Büeckner Rice weight function method was used to analyse mixed mode fracture of center cracked circular disk subjected to uniaxial compression. Based on Wu Carlsson procedure semi analytical modes Ⅰ and Ⅱ weigh...Büeckner Rice weight function method was used to analyse mixed mode fracture of center cracked circular disk subjected to uniaxial compression. Based on Wu Carlsson procedure semi analytical modes Ⅰ and Ⅱ weight functions were derived from corresponding reference displacement fields and stress intensity factors calculated by finite element method. Normalized mode Ⅰ and mode Ⅱ stress intensity factors, f Ⅰ, f Ⅱ , were derived from the obtained semi analytical weight functions. The results were then fitted into polynomials, the precision is within 0.5%. It is interesting to note that when the inclined angle θ of a crack is less than 15°, the f Ⅰvalues are positive. when θ =15°, the f Ⅰ values are positive for the crack length a varying from 0.1 to 0.7, but when a =0.8, the f Ⅰ takes the negative value -0.51. When θ >15°, all the f Ⅰ values become negative, which denotes that the compression shear mode is achieved at crack tips. These results are very useful in the investigation of mixed mode fracture of brittle materials.展开更多
In this paper we consider the class of Bazilevic functions for bi-univalent functions. For this we will estimate the coefficients a2 and a3 using Caratheodory func- tions and the method of differential subordination.
A new specimen geometry-the double edge-cracked Brazilian disk and a relevant fracture analysis byweight function method are proposed for the investigation of rock fracture caused by compression-shear loading. Notonly...A new specimen geometry-the double edge-cracked Brazilian disk and a relevant fracture analysis byweight function method are proposed for the investigation of rock fracture caused by compression-shear loading. Notonly can the mixed mode fracture with any ratio of KⅠ/KⅡ be achieved, but also the pure mode Ⅱ crack extensioncan be obtained. The combined mode fracture analysis for this geometry shows that diametral compression in the far-field can induce a compression-shear stress state in the singular stress field ahead of crack tips. Experimental investi-gations conducted on marble specimens show that the pure mode Ⅱ crack extension can be obtained when the dimen-sionless crack length a＞0.7 and the inclined crack angle 5°≤ψ≤40°. Normalized mode Ⅰ and mode Ⅱ stress inten-sity factors decrease from -0.45 and 2.47 at ψ=5° to -1.65 and 1.52 at ψ=40°, respectively. The strains at threepoints of specimen are also measured in order to investigate the influence of stress singularity on initial crack exten-sion. The results show that the principal orientations of strain at three points are very stable in the loading process.The derived formulae are quite explicit, and the specimen geometry is easy to fabricate and convenient to achieve thepure mode Ⅱ crack extension. Therefore, it can hopefully be used to obtain mode Ⅱ fracture toughness of rock.展开更多
In any completely close complex field C, generalized transcendental meromorphic functions may have some new properties. It is well known that a meromorphic function of characteristic zero is a rational function. This ...In any completely close complex field C, generalized transcendental meromorphic functions may have some new properties. It is well known that a meromorphic function of characteristic zero is a rational function. This paper introduced some mathematical properties of the transcendental meromorphic function, which is generalized to the meromorphic function by multiplying and differentiating the generalized meromorphic function. The analysis shows that the difference between any non-zero constant and the derivative of the general meromorphic function has an infinite zero. In addition, for any natural number n, there are no practically exceptional values for the multiplication of the general meromorphic function and its derivative to the power of n.展开更多
