Pore-Throat Combination Types and Gas-Water Relative Permeability Responses of Tight Gas Sandstone Reservoirs in the Zizhou Area of East Ordos Basin, China

With the aim of better understanding the tight gas reservoirs in the Zizhou area of east Ordos Basin,a total of 222 samples were collected from 50 wells for a series of experiments.In this study,three pore-throat combination types in sandstones were revealed and confirmed to play a controlling role in the distribution of throat size and the characteristics of gas-water relative permeability.The type-I sandstones are dominated by intercrystalline micropores connected by cluster throats,of which the distribution curves of throat size are narrow and have a strong single peak(peak ratio>30%).The pores in the type-II sandstones dominantly consist of secondary dissolution pores and intercrystalline micropores,and throats mainly occur as slice-shaped throats along cleavages between rigid grain margins and cluster throats in clay cement.The distribution curves of throat size for the type-II sandstones show a bimodal distribution with a substantial low-value region between the peaks(peak ratio<15%).Primary intergranular pores and secondary intergranular pores are mainly found in type-III samples,which are connected by various throats.The throat size distribution curves of type-III sandstones show a nearly normal distribution with low kurtosis(peak ratio<10%),and the micro-scale throat radii(>0.5μm)constitute a large proportion.From type-I to type-III sandstones,the irreducible water saturation(Swo)decreased;furthermore,the slope of the curves of Krw/Krg in two-phase saturation zone decreased and the two-phase saturation zone increased,indicating that the gas relative flow ability increased.Variations of the permeability exist in sandstones with different porethroat combination types,which indicate the type-III sandstones are better reservoirs,followed by type-II sandstones and type-I sandstones.As an important factor affecting the reservoir quality,the pore-throat combination type in sandstones is the cumulative expression of lithology and diagenetic modifications with strong heterogeneity.

Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area

Dynamic analysis steps and general flow of fast lagrangian analysis of continua in 3 dimensions(FLAC3D) were discussed. Numerical simulation for influence of excavation and blasting vibration on stability of mined-out area was carried out with FLAC3D. The whole analytical process was divided into two steps, including the static analysis and the dynamic analysis which were used to simulate the influence of excavation process and blasting vibration respectively. The results show that the shape of right upper boundary is extremely irregular after excavation, and stress concentration occurs at many places and higher tensile stress appears. The maximum tensile stress is higher than the tensile strength of rock mass, and surrounding rock of right roof will be damaged with tension fracture. The maximum displacement of surrounding rock is 4.75 mm after excavation. However, the maximum displacement increases to 5.47 mm after the blasting dynamic load is applied. And the covering area of plastic zones expands obviously, especially at the foot of right upper slope. The analytical results are in basic accordance with the observed results on the whole. Damage and disturbance on surrounding rock to some degree are caused by excavation, while blasting dynamic load increases the possibility of occurrence of dynamic instability and destruction further. So the effective supporting and vibration reducing measures should be taken during mining.

A Highly Sensitive Femtosecond Time-Resolved Sum Frequency Generation Vibrational Spectroscopy System with Simultaneous Measurement of Multiple Polarization Combinations

Characterization of real-time and ultrafast motions of the complex molecules at surface and interface is critical to understand how interracial molecules function. It requires to develop surface-sensitive, fast-identification, and time-resolved techniques. In this study, we employ several key technical procedures and successfully develop a highly sensitive femtosecond time-resolved sum frequency generation vibrational spectroscopy （SFG-VS） system. This system is able to measure the spectra with two polarization combinations （ssp and ppp, or psp and ssp） simultaneously. It takes less than several seconds to collect one spectrum. To the best of our knowledge, it is the fastest speed of collecting SFG spectra reported by now. Using the time-resolved measurement, ultrafast vibrational dynamics of the N-H mode of α-helical peptide at water interface is determined. It is found that the membrane environment does not affect the N-H vibrational relaxation dynamics. It is expected that the time-resolved SFG system will play a vital role in the deep understanding of the dynamics and interaction of the complex molecules at surface and interface. Our method may also provide an important technical proposal for the people who plan to develop time-resolved SFG systems with simultaneous measurement of multiple polarization combinations.

