Research on the Spatiotemporal Evolution,and Optimized Paths of Carbon Pressure in Northwestern Sichuan under the Carbon Peaking and Carbon Neutrality Goals

Consolidating carbon sink capacity and reducing carbon pressure are important channels to achieve the carbon peaking and carbon neutrality goals actively yet prudently.In order to study the current situation of carbon pressure in the Northwestern Sichuan,we took the carbon pressure of the Aba Tibetan-Qiang autonomous prefecture(Aba prefecture)as an example and used the Intergovernmental Panel on Climate Change(IPCC)approach to measure the carbon emissions,carbon uptake,and the carbon balance index(CBI)of each county-level city in Aba prefecture from 2012 to 2020.The study found that:(a)There was a continuous trend of declining carbon emissions,increased carbon uptake,and decreased CBI in Aba prefecture during the sample period,but there is a large variability among county-level cities;(b)Aba prefecture differs in the spatiotemporal distribution of carbon emissions,carbon uptake,and CBI.Based on the research results,we propose several optimized paths for alleviating the current carbon pressure situation in the Northwestern Sichuan.

Experimental research on influence mechanism of loading rates on rock pressure stimulated currents

The study of pressure stimulated current(PSC)changes of rocks is significant to monitor dynamic disasters in mines and rock masses.The existing studies focus on change laws and mechanism of currents generated under the loading of rocks.An electrical and mechanics test system was established in this paper to explore the impacts of loading rates on PSCs.The results indicated that PSC curves of different rocks had different change laws under low/high loading rates.When the loading rate was relatively low,PSC curves firstly changed gently and then increased exponentially.Under high loading rates,PSC curves experienced the rapid increase stage,gentle increase stage and sudden change stage.The compressive strength could greatly affect the peak PSC in case of rock failure.The loading rate was a key factor in average PSC.Under low loading rates,the variations of PSCs conformed to the damage charge model of fracture mechanics,while they did not at the fracture moment.Under high loading rates,the PSCs at low stress didn’t fit the model due to the stress impact effects.The experimental results could provide theoretical basis for the influence of loading rates on PSCs.

Comparison of intraocular pressure peak and fluctuations among Filipino patients with non-glaucomatous eyes and glaucoma suspects using water drinking test and diurnal intraocular pressure

AIM:To compare the intraocular pressure(IOP)peaks and fluctuations using water drinking tests(WDTs)and mean diurnal IOP among Filipino patients with normal eyes and glaucoma suspectsMETHODS:This prospective study included normal and glaucoma suspect patients.Each patient underwent both WDT and mean diurnal examination on separate visits.For mean diurnal examination,IOP was recorded every 2 h for 8 h while in WDT,IOP was recorded prior to WDT,and postWDT at 5,15,30,45,and 60 min.IOP peak was recorded as the highest IOP for both methods,and IOP fluctuation was recorded as highest IOP minus lowest IOP.RESULTS:With the comparison of diagnostic tests,both normal eyes and glaucoma suspect groups,the peak IOP was caught at 15 min.Comparative analysis of both groups also showed that the peak IOP measurements were statistically higher for the WDT compared to mean diurnal IOP(P=0.039,P=0.048 under normal group and P=0.032 and P=0.031 under glaucoma suspect group).Similarly,the WDT had a statistically higher mean IOP fluctuation score than the mean diurnal IOP method in both groups(P=0.003,P=0.011 under normal group;P=0.002 and P=0.005 under glaucoma suspect group).CONCLUSION:This study shows that WDT is a comparable diagnostic exam in predicting IOP fluctuations than mean diurnal measurement.WDT is a promising diagnostic procedure for risk assessment in glaucoma.

