前齿

The wheels can be solid or comprised of a fixed stack of toothed disks, concentrically aligned, the teeth of each succeeding disk angularly offset in a common direction from the teeth of the next preceding disk to create a wheel having a plurality of uniform, elongated composite teeth around the circumference of the stack, the teeth being angled from the wheel's axis.

该轮可以是实心的或者由固定的堆叠的带齿盘片构成，它们共心地对齐，每个在后盘片的齿都与前一盘片的齿在角度上朝同一方向错开，以形成具有多个均匀、伸长的复合齿的轮，这些复合齿围绕堆叠盘片的边缘，并与轮的转轴成角度。

Other diagnostic features include the presence of a crest along the anterodorsal midlines of the premaxillae,the edentulous maxilla,the presence of a groove-like trough along with the anterolateral margin of the maxilla on the ventral surface,the presence of six conical premaxillary teeth,and no more than six conical dentary teeth which are restricted to the anterior portion of the dentary.

其他主要特征有：前颌骨沿前背中央有一隆嵴；上颌仅前颌骨有6枚圆锥形齿，无上颌骨齿；上颌骨沿前腹侧缘有一沟槽；下颌齿骨齿都集中在前端且至多不超过6枚。依据上述这些特征很易把短吻贫齿龙与其他已知海龙相区别。短吻贫齿龙头骨顶面松果孔大且很前位，头骨腭面的锄骨和翼骨均无齿，它的颈较长(至少可以辨认出13个颈椎)。

The diagnostic features for the species include deep excavation on the posteroventral margin of the premaxilla, a diastema between the premaxillary and maxillary teeth, a a number of many pits and ridges on the anterolateral surface of the antorbital fossa, the posterolateral process of the parietal being long and sharply posteriorly directed, the column ar -like margin of the pterygoid process of the quadrate, the bifurcated posterior margin of the dentary, a distinctive groove posterior to the anterior carina on the medial surface of the premaxillary tooth crowns, absence of ventrolateral processes on intercentrum of t he atlas, T-shaped centrum of the first caudal in ventral view, transverse process on anterior caudals with rounded , and strongly anteroposteriorly expanded distal end, presence of two fossae separated by an oblique ridge on the lateral side of the anterior chevrons near the articular end, and pubis strongly curved psoteriorly.

这一属种的主要鉴定特征包括：前上颌骨后腹缘有一深凹、前上颌齿和上颌齿之间有一齿缺、眶前窝外表面前部有许多坑窝和脊、顶骨侧后突伸向后方、方骨的翼骨支边缘柱状、靠近前上颌齿齿冠舌面前缘有槽、环椎间椎体外腹突缺失、第一尾椎椎体腹视 T 形、前部尾椎横突远端前后向强烈扩展呈圆形、前部脉弧近端外侧面有两个被一斜脊分离的窝以及耻骨强烈向后弯曲。通过分析千禧中国鸟龙的96个骨骼学特征，发现其中21个特征支持奔龙类与鸟类的亲缘关系最近，9个特征支持奔龙类与伤齿龙类亲缘关系最近，25个特征支持奔龙类、伤齿龙类和鸟类亲缘关系较为接近。

Methods: Injured patients of cervical spine was cayyied on X-ray inspection.,then according to the result of ADI and LADS ,next to CT or MRI inspection ,and that was to guide clinical diagonosis and treatment.To observe atlanto-dental interval (anterior arch of atlas posterior border to odontoid process anterior border) and odontoid process caster(included angle between axis of ordinate of odontoid process and axis of ordinate of odontoid vertebra) on the X-ray lateral projection.

对有颈部外伤史的病人常规行X线检查，然后根据寰齿间距和齿突侧块间隙的结果，行下一步CT检查或者MRI检查，指导临床治疗方法的选择。X线侧位片观察寰齿前间隙(为寰椎前弓后缘与齿突前缘距离)，齿状突后倾角(齿突纵轴与枢椎体纵轴的夹角)；开口正位片上测定齿突侧块间隙。

A compensation approach was proposed to counteract the effect of the cogging force by using a feedforward compensator.

