Table of Content

20 November 2012, Volume 48 Issue 6

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Relationship between Perceived Job Search Progress and Job Search Activities: Mediate Effect of Job Search Emotion

SHENG Zitong,SHI Junqi

2012, 48(6):  873-878. 

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The study concentrated on the path of emotion in job search process. Data was collected in two waves among 295 university graduates. Hierarchical regression analysis show that job search emotion is a fully mediator in the relationship between perceived job search progress and job search activities. This result emphasizes on the role of emotion in the job search process. The authors bring forward some suggestions to college graduate students and employment guidance personnel.

Application of PLC Automatic Control System in the Purification Part of the Conventional ⁴⁰Ar/³⁹Ar Dating System

LIU Xiaoyu,SUN Qiang

2012, 48(6):  879-885. 

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The automation retrofit of purification part in the conventional ⁴⁰Ar/³⁹Ar dating laboratory of Peking University was based on mastering the components and operation processe of the purification part. By clearing the requirements of the system, the authors proposed an automatic control method, using PLC (programmable automation controller) as the core of the control system in order to monitor and control the purification system. The automatic reform include the hardware control part and the software part. First, the manual valves was changed to the automatic valves. The transformation of the hardware is based on the purification system’s demands of automatic valves to allocate the I/O ports (input/output) and design the related electrical schematics. In the software part, by use of anxiliary register, program is designed to realize the interlocking of pneumatic valves and make pneumatic valves in the purification system work automatically. The newly promoted purification system made the ⁴⁰Ar/³⁹Ar dating experiment run automatically, which saved manpower, improved the utilization efficiency of the experimental apparatus, reduced the artificial errors caused by person participation, and laid foundation for further automatic improvement of the laboratory.

Width and Hanging Wall Effect of Surface Rupture Caused by Wenchuan Earthquake

HE Zhongtai,MA Baoqi,LI Yusen,HAO Yanjun,SHA Peng

2012, 48(6):  886-894. 

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The authors make the width of surface rupture caused by 2008 Ms 8.0 Wenchuan earthquake as the object, characterize the width of surface rupture by the thrust fault scarps, flexure-slip folds, and mole tracks, and check out characteristics of the width of the surface rupture along the Beichuan-Yingxiu fault and Hanwang-Bailu fault. The conclusion suggests that there is difference about the width between the Beichuan-Yingxiu fault and Hanwang-Bailu fault and about the width in different section along the same Beichuan-Yingxiu fault. Both of the faults have obvious hanging wall effect. The safety distance away from the fault in the hanging wall in rebuilding is 70 m at least and 23.5 m in the foot wall, and the total safety distance along the fault in rebuilding should be more than 108 m about the Beichuan-Yingxiu fault. The safety distance away from the fault in the hanging wall in rebuilding is 35 m at least and 20 m in the foot wall, and the total distance should be more than 58 m about the Hanwang-Bailu fault. In addition, the width and hanging wall effect of co-seismic surface rupture zone is in accordance with the hight of fault scarp, intensity isoseismal map, and strong earthquake ground motions.

Theory and Application of Numerical Simulation of Asymmetric Hydraulic Fractures in Ultra-Low Permeability Reservoirs

WU Wenjuan,SHI Yongmin,WANG Xiaojun,LIU Hongtao,QIN Xiaoshuang,WANG Lei,CHAI Zhi,LI Xiaomin

2012, 48(6):  895-901. 

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Based on Chang-6 formation of Yanchang group in Erdos basin, built the geology, 3D rock mechanics and 3D stress field models with core and logging data, and obtained the properties of any point between wellbores. With the fracturing principle, the actual geometry of the fractures can be calculated, and the asymmetry fractures model can be built, including the length, height, width and the direction of the fractures. With the analysis of production history, the residual oil distribution can be obtained, and the multiple fracturing procedure can be designed. With the guidance of the asymmetric fracture models, the daily increase of production is more than 4 ton.

Characteristics and Controlling Factors of Volcanic Reservoirs in Cenozoic Group, Qikou Depression

JIANG Yiqin,LUO Jinglan,WANG Naijun,LIU Huaqing,GUO Yongfeng,LI Shuangwen

2012, 48(6):  902-912. 

