Impact of climate change on allowable bearing capacity on theQinghai-Tibetan Plateau

Climate change has a substantial impact on infrastructures in the permafrost on the Qinghai-Tibetan Plateau (QTP). In this study, the mean annual ground temperature (MAGT) and permafrost evolution were investigated in both the historical (1950-2005) and projected (2006-2099) periods. Then, an allowable bearing capacity model was used to discuss the allowable bearing capacity change on the QTP. Results show that the MAGT increased by 0.36 ℃ during 1950-2005. The MAGT will increase by 0.40 (RCP2.6), 0.79 (RCP4.5), 1.07 (RCP6.0), and 1.75 (RCP8.5)℃C during 2006-2099. In addition, the permafrost area has decreased by 0.195 × 10^6 km2 in 1950-2005. The permafrost area will decrease by 0.232 × 10^6 (RCP2.6), 0.468 × 10^6 (RCP4.5), 0.564 × 10^6 (RCP6.0), and 0.803 × 10^6 (RCP8.5) km2 during 2006-2099. With the degradation of permafrost, the allowable bearing capacity in permafrost zones would decrease accordingly. The decreasing trend is 6 kPa per 10 years in 1950-2005, and will be 0.6 (RCP2.6), 5 (RCP4.5), 7 (RCP6.0), and 11 (RCP8.5) kPa per 10 years during 2006-2099. The most remarkable trend would be observed under RCP8.5. Meanwhile, some scientific advices for the design, construction, operation and maintenance of permafrost engineering in the context of climate change were provided.

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mmx28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.

Big-M based MILP method for SCUC considering allowable wind power output interval and its adjustable conservativeness

In contrast to most existing works on robust unit commitment(UC),this study proposes a novel big-M-based mixed-integer linear programming(MILP)method to solve security-constrained UC problems considering the allowable wind power output interval and its adjustable conservativeness.The wind power accommodation capability is usually limited by spinning reserve requirements and transmission line capacity in power systems with large-scale wind power integration.Therefore,by employing the big-M method and adding auxiliary 0-1 binary variables to describe the allowable wind power output interval,a bilinear programming problem meeting the security constraints of system operation is presented.Furthermore,an adjustable confidence level was introduced into the proposed robust optimization model to decrease the level of conservatism of the robust solutions.This can establish a trade-off between economy and security.To develop an MILP problem that can be solved by commercial solvers such as CPLEX,the big-M method is utilized again to represent the bilinear formulation as a series of linear inequality constraints and approximately address the nonlinear formulation caused by the adjustable conservativeness.Simulation studies on a modified IEEE 26-generator reliability test system connected to wind farms were performed to confirm the effectiveness and advantages of the proposed method.

Calculation of Maximum Allowable Free Span Length and Safety Assessment of the DF1-1 Submarine Pipeline

The DF1-1 submarine pipeline was investigated using a dual-frequency side-scan sonar and a swath sounder system.More than a hundred scour pits under the pipeline were found,most of which have caused the span of the pipeline to increase and threatened its safety.The maximum allowable free span length (MAFSL) of the pipeline was determined through the limitations regarding maximum allowable stress under static or quasi-static loads and the onset of Vortex Induced Vibrations (VIV) under different hydrodynamic actions.The results show that the MAFSL under static conditions is 56 m.However,the MAFSLs are 30 m and 20 m under ordinary weather conditions and hurricane-induced currents for the 100-year return period,respectively,to avoid VIV as calculated by using the highest safety class factor.It is suggested that spanning pipelines longer than 20 m should be supported.Additionally,eight successive spans which may also threaten the pipeline were proposed.The most hazardous scour pits are along the pipeline section from KP42 to KP51.

Fast-solving method for air-to-surface guided bombs' allowable attack area

A new method called local accurate search is put forward to calculate the allowable area for air-to-surface missiles based on the conventional methods. Comparing with traditional methods, the local accurate search method can search the area online and reduce the time of search with the required precision. Combining the traditional flight range table with a model calculation method, the new method employs the local search to fred an accurate result, which will meet the fast-calculation requirements for attacking moving targets. In this way, the missiles are adapted for the complex warfare situation.

Determination of allowable subgrade frost heave with the pavement roughness index in numerical analysis

Frost heave is an upward swelling of soil during cryogenic conditions in cold regions. It is caused by the accumulation of ice crystals in subgrade soil, which grow upwards when freezing temperatures penetrate into the subgrade. This study establishes the allowable soil subgrade frost heave based on the roughness standard of asphalt pavement in China, and aims to balance the pavement design and frost heave resistance of subgrades in cold regions. We formulated a mechanical model of pavement supported by the boundary conditions of differential frost heave, based on the elastie layered system theory. The differential soil subgrade frost heave was modeled as a sinusoidal function, and the allowable frost heave and the roughness index were modeled as the displacement boundaries for the top and bottom of the pavement structure. Then the allowable frost heave was back-calculated according to the roughness standard. Numerical results show that the allowable frost heave depends on the pavement structure, material properties, the highway grade, and other factors. In order to ensure that the actual soil subgrade frost heave is lower than the allowable frost heave, pavement structures and materials need to be selected and designed carefully. The numerical method proposed here can be applied to establish the frost heave re- sistance of subgrade when the pavement structure and materials are determined.

