碳的

Polycarbosilane lower the electronic structure and properties of PCS is a kind of high-molecular compound, the main chain by alternating silicon and carbon atoms of the silicon and carbon atoms are connected to hydrogen or organic group, molecular chains of linear or branch structure.

低聚碳硅烷的电子结构及其性质的研究聚碳硅烷是一类高分子化合物，其主链由硅和碳原子交替组成，硅和碳原子上连接有氢或有机基团，分子链为线形或枝化结构。

Corbicula fluminea (Müller 1774) was bred in the laboratory and two shell samples (shell height, A=13 mm, B=9 mm) were selected to determine the carbon isotopic composition of the increment shells (aragonite, CaCO3) and the host water. The results indicate that the carbon isotopic compositions of the two shells increased as the δ^13 C values of the host water increased from -5.24‰ to 1.41‰, showing the influence of δ^13C values on the shell carbon isotopes.δ^13C value ranges from -4.76% to -2.09% and δ^13 C from -8.49% to -2.89%. The δ^13 C values of shells A and B are both more negative than the predicted equilibrium ones, indicating that the shell had used the metabolic CO2 rich in 12C during their growth process.

对双壳类河蚬进行了室内养殖，并选取两个壳体样品（壳高，A=13 mm， B=9 mm），测定其生长部分壳体和生长期间水体碳同位素，研究表明，随着水体碳同位素的升高（δ^13C由－5.24‰升至1.41‰），两壳体碳同位素也随之升高，表明水体对壳体碳同位素的影响；δ^13CA分布范围为－4.76‰~-2.09‰，δ^13CB为－8.49‰~-2.89‰，壳体A和B碳同位素均比预测平衡值偏负，表明壳体在形成过程中利用了新陈代谢产生的富集12C的CO2。

The isopleth's surface and gradient change trend of carbon content in carbon-accumulation field are analyzed, the temporal and lateral change pattern of carbon budget in selected peatland sites are calculated, the effect and feedback of carbon-accumulation process on CO〓 content in atmosphere is investigated in this paper.

通过典型泥炭地实测资料，分析了聚碳场内泥炭品位等值面和泥炭品位梯度变化，计算并研究了三江平原典型泥炭地碳素收支的时空格局，探讨了聚碳作用对大气二氧化碳浓度的影响与反馈机制，分析了本区泥炭地聚碳作用在全球环境变化中的地位，同时针对聚碳环境和聚碳过程对泥炭性质和品位影响，对本区泥炭资源的保护和合理利用提出了建议。

Meanwhile, the isomer with a larger change of dipole moment has larger value of the first hyperpolarizability during the charge-transfer process.

5， 6， 7顶点双取代碳硼烷桥连分子受推拉电子基的影响，5， 6， 7顶点碳硼烷的构型发生一定变化，碳硼烷中两个C原子间的距离变长；同时碳硼烷中两个C原子取代位置的不同，影响了分子的稳定性和极化率，取代基团与碳硼烷中成键数较低的C原子相连的异构体，稳定性较好且具有大的极化率； 5，6，7顶点双取代碳硼烷桥连分子形成一维结构有利于分子内电荷转移，在电荷转移过程中偶极矩变化较大的体系，其二阶NLO系数也较大。

Because of the nondirectional property of ionic bond and the fully delocalized property of pi electrons on carbon layers, translation will not change the electronic structure of carbon layers, resulting in that A-GIC and AE-GIC hare quite good lubrication as well. The electrons come from metals mainly transfer to the delocalized pi orbitals of carbon layers, and the increase of delocalized electrons will make metal graphite intercalation compound more electro-conductive than graphite itself. Because ionic bond between metals and carbon layers is weaker and its lattice energy is much less than that of typical NaCl crystal, so metals could be left from interlayers. The Mulliken populations of C-C in intercalation compounds are smaller than that of graphite, and the HOMO energy level of GIC is higher than that of graphite too. These Lead to that GIC will easier be oxidized.

由于离子键没有方向性，又由于碳层中的π电子是充分离域的，所以碳层不会由于平移而改变其电子结构，金属石墨层间化合物仍具有很好的润滑性；金属失去的电子主要转移到碳层的离域π轨道中，碳层离域电子增多使金属石墨层间化合物的导电性比石墨增强；金属与碳层间的离子键强度比较弱，其晶格能远小于典型的离子晶体，因而金属易从石墨层中脱出；金属石墨层间化合物中的C-C间Mulliken布居值小于石墨中C-C间的值，且金属石墨层间化合物的HOMO能级也高于石墨的HOMO能级，所以石墨层间化合物中的碳原子较石墨更易被氧化。

In this temperature range, medium carbon steel is not weaker than lower and higher carboncontaining steel in resisting crack formation, which reveals that the high susceptiveness of steel slab which contains 0.10%～0.18% of C is not attributed to the d...