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The characteristics and controlling factors of volcanic reservoirs in Cenozoic Group, Qikou Depression were researched using a large amount of data from core observation, ordinary slices, cast slices and well logging interpretation results. The results indicate that basaltic volcanic lava takes the highest proportion in volcanic rocks Cenozoic Group, Qikou Depression. Hypabyssal intrusive diabase takes the second highest. Pyroclastic sedimentary and sedimentary pyroclastic rocks also take certain proportion. Volcanic reservoir space can be classified into two main types: pore and fractures. Reservoir space in basalt is mainly stomata, residual stomata and matrix solution pores. Reservoir space in diabase is mainly intergranular dissolution pores, intragranular dissolution and alteration minerals dissolution pores. Reservoir space in tuffaceous sandstone is mainly intergranular dissolution pores, intragranular dissolution pores and dissolved fracture. Reservoir space in tuff is mainly dissolution pores within the gravel and intergranular dissolution pore. In the growing process of volcanic reservoirs in Cenozoic Group, Qikou Depression, dissolution plays the determining function, volcanic lithology and facies are the base of the growing process, tectonic fracture and weathering erosions also play the important part.

Wavelet Analysis of Precipitation Fluctuation at Saihanba in Hebei Province from 1965 to 2011

REN Yanlin

2012, 48(6):  918-924. 

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The author used Morlet complex wavelet analysis to analyze the precipitation fluctuation from 1965 to 2011 at Saihanba in Hebei Province and to reveal the multi-time scale feature of precipitation pattern. It shows that the anomolies of monthly precipitaion, growing season precipitation (May to September) and annual precipitation in the last 47 years vary at two time-scales: one is 4 years of inter-annual oscillation, which is the low-frequency part of the inter-annual fluctuation after high-frequency filtering; and the other is about 18 years of decadal oscillation. The growing season precipitation of Saihanba accounts for 83.1 percent of the annual precipitation, thus both of them often show the same trends but with some exceptions. The wavelet coefficient curve under the scale of 18 years indicates that precipitation will keep higher than mean annual precipitation with decreased anomalies in 2012?2015.

Effects of Precipitation Change on Inorganic Nitrogen and Net Nitrogen Mineralization Rate at a Plantation of Mongolian Pine

REN Yanlin

2012, 48(6):  925-932. 

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The contents of inorganic Nitrogen (N) and rates of soil N mineralization at soil depths of 0?5, 5?10,10?20 and 20?30 cm were measured by a field manipulative experiment of ±30% throughfall and closed-top tube incubation method in a Pinus sylvetris var. mongolica plantation at PKU-SOGES, China. The results show that the contents of inorganic N, NH₄⁺-N, and NO₃^--N at the soil depths of 0?30 cm are 6.70±2.31, 5.59±1.78, 1.11±0.77 mg/kg, respectively. There is no significant difference among inorganic N contents of different soil depths and throughfall treatments but the NO₃^--N of +30% is lower than that of control. Net N mineralization rates of 0?30 cm was ?0.24 (?6.65 to 10.24) mg/(kg?30d). Throughfall treatments and soil depths have no significant effects on net ammonification rates. According to the net nitrification rates and net N mineralization rates, both of them at 0?5 cm are significantly higher than those at other soil depths, and treatments of ±30% throughfall are higher than the control. In a word, both the ±30% throughfall treatments decrease inorganic N, and increase net N mineralization rates. The results also indicate that impacts of precipitation change on soil NH₄⁺-N and ammonification are weaker than those on NO₃^--N and nitrification. This study will contribute to assessment of precipitation changes on plantation ecosystem service and N biogeochemical cycle.

Cell-ID Positioning Method Based on Linear Weight

WAN Jiahuan,ZHUANG Chunhua,CHEN Xiuwan,ZHANG Weiyi,WAN Wei

2012, 48(6):  913-917. 

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A kind of Cell-ID positioning method is put forward based on linear weight and Google base station database. All of the signal strength and position of the base stations received by the mobile terminal are utilized and it only needs to update the software of the terminal. The result shows that the accuracy is less than 150 m under 2s circumstances and it is more suitable for LBS.

Effects of Precipitation Change on Soil Respiration Rate and Apparent Q₁₀ of Temperature Sensitivity in a Mongolian Pine Plantation

REN Yanlin,DU Enzai

2012, 48(6):  933-941. 

