位置上的

Comparing with the photodissociation of bromobenzene, the extra fluorine atom of fluorobenzene accelerates the rate of the internal conversion from the state to the state, and the different positions on the phenyl ring also have distinct effect on it.

与溴苯相比，氟溴苯上的氟原子显著加快了解离的速度，并且氟原子在苯环上的位置的不同对解离速度也有显著影响。

It is well known that retinal pigment epithelial cells are predominant proliferative cells in PVR which is an excessively wound healing response occurring after RPE cell wounding. The activated RPE cells migrate from their normal, sessile state to vitreous and onto both surfaces of the retina, in which they begin to dedifferentiate, migrate, proliferate, change phenotype and secrete ECM.

既往研究证明视网膜色素上皮(retinal pigmentepithelial，RPE)细胞是参与PVR的主要细胞，PVR是视网膜脱离后RPE细胞损伤的一种自我修复过程，是一种过度的眼内创伤修复反应；RPE细胞在正常位置上处于静止状态，而在某些病理条件下，如视网膜裂孔形成和视网膜脱离后，RPE细胞脱离原位，开始去分化、移行、增生、发生表型转化并分泌胶原等ECM，最终在视网膜前后表面和玻璃体内形成具有收缩能力的增生膜，造成牵拉性视网膜脱离。

The reaction barrier will be lowered by the substituents that delocalize the unpair electron in p z orbital of the central carbon atom.

R1和R2位置上取代基对α-氢转移反应势垒的影响取决于取代基对过渡态中碳原子的未参与sp2杂化的p z 轨道上单电子的离域作用。

Density Functional Theory method was used to optimize the geometries of 209 PCDE molecules, 209 PBDE molecules and 75 PCDD molecules at the B3LYP/6-31G* level. Using computed structural parameters as theoretical descriptors, the forward stepwise multiple regression technique was adopted to obtain QSPR models of environmental partition properties for these POPs by using GQSARF 2.0 and SPSS12.0 for windows programs. The obtained QSPR models are as follows:(1) QSPR models for predicting subcooled liquid vapor pressure, n-octanol/water partition coefficients lgK_(ow and subcooled liquid water solubilities -lgS_(w,l of PCDEs, of which correlative coefficients (R~2) are 0.988, 0.958 and 0.959 and the root-mean-square-error of estimation are 0.134, 0.116 and 0.327 respectively.(2) QSPR models of lgPL and n-octanol/air partition coefficients lgK_(oa for PBDEs, which both contain three structural parameters. The values of R2 for the two models are both 0.997 while the values of RMSEE are 0.073 and 0.062 respectively.(3) QSPR models of lgKow and–lgS_ for PCDEs, which both have one variable (mean molecular polarizability,α). The values of R~2 for the two models are 0.978 and 0.866 and the values of RMSEE are 0.300 and 0.270 respectively.(4) The molecular structures of 24 substituted naphthaline compounds were optimized using Hartree-Fock and DFT methods at four different levels and the same means was used to obtain four three-parameter (EHOMO, q~+ andα) QSPR models of lgK_. The model at the HF/6-311G** level is the best one of which R2 is 0.9662 and RMSEE is 0.380.(5) QSPR study for environmental partition properties of PCDEs was also performed using position of Cl substitution method in which simple parameters of substitution position were taken as descriptors. The multiple linear regression was performed with GQSARF 2.0 and SSPS 12.0 for windows programs to obtain QSPR models of lgP_L, lgK_ and–lgS_ for PCDEs of which R~2 are 0.991, 0.983 and 0.965 and RMSEE are 0.311, 0.100 and 0.300 respectively.

采用密度泛函理论方法在B3LYP/6-31G*水平上对PCDEs、PBDEs和PCDDs的分子结构进行了全优化计算，以计算得到的量子化学参数作为理论描述符，采用GQSARF 2.0和SPSS 12.0 for windows统计程序进行正向逐步回归分析，建立了这些POPs的环境分配性质的QSPR模型：(1) PCDEs的过冷液体蒸汽压、正辛醇/水分配系数lgK_(ow和水溶解度-lgS_(w，l的QSPR模型，这3个QSPR模型的相关系数(R2)分别为0.988、0.958和0.959，估计的均方根误差分别为0.134、0.116和0.327；(2) PBDEs的lgPL和正辛醇/空气分配系数lgK_(oa的QSPR模型，这两个模型都包含三个分子结构参数，其R~2都为0.997，RSMEE分别为0.073和0.062；(3) PCDDs类化合物的lgK_和-lgS_w的QSPR模型，两个模型都只含一个变量，其R~2分别为0.978和0.866，RSMEE分别为0.300和0.270；(4)采用Hartree-Fock和DFT方法，在4种不同水平上优化计算了24个取代萘系列化合物的分子结构，采用上述同样的方法分别建立了四种水平上的三变量lgK_模型，通过比较得到，在HF/6-311G**水平计算得到的模型最好，R为0.966，RSMEE为0.380；(5)同时，采用氯原子取代位置方法对PCDEs的环境分配性质进行QSPR研究，建立了PCDEs的lgPL、lgK_和-lgS_的QSPR模型，其R~2分别为0.991、0.983和0.965，RSMEE分别为0.110、0.100和0.300。

Terpenoids had business with the life of humanbeings. The last twenty years developments of tricyclic diterpenoids were reviewed.Biologic activities of tricyclic diterpenes which had oxygenous guoups on the 1, 2 or 3 position were reviewed. The important applications and some methods of introducing oxygenous groups on these three positions in recent 20 years were also obtained.

萜类化合物与人类生活密切相关，本文简要介绍了近二十年来三环二萜类化合物的最新研究进展，综述了在C-1、C-2、C-3号位上具有含氧官能团的三环二萜类化合物的生物活性、重要应用，并报道了近二十年来在这三个位置上引入含氧官能团的一些常见方法。

The skull appears in a superimposed pan over a nude male, set in place of a blonde crotch, where a dreamer turns in solipsistic reverie.

头骨以摇镜的方式叠加在一个裸体的男人上，停在金色毛发的胯部位置上。一个人沉浸在自我的幻想中，在梦中翻着身。

The histone octamer may protect the wrapped DNA from interacting with other environmental factors such as transcription regulating proteins, thus the positioning of nucleosomes along DNA may play important roles in multiple cellular processes including DNA replication, transcription and damage-repair.

由于核小体结构中的DNA缠绕在组蛋白八聚体上，可能影响这些DNA与细胞内的其他蛋白相互作用，从而影响到DNA复制、转录等生物学过程，因此，核小体在基因组上的位置分布可能对基因组功能具有重要的调控作用。

Essentially, the creature lacks a true head; in its place is the large horn, which warbles and trumpets when the knell beetle communicates to other knell beetles.

从本质上说，这个生物并没有真正的头部；在本该是头部的位置上长的是那支巨大的号角。这只号角在丧钟甲虫联系其他丧钟甲虫时会发出鸣音或颤音。

Orient the new rod coupling such that the hole in the coupling aligns with the hole on the hydrant rod.

确定新的阀杆连接套的位置，连接套上的孔与阀杆上的圆孔对齐，用销钉和开口销将连接套固定。

For example Andrea Pirlo is the best deep-lying playmaker of his generation, and essentially he takes up the same position on the field as Cambiasso.

比如，安德列·皮尔洛在他的位置上，也许是世界上最好的组织者，事实上他活动的领域与坎比亚索是一致的。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。