JOURNAL OF LANZHOU UNIVERSITY(NATURAL SCIENCES)
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2017 Vol.53 Issue.4,
Published 2017-08-28

427 Characteristics of biomarkers of middle Jurassic source rocks#br# and fossil cuticles from Yaojie Basin, Gansu Province
Wang Jin 1, 2,Liu Chun-hui 1,Mao Teng 1,Yuan Xiu-cai 1,Li Yi-jie 1,Sun Bai-nian 1, 2
Based on an analysis of saturated hydrocarbon fraction and aromatic fraction of carbonaceous
mudstone, oil shale and mudstones collected from the middle Jurassic series of Yaojie Basin, Gansu Prov-
ince, as well as similar components of gymnospermous fossil cuticles, biomarkers indicative of a higher
plant input were detected. The results showed that gymnospermous fossil cuticles were one of the source
rocks biomarkers. Integrating an analysis of parameters like hopance precursor types concluded that the
source rock samples were dominated by the input of a higher plant, with contribution from hydrobiontic
algae to some extent. Parameters of fossil plant cuticles samples, which were indicative of microbial
action, sedimentary environment and sample maturity, correlated well with that of source rock samples,
illustrating that the middle Jurassic series were deposited in a weak oxidation-weak reduction semi-deep to shore-shallow lacustrine facies, with the depositional medium fresh to brackish water and the organic
matter having undergone a certain degree of microbiological deterioration at unmatured to low-matured
phases. Our results are significant for further in-depth analysis of the sedimentary environment of the
source rocks during the middle Jurassic from Yaojie Basin.
2017 Vol. 53 (4): 427-435 [Abstract] ( 116 ) [HTML 1KB] [ PDF1883KB] ( 272 )
436 Down-sampling of InSAR surface deformation data
Yang Zhen 1,Zhang Yong-zhi 1,Zhang Wen-jun 2,Jiao Jia-shuang 1,Ye Kai 1,Huai Yan-ke 1
 As InSAR data covers a wide range of surfaces, numerous data points, with a high density and
many error points, the inversion efficiency will be restricted and the accuracy of the results will be
affected when InSAR deformation data are used to carry out an inversion. In order to improve the effi-
ciency of inversion and ensure the convergence of iterations, a down-sampling study on InSAR deforma-
tion data was conducted, taking the co-seismic deformation data of the Mw 6.3 earthquake that occurred
in Dangxiong County in the Tibet Autonomous Region in 2008 as an example. The three resolution-re-
duced down-sampling methods (the nearest neighbor, the biliner interpolation and the cubic convolution
interpolation method) were applied, with the results of these three methods compared and analyzed. The
results showed that the cubic convolution interpolation method was the most suitable for down-sampling
of InSAR surface deformation data; the cubic convolution interpolation method was improved so as to
further improve the outcome quality of down-sampling. After having been improved, the down-sampling
deformation data acquired can effectively reduce the number of sampling points, resulting in well-pre-
served details of the deformation field.
2017 Vol. 53 (4): 436-443 [Abstract] ( 95 ) [HTML 1KB] [ PDF6440KB] ( 59 )
444 Pore structure and characteristics of a Neogene reservoir of No. I#br# Taishen Well, Qaidam Basin
Ye Sheng-xia 1,Xu Rong-hai 1,Du Ding-ding 1,Jin Xing-ming 2,Zhang Cheng-jun 1
Depth studies of the pore structures and micro-electron microscopy of clastic rocks and the mer-
cury analyses of Neogene Taishen Well No. 1 in the Qaidam Basin. The results showed that the main Neo-
gene clastic rocks are of feldspar lithic and lithic sandstone, the interstitials had medium-to-high content,
and the primarily reservoir space is of dissolution pores between grains, dissolution of intragranular
pores, a small number of intergranular pores and molded holes, the throat types are of sheet and bending
sheet throats, the pores are narrow-throated. The reservoir porosity structures mainly had been influenced
by depositional environments and diagenesis. The physical property of the clastic rock in the Shizigou
formation belongs to a high porosity and low-permeability, while the Shangyoushashan formation
belongs to a low-to-super low pore and low permeability. Argillaceous siltstone, sandstone and sandstone
of the Shizigou formation could be relatively good oil and gas reservoirs, with their deeper burial
(3 150-4 290.9 m) and reservoir characteristics of low-to-super low permeability and low porosity.Alarge
number of organic acids formed from thermal maturation of organic matter during the early to late diage- netic stage have had obvious constructiveness on clastic rock porosity and connectivity, being beneficial
to the accumulation of oil and gases. Thus those reservoirs can be intensive objects for oil and gas explo-
ration.
