Interphase migration and enrichment of lead and zinc during copper slag depletion

An interphase migration and enrichment model of lead and zinc during molten copper slag depletion was established.The occurrence of various components in copper slag was predicted using sulfur-oxygen potential calculations and confirmed through high-temperature experiments.The recovery rate of copper can reach 90.13%under the optimal conditions of 1200°C,an iron to silicon mass ratio of 1.0,3 wt.%ferrous sulfide,and a duration of 45 min.Lead(54.07 wt.%)and zinc(17.42 wt.%)are found in the flue dust as lead sulfate,lead sulfide,and zinc oxide,while copper matte contains lead(14.44 wt.%)and zinc sulfide(1.29 wt.%).The remaining lead and zinc are encapsulated as oxides within the fayalite phase.

熔融转炉铜渣贫化法回收铜

为了从铜渣中回收铜,提出熔融铜渣贫化回收铜的新方法。首先计算贫化过程的热力学和FeO−SiO_(2)二元相图,然后研究实验参数对Fe_(3)O_(4)还原和铜回收率的影响规律,分析贫化机理。结果表明:氧化硅的加入可以明显降低黄铁矿还原磁铁矿的初始反应温度。最优条件下,铜渣中的Fe_(3)O_(4)和铜含量分别降低至2.45%和0.39%(质量分数),铜回收率为92.52%。贫化后,超过94%的银和99%的金沉降在铜锍中。大约72%的锌和75%的铅挥发进入烟气。由于磁铁矿的还原,铜渣的黏度从0.68 Pa·s降低到了0.12 Pa·s,并且机械搅拌可以强化铜锍液滴的沉降。

Parallel Building: A Complex System Approach for Smart Building Energy Management

These days' smart buildings have high intensive information and massive operational parameters, not only extensive power consumption. With the development of computation capability and future 5 G, the ACP theory(i.e., artificial systems,computational experiments, and parallel computing) will play a much more crucial role in modeling and control of complex systems like commercial and academic buildings. The necessity of making accurate predictions of energy consumption out of a large number of operational parameters has become a crucial problem in smart buildings. Previous attempts have been made to seek energy consumption predictions based on historical data in buildings. However, there are still questions about parallel building consumption prediction mechanism using a large number of operational parameters. This article proposes a novel hybrid deep learning prediction approach that utilizes long short-term memory as an encoder and gated recurrent unit as a decoder in conjunction with ACP theory. The proposed approach is tested and validated by real-world dataset, and the results outperformed traditional predictive models compared in this paper.

Risk factors and managements of hemorrhage associated with pancreatic fistula after pancreaticoduodenectomy

BACKGROUND: Post-pancreaticoduodenectomy pancreatic fistula associated hemorrhage (PPFH) is one of the leading lethal complications. Our study was to analyze the risk factors and managements of hemorrhage associated with pancreatic fistula after pancreaticoduodenectomy, and to evaluate treatment options. METHOD: We analyzed 445 patients who underwent pancreaticoduodenectomy or pylorus-preserving pancreaticoduodenectomy and evaluated the relevance between clinical data and PPFH. RESULTS: The incidence of postoperative pancreatic fistula (POPF) was 27.42% (122/445), and the incidence of PPFH was 4.49% (20/445). Among the 20 patients with PPFH, 7 died and 13 were cured. Interventional angiographic therapy was performed for 10 patients and 5 were successfully treated. Relaparotomy was performed for 5 patients and 2 were successfully cured. Univariate logistic regression analysis indicated that several risk factors were related to PPFH: the nature of tumor (carcinoid/low-grade or high-grade malignancy), preoperative day 1. serum prealbumin, preoperative day 1 total bilirubin (TBIL), operative time, blood loss in the operation, operative method (vascular resection and revascularization), postoperative day 3 TBIL, biliary fistula, and the grade of POPF. The multivariate stepwise logistic regression analysis demonstrated that the nature of tumor and the grade of POPF were independently risk factors of PPFH. Receiver operating characteristic curve indicated that preoperative day 1 serum prealbumin level <173 mg/L and postoperative day 3 TBIL level.1.68.tmol/L were the risk factors of PPFH. CONCLUSIONS; The risk of PPFH was found to be increased with high potential malignancy and high grade of POPE Angiography-embolization is one of the major and effective therapies for PPFH. Extraluminal-intraluminal PPFH is more serious and needs more aggressive treatments.

