Numerical Analysis on the Viscoelastic Characteristic of Cancellous Bone

A one dimensional creep and stress relaxation response of cancellous bone to instant loading is investigated based on the studies with scanning microscope, can cancellous bone be viewed as a cellar solid consisting of an interconnected skeleton filled with medulla. A two phase poroelastic model is introduced to describe the cancellous bone, in which the tissue(material) densities of the skeleton and medulla are assumed to be unchangeable while the corresponding apparent densities are changeable due to the change of volume fraction. The governing equations are derived for the case of a linear poroelastic solid skeleton saturated with an inviscid medulla. Under the loading, responses of the skeleton stress as well as the medullary pressure are obtained with Laplace transform technique. The computational result shows that the cancellous bone is provided with certain features similar to those appearing in viscoelastic solids, which means the responses do not only depend on time, but furthermore depend on previous loading history. It is worth paying attention to the result that the medullary pressure can be negative. This point is due to the recovery of the skeleton after unloading whereas the medulla is not squeezed out but absorbed into the pores by suction.     

Numerical Analysis of the Streaming Potential in Bone Tissue

Biphasic porous medium model,based on the mixture theory in continuum mechanics frame,is used to depict the distributing disciplinarian of sclerotin's stress field,distortion field and pore pressure when the bone tissue is subjected to various dynamic loadings.The coupling relationship among the distortion,fluid flow and the streaming potential is studied.The penalty finite element formulation for streaming potential is studied.The penalty finite element formulation for streaming potential distributing in bone tissue is obtained by using Galerkin weighted residual method for the biphasic porous medium model with corresponding initial and boundary conditions,in this modeling,the solid phase is assumed to be isotropic elastic medium,and the fluid phase is ideal fluid.The computational results show that because of the distortion of bone tissue the marrow's flow is raised,then the electriferous partical moves in the porous and the streaming potential appears.     

松辽平原高产农田土壤孔性对冻结的响应及机理研究

为了进一步深入系统研究松辽平原玉米带黑土耕作区高产田（平面型）土壤质量的管理与评价提供理论支持和借鉴,并且对黑土资源的利用与保护、为粮食的丰产增收在土壤结构理论方面具有重要的现实意义,并且对黑土资源的利用与保护、为粮食的丰产增收在土壤结构理论方面的探索,以松辽平原玉米带耕作区高产田（波浪型）与低产田（平面型）0~20 cm耕层土壤为研究对象采用田间季节性冻融过程与室内模拟冻融试验相结合的方法,研究松辽平原玉米带高产田土壤的结构性对冻结的响应,包括影响范围较深和程度,进一步阐明高产田土壤对冻结的响应机理。采用高产田与低产田对比的方法,在不同的冻结条件下,设置含水量接近5%,10%,15%,20%,25%;设置冻结频率0、2、4、6次进行室内模拟冻结实验。通过对容重、孔隙度、孔隙面积、Feret直径等指标的测定与分析,研究了不同冻结频率不同含水量,对高产田和低产田0~20 cm耕层的土壤孔隙特征的影响。结果显示：冻融循环能够显著增加松辽平原玉米带高产田与低产田0~20 cm耕层土壤孔隙的数目,高产田增加百分比为32.58%;低产田增加百分比为17.95%。显著降低了低产田0~20 cm土层范围内Feret直径和土壤的平均孔隙面积以,Feret直径由冻结前的2.31降低到冻结后的1.92,降低百分比为16.88%,低产田土壤的平均孔隙面积由冻结前的8.91降低到冻结后的4.65,降低百分率为47.81%(P<0.05)。除了土壤孔隙的成圆率外,冻融循环对高产田与低产田不同径级团聚体的孔隙数目、平均孔隙面积、平均Feret直径均有不同影响程度的差异(P<0.05)。高产田>5 mm团聚体平均孔隙面积由冻结前的37.08降低到冻结后的23.84,降低百分比为38.40%,变化差异显著(P<0.05),这是高产田与低产田相比特有的变化规律。而高产田其他粒级团聚体和低产田所有粒级团聚体的平均孔隙面积对冻结的响应不明显。高产田与低产田都有>5 mm团聚体的孔隙成圆率变化显著,高产田由冻结前的0.36降低到0.27,变化百分比为25%;低产田由冻结前的0.25增加到冻结后的0.34,变化百分比为36%,差异显著(P<0.05),这两者的变化规律截然相反,也体现高产田大粒径团聚体孔隙成圆率对冻结的响应规律有别于低产田的特殊性,以上研究结论对系统研究松辽平原玉米带黑土耕作区高产田（平面型）土壤质量的管理与评价提供理论支持有一定的意义。     