Surface effects on in-shoe plantar pressure and tibial impact during running

Purpose： This study aims to explore the effects of running on different surfaces on the characteristics of in-shoe plantar pressure and tibial acceleration. Methods： Thirteen male recreational runners were required to run at 12 km/h velocity on concrete, synthetic track, natural grass, a normal treadmill, and a treadmill equipped with an ethylene vinyl acetate （EVA） cushioning underlay （treadmill_EVA）, respectively. An in-shoe plantar pressure system and an accelerometer attached to the tibial tuberosity were used to record and analyze the characteristics of plantar pressure and tibial impact during running. Results： The results showed that there were no significant differences in the 1 st and 2nd peak plantar pressures （time of occurrence）, pressure-time integral, and peak pressure distribution for the concrete, synthetic, grass, and normal treadmill surfaces. No significant differences in peak positive acceleration were observed among the five tested surface conditions. Compared to the concrete surface, however, running on treadmillEVA showed a significant decrease in the 1st peak plantar pressure and the pressure time integral for the impact phase （p 〈 0.05）. These can be further ascribed to a reduced peak pressure observed at heel region （p 〈 0.05）. Conclusion： There may not be an inevitable relationship between the surface and the lower-limb impact in runners. It is, however, still noteworthy that the effects of different treadmill surfaces should be considered in the interpretation of plantar pressure performance and translation of such results to overground running.

Side abutment pressure distribution by field measurement

Given the 7123 working face in the Qidong Coal Mine of the Wanbei Mining Group, nine dynamic roof monitors were installed in the crossheading to measure the amount and velocity of roof convergence in different positions and at different times and three steel bored stress sensors were installed in the return airway to measure rock stress at depth. On the basis of this arrange- ment, the rule of change of the distribution of the side abutment pressure with the advance of the working face and movement of overlying strata was studied. The rule of change and the stability of rock stress at depth were measured. Secondly, the affected area and stability time of the side abutment pressure were also studied. The results show that: 1) During working, the face advanced distance was from 157 m to 99 m, the process was not effected by mining induced pressure. When the distance was 82 m, the posi- tion of peak stress was 5 m away from the coal wall. When the distance was 37 m, the position of peak stress away from the coal wall was about 15 m to 20 m and finally reached a steady state; 2) the time and the range of the peak of side rock pressure obtained from stress sensors were consistent with the results from the dynamic roof monitors; 3) the position of the peak pressure was 25 m away from the coal wall.

Cyclic moving average control approach to cylinder pressure and its experimental validation

Cyclic variability is a factor adversely affecting engine performance. In this paper a cyclic moving average regulation approach to cylinder pressure at top dead center （TDC） is proposed, where the ignition time is adopted as the control input. The dynamics from ignition time to the moving average index is described by ARMA model. With this model, a one-step ahead prediction-based minimum variance controller （MVC） is developed for regulation. The performance of the proposed controller is illustrated by experiments with a commercial car engine and experimental results show that the controller has a reliable effect on index regulation when the engine works under different fuel injection strategies, load changing and throttle opening disturbance.

Geologic field evidence for non-lithostatic overpressure recorded in the North American Cordillera hinterland,northeast Nevada

There is a long-standing discrepancy for numerous North American Cordillera metamorphic core complexes between geobarometric pressures recorded in the exhumed rocks and their apparent burial depths based on palinspastic reconstructions from geologic field data.In particular,metamorphic core complexes in eastern Nevada are comprised of well-documented~12-15 km thick Neoproterozoic-Paleozoic stratigraphy of Laurentia’s western passive margin,which allows for critical characterization of field relationships.In this contribution we focus on the Ruby Mountain-East Humboldt Range-Wood Hills-Pequop Mountains(REWP)metamorphic core complex of northeast Nevada to explore reported peak pressure estimates versus geologic field relationships that appear to prohibit deep burial.Relatively high pressure estimates of 6-8 kbar(23-30 km depth,if lithostatic)from the lower section of the Neoproterozoic-Paleozoic passive margin sequence require burial and or repetition of the passive margin sequence by 2-3×stratigraphic depths.Our observations from the least migmatized and/or mylonitized parts of this complex,including field observations,a transect of peak-temperature(T_(p))estimates,and critical evaluation of proposed thickening/burial mechanisms cannot account for such deep burial.From Neoproterozoic-Cambrian(€)rocks part of a continuous stratigraphic section that transitions~8 km upsection to unmetamorphosed Permian strata that were not buried,we obtained new quartz-in-garnet barometry via Raman analysis that suggest pressures of~7 kbar(~26 km).A T_(p)traverse starting at the same basal€rocks reveals a smooth but hot geothermal gradient of≥40℃/km that is inconsistent with deep burial.This observation is clearly at odds with thermal gradients implied by high P-T estimates that are all≤25℃/km.Remarkably similar discrepancies between pressure estimates and field observations have been discussed for the northern Snake Range metamorphic core complex,~200 km to the southeast.We argue that a possible reconciliation of longestablished field observations versus pressures estimated from a variety of barometry techniques is that the rocks experienced non-lithostatic tectonic overpressure.We illustrate how proposed mechanisms to structurally bury the rocks,as have been invoked to justify published high pressure estimates,are entirely atypical of the Cordillera hinterland and unlike structures interpreted from other analogous orogenic plateau hinterlands.Proposed overpressure mechanisms are relevant in the REWP,including impacts from deviatoric/differential stress considerations,tectonic mode switching,and the autoclave effect driven by dehydration melting.Simple mechanical arguments demonstrate how this overpressure could have been achieved.This study highlights that detailed field and structural restorations of the least strained rocks in an orogen are critical to evaluate the tectonic history of more deformed rocks.

