incorporation in an osteoporotic bone regeneration model to evaluate whether Sr could assist in regeneration outcomes.In vitro readout suggested that Sr-incorporated MSC scaffolds could enhance the expression level of osteogenic and angiogenic markers of osteoporotic bone mesenchymal stem cells(OVX BMSCs).Animal experiments showed a larger new bone area;in particular,there was a tendency for blood vessel formation to be enhanced in the Sr-MSC scaffold group,showing its positive osteogenic capacity in bone regeneration.This study systematically illustrated the effective delivery of a low-cost therapeutic Sr agent in an osteoporotic model and provided new insight into the treatment of bone defects in osteoporosis patients. | Qianju Wu Xiao Wang Fei Jiang Ziyuan Zhu Jin Wen Xinquan Jiang | 2020 | International Journal of Oral Science2020,12,3: | 9 |
| 10 | Effect of Process Parameters on Defects,Melt Pool Shape,Microstructure,and Tensile Behavior of 316L Stainless Steel Produced by Selective Laser Melting显示文摘Previous studies have revealed that laser power and energy density are significant factors affecting the quality of parts manufactured by selective laser melting(SLM).The normalized equivalent density E_(0)^(*) and dimensionless laser power q^(*),which can be regarded as a progress on the understanding of the corresponding dimensional quantities,are adopted in this study to examine the defects,melt pool shape,and primary dendrite spacing of the SLM-manufactured 316 L stainless steel,because it reflects the combined effect of process parameters and material features.It is found that the number of large defects decreases with increasing E_(0)^(*) due to enough heat input during the SLM process,but it will show an increasing trend when excessive heat input(i.e.,utilizing a high E_(0)^(*))is imported into the powder bed.The q^(*) plays an important role in controlling maximum temperature rising in the SLM process,and in turn,it affects the number of large defects.A large q^(*) value results in a low value of absolute frequency of large defects,whereas a maximum value of absolute frequency of large defects is achieved at a low q^(*) even if E_(0)^(*) is very high.The density of the built parts is greater at a higher q^(*) when E_(0)^(*)remains constant.Increasing the melt pool depth at relatively low value of E_(0)^(*) enhances the relative density of the parts.A narrow,deep melt pool can be easily generated at a high q^(*) when E_(0)^(*) is sumciently high,but it may increase melt pool instability and cause keyhole defects.It is revealed that a low E_(0)^(*) can lead to a high cooling rate,which results in a refined primary dendrite spacing.Relatively low E_(0)^(*) is emphasized in selecting the process parameters for the tensile test sample fabrication.It shows that excellent tensile properties,namely ultimate tensile strength,yield strength,and elongation to failure of 773 MPa,584 MPa,and 46%,respectively,can be achieved at a relatively low E_(0)^(*) without heat treatment. | Hua-Zhen Jiang Zheng-Yang Li Tao Feng Peng-Yue Wu Qi-Sheng Chen Yun-Long Feng Long-Fei Chen Jing-Yu Hou He-Jian Xu | 2021 | Acta Metallurgica Sinica(English Letters)2021,34,4: | 8 |
| 11 | Pulsed electromagnetic non-destructive evaluation and applications显示文摘This paper introduces recent research work in the field of pulsed electromagnetic non-destructive testing/evaluation.These are pulsed eddy current,pulsed magnetic flux leakage and eddy current pulsed thermography.This paper introduces pulsed electromagnetic techniques and their different case studies on defect detection as well as stress characterisation.Experimental tests have been validated and future research plans are discussed.This paper demonstrates pulsed electromagnetic non-destructive testing and evaluation for not only depth information,but also for multiple parameter measurement and multiple integration,which are important for future development. | TIAN Guiyun ZHOU Xiuyun Ibukun D.Adewale | 2014 | Instrumentation2014,1,1: | 8 |
| 12 | Surface Defects of Cold-Rolled Ti-IF Steel Sheets due to Non-Metallic Inclusions显示文摘Surface defects of the cold-rolled sheets of Ti-IF steel were studied and analyzed. After analyzing surface defects of cold-rolled sheets, such as shelling defects, holes and sliver defects by SEM/EDS, a variety of inclusions were found. In addition, the distribution of macro-inclusions in slabs was analyzed by MIDAS method. The results show the macroscopic inclusion bands of head slabs and normal slabs are in 1/8 slab thickness regions of both inner arc side and outer arc side. The formation process of the defects in the cold-rolled sheets was simulated with an experimental cold-rolling machine for comparison. The results show that there were three kinds of inclusions underneath the surface defects: Al2O3, SiO2 and particles from slag entrainment, which were the main reason for defect formation during cold rolling. | CUI Heng1, WU Hua-jie1, YUE Feng1, WU Wei-shuang1, WANG Min1, BAO Yan-ping1, CHEN Bin2, JI Chen-xi2 (1. Engineering Research Institute, University of Science and Technology Beijing, Beijing 100083, China 2. Shougang Research Institute of Technology, Beijing 100043, China) | 2011 | Journal of Iron and Steel Research(International)2011,18,S2: | 8 |