泡桐叶片总DNA甲基化水平测定方法

采用高效液相色仪,色谱柱为Thermo Hypersil C18BDS,以pH4.0的甲醇-戊烷磺酸钠10mmol/L-三乙胺(10-90-0.2,v/v)为流动相,流速0.5mL/min,柱温30℃,在Waters2487紫外-可见分光光度检测器273nm处,测定泡桐叶片DNA水解样中胞嘧啶和5-甲基胞嘧啶的含量,泡桐叶片DNA总甲基化水平用5-甲基胞嘧啶占DNA样品中总胞嘧啶碱基的百分数表示。     

Method to Determine the Intersection of Two Arbitrary Solid Polygon With Node Operation

The method to polygon' intersection is applied in computational geometry, computer graphics, GIS, evaluation of geo-hazards and civil engineering. Based on the node state of polygon, the authors propose the method and algorithm of polygon' intersection, the key to which is node operation. This method's concept is simple; and it is easy to computer program's implementation. It avoids to singular problem of Boolean Operation, and is easy to solve the problem of overlapping side and sides intersecting in node of polygon. For the arbitrary way of intersecting of arbitrary solid polygon, this method is accurate and general.     

鸡骨泥酱的研制

采用高压蒸煮后捣碎、热干燥后粉碎及冷冻后粉碎对鸡骨进行粉碎比较实验,确定鸡骨泥加工的最佳工艺。利用单因素实验、正交试验得出鸡骨泥酱的最佳配方。结果表明,鸡骨泥加工的最佳工艺为:冷冻后粉碎。鲜鸡骨泥酱中主要成分的最佳配比为:鸡骨泥15%,豆瓣酱25%,牛肉15%。     

苎麻花粉活力测定方法研究

摘要：为了快速准确鉴定苎麻雄性不育种质,本实验室在长沙地区对收集到的15份苎麻雄性不育种质进行了花粉活力鉴定方法的比较研究,结果表明：不同染色法鉴定不同苎麻种质花粉活力有较大的差异,I2-KI、TTC,醋酸洋红染色的效果不是很理想,采用培养基培养花粉萌发法则可以清楚的看到花粉管的伸长,因此对于苎麻来说花粉活力鉴定最好的方法是蔗糖培养基花粉萌发法。15份种质中,当培养基含有10﹪蔗糖浓度时共有11份雄性不育种质有萌发率,20﹪蔗糖浓度时共有12份雄性不育种质有萌发率,蔗糖浓度在30﹪时,所有品种的萌发率都是0。因此苎麻花粉培养所需蔗糖浓度为10%-20%。     

Experimental Analysis on the Physicochemical Characterization of Kiel Bone

Xenograft bone such as Kiel bone has long been used as a grafting materials,but the results of Kiel bone application in clinic are still controversial due to it's some drawbacks. To investigate the novel procession method of xenograft bone, the physicochemical characterization of Kiel bone and it's relationship with the clinical application are studied. Kiel bone is prepared from bovine femoral cortical bone according to Salama's methods.The bone specimens are characterized with a number of physicochemical methods such as FTIR spectroscopy, X-ray diffraction spectroscopy , differential scanning calorimetry (DSC) and uniaxial tension mechanical tests. The result indicates that Kiel bone is composed of hydroxyapatite and organic component ,and the deproteination of Kiel bone is imcomplete, but processes with hydrogen peroxide, the collagen is denatured which reduce the mechanical properties of materials. The immunogenicity of Kiel bone is weakened since the main antigenic protein is removed and collagen is denatured, which not only weakens the strength of materials but influences on it's physiological property, all make the osteoinductive properties of materials unideal. To overcome these problems, it is necessary to develop the novel procession method of the xenogeneic bone.     

畜骨加工及利用的研究进展

畜骨是指家畜和家禽的骨头,所含营养物质非常丰富,是一种理想的天然原料,具有十分独到的功能和作用,并已在许多领域得到广泛的应用。介绍了畜骨的营养价值,简述了骨产品的开发现状,并预测了骨产品的开发前景。     

分光光度法测定土壤中阳离子交换量的优化改进

为了提高土壤中阳离子交换量检测的准确度和效率,针对国标方法的不足,在原理不变的条件下对空白、浸提、离心等实验步骤进行优化。通过对比实验、平行性实验以及条件实验,分析本方法的准确度、精密性和稳定性。结果表明:通过实验测试,对空白试验进行重新定义,将国标方法中的浸提时间由60 min优化为30 min,离心时间由10 min优化为20 min,大大缩减了一个样品的测试时间。在该条件参数下,对4种不同类型的国家土壤有证标准物质进行测试,得出阳离子交换量测定值与土壤标准物质标准值吻合。本方法效率高,准确度和精密性良好,操作简单,适用于大批量土壤中阳离子交换量的测定。     