2017 Vol. 53 (4): 444-451 [Abstract] ( 84 ) [HTML 1KB] [ PDF4508KB] ( 56 )
452 Characteristics of the fractures of E#br# 2#br# 3 reservoir in YingxiArea,#br# Qaidam Basin
Du Jiang-min 1,Zhang Xiao-li 2,Wang Qing-chun 1,Feng Cong-jun 2,Guo Ling 2,
Based on core observations, petrographic and structural microscopic characteristics and mercury
injection experiment analysis, it was found that fractures played an important role in the process of oil
and gas accumulation. The fractures are an important reservoir space type of the Yingxi Area. The results
of mercury injection experiment analysis showed that the total volume of fractures accounted for about
1/4~1/3 of the total volume of all the reservoir space. Many of the oil remains in the fractures could be
found through core and thin section observations. Fractures also play an important role of oil and gas
migration channel in the process of the oil and gas accumulation and the fractures completely filled by
salt minerals have the strong ability of sealing and capping, conducive to the preservation of oil and gas. The fractures in the Yingxi area are very well developed and controll the enrichment and high yield of
oil and gas. The plane distribution characteristics of fractures can be predicted and described by a fine
description using the seismic fracture prediction software called "GeoFrac". This can provide technical
guidance and exploration recommendations for well deployment in searching for fractured reservoirs.
2017 Vol. 53 (4): 452-458 [Abstract] ( 57 ) [HTML 1KB] [ PDF5152KB] ( 69 )
459 Climate characteristics of clouds and their influence on the land-#br# atmosphere system in the Qinghai-Tibet Plateau
Gao Xing-xing 1,Chen Yan 1,Zhang Wu 1,Lu Peng-xue 2
 ISCCP data were used to analyze the spatial and temporal distribution characteristic of cloud
parameters in the Qinghai-Tibet Plateau. The relationships between different classes of clouds and rain-
fall and temperature from NCEP data were determined. The cloud radioactive effects on the land-atmo-
spheric system over the Qinghai-Tibet Plateau were studied by using CERES SSF MODIS Edition 3A da-
ta, with the results that the mean cloud amount, low cloud amount, cloud optical thickness and cloud wa-
ter paths became less or fewer from the east to west; as regarding the cloud water path and cloud optical
thickness the stratus, nimbostratus and deep convective of ice were the largest while altocumulus and cu-
mulus of liquid, cirrus and altocumulus of ice were the smallest; the frequency of occurrence for cirrus
was the highest while ice occurring frequency of stratus, stratocumulus, cumulus and nimbostratus were
lower; the distribution of cumulus, altocumulus, altrostratus of liquid, cirrus and cirrostratus were the
same with the mean cloud amount; for nearly 20 years the trend of mid and high cloud amount were ris-
ing while the trend of the low cloud amount was in a decline, leading to rising temperature; and that the cloud shortwave radioactive forcing dominated the net radioactive forcing and varied remarkably with
seasonal changes.