| 13 | Characterization of atomic defects on the photoluminescence in two-dimensional materials using transmission electron microscope显示文摘Two-dimensional material(2D)that possesses atomic thin geometry and remarkable properties is a star material for the fundamental researches and advanced applications.Defects in 2D materials are critical and fundamental to understand the chemical,physical,and optical properties.Photoluminescence arises in 2D materials owing to various physical phenomena including activator/dopant-induced luminescence and defect-related emissions,and so forth.With the advanced transmission electron microscopy(TEM)technologies,such as aberration correction and low voltage technologies,the morphology,chemical compositions and electronic structures of defects in 2D material could be directly characterized at the atomic scale.In this review,we introduce the applications of state-of-the-art TEM technologies on the studies of the role of atomic defects in the photoluminescence characteristics in 2D material.The challenges in spatial and time resolution are also discussed.It is proved that TEM is a powerful tool to pinpoint the relationship between the defects and the photoluminescence characteristics. | Jiayan Zhang Ye Yu Peng Wang Chen Luo Xing Wu Ziqi Sun Jianlu Wang Wei Da Hu Guozhen Shen | 2019 | InfoMat2019,1,1: | 6 |
| 14 | Extensive full-thickness eyelid reconstruction with rotation flaps through 'subcutaneous tunnel' and palatal mucosal grafts显示文摘· AIM: To reconstruct the extensive full-thickness defects of eyelids is a challenge for the plastic surgeon because of their complex anatomy and special functions.This article presents and discusses an improved surgical technique in which the orbicularis oculi myocutaneous flap is rotated through a 'subcutaneous tunnel' in conjunction with a palatal mucosal graft employed for lining.·METHODS: Data from 22 eyes with extensive full-thickness eyelid defects from various causes between2009 and 2013 were analyzed in this study. After the different layers of eyelid were separated completely, a temporally based orbicularis oculi myocutaneous flap was designed following fishtail lines and was mobilized,leaving the base of the pedicle intact with a submuscular tissue attachment. The flap was then rotated through a 'subcutaneous tunnel' to the defect, and the donor site was closed primarily. Posterior lamellar reconstruction was performed with a mucosal graft harvested from the hard palate.·RESULTS: All the flaps were survived without any healing problems. There was no corneal irritation, flap contraction, or significant donor-site morbidity in the follow-up period. The incision scars were almost invisible.The defects were repaired completely, and the evaluations showed satisfactory function and appearance.·CONCLUSION: This technique is an improved singlestage operation and can be applied to repair large, full-thickness eyelid defects from various causes. With our method, the functional and aesthetic results can be obtained in either the upper or lower eyelids. | Jian-Xia Cheng Lan Zuo Xin-Yu Huang Ji-Zhe Cui Shuai Wu Yuan-Yuan Du | 2015 | International Journal of Ophthalmology(English edition)2015,8,4: | 6 |
| 15 | Transcatheter Closure of Atrial Septal Defects Improves Cardiac Remodeling and Function of Adult Patients with Permanent Atrial Fibrillation显示文摘Background: Permanent atrial fibrillation (AF) is the most common form ofdysrhythmia associated with atrial septal defects (ASDs) in patients older than 40 years. However, little is known about cardiac remodeling after transcatheter closure in patients with permanent AF, This study was designed to compare cardiac events and remodeling effects after transcatheter closure in such patients. Methods: Clinical data of 289 adult patients older than 40 years who underwent ASD closure at our center were analyzed retrospectively, Of them, 63 patients with permanent AF were assigned to the case group, and the other 226 patients without permanent AF were assigned to the control group. Cardiac events and changes in left and right cardiac cavity dimensions before the procedure and 6 months after the procedure were compared between the two groups. Results: Patients in the case group were significantly older than those in the control group. The right ventricular (RV) volume and right atrial (RA) volume were decreased significantly in both the groups during a median follow-up period of 6 months after closure (P 〈 0.001 ). The left atrial dimensions, left ventricular end-systolic dimensions, left ventricular end-diastolic dimensions and left ventricular ejection fi'action showed no significant change before and after the procedure in both the groups. Changes of the RV volume and RA volume in the case group were significantly smaller than those in the control group (P = 0.005 and P 〈 0.001). The New York Heart Association cardiac function was improved in both the groups during the 6 months follow-up period. Conclusions: The transcatheter closure of ASD can improve the cardiac remodeling and cardiac function in patients with or without AF. | Liang Chen Yuan Bai Fei-Yu Wang Zhi-Gang Zhang Xing-Hua Shan Tao Chen Xian-Xian Zhao Yong-Wen Qin | 2015 | Chinese Medical Journal2015,,6: | 6 |