在γ单相区低温域，碳含量较低和较高钢试样的延性显著低于碳含量中等钢。而在γ＋α两相域，钢的低延性区域随碳含量的增加向低温方向移动，碳含量较低钢的延性好于碳含量中等和较高钢。

Based on allotropic transformation of ingot,the definition,strength performance and feature of the iron-carbon alloy basic phase(ferrite,austenite and carburizing) are analyzed on the iron-carbon alloy phase diagram .

在铁碳合金相图上直接从工业纯铁的同素异晶转变开始分析铁碳合金基本相铁素体、奥氏体和渗碳体的定义、力学性能、特点等，再用铁碳合金基本相和相图的规律来分析铁碳合金相图的点、线和各区域组织。

Halogenated aromatic compounds with great q〓(the most negative net atomic charges on an atom of the molecule), ENC (electron-nuclear attraction energy of the one-center term for the carbon atoms of the weakest carbon-halogen bond), qc (thenet atomic charges on the carbon atom of the weakest carbon-halogen bond) and E〓 tend to be reductively dehalogenated slow, while halogenated aromatic compounds with high values of △E (the difference of front-line orbital energy), EEC (electron-electron repulsion energy of the one-center term for the carbon atoms of the weakest carbon-halogen bond), Mw, q〓 and α tend to be reductively dehalogenated fast.

卤代芳烃化合物的整个分子的最负的原子净电荷，键序最小的碳卤键中碳原子的单中心项电子-核吸引能，该碳-卤键上碳原子的净电荷和E〓与该卤代芳烃化合物还原脱卤的速率常数负相关；而前线轨道间隙能，键序最小的碳卤键中碳原子的单中心项电子-电子推斥能，Mw，q〓和α与该卤代芳烃化合物还原脱卤的速率常数正相关。

The β-CA of B.napus was located in chloroplast stroma and had the conservative motif Cys-X(subscript n-His-X2-Cys peculiar to β type carbonic anhydrases. In the secondary structure,α-helix, random coil,β-sheet, and β-turn were 39.88%, 39.27%, 16.31%, and 4.53%, respectively. The three-dimensional structure was constructed by homology modeling. The 3-D alignment of β-CA from B.napus and a monomer of β-CA octamer from pea showed that the 3-D structure of β-CA from B.napus could match well with the monomer. The alignment results Implied that β-CA from B.napus was a monomer of the β-CA octamer from B.napus.

预测结果显示，甘蓝型油菜β破酸酐酶是定位于叶绿体基质的蛋白质，具有β类碳酸酐酶所特有的保守性基序Cys-χ-His-χ2-Cys；SOPMA预测二级结构显示α螺旋(39.88%)、随机卷曲(39.27%)、β折叠(16.31%)和β转角(4.53%)；用同源建模法构建了三维结构图；通过VAST矢量比对工具将甘蓝型油菜β碳酸酐酶与模板进行三维结构比对，显示甘蓝型油菜β碳酸酐酶与碗豆β碳酸酐酶同型八聚体中的一个单体很好的匹配，推测甘蓝型油菜β碳酸酐酶全酶也是同型八聚体。

The contact fatigue strength was measured after the 20CrNi2Mo and 15CrNi6 steel used asdragging gear on quasi high speed locomotive was carburized and quenched as well as peened,com-pared with that of 20CrMnMo steel.The results shown that the contact fatigue strength limits of thesethree types of steel carburized and quenched essentially same,and the contact fatigue strength Iimit hasbeen increased by 5 porcent after peening,and that the failure appoarances of all contact fatiguespecimen were delamination ...

对20CRrNi2Mo、15CrNi6及20CrMnMo渗碳淬火齿轮及15CrNi6渗碳淬火＋喷丸处理齿轮进行了弯曲疲劳试验，介绍了齿轮试件的设计与加工、试验装置与夹具、试验方法及试验数据的统计处理，试验结果表明，20CrNi2Mo和15CrNi6渗碳淬火齿轮在R＝0.99时的σFlim分别为530MPa和375MPa，与20CrMnMo渗碳淬火齿轮相比，弯曲疲劳强度分别提高80％和27％。15CrNi6经渗碳淬火＋喷丸处理齿轮在R＝0.99时的σFlim为490MPa，比未喷丸处理者提高30％。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新