2017 Vol. 53 (4): 459-466 [Abstract] ( 69 ) [HTML 1KB] [ PDF3653KB] ( 71 )
467 Simulation of summer precipitation over arid and semiarid regions in#br# EastAsia
Liu Jun, Ji Ming-xia
The simulated capability of summer precipitation was systematically evaluated using 18 mod-
els from the fifth coupled model intercomparison project during the past 58 years (1948-2005), and was
compared with the observations from the Climate Prediction Center over arid and semiarid regions in East
Asia. According to a comparison of 7 precise and poor models as G1 and G2 multi-model ensembles,
there was a good agreement of the linear trend of summer precipitation between G1 historical simulation
and the observations. The results indicated that summer precipitation decreased significantly in northeast
China and Mongolian regions but increased in Northwest China and that precipitation change of G1 was
a little underestimated in west Mongolia but with large differences between G2 simulation and observa-
tions. For example, the observed linear trend of summer precipitation was conversed with the simulation
over Inner Mongolia and some other regions in Northern China. There was a good relationship between
the anomaly precipitation of G1 simulation and the observations in strong East Asian summer monsoon
years, indicating that there was obviously more precipitation in Northeast China and East Mongolia. There was a large bias between the simulations and observations in weaker East Asian summer monsoon
years. The simulation with RCP4.5 and RCP8.5 emission scenarios indicated that the linear trend of
summer precipitation would increase until 2100.
2017 Vol. 53 (4): 467-480 [Abstract] ( 64 ) [HTML 1KB] [ PDF11355KB] ( 50 )
481 Astudy on the spatial and temporal variations of precipitation and heavy#br# precipitation in the Kumtag Desert
Hu Yu-ling 1,Zhao Zhong-jun 2,Ma Pan 1,Yang Xu 1,Wang Shi-gong 1, 3,Shang Ke-zheng
Based on daily precipitation data from 1960 to 2014 and the Chinese automatic meteorological
station and CMORPH-fusioned hourly rainfall of 0.1° grid data set from 2008 to 2014, the inter-annual
and monthly variability of precipitation and heavy precipitation in the Kumtag Desert were analyzed. The
mean monthly precipitation and heavy precipitation were analyzed on account of the Chinese automatic
meteorological station and CMORPH-fusioned hourly rainfall of 0.1° grid data set, with the results that
heavy precipitation in the Kumtag Desert were mainly concentrated in summer, and the percentage of
heavy precipitation in summer to annual total heavy precipitation was 80%. The pattern of monthly pre-
cipitation thereof was 'the afternoon', while the patterns of monthly heavy precipitation were 'the early
morning' and 'the afternoon'. The distribution of precipitation in the Kumtag Desert and its surrounding areas was in agreement with the distribution of heavy precipitation; the maximum and heavy precipitation
occurred in June. A belt of precipitation existed in the south of the Kumtag Desert around the Altun
Mountains in spring, autumn and winter while, in summer, the belt almost disappeared.
2017 Vol. 53 (4): 481-488 [Abstract] ( 83 ) [HTML 1KB] [ PDF7796KB] ( 59 )
489 Impacts of disposal projects on the groundwater level and degree of#br# mineralization in the lower reaches of Shiyang River
Ma Jian-ping, Yan Zi-zhu, Fu Gui-quan, Liu Hu-jun, Yuan Hong-bo, Liu Shu-juan
 The data of groundwater level and degree of mineralization in 52 wells from 2001 to 2014 were
used to analyze their temporal and spatial changes in Minqin, and correlation analysis was made of the
groundwater level, degree of mineralization and disposal projects. The results showed that in space, the
maximum and minimum groundwater level was in Qushan and Nanhu regions and the degree of mineral-
ization was like: Hu (lake) region>Quanshan region>Ba region>Nanhu region. In time series, the ground-
water level increased (2001-2009) firstly and then maintained at a smooth state, at the same time hav-
ing a tendency to reduce (2001-2009). The monthly variations of groundwater level was in "V", the de-
gree of mineralization was increasing (2001-2012) and then reducing (2012-2014), it was bigger in au-
tumn than spring in the Hu and Nanhu regions, while it was bigger in spring than autumn in Quanshan
and Ba regions. The correlation analysis showed that the groundwater level, degree of mineralization of
groundwater and disposal projects had a remarkable correlation between them.
