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1.
目的 评价禹城洼陷的生烃潜力,以指导下一步勘探。方法利用烃源岩分析数据对禹城洼陷的生烃潜力进行研究和评价,利用包裹体测温等分析资料对影响烃源岩发育和分布的因素进行分析和总结,利用生物标志化合物指标(C29S/S+R)对生油门限进行了重新认识和探讨。结果禹城洼陷烃源岩发育较差、分布不均,总体上处于未熟一低熟阶段;其主要影响因素是异常高压带的分布和火成岩的入侵;本区生油门限应在3500m以下。结论禹城洼陷下第三系生烃潜力不足。 相似文献
2.
以八乙烯基多面体低聚倍半硅氧烷(OVPOSS)和含氢硅氧烷为单体,通过硅氢加成反应制备了一种新型POSS交联剂V2-POSS。将V2-POSS加入到聚甲基硅氧烷中,制备了一系列不同POSS含量的聚甲基硅氧烷。采用热重分析(TGA)、热重-红外联用(TGA-IR)、裂解气相色谱-质谱(PyGC-MS)等手段对POSS杂化聚甲基硅氧烷的热性能、热分解动力学及动态热解性能进行研究,结果表明:V2-POSS在聚甲基硅氧烷中均匀分散,POSS纳米结构的引入可显著提高聚甲基硅氧烷的热性能;V2-POSS添加量(V2-POSS占聚甲基硅氧烷的质量分数)为10%时,氮气氛5%热失重温度从纯树脂的442.2℃提高至469.4℃;热失重率为15%时,热解表观活化能由纯树脂的87.53 kJ/mol提高至杂化树脂的251.12 kJ/mol。POSS杂化聚甲基硅氧烷的热解机理主要包括聚硅氧烷主链的断裂、高分子链回咬、含硅基团的重排、碳氢化合物的形成以及小分子的逸出。 相似文献
3.
In this paper,liquid droplet master was for the first time used to fabricate thin membranes integrated polymeric microfluidic devices.As demonstration,water liquid droplet master was used to make a thin membrane in PDMS microfluidic devices which were prepared by using printed master.The PDMS membrane can be controlled down to approximately 10 μm thick with considerable vapour permeation which was adjusted by environmental humidity.An array of the microfluidic devices with thin PDMS membranes was also used ... 相似文献
4.
The startup process of a thermoacoustic engine is a self-excited oscillation process generated in inhomogeneous acoustic media.
To reveal these coupling relations between various influential factors is an important task of basic research on thermoacoustics.
In this paper thermoacoustic engines are regarded as thermoacoustic oscillators consisting of the active network and the passive
network. Accordingly, the two-port Y-parameter for relevant component is derived, and standing wave and traveling wave thermoacoustic engine are described by
the negative-resistance and feedback model, respectively. The relevant two-port network topology is given as well. The startup
criteria for thermoacoustic oscillators are obtained by using Nyquist instability criterion. The model prediction of startup
parameters, particularly, startup frequency and mode characteristic are in agreement with that of experimental results reported
in the literature. Moreover, with topological graphs it is verified that standing wave engines would start up in a negative-resistance
state and there would exist high frequency modes in thermoacoustic-Stirling engines. By investigating into the frequency response
of thermoacoustic system, this method proposed can achieve such an objective that these effects of operating and structural
parameters of engine on startup modes and startup temperature can be revealed in an analytical way. Thus this approach to
test and check thermal stability can be provided in a design phase, instead of using empirical frequency to design thermoacoustic
systems.
Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.
Supported by National Natural Science Foundation of China (Grant Nos. 50576024 and 51076013) 相似文献
5.
YongLan Li LianBin Zheng KeLi Yu ShunHua Lu XingHua Zhang YuLing Li Yang Wang Hong Xue Wei Deng 《科学通报(英文版)》2013,58(4-5):517-524
We investigated 13940 (6735 male, 7250 female) adult head and facial physical attributes from 19 different Han ethnic groups in 10 southern-China provinces, and calculated 12 head and facial indexes. Indexes were used to analyze the variation of head and facial morphological characteristics with increased age. Results showed that as age increases: (1) Head breadth, minimum frontal breadth, face breadth, interocular breadth, external biocular breadth, lip height, lip thickness, head circumference, auricular height, length-breadth head index, length-height head index, and lip-index values decline significantly in a linear fashion. (2) Nose breadth, mouth breadth, morphological facial height, upper-lip height, physiognomic ear length, physiognomic ear breadth, visor skin-fold, and vertical head-facial index values significantly increase in a linear fashion. 相似文献
6.