Probability Analysis of the Wave-Slamming Pressure Values of the Horizontal Deck with Elastic Support

This paper presents the probability distribution of the slamming pressure from an experimental study of regular wave slamming on an elastically supported horizontal deck. The time series of the slamming pressure during the wave impact were first obtained through statistical analyses on experimental data. The exceeding probability distribution of the maximum slamming pressure peak and distribution parameters were analyzed, and the results show that the exceeding probability distribution of the maximum slamming pressure peak accords with the three-parameter Weibull distribution. Furthermore, the range and relationships of the distribution parameters were studied. The sum of the location parameter D and the scale parameter L was approximately equal to 1.0, and the exceeding probability was more than 36.79% when the random peak was equal to the sample average during the wave impact. The variation of the distribution parameters and slamming pressure under different model conditions were comprehensively presented, and the parameter values of the Weibull distribution of wave-slamming pressure peaks were different due to different test models. The parameter values were found to decrease due to the increased stiffness of the elastic support. The damage criterion of the structure model caused by the wave impact was initially discussed, and the structure model was destroyed when the average slamming time was greater than a certain value during the duration of the wave impact. The conclusions of the experimental study were then described.

An Experimental and Numerical Study on the Cleaning of Pleated Bag Filters Using Low-Pressure Pulsed-Jets

Pulsed-jet cleaning is recognized as the most efficient method to regenerate bag dust collectors traditionally used in industrial processes to control the emission of particulates.In this study,non-woven needle felt filter bags with and without a film coating material have been analyzed considering different geometries(different number N of pairs of pleated filter bag sides)in the frame of dedicated low-pressure pulsed-jet cleaning experiments.The flow structure inside the bag and the response characteristics of its wall have also been analyzed numerically through a computational fluid-dynamics/structural-dynamics(CFD-CSD)unidirectional fluid-solid coupling method.As shown by the experiments,the peak pressure(P_(0))on the wall of the filter bag with N=8 and 12 is higher,which indicates dust can be removed more effectively in these cases.The peak pressure on the wall increases first and then decreases along the direction of the bag length,while the peak pressure of the pleated filter bag with nonwoven needled felt film coating is greater than that without film coating.A comprehensive analysis of the time variation of acceleration,deformation,strain,stress and other factors,has led to the conclusion that the pleated filter bag with N=12 would be the optimal choice.

PRESSUREEFFECTONTHEHEATTRANSFERINBATHOFSUPERFLUIDHELIUM

Considering the basic heat transfer rules of superfluid helium and the phase diagram of helium, pressure effects on heat transfer to HeⅡ are especially studied. If the bath pressure is less than λ pressure ( P λ ), special peak heat flux density relations are shown to correlate bath pressure, hydrostatic head and modified pressure items (Van der waals pressure and fountain pressure). If the bath pressure is greater than λ pressure( P>P λ), a generalized formula of peak flux density of HeⅡp bath is shown.

PRESSURE DISTRIBUTION UNDER NORMAL FEET DURING STANDING AND LEVEL WALKING

Foot pressure measurements were performed during standing and level walkingon a series of 30 normal subjects (15 males, 15 females, a total of 60 feet) with amean age of 37.6 yrs and a mean body weight of 66.3 kg. A significant difference wasfound in the peak pressure under the second metatarsal head between males and femaleswith females showing higher pressures than males daring walking (P【0. 01). The meanpeak pressure and standard deviation for all 7 areas selected for 30 adult subjects duringstanding and walding were obtained. The rise time to peak pressure at each selected areafor walking was recorded and analysed. The practical application and clinical significanceof these data were also discussed.