Reduction of Cogging Torque and Electromagnetic Vibration Based on Different Combination of Pole Arc Coefficient for Interior Permanent Magnet Synchronous Machine

Cogging torque and electromagnetic vibration are two important factors for evaluating permanent magnet synchronous machine(PMSM)and are key issues that must be considered and resolved in the design and manufacture of high-performance PMSM for electric vehicles.A fast and accurate magnetic field calculation model for interior permanent magnet synchronous machine(IPMSM)is proposed in this article.Based on the traditional magnetic potential permeance method,the stator cogging effect and complex boundary conditions of the IPMSM can be fully considered in this model,so as to realize the rapid calculation of equivalent magnetomotive force(MMF),air gap permeance,and other key electromagnetic properties.In this article,a 6-pole 36-slot IPMSM is taken as an example to establish its equivalent solution model,thereby the cogging torque is accurately calculated.And the validity of this model is verified by a variety of different magnetic pole structures,pole slot combinations machines,and prototype experiments.In addition,the improvement measure of the machine with different combination of pole arc coefficient is also studied based on this model.Cogging torque and electromagnetic vibration can be effectively weakened.Combined with the finite element model and multi-physics coupling model,the electromagnetic characteristics and vibration performance of this machine are comprehensively compared and analyzed.The analysis results have well verified its effectiveness.It can be extended to other structures or types of PMSM and has very important practical value and research significance.

Effects of vibration in desert area caused by moving trains

The ballast layer, filled with fine particles like blown sand, is one of the important problems of ballasted railway tracks in desert areas. Blown sand, as a contaminator of ballast layer, increases track stiffness and may cause serious damage to sleepers, pads, rails, and vehicles. In this paper, the effects of increasing track stiffness due to windy sands in the ballast layer and the train induced vibrations due to this phenomenon were studied. Based on field studies in a desert area in Iran, a two-dimensional finite/infinite element model for a railway track with plane strain condition was analyzed using the software ABAQUS, and the track vibrations were examined by changing the values of stiffness of ballast layer. Vibrations caused by the load of train at different distances from the cross-section of track were inves- tigated, and the values of vertical vibration displacement, velocity, and acceleration were calculated. Results show that acceleration values of vertical vibration increase with the increasing of ballast layer stiffness caused by the filling of sand, while the vertical vibration velocity of track and the induced ground displacement decrease. The farther the distance from the source of vibration, the less the displacement, velocity, and acceleration. In addition, the methods for reducing train-induced vibrations were introduced.