Making use of the fractional differential operator, we impose and study a new class of analytic functions in the unit disk （type fractional differential equation）. The main object of this paper is to investigate inc...Making use of the fractional differential operator, we impose and study a new class of analytic functions in the unit disk （type fractional differential equation）. The main object of this paper is to investigate inclusion relations, coefficient bound for this class. Moreover, we discuss some geometric properties of the fractional differential operator.展开更多
In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theor...In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theorems of meromorphic functions.展开更多
A dynamic weight function method is presented for dynamic stress intensity factors of circular disk with a radial edge crack under external impulsive pressure. The dynamic stresses in a circular disk are solved under ...A dynamic weight function method is presented for dynamic stress intensity factors of circular disk with a radial edge crack under external impulsive pressure. The dynamic stresses in a circular disk are solved under abrupt step external pressure using the eigenfunction method. The solution consists of a quasi-static solution satisfying inhomogeneous boundary conditions and a dynamic solution satisfying homogeneous boundary conditions. By making use of Fourier- Bessel series expansion, the history and distribution of dynamic stresses in the circular disk are derived. Furthermore, the equation for stress intensity factors under uniform pressure is used as the reference case, the weight function equation for the circular disk containing an edge crack is worked out, and the dynamic stress intensity factor equation for the circular disk containing a radial edge crack can be given. The results indicate that the stress intensity factors under sudden step external pressure vary periodically with time, and the ratio of the maximum value of dynamic stress intensity factors to the corresponding static value is about 2.0.展开更多
目的分析接纳与承诺护理与腰背功能锻炼在骶管阻滞镇痛术治疗腰椎间盘突出(lumbar intervertebral disk protrusion,LIDP)引起坐骨神经痛患者中的应用价值。方法选取2022年8月至2023年8月绵阳市中心医院收治的100例行骶管阻滞镇痛术治疗...目的分析接纳与承诺护理与腰背功能锻炼在骶管阻滞镇痛术治疗腰椎间盘突出(lumbar intervertebral disk protrusion,LIDP)引起坐骨神经痛患者中的应用价值。方法选取2022年8月至2023年8月绵阳市中心医院收治的100例行骶管阻滞镇痛术治疗的LIDP坐骨神经痛患者作为研究对象,按照随机数字表法分为观察组与对照组,每组50例。观察组采取接纳与承诺护理与腰背功能锻炼,对照组采取腰背功能锻炼,比较两组护理满意度、日本骨科协会下腰痛评估量表(Japanese Orthopaedic Association low back pain scale,JOA)评分、视觉模拟评分法(visual analogue scale,VAS)、接纳与行动问卷第二版(acceptance and action questionnaire-second edition,AAQ-Ⅱ)、焦虑自评量表(self-rating anxiety scale,SAS)评分、抑郁自评量表(self-rating depression scale,SDS)。结果观察组护理总满意度为96.00%,高于对照组的78.00%,差异有统计学意义(P<0.05);护理后,两组JOA评分均高于护理前,VAS、AAQ-Ⅱ评分均低于护理前,且观察组JOA评分高于对照组,VAS、AAQ-Ⅱ评分均低于对照组,差异有统计学意义(P<0.05);护理后,两组SAS、SDS评分均低于护理前,且观察组低于对照组,差异有统计学意义(P<0.05)。结论对LIDP骶管阻滞镇痛术后引起的坐骨神经痛患者采取接纳与承诺护理联合腰背功能锻炼可增强护理效果,改善腰背功能,较单独腰背功能锻炼更能缓解患者负面情绪,减轻术后疼痛,提高自我接纳能力。展开更多
目的：应用MRI定量分析功能矫治器在颞下颌关节（temporomandibular joint,TMJ） 可复性盘移位（disc displacement with reduction,DDWR）治疗中对关节间隙的影响,初步探讨间隙改变的实质及意义。方法：选择42例应用功能矫治器复位单侧...目的：应用MRI定量分析功能矫治器在颞下颌关节（temporomandibular joint,TMJ） 可复性盘移位（disc displacement with reduction,DDWR）治疗中对关节间隙的影响,初步探讨间隙改变的实质及意义。方法：选择42例应用功能矫治器复位单侧DDWR 的Ⅱ类错畸形,以正常侧作为对照,在斜矢状MRI图像上,计算治疗前、后关节间隙指数（joint space index,JSI）的改变。定量测量功能矫治器治疗前（T1）、戴用功能矫治器初期（T2）和治疗结束（T3）后关节间隙的变化。采用SPSS16.0软件包对数据进行t检验。结果：T2与T1的平均间隔时间为3周（2周~1个月）,T3与T1的平均间隔时间为9个月（6~14个月）。年龄小者治疗周期短。对DDWR患者,治疗前患侧JSI显著大于对照侧;治疗结束,患侧JSI与对照侧相似。表明在T1阶段患侧关节前间隙明显大于后间隙。在T2阶段,患侧前间隙减小,后上间隙明显增加。与T2比较,T3阶段关节前间隙变大,后上间隙明显变小。与T1相比,患侧治疗后前间隙变小,无显著差异;后上间隙变大,有显著差异。结论：DDWR患者通过矫形治疗前移下颌骨,复位关节盘,关节间隙分布更趋均匀。矫形治疗主要改变后上间隙,对前间隙影响较小。展开更多
