Research on Safety Risk Assessment Method for Large Scale Field Operation Project

By applying man-machine-environment system engineering theory, safety risks on large scale field operation project have been evaluated in this article. The factors concerning with the man, machine and environment in system were proposed separately. The value for lowest indexs was determined by decision-making of expert group. The weights were calculated based on AHP, and then safety risk assessment in different layers was made. The results show that the assessment method is reasonable, and it is significant for large scale field operation project safety managerment.

Method of accurately calculating mean field operator in multi-configuration time-dependent Hartree-Fock frame

The accurate theoretical expressions of the mean field operator associated with the multi-configuration time-dependent Hartree-Fock （MCTDHF） method are presented in this paper. By using a theoretical formula, derived without approxima- tion, we can study the multi-electron correlation dynamics accurately. Some illustrative calculations are carried out to check the accuracy of the expression of the mean field operator. The results of illustrative calculations indicate the reliability of the accurate expression of the mean field operator. This theoretical calculation method for the mean field operator may be of considerable help in future studies of the correlated dynamics of many-electron systems in strong laser fields.

Employing Diversity and Similarity Indices to Evaluate Geopedological Soil Mapping in Miyaneh, East Azerbaijan Province, Iran

The geopedological viewpoint attempts to distinguish and introduce the smallest map unit that has the highest levels of homogeneity and uniformity with respect to landform, lithology, and soil, especially if the relationship between geomorphology and soils in the region is well defined. This research intended to investigate the degree of validity generalization of results obtained in the geopedology approach for similar landforms in the Miayneh region of East Azerbaijan Province, Iran. For this purpose, soil diversity study was conducted through measuring it in a hierarchical sequence in categories of USDA soil taxonomy and by comparing similar units in the geopedological method through employing pedodiversity and similarity indices. After preparing the initial interpretative map (based on aerial photographs) at a scale of 1:20,000, the HPu211 unit that covered the greatest delineation of study area was selected and 28 soil profiles, about 90 meters apart, were excavated, described, and sampled in this unit. The degree of validity generalization of geopedological results for the mentioned unit was determined by digging 14 other soil profiles in a similar unit, called the validation area, which was located outside of the sample area. Results indicated that the value of Shannon’s diversity index increased from the level of soil order to soil family in both the sample and the generalization areas;however, only at the soil family level were there significant differences between soil diversity in the two areas at the confidence level of 95%. As well as classification of the profiles dug in the generalization area was different from that of the profiles dug in the sample area at the category of soil family. Therefore, it is possible that management generalizability in this method, even at the detailed scale, can satisfy the related needs. Consequently, interpretative or managerial purity of geopedological units must be considered in future research.

体育现代化指标体系中“体育人口”指标合理性论证

采用文献资料、人文田野调查等研究方法,对体育人口作为体育现代化指标体系中的一项主要指标的合理性进行论证。研究结果表明:体育人口作为反映群众体育发展程度的一项重要指标,已经成为我国体育现代化指标体系中的一项主要指标,然而从体育人口概念研究的不确定性、体育人口判定标准不能科学解释亲身参与体育活动的全部人群、体育人口概念和判定标准在体育现代化试点过程中难以操作等层面来看,体育人口作为体育现代化指标体系中的一项主要指标缺乏逻辑的自洽性和科学性。

Design, development and field assessment of a controlled seed metering unit to be used in grain drills for direct seeding of wheat

A newcontrolled seed metering unit was designed and mounted on a common grain drill for direct seeding of wheat(DSW).It comprised the following main parts:(a)a variable-rate controlled direct current motor(DCM)as seed metering shaft driver,(b)two digital encoders for sensing the rotational speed of supplemental ground wheel(SGW)and seed metering shaft and(c)a control box to handle and process the data of the unit.According to the considered closed-loop control system,the designed control box regularly checked the revolution per minute(RPM)of seed metering shaft,as operation feedback,using its digital encoder output.The seeding ratewas determined based on the calculated error signal and output signal of the digital encoder of the SGW.A field with four different levels of wheat stubble coverage(10%,30%,40%and 50%)was selected for evaluation of the fabricated seed metering unit(FSMU).The dynamic tests were conducted to compare the performance of installed FSMU on the grain drill and equipped grain drill with common seed metering unit(CSMU)at three forward speeds of 4,6 and 8(Km/h)for DSW.Results of the FSMU assessment demonstrated that an increase in forwardspeed of grain drill(FSGD)and stubble coverage did not significantly affect the seeding rate in the grain drill forDSW.Using theFSMU reduced the coefficient of variation(CV)by approximately 50%.Consequently,applying the FSMU on the common grain drill led to a desirable seeding rate at different forward speeds of the grain drill and stubble existence.

Physical-property cutoffs of tight reservoirs by field and laboratory experiments: a case study from Chang 6, 8–9 in Ordos Basin

Tight sandstone reservoirs are generally characterized by complex reservoir quality,non-Darcy flow,and strong heterogeneity.Approaches utilized for evaluating physical property cutoffs of conventional reservoirs maybe inapplicable.Thus,a comprehensive investigation on physical property cutoffs of tight sandstone reservoirs is crucial for the reserve evaluation and successful exploration.In this study,a set of evaluation approaches take advantage of field operations(i.e.,core drilling,oil testing,and wireline well logging data),and simulation experiments(i.e.,high-pressure mercury injection-capillary pressure(MICP)experiment,oil-water relative permeability experiment,nuclear magnetic resonance(NMR)experiment,and biaxial pressure simulation experiment)were comparatively optimized to determine the physical property cutoffs of effective reservoirs in the Upper Triassic Chang 6,Chang 8 and Chang 9 oil layers of the Zhenjing Block.The results show that the porosity cutoffs of the Chang 6,Chang 8,and Chang 9 oil layers are 7.9%,6.4%,and 8.6%,and the corresponding permeability are 0.08 mD,0.05 mD,and 0.09 mD,respectively.Coupled with wireline well logging,mud logging,and oil testing,the cut-off of the thickness of single-layer effective reservoirs are approximately 3.0 m,3.0 m,and 2.0 m,respectively.Depending on the cutoffs of critical properties,a superimposed map showing the planar distribution of the prospective targets can be mapped,which may delineate the effective boundary of prospective targets for petroleum exploration of tight sandstone reservoirs.

SIMULATION OF TANK SLOSHING BASED ON OPENFOAM AND COUPLING WITH SHIP MOTIONS IN TIME DOMAIN

Tank sloshing in ship cargo is excited by ship motions, which induces impact load on tank wall and then affects the ship motion. Wave forces acting on ship hull and the retardation function are solved by using three-dimensional frequency domain theory and an impulse response function method based on the potential flow theory, and global ship motion is examined coupling with nonlinear tank sloshing which is simulated by viscous flow theory. Based on the open source Computational Fluid Dynamics （CFD） development platform Open Field Operation and Manipulation （OpenFOAM）, numerical calculation of ship motion coupled with tank sloshing is achieved and the corresponding numerical simulation and validation are carried out. With this method, the interactions of wave, ship body and tank sloshing are completely taken into consideration. This method has quite high efficiency for it takes advantage of potential flow theory for outer flow field and viscous flow theory for inside tank sloshing respectively. The numerical and experimental results of the ship motion agree well with each other.