原子沉积台控制系统实验研究

研究了以稳定F-P腔腔长来控制原子沉积台与驻波光场之间相对位置的稳定性。在简要分析F-P腔工作原理的基础上,设计了F-P腔腔长锁定反馈控制系统。该系统以633nm稳频激光作为基准光源,通过光电转换、调制与解调、比例积分等控制环节,实现了将F-P腔的谐振频率锁定到基准光源的频率上。实验结果表明,锁定后的F-P腔腔长的稳定度达到了10-8以上,可满足原子光刻技术中对沉积台与驻波光场相对位置稳定的应用要求。

利用稳频激光稳定F-P腔腔长的研究

为实现对F-P腔腔长的控制,设计了F-P腔腔长锁定控制系统。该系统以633nm稳频激光作为基准光源,通过控制系统驱动压电陶瓷调节F-P腔的腔长,以实现将F-P腔的谐振频率锁定到基准光源的频率上。实验结果表明,该方案切实可行,锁定后的F-P腔腔长的不确定度可达10-10量级。该方法在原子沉积技术中对于实现沉积台的稳定具有重要的指导意义。

2英寸MPCVD光学级均匀金刚石膜的制备研究

均匀生长大尺寸光学级金刚石膜一直是微波化学气相沉积(Microwave plasma chemical vapor deposition,MPCVD)金刚石研究领域的热点和难点,沉积台的结构与位置对于金刚石膜均匀性以及厚膜生长的长期稳定性至关重要。本研究通过COMSOL模拟结合实验研究了沉积台高度对衬底表面电场均匀性、等离子体状态和温度均匀性的影响规律,优化了光学级金刚石膜均匀生长的工艺参数,在最佳沉积台高度(2 mm)下沉积得到的2英寸金刚石膜(最大厚度337μm),厚度不均匀性<11%,从膜中心到边缘的拉曼半峰全宽为3~4 cm^(-1),可见光波段内最高透过率为69%~70%,10.6μm处红外透过率为70%。结果表明:金刚石膜的厚度和品质较为均匀,实现了两英寸光学级金刚石膜的均匀沉积。沉积台高度对衬底表面的电场分布、等离子体形状和温度分布都有一定影响,随着沉积台高度增加,衬底表面电场分布均匀性和温度均匀性得到明显改善,且衬底表面的等离子体分布更均匀,H原子和含碳基团的浓度增加。

西藏西北部胸隔藻属Mastogloia Thwaites中的一个新化石种

从西藏西北部阿里地区日土县多玛乡台错古湖沉积物中获得的硅藻新化石种Mastogloia tibetica(sp.nov.),是首次在西藏地区Mastogloia属中确立的新种,该化石种的发现在分类学上具有重要意义,文中对该化石种盐度的适应性和与其他硅藻的相似性进行了讨论,并结合沉积物的化学分析结果,讨论了新种具有适应高渗透性的微咸水至咸水环境的习性,对今后未发现的古湖沉积物的古生态研究有着重要的参考意义。

Concentrations,Accumulation and Sources of PAHs in Surface Layer Sediments of Taizhou Bay

The concentrations, accumulation and sources of 15 polycyclic aromatic hydrocarbons （PAHs） had been studied or evaluated in the surface layer sediments of Taizhou Bay, China. It showed that the concentrations of PAHs ranged from 85.4 to 167.6 ng/g （averaged 138.62 ng/g）, and the highest level was found in Jiao Jiang Dock. Percentages of 2-, 3-, 4-, 5- and 6-cyclic aromatic hydrocarbons were 7.8 %, 42.1%, 33.3 %, 9.6 % and 7.2 % respectively. The accumulation indices of PAHs ranged from 532.7 to 1068.9 （averaged 807.5）, and the index of Phenanthrene was the highest （122.7）, while that of Benzo （a） Pyrene was the lowest （2.7） among them. In Taizhou Bay, PAHs in surface layer sediments came mainly from coal burning, partly from direct pollution of petroleum hydrocarbons.

A Cenozoic tectono-sedimentary model of the Tainan Basin, the South China Sea: evidence from a multi-channel seismic profile

The Tainan Basin is one of the set of Cenozoic extensional basins along northern margin of the South China Sea that experienced extension and subsequently thermal subsidence. The Tainan Basin is close to the Taiwan Arc-Trench System and straddles a transition zone between oceanic and continental crust. A new regional multi-channel seismic profile （973-01） across the region of NE South China Sea is introduced in this paper. In seismic stratigraphy and structural geology, a model of Cenozoic tectono-sedimentation of the Tainan Basin is established. The results show that three stages can be suggested in Tainan Basin; In Stage A （Oligocene （？）-Lower Miocene） the stratigraphy shows restricted rifting, indicating crustal extension. Terrestrial sedi- ments mostly filled the faulted sags of the North Depression on the continental shelf. Structural highs, including the Central Uplift, blocked material transportation to the South Depression in abyssal basin. In Stage B the Tainan Basin （Middle-Upper Miocene） exhibits a broad subsidence resulting from the post-rifting thermal cooling. The faulted-sags in North Depression had been filled up. Terrestrial materials were transported over the structural highs and deposited directly in the South Depression through sub- marine gullies or canyons. This sedimentation resulted in a crucial change in the slope to a modem shape. In Stage C （Latest Miocene-Recent） a phase change from extension to compression took place due to the orogeny caused by the overthrusting of the Luzon volcanic arc. Many inverse structures, such as thrusts, fault bend folds, and a regional unconformity were formed. Forland basin began developing.