农村地区高血压患者服药情况及影响因素研究:基于家庭医生签约服务

背景高血压是心血管疾病主要的危险因素,降压用药不仅要考虑患者血压特征,也要考虑患者合并症情况。现阶段,基于家庭医生签约服务对高血压患者的服药状况及影响因素研究比较缺乏。目的调查安徽省界首市家庭医生签约服务的高血压患者服药现状,描述患者服药行为与患者特征之间的关联,探索患者用药调整的影响因素,并分析基层高血压患者用药的合理性。方法采用整群抽样的方法,于2021年7—8月从安徽省界首市随机抽取48个行政村,通过面对面调查法采用自制问卷收集患者特征和服药数据,参照《国家基层高血压防治管理指南2020版》将问卷中患者提到的降压药分为如下5类:A类为血管紧张素转换酶抑制剂(ACEI)和血管紧张素受体阻滞剂(ARB),B类为β受体阻滞剂,C类为钙通道阻滞剂(CCB),D类为利尿剂,E类为单片复方制剂。通过科大讯飞智能语音血压计的后台获取患者上传的近1年血压数据,分析不同特征患者的服药行为。采用多因素Logistic回归分析探讨高血压患者用药调整的影响因素。本研究中联合用药是指服用复方制剂或2种以上降压药,用药调整是指患者过去服用其他降压药。结果本研究共纳入高血压患者3005例,其中男1291例(43.0%)、女1714例(57.0%),平均年龄为(65.5±9.8)岁,高血压服药率为79.1%,联合用药率为40.2%。2376例服用降压药的患者中,不同类型降压药服用率从高到低依次为(部分患者存在联合用药):E类(39.6%)、C类(35.1%)、D类(20.3%)、A类(20.1%)、B类(3.7%);服用最多的降压药为复方利血平(33.7%)。对于年均血压≥160/100mm Hg的患者,仍有12.2%和4.9%未服用降压药。患者联合用药以E类降压药为主。年均“舒张压≥100 mm Hg”且“患合并症”的患者,调整后A类和C类降压药的服用率增加相对较多,年均“收缩压≥160 mm Hg”且“未患合并症”的患者,调整后E类降压药的服用率增加相对较多。多因素Logistic回归结果显示,服药年数长(OR=1.042,95%CI=1.031~1.053,P<0.001)、初中以上文化程度(OR=1.488,95%CI=1.195~1.853,P<0.001)、合并高脂血症(OR=1.267,95%CI=1.052~1.525,P=0.013)、合并心血管疾病(OR=1.394,95%CI=1.166~1.667,P<0.001)、合并脑血管疾病(OR=1.258,95%CI=1.040~1.522,P=0.018)是患者用药调整的促进因素,高龄(OR=0.980,95%CI=0.971~0.990,P<0.001)是用药调整的抑制因素。结论界首市农村地区高血压患者的服药率较高,主要服用E类和C类降压药。服药年数长、初中以上文化程度、合并高脂血症、合并心脑血管疾病是患者用药调整的促进因素,高龄是用药调整的抑制因素。

Selection of Indigenous Plants in Roads in Northwestern Loess Plateau Area

[Objective] The aim was to study on resource utilization of indigenous plants in roads in order to solve resource shortage of indigenous plant in bioengi- neering. [Method] Based on northwestern loess plateau area, we conducted research on selection of indigenous plants and survey on the species which could live in adverse condition, mainly by surveying, with frequent tests as a supplement, to make a comprehensive observation and evaluation on plant combinations which are to be extensively applied. [Result] The research indicated that in central dividing strips, four arbors, including Platycladus orientalis （Linn.）Franco, Sabina chinensis, Sabinachinen- sis（Linn.）Ant., and Ulmus purnila L., and nine frutices, including Lycium chinense, Tamarix austromongolica, Rosa xanthina Lindl., Forsythia suspense, Atriplex canescens, Amygdalus triloba, Hippophae rharnnoides Linn., Arnorpha fruticosa L., and Syzygium aromaticum could be planted. In addition, Gleditsia sinensis Lain, Robinia pseudoacacia L, Elaeagnus angustifolia L., Rhus typhina, Salix babylonica, Salixmatsudana and Fraxinus chinensis, tall and strong, are suitable to be planted as border trees, presenting a good vision. Frutices, limited by height, are usually with more branches, which will provide a good landscape if grown with tall plants. Prunus dacidiana and Ulmus pumila L., prone to be damaged by insects, should be planted with other species to stop the infestation in space. [Conclusion] The research laid foundation for selection of indigenous plants in roads, providing references for resource shortage of indigenous plant for bioengineedng.

Field experiment of subgrade vibration induced by passing train in a seasonally frozen region of Daqing

The vibration characteristics and attenuation of the subgrade caused by passing trains in a seasonally frozen region of Daqing, China are investigated. Three field experiments were conducted during different times through the year, in normal, freezing and thawing periods, respectively, and the influence of the season, train speed and train type, is described in this paper. The results show that： （1） the vertical component is the greatest among the three components of the measured vibration near the rail track, and as the distance to the railway track increases, the dominant vibration depends on the season. （2） Compared with the vibration in the normal period, the vertical and longitudinal vibrations increase while the lateral vibration decreases in the freezing period. However, in the thawing period, the vertical and longitudinal vibrations decrease, and the lateral vibration increases. （3） As train speeds increase, the subgrade vibration increases. （4） The vibration induced by a freight train is greater than by a passenger train. These observations provide a better understanding of the vibration and dynamic stability of the subgrade and may be useful in developing criteria for railway and building construction in cold regions.