采用线性插值计算方法建立齿槽推力波动的前馈补偿控制模型，并给出齿槽推力波动的标定结果，对比齿槽推力前馈补偿前后的位置跟踪误差。

Based on the relevant movement between hard shaper cutter and grinding wheel, the movements of grinding wheel are studied. The shaping grinding point and the shaping grinding edge are made up with. In order to easily compare when shaping errors and cutting edge"s angles are the most excellent, uniform expressions for convex curved rake face of hard shaping cutter and spatial cutting edge curve are separately developed. The distributions of new profiling cutter"s shaping errors and cutting edges angles are analyzed. The relevant grinding wheel and cam are designed. Due to this paper, a new profiling hard shaping cutter has been manufactured successfully. At last experiments are made to test the performance of hard shaping cutter and all kinds of precision of hard gear.

本文直接从插齿刀与砂轮之间的相对运动关系出发，单独研究砂轮的运动，提出砂轮成形磨削点和砂轮成形磨削刃的概念；分别建立圆柱砂轮和圆锥砂轮磨削后硬齿面插齿刀的波形前刀面方程及空间切削刃方程；为便于比较何种情况下插齿刀的构形误差和切削角度能同时达到最优，分别对磨削五种不同硬齿面插齿刀所用的砂轮进行了廓形设计，并分析了插齿刀的构形误差和侧切削刃切削角度的分布规律；为插齿刀波形前刀面的磨削加工设计了相应的凸轮，用所设计的凸轮和近似的砂轮成功地制造出新构形法硬齿面插齿刀；最后进行插齿加工试验，检验新构形法硬齿面插齿刀的抗崩刃能力、耐磨性及被加工硬齿面齿轮的各项精度。

According to the design principle and basic characteristic of the gear shaper cutter , its rake angle and top face are adjusted, and the cutter blade projection on the datum plane is modified appropriately to finish the profile modification of K-teeth in gear shaper cutting process.

针对插齿加工过程中K形齿的修形问题，根据插齿刀的设计原理和基本特点，提出了以改变插齿刀的前角和前刀面形状来改变切削刃在其基面上的投影，达到在插齿加工中对齿形的修形的目的。

Based on the research on the meshing between hobs and gears the optimum proflie design method of the pre-gringding hob is given,and the optimum profile of the pre-gringding hob used to cut the quasi high-speed locomotive traction gear has been designed according to the application of the traction and their proceeding technolog.

通过对刀齿啮合关系的研究，提出了磨前滚刀齿形优化设计方法，针对准高速机车牵引齿轮的应用和加工工艺特点，对准高速机车牵引齿轮磨前滚刀齿形进行了优化设计。

From the simulations, we can see the distributions and transmission of strain and stress in model under different loadings, and the results explained the fractures very well. 4. Similarly, a axis FEM model was constructed to simulate the axis fracture, emphasized on the odontoid process. Three kind of odontoid process fracture were analysed on this model, which occurred respectively on the tip, the middle and the fundus. The results gave the best angle to fracture the odontoid process of the axis.

四、建立了枢椎的三维有限元模型，对枢椎齿状突骨折机理进行了理论上的研究，重点针对临床上齿突骨折的三种分类：1、齿突尖骨折；2、齿突腰部骨折；3、齿突基底部骨折，赋予齿状突在矢状面沿各种角度下受力条件，模拟衰椎前弓、襄椎横韧带以及CZ－3棘间韧带对枢椎造成的暴力破坏，确定了最可能引起齿状突暴力骨折的受力角度。

Similarly, a axis FEM model was constructed to simulate the axis fracture, emphasized on the odontoid process. Three kind of odontoid process fracture were analysed on this model, which occurred respectively on the tip, the middle and the fundus. The results gave the best angle to fracture the odontoid process of the axis.

四、建立了枢椎的三维有限元模型，对枢椎齿状突骨折机理进行了理论上的研究，重点针对临床上齿突骨折的三种分类：1、齿突尖骨折：2、齿突腰部骨折：3、齿突基底部骨折，赋予齿状突在矢状面沿各种角度下受力条件，模拟寰椎前弓、寰椎横韧带以及C2-3棘间韧带对枢椎造成的暴力破坏，确定了最可能引起齿状突暴力骨折的受力角度。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。