Strong Negation and Equivalence in the Safe Belief Semantics

The safe belief semantics uses intermediate logics to definean extension of answer sets to all propositional formulas, butonly considering one kind of negation. In this work we extendsafe beliefs adding the strong negation connective. The mainfeature of our extension is that strong negation can occur beforeany formula, and not only at the atomic level. We give resultsconcerning the relation between strong negation extensions ofintermediate logics and safe beliefs and consider the way inwhich strong negation can be eliminated from any formula whilepreserving its semantics. We also propose two new notions ofequivalence: substitution equivalence and contextualized equivalence.We prove that they are both more general than strong equivalenceand, for propositional formulas where strong negation may occurat the non-atomic level, substitution equivalence captures anotion of equivalence that cannot be captured by strong equivalencealone.     

在磨矿回路中回收粗粒金的生产实践

在磨矿分级回路中及时回收粗颗粒单体金，直接获得成品金，可提高金的回收率，加速资金周转，使企业获得较好的经济效益。本文论述了多种回收方法的特点及应用情况。     

三种压力容器用钢的抗氢蚀能力及其服役寿命估算

研究了三种常用压力容器用钢20G、1．25Cr—0．5Mo和2．25Cr-1Mo的抗氢蚀能力。充氢试验后，20G钢发生了严重的氢腐蚀，出现整体脱碳，并导致抗拉和屈服强度以及伸长率的严重下降；1．25Cr-0．5Mo钢在原奥氏体晶界上出现少量氢蚀孔洞，抗拉和屈服强度有少量下降，但伸长率没有明显变化；而2．25Cr-1Mo钢则没有任何氢蚀迹象。同时，通过对这三种钢的临氢服役寿命的估算也表明，2．25Cr-1Mo钢的抗氢蚀能力远高于1．25Cr-0．5Mo钢，而20G钢只有极低的抗氢蚀能力，与试验结论完全符合。该估算方法可以替代经验Nelson曲线并补充其应用的不足。     

水泥充填体的混入对某金矿石浮选的影响及解决措施

河北某地下金矿采出矿石中水泥充填体混入率约为5%,由此造成了自然金及载金矿物黄铁矿等可浮性下降、浮选泡沫变小变黏、磨矿产品细度虚高等问题,严重影响了金的回收和生产过程的稳定。为消除水泥充填体混入带来的诸多问题,在实验室试验和工业试验基础上,对流程结构及药剂制度等进行了优化与完善,同时对尼尔森选矿机的工况等其他问题进行了完善,改造后的2014年,选矿厂的尼尔森精矿金品位和金回收率达1 656.37 g/t、21.79%,浮选精矿金品位和金回收率达107.61 g/t和70.03%,尼尔森精矿金回收率和流程总金回收率分别提高了4.42和6.47个百分点。因此,对现场暴露出的问题而言,试验确定的措施行之有效,对类似矿山具有借鉴意义。     

Adsorption separation of condensate oil from produced water using ACTF prepared of oil palm leaves by batch and fixed bed techniques

A novel method is applied to produce amorphous carbon thin film (ACTF) from oil palm leaves. The novel prepared ACTF is in the form of thin films like graphene sheets having winding surface. ACTF was characterized by different methods of characterization: FTIR, BET, SEM, EDX, TEM, and Raman. ACTF employed as an adsorbent to separate emulsified condensate oil from synthetic produced water as a treatment process before reinjection in oil reservoirs. The adsorption performance of batch and fixed bed adsorption systems were investigated. Contact time, initial concentration of condensate oil ($C_o$ = 100–2500 mg/l) and temperature were studied by batch experiments. The obtained results indicated that the adsorption capacity and the removal efficiency increased with time up to 132.77 mg condensate/g adsorbent and 66.38% respectively, within 6 h equilibrium time at 308 K. The thermodynamic adsorption experiments conducted at 288, 308 and 318 K, referring exothermic nature of the adsorption process.The performance study of fixed bed adsorption described through the breakthrough curves concept with two parameters: column bed heights (5, 10 and 15 mm) and flow rate (2.2, 5 and 8.4 ml/min). Two models (Thomas and Yoon-Nelson models) were applied to expect different parameters of fixed bed as adsorption capacity and time need for 50% breakthrough. The results exhibited that 2.2 ml /min feed flowrate and 5 mm bed height at 1000 mg/l initial oil condensate concentration were the optimum conditions for the ACTF column. The experimental breakthrough curves showed acceptable fit with the calculated breakthrough profiles obtained by Thomas model.     

陕西某金矿石尼尔森选矿试验

陕西某金矿石矿物成分复杂,金主要为裸露金和半裸露金,以粒间分布为主,包裹金少量,极粗粒金占总金量的95.68%,主要为片状、麦粒状,容易单体解离;在磨矿细度为-0.074 mm占65%时,78～300目粒级富集了79.37%的金。尼尔森选矿机回收试验结果表明,在矿石磨矿细度为-0.074 mm占65%,给矿浓度为30%,给矿速度为6 kg/h,流态化水水量为2.0 L/min,重力扩大倍数为60倍时,可取得金品位为233.33 g/t、回收率为87.38%的金精矿。     

Failing the Informal City: How Rio de Janeiro's Mega Sporting Events Derailed the Legacy of Favela-Bairro

The eviction of thousands of inhabitants from informal settlements has been a regressive feature in the lead up to Rio 2016. Writer and curator Justin McGuirk describes why, on the eve of the Olympic Games, the government reverted to favela removals after the enlightened era of the Favela-Bairro in the 1990s, which saw informal communities upgraded and integrated into the formal city.     

McLaren Technology Centre

The product of a highly customised production process, the racing car is the very antithesis of the modular and the mass produced. Jeremy Melvin reveals how Foster and Partners has designed a headquarters for the McLaren Group - a premier producer and promoter of Formula One cars - that, despite its location on the site of an old farm in Woking, Surrey, is resplendent as a ‘late industrial vision of the object perfectly refined to fulfil its allotted task’.     

新疆那拉提成矿带某金矿选矿工艺试验研究

新疆那拉提成矿带某金矿矿石结构主要为半自形—他形粒状结构,矿石中主要硫化物为黄铁矿,金主要以显微自然金形式存在。针对矿石性质特征,开展了尼尔森重选、全泥浸出和浮选探索试验。结果表明:相比尼尔森重选、全泥浸出工艺,浮选工艺适于处理该矿石,其闭路流程可获得金精矿金品位50.44 g/t、金回收率92.90%的良好指标。     

Learning in Newbern: Rural Studio in Year Ten

Amidst the regulated and increasingly fraught business of architectural practice, particularly within its homestead of the town of Newbern, Hale County, Alabama, Rural Studio has entered its second decade as a force to contradict normative modes of architectural education and practice. In the coming years, we will see if the wider consequences triggered by this innovative organisation will take root elsewhere. In the meantime, John Forney 's reflective examination of its roots substantiates the condition that, in times of change, the periphery is a place that matters greatly. Copyright © 2005 John Wiley & Sons, Ltd.