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A chronic field manipulative experiment of ±30% throughfall (+30%, ?30%, and control, respectively) in a Mongolian pine plantation was carried out to detect the responses of forest soil respiration and its temperature sensitivity to precipitation change at PKU-SOGES, China. Results of repeated measures ANOVA indicate that there is no statistically significant effect of three throughfall treatments on soil respiration rates and apparent Q₁₀ generally (p>0.05). Multiple comparisons of paired t-test show that the soil respiration rates of +30% is statistically higher than that of the control (p<0.001), and the latter is not different from ?30% statistically (p >0.05). The order of apparent temperature sensitivity of soil respiration for three throughfall treatments is ?30% < control < +30% (p >0.05), which has a weak increasing trend along with increased precipitation. The results imply that the impact of chronic precipitation decrease of 30% on forest soil respiration may be rather limited, but the precipitation increase of 30% will stimulate soil CO₂ efflux dramatically.

Sensitivity of Risk Explicit Interval Linear Programming (REILP) Solutions to Constraint Risk Preferences: Numerical Analysis and Implications

CHEN Xing,ZOU Rui,LIU Yong,SHENG Hu,GUO Huaicheng

2012, 48(6):  942-948. 

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The authors study the solution robustness of the Risk Explicit Interval Linear Programming (REILP) model using numerical experimentations, investigating whether optimal solutions of a REILP would vary under various preferences to different constraints. The first numerical experiment deals with an optimal land use planning subject to nutrient loading constraints. The second one deals with an optimal water resource allocation subject to pollutant loading constraints. The results show that REILP solutions have different sensitivities to constraint preferences in different cases. This phenomenon suggests that in practice it is necessary to conduct thorough analysis on the robustness of REILP solutions to constraint preferences before reaching reliable decision support. In addition, the variability of REILP solutions with regard to various constraint preferences makes it possible to efficiently generate alternative management schemes within the frame work of REILP.

A Multi-scale Encoding System for Landslide and Rock Fall Hazard and Interpretation with Monte Carlo Model

WANG Wei,LI Tianhong,NI Jinren

2012, 48(6):  949-956. 

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An encoding system for landslide and rock fall hazard, applicable to multi-scale, is proposed. Multi-factor information that can affect the landslide and rock fall hazard occurrences and their hazard degrees is given to study units by codes at different scales. Some study units with historical disaster records are selected as reference, and codes of these units in reference are interpreted by Monte Carlo model. Then a large number of other units can be interpreted according to the assumption that regions with similar codes should have similar hazards. Wide range applications, paying more attention to uncertainty study, low requirements for data, intuitive and detailed information presented by codes, avoiding redundancy of data and simplifying calculation are advantages of this approach. This study has great significance for identification of landslide and rock fall hazard characteristics and hazard assessment and prevention.

Encode Landslide and Rock Fall Hazard and Interpretation with Monte Carlo Model in China

WANG Wei,LI Tianhong

2012, 48(6):  957-964. 

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The multi-scale encoding system for landslide and rock fall hazard and interpretation with Monte Carlo model is applied to hazard assessment in China. Counties and cities of China are encoded according to landslide and rock fall hazard information. Monte Carlo simulation is used to interpret some codes as reference, and the other codes are interpreted by matching them with reference. The whole China is zoned into five regions according to interpreted code hazard degrees that include very low, low, medium, high and very high. The correlation analysis shows that landslide and rock fall codes have high correlations with codes of geology factor and geomorphology factor. Verification of BP neural network, comparison between results interpreted by Monte Carlo model and historical disaster record and comparison between proposed approach and other approach indicate that results given by proposed approach are sufficient accuracy.

Screening of Lead-Tolerant Microbes and Preliminary Study on Their Removal Capability to Lead

YANG Liang,HAO Ruixia,WU Feng,XIAO Yuxiong

2012, 48(6):  965-970. 

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Four lead-tolerant strains were isolated from lead-contaminated soil around the lead-zinc ore deposit. All strains could grow in nutrient solution containing 100?1000 mg/L Pb(II). The removal rates of Pb(II) by Pb-X-1, Pb-Z-3 and Pb-Z-4 were 78.31%, 77.8% and 87% respectively in the following conditions: pH was 6, 25℃, 160 r/min, initial Pb²⁺ concentration was 600 mg/L. The Pb(II) removal rate by Pb-X-2 was higher than 95%, when initial Pb(II)concentration was 100?400 mg/L. The result of 16S rRNA sequencing indicates that Pb-X-2 belonged to Stenotrophomonas maltophilia. The removal mechanism of Pb(II) removal by Pb-X-2 was mainly cellular surface adsorption and intracellular enrichment.