A Numerical Investigation of Vortex-Induced Vibration Response and Fatigue Damage for Flexible Cylinders Under Combined Uniform and Oscillatory Flow

Vortex-induced vibration(VIV)for flexible cylinders under combined uniform and oscillatory flow is a challenging and practical issue in ocean engineering.In this paper,a time domain numerical model is adopted to investigate the characteristics of cross-flow VIV response and fatigue damage under different combined flow cases.Firstly,the adopted VIV model and fatigue analysis procedure are validated well against the published experimental results of a4-m cylinder model under pure oscillatory flows.Then,forty-five combined flow cases of the same cylinder model are designed to reveal the VIV response characteristics with different non-dimensional oscillation period T^*and combined ratio r.The combined flow cases are classified into three categories to investigate the effect of r on cylinder’s dynamic response,and the effect of T*is described under long and short period cases.Finally,fatigue analysis is carried out to investigate how the structural fatigue damage varies with the variations of r and T^*.The captured characteristics of structural response and fatigue damage are explained through the VIV mechanism analysis.

SOME KEY ISSUES ON THE APPLICATION OF SATELLITE REMOTE SENSING TO MINING AREAS

In order to apply Satellite Remote Sensing (RS) to mining areas, some key issues should be solved. Based on an introduction to relative studying background, related key issues are proposed and analyzed oriented to the development of RS information science and demands of mining areas. Band selection and combination optimization of Landsat TM is discussed firstly, and it proved that the combination of Band 3, Band 4 and Band 5 has the largest information amount in all three-band combination schemes by both N-dimensional entropy method and Genetic Algorithm (GA). After that the filtering of Radarsat image is discussed. Different filtering methods are experimented and compared, and adaptive methods are more efficient than others. Finally the classification of satellite RS image is studied, and some new methods including classification by improved BPNN(Back Propagation Neural Network) and classification based on GIS and knowledge are proposed.

Application of a New Qeneration of Geophonesto Improve Seismic Acquisitionin Onshore-offshore Transition Areas

In this paper, we review the differences between velocity geophones （VG） and acceleration geophones （AG） and their effect on seismic signals acquired in onshore-offshore transition areas. We present a new generation of Land Piezoelectric Geophone （LPG） and analyze its performance. Our field experiments demonstrate that our new LPG can be used to substitute for VGs in order to eliminate phase, frequency and energy differences between different geophone systems commonlv used in transition areas.

GEOFEATURES AND RESOURCE ELEMENT COMBINATION OF TUMEN RIVER ECONOMIC GROWTH TRIANGLE

The development of world economy has been heading for globalization and regionalization. In recent years, this tendency has born great impact on the rapid economic development of the Asian and Pacific countries, which assumes the form of economic growth triangle as their major way for regional cooperation involving multiple nations. Among these, the Tumen River Triangle consisting of six countries' cooperation may have attracted great attention. Since 1991 when UNDP began to draw up plans for such a mammoth project which is called the Tumen River Area Development Project (or TRADP), the international economic cooperation in this area has been developing energetically. It is now necessary to assess the characteristics of geographical conditions and various economic resources from the viewpoints of economic geography and expound the mammoth benefits both in economy and to society. The demonstration would undoubtedly absorb more international capital to this area and enhance its economic and social development.