Anomalies of bromine in the estuarine sediments as a signal of floods associated with typhoons

X-ray fluorescence scanning with synchrotron radiation was performed to study sediment core records of floods in Amur Bay,Sea of Japan.Interlayers of 3–8 mm with abnormally low bromine content were formed by the Razdolnaya River discharge to the central part of the bay during extreme floods,accompanied by severe storms at sea.Such conditions in the region are typical for periods of deep tropical cyclones(typhoons),to which the distinguished interlayers were compared on the timescale.This approach was made possible thanks to the high rate of sedimentation in the bay(3–5 mm/a) and low bioturbation of sediments under anoxic conditions.

Long-Term Impact of Extra Sediment on Notches and Incised Meanders in the Hoshe River, Taiwan

The extra sediment load induced by typhoons and rainstorms in the Heshe River, Taiwan, are the principal reason for severe sediment-related disasters. The total sediment load during Typhoon Morakot in 9009 was 31 x lo6 m3, accounting for 95% of the annual sediment discharge. Large amounts of sediment load entered the Hoshe River, causing the braiding index （BI） to increase. Subsequently, the BI became positively correlated with the channel width in the Hoshe River. The specific typhoon and rainstorm events decreased after Typhoon Morakot, the sediment input decreased, inducing the fluvial morphology of the braided river to develop into a meandering river. The extra sediment load induced the deposition depth to increase and produce a headward deposition in the main channel and its tributaries. In addition, the river bend and the topographical notch restrained the sediment from moving downstream and being stored locally, indirectly increasing the erosion density of the river banks from 2.5 to lo.5 times.

Dynamics of settling participate matter during typhoon Muifa in Heini Bay,China

Settling particulate matter(SPM) is widely used to describe the sedimentary environment.We have investigated here the SPM collected with a time-series sediment trap in the Heini Bay,Weihai,Shandong Peninsula,China,during the super typhoon Muifa(August 2011,maximum wind speed 55 m/s).Meteorological and hydrological parameters were measured for 18 days.By analyzing the particle flux,grain size,and loss-on-ignition(organic matter content) of SPM we found dramatic changes in these parameters,induced by typhoon Muifa for about 6 days.With the arrival of typhoon,the daily SPM fluxes increased sharply to the maximum at 76.4 g/(m^2·d) on the first day and this increase is about 9 times of the normal value,and after 6 days the SPM decreased to the normal value gradually.Other parameters,such as grain size of SPM and organic matter also experienced similar changes.Using these SPM parameters,we divided the settling progress by cluster analysis into three phases:strong(for 3 days),weak(for 3 days),and zero typhoon impact.

Synergy effects on Sn-Cu alloy catalyst for efficient CO2 electroreduction to formate with high mass activity

To acquire the synergy effects between Sn and Cu for the jointly high Faradaic efficiency and current density,we develop a novel strategy to design the Sn-Cu alloy catalyst via a decorated co-electrodeposition method for CO2 electroreduction to formate.The Sn-Cu alloy shows high formate Faradaic efficiency of 82.3%±2.1% and total C1 products Faradaic efficiency of 90.0%±2.7% at^-1.14 V vs.reversible hydrogen electrode(RHE).The current density and mass activity of formate reach as high as(79.0±0.4)mA cm^-2 and(1490.6±7.5)m A mg^-1 at^-1.14 V vs.RHE.Theoretical calculations suggest that Sn-Cu alloy can obtain high Faradaic efficiency for CO2 electroreduction by suppressing the competitive hydrogen evolution reaction and that the formate formation follows the path of CO2→HCOO*→HCOOH.The stepped(211)surface of Sn-Cu alloy is beneficial towards selective formate production.