Allowable Bearing Capacity for Shallow Foundation in Eket Local Government Area, Akwa Ibom State, Southern Nigeria

P-wave and S-wave velocities were obtained from seismic refraction survey in the foundation layer of Eket, the study area. The Tezcan’s approach discussed extensively in the work was used in conjunction with the existing mathematical relations between elastic parameters and seismic refraction velocities for the study of foundation layers in the study area. Based on the results, the elastic constants, allowable bearing pressure/capacity, ultimate bearing capacity and other parameters in Table 1 were determined. The result shows that allowable bearing pressure increases with increase in shear modulus and shear wave velocity. The empirical relation between allowable bearing capacity and shear modulus shows that the allowable bearing capacity increases with depth. Comparing our findings with some ranges of safe allowable bearing capacities of similar non cohesive/granular soils in literatures, the second layer with allowable bearing capacity range of 72.56 - 206.63 kN·m-2?(average = 154.78 kN·m-2) has been considered to be the safe shallow engineering foundation in the study area. The empirical relations between allowable bearing capacities shear modulus and shear wave velocity, in conjunction with the inferred maps, which serve as our findings, will be used as guide in the location of foundations. The inferred ultimate and allowable capacities correlate maximally for the two shallow foundations penetrated by the seismic waves. This perfect correlation reflects the uniqueness of the method.

Study on the Design Method of the Jack-up＇s X-Type Cantilever Allowable Load Nephogram

The extending of a cantilever and transverse moving of a drilling floor enable the jack-up to operate in several well positions after the Jack-up has pitched. The cantilever allowable load nephogram is the critical reference which can evaluate the jack-up's drilling ability, design the cantilever structure and instruct a jack-up manager to make the operations safe. The intent of this paper is to explore the interrelationships between the cantilever position, drilling floor and the loads including wind force, the stand set-back weight etc., through analyzing the structure and load characteristics of the x-type cantilever and the simplified mechanics model with the restriction of the maximum moment capacity of the cantilever single side beam. Referring to several typical position designs load values, the cantilever allowable load nephogram is obtained by using the suitable interpolation method. The paper gives a method for cantilever allowable load design, which is proved reliable and effective by the calculation example.

Studies on the Hazardous Effects and the Maximum Allowable Concentration of Pyrophyllite Dust

Pyrophyllite (H2Al2,Si4 O22, ) dust (P-dust) is a mixture of silica (10-40% ), differentproportions of a luminium oxide (Al2O3 ), and various metal compounds. People with occupa-tions known to be associated with exposure to P-dust include miners, other industrial workersand persons engaged in artistic carving. Currently, little is known about pyrophyllite pneumo-coniosis from P-dust. This study was designed to investigate the hazardous effects of P-dustand to suggest a maximum allowable concentration (MAC) of the dust.This.study included four parts: (i) Occupational epidemiology surveys in 781 workersfrom 1 pyrophyllite mine (PM) and four pyrophyllite carving mills (PCM), with a registra-tion rate of 98 %. (ii) In vitro studies: Six groups of rats were expeed to different levels ofP-dust; the cytotoxicity of P-dust on rat alveolar macrophages (AM) was investigated by de-termining the potassium'content of AM and the activity levels of lactate dehydrogenase (LDH)in AM culture fluid. (iii) Mineralogical analysis of P-dust: The contents of silica (SiO2 ), alu-minium (Al), ferrum (Fe), niikel (Ni), zinc (Zn) and copper (Cu) in hath PM-dust andPCMdust were determined. (iv ) Determination of P-dust MAC: Using the life-talbemethod, an investigation of the hygiene standard of P-dust was carried out in 625 workers ex-POSed to either PM-dust or PCM-dust, uPon whom routine radiographs were Performed.The results suggest that the risk of developing pneumoconiosis from pyrophyllite dust issignificantly higher for PM workers than for PCM workers. The prevalence rate of PCM-dustpneumoconiosis is significantly higher in men than in women. The content of SiO2 and AlO3in the mixture of P-dust is the most important factor in the etiology of pyrophyllitosis. De-pending on the different P-dust MAC values, we suggest that 2 rng/m3 and 4 mg/m' shouldbe considered as the MAC for PM-dust and PCM-dust, respectively, and 3 mg/m' fOr P-dust. We believe that establishing different hygiene standards is more accurate even thoughworkers are exposured to the 'same' dust