YueChun Shi XingHua Tu SiMin Li YaTing Zhou LingHui Jia XiangFei Chen 《科学通报(英文版)》2010,55(35):4083-4088
A distributed feedback (DFB) semiconductor laser with three phase shifts based on reconstruction equivalent chirp (REC) tech-nology is proposed and investigated numerically. With the combination of multiple phase shifts and corrugation pitch modulated (CPM) structure, we also propose a novel and more complex structure named dual CPM, which has a flatter light power distribution along the laser cavity compared with the true double phase shifts DFB laser diode (LD), while the P-I curves are nearly the same. The proposed dual CPM structure is also designed and analyzed based on REC technology. The simulation results show that, the DFB semiconductor laser with complex structure such as phase shifts, or even arbitrary variation of the grating period can be achieved equivalently and easily by changing the sampling structure. But its external characteristics are almost the same as those DFB lasers with true phase shifts, or true arbitrary variation of the grating period. The key advantage of the REC technology is that it varies only the sampling structure and keeps the seed grating (actual grating in sampling structure) period constant. So its fabrication needs only low-cost and standard holographic exposure technology. Therefore we believe this method can achieve the high-end and low-cost DFB LD for mass production. 相似文献
7.
XianXian Gao WeiZhong Chen Wei Huang JunFeng Xu XingHua Xu YaNan Liu Yue Liang 《科学通报(英文版)》2009,54(7):1152-1157
The mass-exchange between the inside and outside of a cavitation bubble is a complicated process with several kinds of exchange
forms acting together, such as gas diffusion, gas-liquid phase transition, chemical reactions and so on. A phenomenological
model of mass-exchange was proposed, in which the pressure difference is considered as the drive. Compared with the previous
physical models, it has a simpler form and less computational cost. Combining it with Rayleigh-Plesset equation, the equilibrium
radius is calculated when the mass-exchange achieves the dynamic balance. The result shows that the equilibrium radius has
multiple values. The relationships between the equilibrium radius and the driving ultrasound (pressure amplitude and frequency)
are evaluated. We also investigated how these relationships were affected by the model parameters. Finally, the bubble radius
evolution in the sulfuric acid driven by different pressures was measured. The experimental result that the equilibrium radius
changes with the pressure agrees with the numerical results well.
Supported by the National Natural Science Foundation of China (Grant Nos. 10434070, 10704037), the Key Project of Chinese
Ministry of Education (Grant No. 103078) and the Young Scholar Technological Innovation Projects of Jiangsu Province (Grant
No. BK2007569) 相似文献
8.
研究了两个有瓣蝇种的细胞遗传学特征。结果表明:棕尾别麻蝇核型为2n=12,8M+2SM+2m,XX/XY,性染色体为微小的点状;C带主要分布于常染色体的着丝粒和次缢痕,性染色体Y普遍深染而X淡染;G带数(2n)为88条。铜绿蝇核型为2n=12,12M,XX/XY;常染色体以中央型C带为主,性染色体呈不同程度的深染;G带数(2n)为107条(雄)或110条(雌)。两蝇种染色体均存在多个随体,C带带型呈分散、杂合、多态或不稳定性。结合有关资料,探讨了有瓣蝇类演化的细胞遗传学机制。 相似文献
9.
With atomic force microscopy (AFM) we systematically studied the DNA condensations on mica surfaces induced by multivalent cation spermidine. The pattern of the DNA condensates is a flat single layer, with a core in the centre and DNA wrapping around it at high density. We assume this to be a two-dimensional condensation of free coiled DNA onto negatively charged mica surfaces by the multivalent cation. The DNA molecules condense on mica surfaces via a pathway different from the formation of toroids, rods or globules in bulk solutions. We give an explanation to why toroid structures are difficult to be observed by AFM, and further discuss the relationship between DNA condensations in solutions and on mica surfaces. The present work will be helpful for understanding the behaviors of DNA on charged surfaces, which might be significantly different from that in solutions. 相似文献
10.
A set of Bell inequalities classifying the quantum entanglement of four-qubit states is presented. These inequalities involve only two measurement settings per observer and can characterize fully separable, bi-separable and tri-separable quantum states. In addition, a quadratic inequality of the Bell operators for four-qubit systems is derived. 相似文献