双管的

In this study we used a more accurate Kolmogorov-Crespi potential to describe the corrugation of the nanotubes.

第三，我们通过使用更加准确的Kolmogorov-Crespi势函数描述双壁碳纳米管的层间相互作用，研究了双壁碳纳米管的滑动和转动磨擦。

Type 1-1-1,2-2-1 and 2-2-2 account for 91 4%;The appearing rats of distal lingual canal are 24 7%;The appearing rats of double root canal orifices are as follows:Medial canal 78 3%,distalcanalIt don't ...

远中舌根的发生率为 2 4 。7%；双根管口率：近中根为 78.3%，远中根(不含远中舌根，下同)为 19.3%；双根管率：近中根为 88.3%，远中根为 2 3.3%；双根尖孔率：近中根为 5 6 。7%，远中根 8.3%，单根管口而有双根尖孔者，近中为 6 。7%，远中为 3.3%。结论下颌第一恒磨牙根管的类型复杂，充分了解其根管解剖对提高根管预备效果、减少根管遗漏有重要意义。

The raw data was processed by using axial, coronal and double oblique multi-planar reformation; Images obtained were graded in terms of quality with a 5-point scale(5=excellent, 4=good, 3=fair, 2=poor, and 1=nondiagnostic). In grading image quality at axial MPR, The radiologic specialists focused on the subarcuate fossa, tendon of tensor tympani, facial recess, vestibular aqueduct and pyramidal eminence, In grading image quality at coronal MPR, attention was given to the scute, crista transversa, fenestra cochleae, lateral malleal ligament and snake eyes signature of cranial nerve, In the grading of the image quality at double oblique MPR, the radiologic specialists concentrated on the malleus, incus, stirrup bone, upper bony semicircular and aquaeductus fallopii, and then to implement statistical analysis. In order to choose the minimum tube current values and the maximum pitch that can satisfy the diagnosis request, image quality of axial, coronal and double oblique reformation images was compared with different tube current groups. 15 ears of volunteers were used to test the validity with the scanning parameter. Subsequently noise, MTF and dose length product were measured by phantoms in different tube current and pitch, the parameters obtained were compared and taken into statistics analysis.

扫描模式使用临床常用的颞骨螺旋扫描方式：管电压120 kV，准直宽度20×0.6 mm，视野200 mm，重建矩阵512×512，旋转时间1 s/r，重建层厚0.6 mm，重建间隔0.3 mm，分别改变管电流(380、300、200、160、120和80 mA)和螺距(0.8、1.0和1.2)进行扫描和重建，然后对颞骨进行横断面、冠状面和双斜面多平面重组，于重组后的横断层面图像上选取弓形下窝、鼓膜张肌腱、面神经隐窝、前庭导水管和锥隆起5个解剖结构，冠状面重组图像上选取盾板、横嵴、蜗窗、面神经的蛇眼征和锤骨外侧韧带5个解剖结构，双斜面重组图像上选取锤骨、砧骨、镫骨、上骨半规管和面神经管5个解剖结构，在双盲的情况下由放射学专家分别对各管电流和螺距下扫描的重组图像进行评分，随后进行统计学处理，从中筛选出满足诊断要求的最低管电流值和最大的螺距，分别采用患者25例(15耳)用该管电流值和螺距验证其可行性；然后利用模体分别测试各管电流和螺距下的图像的空间分辨率、噪声及其剂量长度积，并对测试所得参数数值进行比较和统计学处理。

This paper analyzes the effect of gravity head on different forms of low temperature hot water heating system common riser, by using Kirchhoff s law analyzes downfeed and upfeed two-pipe system s hydraulic balance status.

本文分析了重力作用压头对低温热水计量采暖系统共用立管形式的影响，通过运用基尔霍夫定律分析了下分异程式双管系统和下分同程式双管系统的水力平衡状况，得出了下分异程式双管系统更适用于低温热水采暖系统的结论，并确定了立管经济比摩阻的范围和下分异程式双管可以负担的楼层数。

This is tantamount to a "dual" structure. But

这无形中形成了一种"双管"的格局。

The thickness of the inner wall was (0.68±0.46) mm. It showed no significant difference between the two sides of the optic canal in diameters(P＞0.05).(2)The optic canal, the superior orbital fissure and the inferior orbital fissure were respectively shown as track, crack and gorge type in CT axial pictures, while in the coronal pictures, they were respectively shown as butterfly eyes, horizontal fissure and vertical fissure type.(3)The relationship of the posterior ethmoid sinus and the optic canal was: anterocanal(42.00%), semicanal(27.5%), whole-canal(18.75%),sella turcica(9.75%) and circumcanal(2.00%).(4)The relationship of the position of the sphenoidal sinus and the optic canal was:Ι degree sphenoidal sinus(20%),Π degree (63%) and Ш degree (17%).