Allowance Extraction Considering of Inner and Outer Contour and Experimental Research on Belt Grinding of Hollow Blade

Aero-engine fan blades of ten use a cavity structure to improve the thrust-to-weight ratio of the aircraft.However,the use of the cavity structure brings a series of difficulties to the manufacturing and processing of the blades.Due to the limitation of blade manufacturing technology,it is difficult for the internal cavity structure to achieve the designed contour shape,so the blade has uneven wall thickness and poor consistency,which affects the fatigue performance and airflow dynamic performance of the blade.In order to reduce the influence of uneven wall thickness,this paper proposes a grinding allowance extraction method considering the double dimension constraints(DDC)of the inner and outer contours of the hollow blade.Constrain the two dimensions of the inner and outer contours of the hollow blade.On the premise of satisfying the outer contour constraints,the machining model of the blade is modified according to the distribution of the inwall contour to obtain a more reasonable distribution of the grinding allowance.On the premise of satisfying the contour constraints,according to the distribution of the inwall contour,the machining model of the blade is modified to obtain a more reasonable distribution of the grinding allowance.Through the grinding experiment of the hollow blade,the surface roughness is below Ra0.4μm,and the contour accuracy is between-0.05~0.14 mm,which meets the processing requirements.Compared with the allowance extraction method that only considers the contour,the problem of poor wall thickness consistency can be effectively improved.It can be used to extract the allowance of aero-engine blades with hollow features,which lays a foundation for the study of hollow blade grinding methods with high service performance.

Optimal reduction and equilibrium carbon allowance price for the thermal power industry under China’s peak carbon emissions target

As the largest source of carbon emissions in China,the thermal power industry is the only emission-controlled industry in the first national carbon market compliance cycle.Its conversion to clean-energy generation technologies is also an important means of reducing CO_(2)emissions and achieving the carbon peak and carbon neutral commitments.This study used fractional Brownian motion to describe the energy-switching cost and constructed a stochastic optimization model on carbon allowance(CA)trading volume and emission-reduction strategy during compliance period with the Hurst exponent and volatility coefficient in the model estimated.We defined the optimal compliance cost of thermal power enterprises as the form of the unique solution of the Hamilton–Jacobi–Bellman equation by combining the dynamic optimization principle and the fractional It?’s formula.In this manner,we obtained the models for optimal emission reduction and equilibrium CA price.Our numerical analysis revealed that,within a compliance period of 2021–2030,the optimal reductions and desired equilibrium prices of CAs changed concurrently,with an increasing trend annually in different peak-year scenarios.Furthermore,sensitivity analysis revealed that the energy price indirectly affected the equilibrium CA price by influencing the Hurst exponent,the depreciation rate positively impacted the CA price,and increasing the initial CA reduced the optimal reduction and the CA price.Our findings can be used to develop optimal emission-reduction strategies for thermal power enterprises and carbon pricing in the carbon market.

碳中和背景下中美欧印2035年碳减排力度及经济代价探究

根据《巴黎协定》共同时间框架,2025年前各缔约方要提交面向2035年的新一轮国家自主贡献(NDC)。2035年的减排雄心将是连接当前NDC与长期碳中和承诺的重要纽带,对全球能否最终实现2℃/1.5℃温升控制目标具有重要意义。该研究聚焦美国、欧盟这两个碳排放量最大的发达经济体和中国、印度这两个碳排放量最大的新兴经济体,从衔接NDC与碳中和承诺的角度预估四大排放体2035年潜在的碳减排力度,并利用碳配额分配体系和可计算一般均衡模型探究对2℃/1.5℃支持情况以及减排经济代价。结果显示:(1)从NDC迈向碳中和,2035年中国单位GDP二氧化碳排放可能比2005年下降73%~77%,美国碳排放可能比2005年下降61%~67%,欧盟碳排放可能比1990年下降65%~70%,印度单位GDP二氧化碳排放可能比2005年下降51%~58%。(2)上述碳减排力度有可能支持全球2035年走上2℃温控目标碳排放路径,但若要支持走上1.5℃路径,美国和欧盟2035年要达到零碳乃至负碳排放,中国碳排放要降至50亿t左右。(3)在不合作情景下,2035年中国实现上述碳减排力度面临的GDP损失为0.36%~0.58%,与美国(0.36%~0.52%)相当,略低于欧盟(0.49%~0.80%),印度所处发展阶段相对滞后,GDP损失更易受碳减排力度影响(0.26%~0.81%);增强合作有助于以更低的经济代价实现碳减排,2035年四大排放体整体GDP损失有望从0.39%~0.65%下降至0.21%~0.41%。建议尽快深化面向2035年减排目标和实施路径的研究,进一步推动国家间应对气候变化合作交流,以助力全球实现巴黎气候目标。