Individual and combined influences of main loading parameters on granite damage development under ultrasonic vibration

Ultrasonic vibration technology has great potential to weaken hard rocks.Understanding the effect of ultrasonic vibration loading parameters is essential to accelerate the application of this technology in practical rock engineering.In the present work,three-factor mixed-level orthogonal ultrasonic vibration rock breaking tests were conducted to investigate the influence of the main loading parameters,including confining pressure,vibration frequency,and static force,on the damage of granite specimens.The individual and combined influences were analyzed according to the porosity increase and P-wave decrease of granite specimens using the variance analysis method.The results show that the combined effect of the static force and vibration frequency mainly promotes fatigue damage of specimens,that the confining pressure determines the damage behaviour and failure mode of specimens under ultrasonic vibration,and that the confining pressure and vibration frequency are the main factors that cause the fracture concentration in the upper part of specimens,an effect mechanistically driven by the obvious load energy attenuation.The research results provide theoretical guidance for the application of ultrasonic vibration technology.

Combined deformation of filament-wound cylinder and application to torsion vibration control

The combined deformation and mechanical properties of filament-wound cylinder of filament reinforced composite materials are investigated. A method of using filament-winding composites to reduce the amplitude of torsion vibration in the case of special stimulated vibration is established. A design formula of anisotropic filament-wound cylinder to reduce the torsion vibration of axle components is obtained. The results indicate that by putting the filament-wound cylinder on an axis, the torsion vibration of the axis can be reduced effectively.

Combined Effects of Exposure to Noise and Vibration on Human Postural Equilibrium under Simulated Driving Conditions

There is little information about drivers’body balance responses to combined exposure of noise and vibration.To fill the gap,this study aims to investigate the combined effects of exposure to noise and whole-body vibration(WBV)on the body balance under simulated driving conditions.For this purpose,30 male participants were exposed to noise level at 85 dB(A)and two vibration levels(0.87 and 1.3 m/s^(2))in five sessions.The design of the study was repeated-measures,and it attempted to assess the effects of 40 minutes of exposure to noise and/or WBV.Moreover,the participants’fatigue was measured with the Borg scale(CR 10).The findings revealed there was a significant change in body sway after WBV and combined noise and WBV exposure(p<0.05).However,no significant difference was found in exposure to noise alone(p>0.05).The effect sizes of exposure to noise,WBV(1.3 m/s^(2)),and combined noise and WBV(1.3 m/s^(2))on body balance were 0.035,0.425,and 0.635,respectively.Also,single exposure to WBV caused more fatigue than single exposure to noise(p<0.05).Combined noise and WBV exposure descriptively caused more fatigue in comparison with the influence of WBV alone.The study concluded that the combined effects of exposure to noise and vibration are more than the sum of them.So,some synergistic effects may be observed in human body balance.It is essential to increase drivers’awareness and revise current health care interventions about new possible effects of combined exposures.

Effect of combined spinal and epidural anesthesia on the level of pain media, stress indicators and inflammatory factors in patients undergoing high altitude cesarean section

Objective: To discuss the effect of combined spinal and epidural anesthesia on the levels of pain media, stress indicators and inflammatory factors in patients undergoing high altitude cesarean section. Methods: Eighty patients who underwent cesarean section in our hospital from January 2017 to April 2019 were enrolled in the hospital. They were divided into two groups according to the patient's anesthesia. Fourty patients receiving epidural anesthesia were included in the control group, and another 40 patients received lumbar stiffness. The combined anesthesia patient was included in the observation group. Changes in pain mediators [Serum neuropeptide Y (NPY), endorphin (β-EP), substance P (SP)], stress indicators [Serum cortisol (Cor), C-peptide (C-P), advanced oxidative protein product (AOPP)], inflammatory factor levels [Hypersensitive C-reactive protein (hs-CRP), tumor necrosis factor-alpha (TNF-α)], and immunoglobulin levels [Serum IgA, IgG, IgM] were compared between the two groups. Results: Before anesthesia, there were no significant difference in pain media, stress index, inflammatory factor level and immunoglobulin level between the two groups (P>0.05). At 12 h after operation, the two groups of patients were NPY, β-EP, SP, Cor. The levels of C-P, AOPP, hs-CRP and TNF-α were higher than those before operation (P<0.05). The levels of IgA, IgG and IgM were lower than those before operation (P<0.05). Among them, observation group NPY, β-EP, SP, Cor, C-P, AOPP, hs-CRP and TNF-α were significantly lower than those of the control group (P<0.05). The serum levels of IgA, IgG and IgM were significantly higher than those of the control group (P<0.05). Conclusion: Combined spinal and epidural anesthesia can more effectively alleviate maternal pain in high altitude cesarean section, more effectively reduce the inflammatory stress response of patients, promote the humoral immune function of patients, and is beneficial to the early recovery of maternal postoperative, and has high clinical value.