Origin of Taiwan Canyon and its effects on deepwater sediment

The continental slope of the Taiwan Shoal, which has cultivated numerous submarine canyons, is located in a passive conti- nental margin environment. However, the trend of the Taiwan Canyon, with its 45° intersection angle, is obviously different from that of the erosion valley downward along the continental slope. A distinct break is present in the lower segment of the Taiwan Canyon, which then extends from west to east parallel to the continental slope until finally joining the Manila Trench. By utilizing multiple-beam water depth data, high-resolution seismic data, and sediment cores, this study describes the topo- graphic characteristics of the Taiwan Canyon and provides a preliminary discussion on the origin of the Taiwan Canyon and its effect on deepwater sediment. The terrain, landform, and sediment of the Taiwan Canyon exhibit segmentation characteristics. The upper segment is characterized primarily by erosion, downward cutting with a V shape, and wide development of sliding, slumping, and other gravity flow types. The middle segment is characterized mostly by U-shaped erosion-sedimentation transi- tion and development of an inner levee. The lower segment is characterized primarily by sedimentation and development of a sediment wave. The bottom current has a significant reworking effect on the interior sediments of the canyon and forms re- worked sands. The formation and evolution of the Taiwan Canyon is closely related to sediment supply, gravity sliding （slumping）, faulting activities, and submarine impaling. Given the sufficient terrigenous clastic supply, the sediments along the continental shelf edge continuously proceed seaward; gliding and slumping in the front edge provide driving forces for the formation of the canyon. Faulting activities result in stratum crushing, and the gravity flow takes priority in eroding the relatively fragile stratum. Thus, the direction of the extension of the canyon crosses the surrounding erosion valley obliquely. Seamounts are formed through submarine impaling. Owing to seamount blocking, the lower segment of the canyon is turned toward the east-west direction. Large amounts of sediments overflow at the turning, formin~ sediment waves.

The Cambrian sedimentary characteristics and their implications for oil and gas exploration in north margin of Middle-Upper Yangtze Plate

Using data from tens of measured and observed outcrop successions,thin rock slices and sample analyses,we comprehensively studied the Cambrian sedimentary environments and evolutionary characteristics in the north margin of the Middle-Upper Yangtze Plate.During the Cambrian,platform,slope,and deep sea basin environments were developed in the study area.On the platform,both clastic rocks and carbonate rocks were deposited.Clastic rocks mainly occur in the Lower Cambrian,and were deposited in marine shore and shelf environments.Carbonate rocks are dominant in the Middle and Upper Cambrian,and were deposited in the open platform,restricted platform,tidal flat,beach,and reef environments.Carbonate gravity flow deposits were developed on the slope.In the basin,mainly black shales and chert beds were deposited.The Cambrian represents one large transgression-regression cycle,and maximum transgression occurred in the Qiongzhusi Age of the Early Cambrian.Tectonics and sea level fluctuations had important impacts on sedimentary environments.The Chengkou-Fangxian-Xiangfan Fracture controlled the position of the platform,slope and basin,as well as the silica supply for chert deposition in basin.Sea level fluctuations controlled types of sediments and sedimentary facies on the platform.In the study area,there are good reservoir rocks,including dolomites,grainstones,debris flow deposits,sandstones,and conglomerates;there are good source rocks,including black shales,dark micrites,and chert beds;and there are also good reservoir-source rock assemblages.The hydrocarbon potential of the study area is great.

Distinct sedimentary environments and their influences on carbonate reservoir evolution of the Lianglitag Formation in the Tarim Basin,Northwest China

The Upper Ordovician Lianglitag Formation carbonate rocks are important oil and gas reservoirs in the Tarim Basin, Northwest China, with obviously distinct reservoir properties among different oilfields. As a case area of the above carbonate reser- voirs correlation, Tahe and Tazhong oilfields are chosen for the study through an integrated analysis of biostratigraphic isoch- ronous framework, cores, thin sections, logs, and strontium isotopes. The research shows that the two areas were respectively attributed to different carbonate platforms during the Lianglitag Formation depositional phase. For the Lianglitag Formation, five fourth-order sequences may be divided in Tazhong, whereas only four fourth-order sequences are preserved in Tahe that correspond to the lower ones observed in Tazhong. The Lianglitag Formation carbonate platform in Tahe was characterized by ramp and/or weak rimmed types, with low depositional rates （37 ktm/a）, higher whole-rock clastic contents, and higher 878r/86Sr isotope ratios of carbonate matrix, showing relatively deep-water environment and evident terrigenous input for car- bonate deposition. However, a strongly rimmed carbonate platform was developed in Tazhong, with high depositional rates of 250 p.m/a and less whole-rock clastic contents, indicating a high-energy depositional environment. Because of the sedimentary environment differences mentioned above, less high-energy facies but relatively intense syndepositional （early diagenetic） sea-water cementation of carbonates were developed in Tahe, and ubiquitous high-energy reef and shoal facies, with a frequent exposure to subaerial, and weak syndepositional sea-water cementation of carbonates in Tazhong. Therefore, fewer primary pores occurred in the Lianglitag Formation carbonate rocks of Tahe, whereas more primary pores were preserved in the same lithostratigraphic unit of the Tazhong （No. 1 fault zone）. Available high-energy reef-shoal facies and early diagenesis, with more primary pores preserved, provided a key material basis for the Lianglitag Formation carbonate reservoirs that largely oc- curred in Tazhong.