2017 Vol. 53 (4): 489-493 [Abstract] ( 79 ) [HTML 1KB] [ PDF1242KB] ( 53 )
494 Evaluation of the hydrological status and water quality in the gobi#br# areas of Hexi Corridor, Gansu Province
Sun Tao 1, 2, 3,Liu Shi-zeng 1,Ji Yong-fu 1, 4,Tang Jing-nian 1,Fang E-tian 1, 4,Ding Feng 1,
 The hydrological data in the gobi areas of Hexi Corridor were surveyed and the water quality
of water samples collected therein were analyzed. The results showed that water quality in the gobi areas
of Hexi Corridor was generally fine, while it was of a different quality in different areas. The gobi in the
lower reaches of Danghe River and Heihe River were dominated with classⅠwater, while Ⅲ and Ⅳwere
not found. Water quality in the gobi areas of the middle and lower reaches of Shulehe River and Beishan
Mountain were relatively bad, where the class Ⅲ water had been detected all. The gobi area in the lower
reaches of Shiyang River
2017 Vol. 53 (4): 494-500 [Abstract] ( 56 ) [HTML 1KB] [ PDF0KB] ( 8 )
501 Optimized conditions of Chlorella vulgaris adsorbing cadmium by the#br# response surface methodology
Xi Yu-qin, Ren Chun-yan, Zhu Qiao-qiao, Yang Hong, Sun Dui-xiong
With the adsorption rate and biomass as indicators and on the basis of single factors, the opti-
mal conditions of Chlorella vulgaris adsorbing Cd 2+ were determined using the response surface method,
with the result that various factors on the adsorption of Cd 2+ were significantly affected and the order of
influence of the concentration being cadmium>solution pH>culture temperature. Using the regression
equation to predict the optimal conditions for the adsorption of Cd 2+ , the biomass and chlorella adsorption
rate reached 0.71 g/L and 85.2% when the temperature, pH and the concentration of the culture fluid were
maintained at 29.14 ℃ , 6.67 and 30.74 μmol/L, respectively.
2017 Vol. 53 (4): 501-505 [Abstract] ( 83 ) [HTML 1KB] [ PDF3037KB] ( 51 )
506 Effects of temperature on the respiration of biocrusts-dominated soils#br# under extreme rainfall events
Guan Chao 1, 2,Zhang Peng 1,Li Xin-rong 1
To study the effects of temperature on the respiration of biocrust-dominated soil, intact soil col-
umns with two types of biocrusts (moss and algae-lichen crusts) were collected in a natural vegetation ar-
ea in the southeast fringe of the Tengger Desert. Automated soil respiration system (Li-8150) was used to
measure the respiration rates of biocrust-dominated soils under warming (by placing them in an open top
chamber) and non-warming treatments during an extreme rainfall event. The results showed that diurnal
variation of the respiration of two types of biocrust-dominated soil showed a single peak at 12:00-14:00,
after which it began to decrease, reaching a minimum value at 00:00-2:00. During the whole observation
period, imitated climate warming impeded respiration rates of the two biocrust-dominated soils. Under an
extreme rainfall event, the relationship between the daily mean respiration rate of biocrust-dominated soil
and soil temperature could not correctly reflect their relationship. But the diurnal variations of the respira-
tion rate of biocrust-dominated soil could properly reflect their relationship, and the respiration rates of
biocrust-dominated soil showed significantly positive linear correlations with soil temperature.
2017 Vol. 53 (4): 506-511 [Abstract] ( 67 ) [HTML 1KB] [ PDF2690KB] ( 40 )
512 Effects of environment factors on the carbon flux of artificial vegetation#br# in Shapotou
Zhou Yuan-yuan 1, 2,Li Xin-rong 1,Gao Yan-hong 1,Chen Yong-le 1, 2,Song Guang 1, 2,
Based on the eddy covariance data of artificial vegetation in the southeastern margin of the
Tengger desert, the carbon flux and environmental factors in the artificial vegetation area were analyzed.