文摘Büeckner Rice weight function method was used to analyse mixed mode fracture of center cracked circular disk subjected to uniaxial compression. Based on Wu Carlsson procedure semi analytical modes Ⅰ and Ⅱ weight functions were derived from corresponding reference displacement fields and stress intensity factors calculated by finite element method. Normalized mode Ⅰ and mode Ⅱ stress intensity factors, f Ⅰ, f Ⅱ , were derived from the obtained semi analytical weight functions. The results were then fitted into polynomials, the precision is within 0.5%. It is interesting to note that when the inclined angle θ of a crack is less than 15°, the f Ⅰvalues are positive. when θ =15°, the f Ⅰ values are positive for the crack length a varying from 0.1 to 0.7, but when a =0.8, the f Ⅰ takes the negative value -0.51. When θ >15°, all the f Ⅰ values become negative, which denotes that the compression shear mode is achieved at crack tips. These results are very useful in the investigation of mixed mode fracture of brittle materials.
文摘In this paper we consider the class of Bazilevic functions for bi-univalent functions. For this we will estimate the coefficients a2 and a3 using Caratheodory func- tions and the method of differential subordination.
基金Project (50274074) supported by the National Natural Science Foundation of China
文摘A new specimen geometry-the double edge-cracked Brazilian disk and a relevant fracture analysis byweight function method are proposed for the investigation of rock fracture caused by compression-shear loading. Notonly can the mixed mode fracture with any ratio of KⅠ/KⅡ be achieved, but also the pure mode Ⅱ crack extensioncan be obtained. The combined mode fracture analysis for this geometry shows that diametral compression in the far-field can induce a compression-shear stress state in the singular stress field ahead of crack tips. Experimental investi-gations conducted on marble specimens show that the pure mode Ⅱ crack extension can be obtained when the dimen-sionless crack length a＞0.7 and the inclined crack angle 5°≤ψ≤40°. Normalized mode Ⅰ and mode Ⅱ stress inten-sity factors decrease from -0.45 and 2.47 at ψ=5° to -1.65 and 1.52 at ψ=40°, respectively. The strains at threepoints of specimen are also measured in order to investigate the influence of stress singularity on initial crack exten-sion. The results show that the principal orientations of strain at three points are very stable in the loading process.The derived formulae are quite explicit, and the specimen geometry is easy to fabricate and convenient to achieve thepure mode Ⅱ crack extension. Therefore, it can hopefully be used to obtain mode Ⅱ fracture toughness of rock.
文摘In any completely close complex field C, generalized transcendental meromorphic functions may have some new properties. It is well known that a meromorphic function of characteristic zero is a rational function. This paper introduced some mathematical properties of the transcendental meromorphic function, which is generalized to the meromorphic function by multiplying and differentiating the generalized meromorphic function. The analysis shows that the difference between any non-zero constant and the derivative of the general meromorphic function has an infinite zero. In addition, for any natural number n, there are no practically exceptional values for the multiplication of the general meromorphic function and its derivative to the power of n.
文摘Making use of the fractional differential operator, we impose and study a new class of analytic functions in the unit disk （type fractional differential equation）. The main object of this paper is to investigate inclusion relations, coefficient bound for this class. Moreover, we discuss some geometric properties of the fractional differential operator.
基金Supported by the NNSF of China(10471048)Supported by the Doctoral Foundation of the Education Committee of China(20050574002)
文摘In this paper, discussed are the problems about uniqueness of algebroidal functions in the unit disc with share-values in a sector domain instead of the whole disk. Results are obtained extending some uniqueness theorems of meromorphic functions.