Performance Analysis of Cushioned Sport Soles with Plantar Pressure Test

Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plantar force,the peak plantar pressure,force-time integrals and pressure-time integrals,and one-way analysis of variance was used to analyze the performance of the designed cushioned shoes.The results revealed that in normal walking and jogging states,compared with the commercially available sport shoes,the peak plantar pressure in the heel region decreased by 13.65%and 6.05%,respectively.The peak plantar force decreased by 15.98%and 15.32%,respectively.The force-time integral decreased by 4.36%and 6.83%,respectively,and the pressure-time integral decreased by 10.58%and 11.00%,respectively.In conclusion,the cushioning performance of shoes is related to the exercise mode.For normal walking,the designed cushioned soles absorbed greater impact in the heel region,which was effectively cushioned,whereas in the jogging state,the designed cushioned soles exhibited a favorable cushioning effect in the forefoot region.The designed cushioned soles exhibited cushioning performance through the coupling design of material and structure,which effectively reduced impact force when landing and could optimize plantar pressure distribution.

The Circular Birefringence-Insensitive FBG Sensor for Weak Pressure

The influence of the circular birefringence on the measurement performance was analyzed based on the Polarization Properties of FBG in this paper. Due to the circular birefringence, the linear relationship between the max of PDL and pressure has been broken down. To estimate the cross sensitivity, a new parameter named relative peak of PDL (RPPDL) is proposed. Under different circular birefringence, the same pressure sensitivity of sensor has been achieved. The theo- retical analysis and experiment results prove that transverse strain sensor of FBG is insensitive to the circular birefrin- gence by applying the RPPDL. This research can be provided to useful and practical application.

Characteristics of wind pressure pulse on large-span flat roofs

The wind pressure pulse events, among the most important characteristics of wind pressure fluctuations on large-span flat roofs, were investigated by wind tunnel tests in this paper. Incorporating the formation mechanism of wind pressure pulse events, the peak over threshold method was employed to study properties of this kind of events. The event duration time, the energy contribution, the number of the pulse events, and the distribution of average peak pressure were calculated. Probability density functions of some typical samples in separation region were also given. Results show that the non-Gaussian roof pressure is strong in the flow separation region owing to the wind pressure pulse events. Evaluations of the extreme peak pressures, which can be determined by the peak over threshold method effectively, are important to the design of building cladding.

Exercise Blood Pressure Response and Cardiometabolic Risk Factors in Middle Aged Women: A MONET Group Study

Objective: To investigate if an exaggerated peak exercise systolic blood pressure (peak ESBP) is associated with alteration of cardiometabolic risk factors and predict future resting hypertension in middle aged women. Methods: Data analysis was performed in 95 healthy normotensive premeno-pausal women at baseline and 84 after 5-year follow-up (age, 49.9 ± 1.9 years;BMI, 23.3 ± 2.2 kg/m2;resting BP, 117/73 ± 11.8/7.6 mmHg). Blood pressure was measured at rest and during a progressive exercise test on treadmill. Women were divided into two groups according to their peak ESBP <190 mmHg vs. ≥190 mmHg. Other outcome measures were: cardiorespiratory fitness (VO2 peak), body composition, body fat distribution and fasting plasma lipids, glucose and insulin levels. Results: 15% and 27% of women presented an exaggerated peak ESBP response (≥190 mmHg) at baseline and year 5 respectively. Linear mixed model repeated measures analysis revealed higher values of fasting glucose, resting systolic and diastolic BP in women with an exaggerated peak ESBP (≥190 mmHg) compared to women with a peak ESBP (<190 mmHg). No significant difference was observed between the two groups for VO2 peak, body composition and body fat distribution indices and other cardiometabolic risk factors. Finally, baseline peak ESBP was not a significant risk factor for future resting hypertension (OR: 2.96, 95%CI [0.48 - 18.12];P = 0.24). Conclusion: Our results, despite being non significant, are of great interest because in healthy and active premenopausal women, exaggerated peak ESBP is not predictive of future hypertension after 5-year follow-up throughout menopause transition.