The results indicated that the daily diurnal and seasonal variations of carbon flux were significant. From
April to October, this ecosystem was mainly of carbon sink, and the carbon absorption in June was high-
est. The highest daily absorption also happened in June. Net ecosystem exchange in July, compared with
the adjacent month, was smaller, due to the fact that, in this period, the temperature, radiation and vapor pressure deficit were too high and, as a result, plant photosynthesis was restrained. We also analyzed the
correlations between the net ecosystem exchange and environment factors which included photosynthetic
photon flux density, net radiation, vapor pressure deficit, air temperature, air relative humidity, 5 cm soil
temperature, 5 cm soil water content and wind speed. The results showed that the influence factor of
daytime carbon flux were mainly based on photosynthetic photon flux density and vapor pressure deficit,
photosynthetic photon flux density were the main factors that affected the net ecosystem exchange, fol-
lowed by vapor pressure deficit. Photosynthetic photon flux density and net ecosystem exchange were
in a rectangular hyperbolic relationship. The net ecosystem exchange decreased with the increase of pho-
tosynthetic photon flux density, but when the vapor pressure deficit was greater than 1.5 kPa, the de-
gree of decrease in this relationship had been weakened. The maximal assimilation rate, apparent initial
light use efficiency and dark respiration rate were different in the light response model parameters of
different months, and the maximum values of the three were in June. At night, the dominant factor of
respiration was air temperature and the secondary factor was soil water content. When the soil moisture
content was less than 3.5%, the air temperature rose above 21.25 ℃ , and that would reduce the rate of
nocturnal respiration.
2017 Vol. 53 (4): 512-520 [Abstract] ( 75 ) [HTML 1KB] [ PDF1965KB] ( 46 )
521 Physical effect of biological soil crusts on germination of exotic species in#br# the desert
Song Guang 1, 2,Li Xin-rong 1,Hui Rong 1,Zhao Yang 1,Zhou Yuan-yuan 1, 2,Guan Chao 1, 2
The influence of biological soil crusts on two exotic plant species, Setaria viridis and Ceratoi-
des latens in the re-vegetation region at the north of the Baotou-Lanzhou Railway was analyzed and the
results showed that intact algal and lichen crust inhibited seed germination of Setaria viridis and Ceratoi-
des latens, but once algal and lichen crust were disturbed, the germination of the two exotic plants in-
creased significantly. The size and morphological characteristics of the seeds also determined the inhibi-
tion degree of biological soil crust on seed germination of the exotic plants. It was concluded that the
presence of biological soil crusts might effectively reduce the exotic plant seeds in the soil and resist es-
tablishment and threats of exotic plant in desert ecosystem.
2017 Vol. 53 (4): 521-525 [Abstract] ( 66 ) [HTML 1KB] [ PDF1292KB] ( 41 )
526 Bacterial community in naturally fermentative maize straw by#br# high-throughput sequencing
Ling Li-jun, He Nan, Bai Xue, Pu Wei-jun, Ma Min-juan, Liu Yan
 Every two days, DNS and phenol-sulfuric method were used to determine the contents of reduc-
ing sugar and total sugar, respectively. The composition and structure of bacterial communities in initial,
interim and tail stages of fermentative maize straw were analyzed based on high-throughput sequencing
of the V4-V5 region of the 16S rRNA gene. The results showed that, as fermentative time went by, two
kinds of sugar even presented a down-up-down trend. A total of 80 575 effective sequences and 3 307 op-
erational taxonomic units were obtained, which were classified into 194 genera from 18 phyla. Bacterial
diversity and richness of the fermentative samples changed significantly. The analysis of the bacterial com-
position indicated that, in the middle and late periods, bacteroidetes phyla increased significantly, proteo-
bacteria decreased obviously and firmicutes showed a down-up trend. The number of bacterial genera in
tail stage increased by 69.3% relative to the initial stage, proving the existence of an extremely rich bac-
terial diversity in fermentative maize straw and in the different periods different dominant bacterial com-
munities appear.