文摘A dynamic weight function method is presented for dynamic stress intensity factors of circular disk with a radial edge crack under external impulsive pressure. The dynamic stresses in a circular disk are solved under abrupt step external pressure using the eigenfunction method. The solution consists of a quasi-static solution satisfying inhomogeneous boundary conditions and a dynamic solution satisfying homogeneous boundary conditions. By making use of Fourier- Bessel series expansion, the history and distribution of dynamic stresses in the circular disk are derived. Furthermore, the equation for stress intensity factors under uniform pressure is used as the reference case, the weight function equation for the circular disk containing an edge crack is worked out, and the dynamic stress intensity factor equation for the circular disk containing a radial edge crack can be given. The results indicate that the stress intensity factors under sudden step external pressure vary periodically with time, and the ratio of the maximum value of dynamic stress intensity factors to the corresponding static value is about 2.0.
文摘目的分析接纳与承诺护理与腰背功能锻炼在骶管阻滞镇痛术治疗腰椎间盘突出(lumbar intervertebral disk protrusion,LIDP)引起坐骨神经痛患者中的应用价值。方法选取2022年8月至2023年8月绵阳市中心医院收治的100例行骶管阻滞镇痛术治疗的LIDP坐骨神经痛患者作为研究对象,按照随机数字表法分为观察组与对照组,每组50例。观察组采取接纳与承诺护理与腰背功能锻炼,对照组采取腰背功能锻炼,比较两组护理满意度、日本骨科协会下腰痛评估量表(Japanese Orthopaedic Association low back pain scale,JOA)评分、视觉模拟评分法(visual analogue scale,VAS)、接纳与行动问卷第二版(acceptance and action questionnaire-second edition,AAQ-Ⅱ)、焦虑自评量表(self-rating anxiety scale,SAS)评分、抑郁自评量表(self-rating depression scale,SDS)。结果观察组护理总满意度为96.00%,高于对照组的78.00%,差异有统计学意义(P<0.05);护理后,两组JOA评分均高于护理前,VAS、AAQ-Ⅱ评分均低于护理前,且观察组JOA评分高于对照组,VAS、AAQ-Ⅱ评分均低于对照组,差异有统计学意义(P<0.05);护理后,两组SAS、SDS评分均低于护理前,且观察组低于对照组,差异有统计学意义(P<0.05)。结论对LIDP骶管阻滞镇痛术后引起的坐骨神经痛患者采取接纳与承诺护理联合腰背功能锻炼可增强护理效果,改善腰背功能,较单独腰背功能锻炼更能缓解患者负面情绪,减轻术后疼痛,提高自我接纳能力。
文摘目的：应用MRI定量分析功能矫治器在颞下颌关节（temporomandibular joint,TMJ） 可复性盘移位（disc displacement with reduction,DDWR）治疗中对关节间隙的影响,初步探讨间隙改变的实质及意义。方法：选择42例应用功能矫治器复位单侧DDWR 的Ⅱ类错畸形,以正常侧作为对照,在斜矢状MRI图像上,计算治疗前、后关节间隙指数（joint space index,JSI）的改变。定量测量功能矫治器治疗前（T1）、戴用功能矫治器初期（T2）和治疗结束（T3）后关节间隙的变化。采用SPSS16.0软件包对数据进行t检验。结果：T2与T1的平均间隔时间为3周（2周~1个月）,T3与T1的平均间隔时间为9个月（6~14个月）。年龄小者治疗周期短。对DDWR患者,治疗前患侧JSI显著大于对照侧;治疗结束,患侧JSI与对照侧相似。表明在T1阶段患侧关节前间隙明显大于后间隙。在T2阶段,患侧前间隙减小,后上间隙明显增加。与T2比较,T3阶段关节前间隙变大,后上间隙明显变小。与T1相比,患侧治疗后前间隙变小,无显著差异;后上间隙变大,有显著差异。结论：DDWR患者通过矫形治疗前移下颌骨,复位关节盘,关节间隙分布更趋均匀。矫形治疗主要改变后上间隙,对前间隙影响较小。