A DPSIR-Based Indicator System for Ecological Security Assessment at the Basin Scale

LI Yuzhao,LIU Yong,YAN Xiaopin

2012, 48(6):  971-981. 

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The DPSIR model was modified to meet the urgent decision making requirements on restoring the impaired basins under human’s disturbance. From the point of improved DPSIR model, an indicator system reflecting the panoramic view of ecological security for basin-scale assessment was established. This system has successfully revealed a causal chain of how social-economic behaviors as a driving force could make a pressure to ecological security so as to change its state and how such changes would affect human activities thus lead to a series of “response” measures. Given the specific environment of River Jinsha basin into consideration, an indicator system of 59 indicators i.e. per capital GDP, soil erosion ratio, forest coverage rate etceteraly was established to verify the applicability and importance of improved DPSIR model in basin-scale ecological security assessment. It is believed that the improved DPSIR model is of great value to provide scientific support and practical basis for basin-scale ecological assessment.

Study on Land Ecological Assessment Based on GIS in Village Scale: A Case Study of Yan Ba Village in Jiangjin, Chongqing

CHENG Wei,WU Xiuqin,CAI Yumei

2012, 48(6):  982-988. 

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The authors clarified the content of land ecological evaluation, and summarized the research status in China and abroad. The land ecological evaluation of Yan Ba village in Jiangjin Chongqing was carried out, based on GIS. According to actual condition of Yan Ba village and Materials availability, the index system is constructed by 4 target layers, 10 index layers and 18 factors. The score of each index layers and target layers were calculated, using GIS raster analysis function, by expert scoring method to determine the weight. The comprehensively ecological evaluation score of each grid unit was finally calculated. As a result, the ecological quality is preferable in the first class and the second class, occupying about 32 percent of the total area of Yan Ba and distributing in the relative flat area in the middle and southeast of Yan Ba village. The ecological quality is moderate in the third class, occupying about 42.87 percent of the total area, which mainly distributes in the flood plain of Jia-Ling River. The others are the fourth class and fifth class, in which the land ecological quality is range, mainly distributing on the hill and geology damage buffering area. The research of land ecological assessment in village scale is an important support for the further implementation of village scale participatory land use planning.

Removal of Lead from the Simulated MSW Incineration Flue Gas by Sulfur-Impregnated Activated Carbon Fiber (ACF/S)

MIN Yutao,YUAN Li,LIU Yangsheng

2012, 48(6):  989-997. 

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The removal efficiency of Pb by activated carbon filters (ACF) modified by sulfur (ACF/S) was investigated. Two parameters (mass fractions of sulfur and atmosphere of simulated flue gas) were examined for their effects on the removal efficiencies. SEM (scanning electron microscopy) and FTIR (Fourier transform infrared spectroscopy) were used to investigate the mechanism of Pb captured by ACF/S. SEM images indicate that a large quantity of the sulfur is distributed onto the surface of ACF, and aggregation is present. Experimental results show that, the sulfur significantly enhance the ACF performance for Pb removal in different atmosphere of the simulated MSW flue gas (HCl, SO₂, HCl+SO₂) with efficiencies higher than 65% for particulate lead and 80% for volatile lead. In conclusion, ACF/S is a promising material for Pb removal from flue gas.

Spatio-temporal Differentiation of County Multi-functions along the Bohai Rim in China

LIU Yu,LIU Yansui,GUO Liying

2012, 48(6):  998-1008. 

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Based on the definition of dominant functions as well as the building of multifunctionality evaluation index system and analysis models, the authors evaluated the functions of economic development, grain production, social security and eco-conservation. Major findings are summarized as follows. 1) In 2008, economic-oriented functional areas were mainly distributed in Beijing-Tianjin-Tangshan region, Shenyang Metropolitan area, Jiaodong Peninsula and other municipal districts; grain-oriented functional areas were mainly distributed in central plain of Liaoning, western plain of Shandong, piedmont plain of Taihang Mountain and alluvial plain of Haihe River; the spatial pattern of social security function was closely related to that of economic development; eco-conservation functional areas were concentrated in eastern mountain areas and northwest hill areas of Liaoning, and northeast mountainous-hilly areas in Hebei. 2) Compared with 1990, the indices of multi-functions demonstrated an upward trend, and functions of economic development and social security have been improved significantly. The increasing degree of grain production function was smaller with the gravity center of grain production gradually concentrated on the plain agricultural areas, while the distribution of eco-conservation function hadn’t change considerably.