排污指标法律属性辨析——兼及“排污权”交易制度的走向

“排污权”实为排污指标。对生产者的法律意义是,在许可的种类和数量范围内排污,它既包含权利,也包含义务。从排污不受限制到受法律规制的变化来看,排污指标的功能是设置义务。排污指标本身既不是权利,也不是财产。各种“排污权”权利说都不成立,无法为排污指标交易提供理论支持。排污指标具有某些财产属性是权力发挥作用的结果,其在交易过程中以财产的面貌出现,回到生产过程则回归到义务分配机制的本来属性。受自身本质属性的限制,排污指标的财产权能是不完整的。根据排污指标的性质和指标交易的目的,排污指标交易制度这样安排比较合适:排污指标初始分配采用当前占有无偿分配的方式;政府可以预留一定比例的储备指标,以便对排污指标的供给进行宏观调控;排污指标的交易价格由市场根据供求关系决定。

广东省陶瓷行业碳排放配额分配方法初探

陶瓷行业是国民经济和社会发展的重要基础材料,也是我国实现双碳目标的重要工业行业。全国碳市场启动以来,电力行业由广东试点市场转入全国碳市场交易,陶瓷作为高碳排放行业,已经确定作为下一批纳入广东试点市场的行业之一。基于陶瓷企业工艺特点,结合各碳交易试点陶瓷行业配额分配方法,以及广东省陶瓷企业碳排放核算方法和现行其他行业碳排放配额分配方案,采用基准法结合历史强度法或全部采用历史强度法是广东省陶瓷企业碳排放配额的选择方向,同时在配额分配时可以考虑兼顾能源结构优化的鼓励政策。

中国普惠性生育保障制度设计及其筹资需求

中国生育保障制度缺乏统一制度设计,覆盖范围窄,待遇水平低,难以适应当前人口发展状况。本文提出应建立普惠性生育保障制度,覆盖全体国民,由基本医疗保险支付生育相关医疗费用,设立面向所有分娩女性的生育津贴。本文测算了2021—2035年,不同方案下普惠性生育保障制度的筹资需求及其财政负担。结果发现,不同方案的筹资需求差异较大。总筹资需求中,从儿童类型来看(一孩、二孩和三孩),一孩和二孩的筹资占比约90%;从保障内容来看(生育津贴、产检和分娩报销),生育津贴筹资占比约70%;从城乡来看,城市和镇筹资占比约85%。财政为城乡居民医疗保险参保人提供普惠性生育津贴所需的额外筹资占财政收入的0.31%-0.62%,可负担性较强。本文建议:建立普惠性生育保障制度;制定全国统一的、标准化的产检一揽子服务包,并将其纳入门诊特种病报销,实行按服务项目付费;提高生育相关医疗费用的报销比例;普惠性生育津贴可从低起点起步,保证财务可持续性。

“关怀-照护”理论、老年照护体系和照护型社会

本文讨论了关于老年照护的三个关键性问题,这三个问题分别对应“照护”的理论背景、现实需要和未来发展。其一,“关怀-照护”理论,是一个围绕英文名词“Care”演绎而成的理论体系,涉及关怀伦理学、照护人类学等,本文用一个三角形图示来阐明以这个理论为基础的老年照护体系中的功能耦合和互动;其二,以上述理论为基础,本文认为居家照护既是中国老年人的刚性需要,也是整个老年照护体系的基础;其三,本文从人工智能的发展及其对未来社会的影响来讨论老年照护体系和居家照护如何适应这一发展趋势,同时对老年照护体系的发展前景提出了较为详细的政策创意和方案设计。

考虑用户碳配额的售电公司新能源电力购售策略研究

随着碳配额制度改革的深入,高排放企业日益增加的新能源电力需求给售电公司传统运营模式带来了新的机遇和挑战。针对高排放企业日益提升的绿色用电需求难以满足的问题,提出主从博弈框架下考虑用户碳配额的售电公司新能源电力购售策略模型。研究通过运用Copula函数、拉丁超立方抽样及K-means聚类生成风光出力典型场景,构建了考虑中长期市场、现货市场、储能、碳交易、绿证交易及差异化售电合同的多市场主从博弈双层优化模型。最后,通过算例分析验证了模型的有效性。

《普通照明用荧光灯能效限定值及能效等级》国家标准解读

本文介绍了国家标准《普通照明用荧光灯能效限定值及能效等级》的修订背景,对标准的主要技术内容进行了阐释和说明,并与欧盟法规(EU)2019/2020中的荧光灯能效要求进行了比对,结合《关于汞的水俣公约》修正案对荧光灯市场趋势进行了分析。