2017 Vol. 53 (4): 526-533 [Abstract] ( 75 ) [HTML 1KB] [ PDF1096KB] ( 38 )
534 Apriori estimates and existence of positive solutions to quasilinear elliptic#br# equations with critical convection terms and nonlinear Neumann#br# boundary conditions
Hu Zhe
The paper was concerned with the existence of positive solutions to quasilinear elliptic equa-
tions with critical convection terms and nonlinear Neumann boundary conditions. Blow-up arguments
and Liouville-type theorems were used to obtain a priori estimates and prove the existence of positive so-
lutions by the fixed point theorem.
2017 Vol. 53 (4): 534-540 [Abstract] ( 69 ) [HTML 1KB] [ PDF821KB] ( 52 )
541 Generalized equilibrium problems and their duality
Huang Long-guang
The equivalence of duality on equilibrium problems and generalized equilibrium problems in
some sense was presented. The dual characterization of equilibrium problems was established in the
frame of generalized equilibrium problems and then, with some conditions, the equivalence results of the
duality for equilibrium and generalized equilibrium problems were shown by duality condition-derived
generalized equilibrium problems.
2017 Vol. 53 (4): 541-544 [Abstract] ( 57 ) [HTML 1KB] [ PDF583KB] ( 42 )
545 Pricing and hedging of the defaultable CPPI with jump processes
Guo Wen-jing, Li Si-jie
 Stocks and corporate bonds with credit risks were chosen as investment objectives of constant
proportation portfolio insurance (CPPI) strategy. Under the condition of continuous time and jump market,
the explicit expression of CPPI was given. The hedging relationship between CPPI and contingent claims
was proven through the martingale approach, and a simulation was conducted through an investment case.
2017 Vol. 53 (4): 545-551 [Abstract] ( 66 ) [HTML 1KB] [ PDF885KB] ( 39 )
552 Athree-dimensional heterogeneous IoTs routing decision-making#br# mechanism based on cellular address
Wang Yi-jun, Han Tai-lin, Zhou Xin
 A three-dimensional heterogeneous routing decision-making mechanism may have some prob-
lems, including low data transmission efficiency, high energy consumption and poor end-to-end delay in
Internet of things (IoTs). One routing decision-making mechanism based on cellular address (RDCA) was
proposed with the establishment of a three-dimensional communication model. The RDCA established
network node data forwarding guidelines based on cellular automata and node average received signal
strength. The RDCA completed the route optimization and control by IPv6 addressing. The routing deci-
sion-making mechanism was resolved by the cellular address. The simulation results showed that the
packet delivery fraction of RDCA was between 82% and 95%, routing consumption ratio was between
20% and 35%, and average end-to-end delay was 20 ms. It can not only ensure IoTs communication per-
formance index, but also improve network reliability and stability.
2017 Vol. 53 (4): 552-557 [Abstract] ( 57 ) [HTML 1KB] [ PDF1992KB] ( 35 )
558 Amechanic model for the micro-cantilever-based gene#br# detection of single nucleotide mismatches
Wang De-peng, Wang Ji-zeng
 The influence of surface distribution was incorporated with the configuration of charged DNA
chains to propose a new theoretical model to quantitatively describe both complete and incomplete hybrid-
ization induced deflections. The deflection radius of curvature was treated as the only variable for the DNA
detection. Predictions on relations between cantilever deflection and the incomplete DNA hybridization
given by the proposed model could perfectly match experiments of reference [2]. The prediction accura-
cy could even allow the detection of changes in a single base pair. The model developed in this work
may help decipher the familiar mismatch phenomenon in DNA-based disease detections.
2017 Vol. 53 (4): 558-568 [Abstract] ( 66 ) [HTML 1KB] [ PDF2037KB] ( 42 )
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