有界流场中潜艇水压场特性的预报方法和重要特征

潜艇水压场特性是信息化海战场的重要信息源。基于势流理论研究潜艇水压场特性的工程简化预报方法,构建基于兰金体线型的解析模型和基于回转体线型的数值模型,预估多种线型的潜艇水压场特性,并在验证性研究基础上,揭示潜艇线型、潜深等因素对潜艇水压场负压峰值、负压持续时间等重要特征的影响规律。研究结果表明:随着潜深增大,潜艇水压场负压区形状由单峰值的V形逐渐变为U形,甚至双峰值的W形,线型、潜深等因素对重要特征的影响逐渐增强;同一潜深下,随着航速增大,负压持续时间均呈现先突增、后缓降规律,且无论艇体胖瘦,其水压场重要特征在1倍艇长的横距外均已衰减,即该横距外水雷已难以捕捉其目标特性。

3种现场混装炸药耦合装药炮孔壁峰值压力计算

炮孔壁峰值压力是产生炮孔周围应力场的源头,是造成孔壁附近岩石破坏的强动载荷。对于耦合装药,炮孔壁峰值压力是由爆轰波碰撞孔壁而生产的,通常这种碰撞是斜碰撞,并不是正碰撞。基于这样的物理事实,通过对现有耦合装药孔壁压力计算方法行了评述,并提出斜碰撞的炮孔壁峰值压力计算方法。结果表明,爆轰冲击理论计算结果接近实测值和数值模拟值;引入斜入射系数可计算爆轰波斜入射时孔壁压力,爆轰波碰撞在炸药与孔壁的分界面上,在不同的入射角度下,作用在孔壁的压力是不同的。孔壁压力与炸药特性、岩体特性、爆轰波曲率半径、爆轰波入射角等有关。

300 MW供热机组低压缸零出力热力性能、调峰性能和经济性能分析

供热机组低压缸零出力运行可有效提升机组供热能力和调峰深度。该文基于Ebsilon软件,建立300 MW供热机组抽凝工况和低压缸零出力工况的数学模型,从热力性能、调峰性能和经济性能三个维度对常规抽凝模式和低压缸零出力模式进行分析。结果表明,低压缸零出力模式能够有效增加机组的供热能力,并降低发电标准煤耗率,当主蒸汽量为957.6 t/h时,供热量比常规抽凝供热模式提高16.25%,发电标准煤耗率下降27.2 g/kWh。低压缸零出力模式下,虽然供热机组的电负荷不具备调节能力,但其最小电负荷低于常规抽凝供热模式,适宜参与电网的深度调峰。从净收益最大化的角度,当热负荷在162~310 MW时,应采用低压缸零出力模式进行供热;当热负荷在310~375 MW时,应采用抽凝模式进行供热。

低空封闭连廊的表面风压和整体体型系数

采用刚性模型测压风洞试验研究低空封闭连廊的风压分布和整体体型系数,分析连廊4个表面测点的体型系数和非高斯分布特性,研究连廊整体体型系数随风向角和连廊长度的变化,给出低空封闭连廊的正迎风整体体型系数和角度风分配系数,基于极值分析方法给出连廊的全风向极值风压系数,最后给出连廊抗风设计的建议值.研究表明,低空封闭连廊在正吹情况下背风面的体型系数约为-1.04~-0.86,绝对值均大于规范中方柱的-0.6,导致连廊的整体体型系数大于规范中方柱的1.4,30 m长低空封闭连廊的整体阻力系数为1.61;正吹情况下连廊中间截面的整体体型系数大于其他截面,正吹风向角的整体体型系数大于其他风向角,连廊越长正迎风整体体型系数越大;在正吹情况下,连廊迎风面风压主要为高斯分布,其他表面主要为非高斯分布;给出正迎风整体体型系数和角度风分配系数以用于低空封闭连廊主体结构的抗风设计.

基于FLACS的地下暗厨房燃气爆炸数值模拟

为更好地按抗爆要求设计地下暗厨房,利用FLACS软件建立含地下暗厨房的某民用建筑有限元模型,研究气云尺寸、点火位置、障碍物的形状以及位置和尺寸对燃气爆炸压力的影响,并根据数值模拟结果确定爆炸对暗厨房结构的损伤程度。研究表明:在暗厨房中,随着气云尺寸增大,爆炸对建筑物损坏程度也加大。点火位置在厨房、通风井和客厅时,压力峰值分别为41.9、19.5和3.25 kPa。障碍物的存在会使爆炸产生更大的压力,障碍物截面形状为正方形时的压力峰值远大于圆形和长方形;障碍物越靠近点火位置,压力峰值越大;随着障碍物截面尺寸增加,压力峰值不断升高,电梯区域附近压力峰值上升幅度最大。地下暗厨房燃气爆炸产生的冲击波对地上空间影响大于传统厨房。