| 16 | Genetic analysis and preimplantation genetic diagnosis of Chinese Marfan syndrome patients显示文摘Marfan syndrome (MFS)(OMIM 154700) is a relatively common autosomal dominant genetic disease that causes skeletal, ocular, and cardiovascular defects and was first described by a French pediatrician in 1896 (Bitterman and Sponseller, 2017). Its prevalence rate is 1/3000—1/5000, and more than 25% of cases are sporadic (Chiu et al., 2014). Studies have shown that about 90% of MFS is caused by variants in the fibrillin-1 gene (FBN1, OMIM 134797). FBN1, located on chromosome 15q21.1, encodes a macromolecular glycoprotein-fibrin 1, which aggregates to form microfibers in the extracellular matrix and distributes in various human connective tissues, such as periosteum, vessel wall, and crystal suspensor ligament. Variants in FNB1 have been reported in 65 exons, but the relationship between genotype and phenotype remains rather unclear (Sakai et al., 2016). Studies have also shown that patients with MFS and similar diseases may have variants in other related genes such as members of the transforming growth factor beta receptor (TGFBR) family (Mizuguchi et al., 2004;Sakai et al., 2006;Bolar et al., 2012;De Cario et al., 2018). For better prevention and treatment of MFS as well as for suspected MFS patients, there is a strong need for efficient genetic testing for early diagnosis and differential diagnoses of patients with related phenotypes (Aubart et al., 2018). | Meng Qin Xiaohui Zhu Zhe Zhang Xuemin Li Zhiqiang Yan Yuqian Wang Shuo Guan Yihua He Wenxin Zhang Liying Yan Jie Qiao Xu Zhi | 2019 | Journal of Genetics and Genomics2019,46,6: | 6 |
| 17 | Demographic Characteristics and Environmental Risk Factors Exposure of Birth Defects in Pregnant Women: A Population-based Study显示文摘Worldwide, the incidence of birth defects in low-income countries is 6.42%, while in middle-income and high-income countries it is 5.57% and 4.72%, respectively;approximately 303, 000 newborns die from birth defects each year. In China, the incidence of birth defects is about 5.6%, and around 8.14 million people have congenital disabilities, accounting for 9.6% of total disabled people[1]. Birth defect remains a major clinical and public health challenge because of its high fatality rate and protracted and severe sequela. | LIN Hong LUO Mi Yang LUO Jia You ZENG Rong LI Ya Mei DU Qi Yun FANG Jun Qun | 2019 | Biomedical and Environmental Sciences2019,32,1: | 5 |
| 18 | Single-crystalline layered double hydroxides with rich defects and hierarchical structure by mild reduction for enhancing the oxygen evolution reaction显示文摘The oxygen evolution reaction(OER)with sluggish reaction kinetics and large overpotential is the critical reaction in water splitting that is promising for energy storage and conversion.Layered double hydroxides(LDHs),due to their unique lamellar structure and flexibility of chemical component,are very competing material candidates for OER.Herein,the morphology structure and the electronic structure of LDHs were simultaneously tuned to improve the OER catalytic activity by mild solvothermal reduction using ethylene glycol.The increased surface area,the introduction of oxygen vacancies and the construction of hierarchical structure greatly enhanced the electro-catalytic activity of LDHs for OER.The as-prepared LDHs showed a lower over-potential as low as 276 mV at a current density of 10 mA cm-2,and a small Tafel slope of 40.3 mV dec-1 accompanied with good stability.This work provides an efficient way to the design and optimization of advanced catalysts in the future. | Peng Zhou Junying He Yuqin Zou Yanyong Wang Chao Xie Ru Chen Shuangquan Zang Shuangyin Wang | 2019 | Science China Chemistry2019,62,10: | 5 |
| 19 | Supermicrosurgery in fingertip defects-split tibial flap of the second toe to reconstruct multiple fingertip defects: A case report显示文摘BACKGROUND Injuries to multiple fingertips pose a significant treatment dilemma.Numerous reconstructive options exist,all with the ultimate goal of restoring function and sensibility to the injured fingertips.CASE SUMMARY A 24-year-old male suffered injury to multiple fingertips of the right hand,resulting in exposed distal phalanges of the middle,ring,and small fingers.The amputated distal stumps were not possible for replantation.Free flap coverage was selected in order to achieve better functional outcome.The fingertip defects were covered by performing a right second toe split tibial flap using local anesthesia at the harvest site and brachial plexus nerve block for the right upper extremity.At 6-month follow-up,all three of the reconstructed fingertips had some preserved nail growth,Semmes-Weinstein Monofilaments testing was equal to the contralateral side and the Static Two-Point Discrimination were comparable to the contralateral side.CONCLUSION This report provides a novel reconstructive option for the management of multiple fingertip injuries and demonstrates the utility of supermicrosurgery in management of these injuries. | Ke-Lie Wang Zi-Qing Zhang Joseph A Buckwalter Yi Yang | 2019 | World Journal of Clinical Cases2019,7,17: | 5 |
| 20 | Mathematical methods for a class of mixed boundary-value problems of planar pentagonal quasicrystal and some solutions显示文摘The mathematical theory of elasticity for planar pentagonal quasicrystals is developed and some analytic solutions for a class of mixed boundary-value problems (corresponding to a Griffith crack) of the theory are offered.An alternate procedure and a direct integral approach are proposed.Some analytical solutions are constructed and the stress and displacement fields of a Griffith crack in the quasicrystals are determined.A basis for further studying the mechanical behavior of the material related to planar defects is provided. | 范天佑 郭玉翠 | 1997 | Science China Mathematics1997,40,9: | 5 |