双侧间差异均无显著性（P＞0.05）；②视神经管、眶上裂、眶下裂在CT轴位像上分别表现为&轨道状&、&裂隙状&和&狭谷状&，在冠状位像上分别表现为&蝶眼状&、水平状裂隙和垂直状裂隙；③后组筛窦与视神经管的位置关系为：管前型占42.00%、半管型占27.50%、全管型占18.75%、蝶鞍型占9.75%和管周型占2.00%；④蝶窦气化度与视神经管的位置关系为：Ι度蝶窦占20%、Π度蝶窦占63%和Ш度蝶窦占17%；⑤视神经管内侧壁骨质缺损发生率为25.5%，缺损平均长度为(5.07±2.52)mm。

Common transparent quartz tube SiO2 more than 99.9% purity, geometry, chemical stability, thermal stability, resistance to thermal denaturation and anti-crystallization properties of the fine, optical transmittance above 93%; from hydroxyl in hydroxyl tube below 10ppm, after vacuum from hydroxyl, hydroxy-up to 5ppm below apply to high-pressure mercury lamp, sodium lamp, metal halide lamp, such as low-hydroxy products; white pipe, used mainly for heating tube, heating tube, far infrared control the manufacture, milky quartz pearl quartz tube possession of new technology, the management side as if the surface of pearls, all aspects of performance than ordinary white tube better; filter tube to filter out ultraviolet UV band in the harmful wavelengths of 190-320nm ultraviolet light source applied to environmental protection manufacturing; no ozone UV filter tube and pipe the contrary, through the ultraviolet wavelength around 253.7nm, there is no ozone UV lamp main material, widely used in medical equipment, water treatment, food hygiene, such as sterilization; quartz casing diameter 8-120mm in between, has a single opening, double opening round, flat-top shape and widen the mouth of necking, flanging, sanding and other processing, high temperature resistance, corrosion resistance, good light transmission and moisture-proof, explosion-proof characteristics such as widely used in aquarium thermostat, disinfection equipment, heating pipes, water treatment, metal halide lamp, such as product manufacturing and environmental protection, health, chemical and other fields; quartz Clamshell specifications 8-180mm, the shape according to the customer requirements, the bubble shell can take capillary has to carry out the exhaust, high temperature, light transmission is good, mainly for JC, JD, H1-H7, the stage lights and high-pressure mercury lamp, sodium lamp, metal halide lamp, such as product manufacturing; quartz water jacket mainly used in printing and packaging processing industry ---- UV light-curing, UV light curing is a very reliable and can be used to replace hot air dryers and other drying technique of curing technology, which in the printing and packaging of the processing industry has been widely.

普通透明石英管SiO2纯度达99.9%以上，几何尺寸、化学稳定性、热稳定性、抗热变性和抗析晶性能优良，光学透过率达93%以上；脱羟管羟基在10ppm以下，经过真空脱羟，羟基可达5ppm以下，适用于高压汞灯、钠灯、金卤灯等低羟基产品；乳白管，主要用于发热管、加热管、远红外管的制造，珠光石英管乳白石英管之新工艺，管面好象珍珠的表面，各方面性能比普通乳白管更优；滤紫外线管能够滤除紫外光谱波段中对人体有害的190-320nm波长的紫外线，适用于环保光源的制造；无臭氧管与滤紫外线管相反，可透过253.7nm左右波长的紫外线，是无臭氧紫外线杀菌灯的主要材料，广泛用于医疗器械、水处理、食品卫生等杀菌；石英套管直径范围在8-120mm之间，有单开口、双开口、圆头、平头等外形和扩口、缩口、翻边、磨砂等加工，具有耐高温、耐腐蚀、透光性好及防潮、防爆等特点，广泛使用于水族恒温器、消毒设备、加热管、水处理、金卤灯等产品的制造和环保、卫生、化工等领域；石英泡壳规格Φ8-180mm，形状根据客户要求，泡壳上可以接有毛细管，可进行排气，耐高温，透光性好，主要用于JC、JD、H1-H7、舞台灯和高压汞灯、钠灯、金卤灯等产品的制造；石英水套主要用于印刷和包装加工工业---- UV光固化， UV光固化是一种十分可靠的、可取代热空气干燥机和其他干燥技术的固化技术，它在印刷和包装加工工业已经得到广泛应用。

This paper analyses the advantages of down feed two pipe horizontal cascade system in all aspects and influencing degree by natural circulation pressure.

分析了下供下回水平双管系统的优点以及自然循环作用压力的影响程度，计算数据证明下供下回水平双管系统的垂直热力失调基本不存在；因为每层供回水采用双管系统，所以也不存在距离热源最远的散热器不热问题。

Through hydraulic calculation, determines and tests mean friction resistance of riser and horizontal branch circuit of new two-pipe heating system, provides reference for its hydraulic design calculation.

本文分析了新双管系统与传统双管系统的不同，提出了确定新双管系统平均比摩阻联值的方法，并通过水力计算，确定并验证了新双管系统中立管与水平支路的平均比摩阻的取值，为新双管系统水力设计计算提供参考。

Production of intellectual property rights have an independent national patent products - Bergen plates lined with plastic pipe embedded tendons, Bergen licensing stainless steel double-layer steel-lined metal tube, Bergen tendons embedded double-sided plates lined with plastic pipe, condensation-type lined with plastic pipe, steel mesh skeleton reinforced plastic composite pipe, high pressure bi-metallic tubes, thin-walled stainless steel pipes, galvanized pipes are an alternative to traditional ideals of environmental protection pipe.

公司生产拥有独立知识产权的国家专利产品--贝根牌内筋嵌入式衬塑钢管、贝根牌钢衬不锈钢管双层金属管、贝根牌内筋嵌入式双面衬塑钢管、缩合式衬塑钢管、钢丝网骨架增强塑料复合管、高压双金属管、薄壁不锈钢管，是替代传统镀锌管的理想环保管材。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