Some Inequalities for L_p-mixed Affine Surface Area

In this paper, the concepts of the ith L;-mixed affine surface area and Lp-polar curvature images are introduced, some new inequalities connecting these new notions with Lρ-centroid bodies and ρ-Blaschke bodies are showed. Moreover, a Blaschke-Santalo type inequality for Lρ-mixed affine surface area is established. Our results also imply the similar to the inequalities for Marcus-Lopes, Bergstrom and Ky Fan.

Mapping of oil-source faults in reservoire-cap rock combinations without a source rock

Oil and gas exploration near faults in shallow strata is investigated in this study based on an analysis of oil-source faults in reservoire-cap rock combinations without a source rock.The oil-source faults were mapped by superimposition of the distribution area of oil-source faults and the leakage area of cap rocks.This method is applied to the mapping of oil-source faults for two sets of reservoire-cap rock combinations without a source rock in the Banqiao area of the Qikou Sag in the Bohai Bay Basin,eastern China.Combination B is formed by a mudstone cap rock of the middle sub-member of the 1st member of the Shahejie Formation(E3s1 M)with its underlying reservoir,while Combination C is formed by a mudstone cap rock of the 2nd member of the Dongying Formation(E_(3)d_(2))with its underlying reservoir.The results show that the oil-source faults of Combination B are relatively better developed and mainly occur in the northeast and southeast,while those of Combination C are not as well developed and are only distributed at the southeastern edge of the study area with a small proportion in the north.These results are consistent with the fact that oil and gas are mainly distributed near oil-source faults,proving the method proposed is workable in determining the oil-source faults in reservoire-cap rock combinations without a source rock.

结合型式对地铁车站上盖物业的振动响应影响

为研究地铁振动对不同结合类型地铁车站及其上方的动力反应影响,基于地铁车站与上盖物业连接型式的主要承载区别,提出“软结合”“硬结合Ⅰ”“硬结合Ⅱ”3种结合型式;然后,采用车-轨耦合模型得到列车荷载谱,利用有限差分软件FLAC^(3D)建立地铁车站-上盖物业数值仿真模型,并与实测数据进行对比,验证数值仿真模型与参数的正确性;最后,基于数值仿真,从时域、频域出发,研究3种结合型式下上盖物业的振动响应.研究结果表明:软结合型式下站厅层到上盖物业一层加速度峰值减小69.10%,硬结合Ⅰ型减小2.08%,硬结合Ⅱ型增大2.94%,硬结合型式下上盖物业振动加速度较软结合型式大;3种结合型式下上盖物业振动的频率主要在40~90 Hz,且对于上盖物业同一楼层,振动随距振源距离的增大而逐渐减小;软结合型式下上盖物业一层加速度级最大值为68.2 dB,较站厅层减小11.3 dB;硬结合Ⅰ型、硬结合Ⅱ型的上盖物业加速度级最大值分别为83.4、79.4 dB;地铁振动造成上盖物业附加第一主应力很小,且在向上传播过程中衰减很快;从站厅层到上盖物业,软结合型式第一主应力衰减85.81%,硬结合Ⅰ、Ⅱ型式分别衰减63.46%、72.27%,间隔土对附加应力有明显衰减作用.在地铁实际建设工程中建议选用软结合型式.