Travel Mode Choice Model Accounting for Individual Preference Heterogeneity and Correlation among Choice Alternatives

YANG Liya,ZHAO Pengjun

2012, 48(6):  1009-1015. 

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The authors proposed a new travel mode choice model to overcome the limitation of traditional logit model. Combining generalized extreme value model and latent class model, the authors present a modeling methodology capable of accounting for individual preference heterogeneity and correlation across choice alterna- tives. Travel cost, travel time, parking fee, and waiting time are defined as utility variables for mode choice, while individual income, travel purpose, and travel distance are selected as variables of segment membership function. This model can depict the correlation among choice alternatives and individual preference heterogeneity simultaneously. Using Beijing traffic survey data of 2005, the model parameters are estimated. Estimation results show that the latent class paired nested logit model outperforms the traditional models. Most travelers are cost-sensitive to travel modes, and thus strategies that reduce the travel cost can be more effective than reducing the travel time.

Removal of Cadmium and Copper from Aqueous Solution by the Adsorption Resin Coated Manganese Oxide

LU Xuemei,XIONG Ying,ZHANG Guangzhi,NI Jinren

2012, 48(6):  1016-1022. 

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A new hybrid material (Mn-SD300) was prepared by coating manganese oxide onto the adsorption resin SD300, which adopted the method of in-suit potassium permanganate oxidation and reduction. The adsorption ability of Mn-SD300 for Cd²⁺ and Cu²⁺ was studied. The results of TEM, XRD and XPS demonstrated that the form of manganese oxide loaded on the resin was MnO₂. A good adsorption property of Cd²⁺ and Cu²⁺ onto Mn-SD300 was indicated by the batch experiments. The adsorption behavior of Cd²⁺ and Cu²⁺ on Mn-SD300 was well described by pseudo-first-order kinetic model and Langmuir isotherm model (R²>0.99), and the maximum adsorption capacity of Mn-SD300 towards Cd²⁺ and Cu²⁺, were up to 76.92 mg/g and 142.86 mg/g respectively at 303 K. Compared to the conventional cation exchange resin D001, Mn-SD300 had a better adsorption selectivity to Cd²⁺ and Cu²⁺, when Ca²⁺, Mg²⁺ and Na⁺ coexisted at high concentration.

Particulate Number Emission Factors and Charactization from Road Traffic

WANG Fenjuan,FANG Dong,Matthias Ketzel

2012, 48(6):  1023-1029. 

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The authors studied the vehicle particle number emission and its characterization in the real world driving conditions. Emission factors were estimated based on the long-term field measurement data from both background and kerbsides stations near highway and urban street in Copenhagen, Danmark. The results show that the particle number emission factors of average fleet for highway and urban street are (215.4±5.3) ×10¹² km^-1 and (187.1±3.1) ×10¹² km^-1, respectively. Emission factors of heavy-duty and light-duty vehicle are also estimated. The ratio of heavy-duty vehicle particle number emission factors to that of light-duty vehicle are around 20, both higher at urban site than them at highway site. Particle size distribution varies with measurement locations. There are dominating Bi-modes of particle number concentration appeared at both sites, a 10 nm mode at highway site, a 20?30 nm mode at urban site and a common 50?80 nm mode at both sites. There is uncertainty of estimating the emission factor in real environment caused by measurement locations, environment etc. and vehicle count of different types, which affects the emission factors for heavy-duty and light-duty vehicles.

Application of Resins on the Treatment of Waters Polluted by Heavy Metals

LU Xuemei,XIONG Ying,ZHANG Guangzhi

2012, 48(6):  1030-1038. 

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A review on the research progress of resins in the treatment of heavy metal contaminating waters was carried out, in which the properties and applications of both ion exchange resins and adsorption resins were elaborately discussed. In addition, the research prospects concerning current problems were also proposed.