羊驼前肢骨的解剖学研究

用大体解剖学方法研究了羊驼前肢骨的解剖结构,与文献报道双峰驼的前肢进行对照,同时与马、牛、羊、猪等的前肢骨进行了比较。结果发现：羊驼前肢骨由肩胛骨、肱骨、前臂骨(包括桡骨和尺骨)与前脚骨(包括腕骨、掌骨、指骨和籽骨)组成;前肢各骨的组成、形态特征与骆驼相似。羊驼肩胛骨与牛羊肩胛骨相似,肱骨与马肱骨相近,前臂骨与马相近,桡骨与尺骨大部愈合,腕骨与马腕骨相近。结论：羊驼前肢骨的解剖结构与骆驼相似,形制略小;与马、牛、羊前肢骨有不同程度的相似,与猪前肢骨差别较大。     

酸奶发酵剂增殖条件的初步研究

为优化乳酸菌增殖培养基配方。通过正交筛选试验研究了在MRS基础培养基中添加不同营养物质对乳酸菌生长的影响。结果表明：往液体MRS基础培养基中添加1%的胡萝卜汁、1.5%的麦芽汁和0.5%的大豆汁配成增殖培养基,增殖培养10 h后,每隔2 h添加1%的KH2PO4-Na2HPO4缓冲剂(pH 6.86),培养16 h后,乳酸菌活菌数为3.94×109 cfu/mL,比优化前提高了11.6%。为进一步开展营养强化因子筛选打下了基础。     

A Study on the Test Method for Post-tensioned Prestressed Concrete Frame

A creative test method for post-tensioned prestressed frame is presented in this paper. In the test, the stationary supports at the column base are simulated and the forces at the column base can be tested while the two column bases are not connected with concrete beam. The prestressed secondary moment and the weight-produced moment are established by adjusting the support device at the column base. In this paper, the necessary conditions of the method and the basic process are recommended. It is proved theoretically that the prestressed concrete frame built by this method is equivalent to that used in practice.     

Using BP Neural Network to Determine the Membership Function of the Input of Fuzzy Control System

While design the fuzzy controller, it is very important to determine the membership function of fuzzy variables.The data can be broadly classified as fuzzy sets by using the classification property of the BP neural network. The author selects a BP neural network with one hide layer and uses S function to the input and hide layer, and linear function to the output layer.Advanced BP algorithm isused to train the BP neural network in the environment of MATLAB . The nearer to the target values is the better the last output is.With the trained BP network , the membership values of the inputs can be got ten. This method has high rate and low error.     

Experimental Analysis on Mechanical Characteristic Effect of Mortar Specimen Sbujected to Hydrochloric Damage Under the Triaxial Stress

Triaxial compression tests of mortar specimens under various hydrochemical environments were carried out. The effects of the pH、concentration and composition of chemical solution on the corrosiveness and micro/meso structure of the mortar specimens were evaluated. The hydrochemical corrosion mechanisms of the mortar specimens were explored and the results revealed further influence of various hydrochemical actions on physical and mechanical parameters of the mortar specimens. A new damage parameter was proposed based on the mortar secondary porosity caused by chemical corrosion, which can quantify the evolution process of the physical & mechanical parameters of the mortar specimens during its hydrochemical damage.     

Double-Face Dynamic Balance Method of Spot Rotator without Removing the Test Weights

Site dynamic balance is a important element in installation and maintenance of heavy rotary mechanism. It's hard to discharge testing weights, and the remanent weights will effect the result of balance test. The paper presents a kind of dynamic balance algorithm which need not to discharge the test weights, basing on influence coefficient. The principle of the algorithm is to balance the sum of original unbalance weights and testing weights by the result balance weights. In the algorithm , the influence coefficient of last time can be used optionally for the same rotor. Then developing a dynamic balance system building on it. The site experimental results indicates that this algorithm has a high balance precision, predigests the steps and reduces the operation time.     

A Study on the Test Method of Post-tensioned Prestressed Concrete Continuous Beam

A test method of post-tensioned prestressed concrete continuous beam is presented in this paper.In the test,the prestressed secondary moment is established by adjusting middle support height.The prestressed concrete continuous beam built by the method is equivalent to the beam in practice.