Infective severe acute pancreatitis:A comparison of ^(99m)Tc-ciprofloxacin scintigraphy and computed tomography

AIM:To evaluate 99mTc-ciprofloxacin scintigraphy compared with computed tomography(CT)for detecting secondary infections associated with severe acute pancreatitis(SAP)in swine.METHODS:Six healthy swine were assigned to a normal control group(group A,n = 6).SAP was induced in group B(n = 9)and C(n = 18),followed by inoculation of the resulting pancreatic necroses with inactive Escherichia coli(E.coli)(group B)and active E.coli(group C),respectively.At 7 d after inoculation,a CT scan and a series of analyses using infecton imaging(at 0.5,1,2,3,4 and 6 h after the administration of 370 MBq of intravenous infecton)were performed.The scintigrams were visually evaluated and semi-quantitatively analyzed using region of interest assignments.The differences in infecton uptake and changes in the lesion-background radioactive count ratios(L/B)in the 3 groups were recorded and compared.After imaging detection,histopathology and bacterial examinations were performed,and infected SAP was regarded as positive.The imaging findings were compared with histopathological and bacteriological results.RESULTS:In group A,6 animals survived without infection in the pancreas.In group B,7/9 swine survived and one suffered from infection.In group C,15/18 animals survived with infection.Hence,the number of normal,non-infected and infected SAP swine was 6,6 and 16,respectively.The sensitivity,specificity,accuracy,positive predictive value and negative predictive value of the infecton method were 93.8%(15/16),91.7%(11/12),92.9%(26/28),93.8%(15/16)and 91.7%(11/12),whereas these values for CT were 12.5%(2/16),100.0%(12/12),50.0%(14/28),100.0%(2/2)and 46.2%(12/26),respectively.The changes in L/B for the infected SAP were significantly different from those of the non-infected and normal swine(P < 0.001).The mean L/B of the infectious foci at 0.5,1,2,3,4 and 6 h was 1.17 ± 0.10,1.71 ± 0.30,2.46 ± 0.45,3.36 ± 0.33,2.04 ± 0.37 and 1.1988 ± 0.09,respectively.At 3 h,the radioactive counts(2350.25 ± 602.35 k)and the mean L/B of the infectious foci were significantly higher than that at 0.5 h(P = 0.000),1 h(P = 0.000),2 h(P = 0.04),4 h(P = 0.000)and 6 h(P = 0.000).CONCLUSION:99m Tc-ciprofloxacin scintigraphy may be an effective procedure for detecting SAP secondary infections with higher sensitivity and accuracy than CT.

Social Energy:Mining Energy From the Society

The inherent nature of energy,i.e.,physicality,sociality and informatization,implies the inevitable and intensive interaction between energy systems and social systems.From this perspective,we define "social energy" as a complex sociotechnical system of energy systems,social systems and the derived artificial virtual systems which characterize the intense intersystem and intra-system interactions.The recent advancement in intelligent technology,including artificial intelligence and machine learning technologies,sensing and communication in Internet of Things technologies,and massive high performance computing and extreme-scale data analytics technologies,enables the possibility of substantial advancement in socio-technical system optimization,scheduling,control and management.In this paper,we provide a discussion on the nature of energy,and then propose the concept and intention of social energy systems for electrical power.A general methodology of establishing and investigating social energy is proposed,which is based on the ACP approach,i.e., "artificial systems"(A), "computational experiments"(C) and "parallel execution"(P),and parallel system methodology.A case study on the University of Denver(DU) campus grid is provided and studied to demonstrate the social energy concept.In the concluding remarks,we discuss the technical pathway,in both social and nature sciences,to social energy,and our vision on its future.

高中生物教学中促进深度学习的策略构想与探索

深度学习是近代提出的一种科学、先进的重要学习思想。它更加强调和关注学习者学习的主动性、真实性与体验性,注重学习者已有知识与新知识的整体联系,自主构建形成完整的知识体系,并通过应用已有的知识分析和解决生产、生活中的实际问题,从而使学习者的知识体系得到不断完善、综合素养得到全面的提高。深度学习的目标是培养学生适应社会发展的核心能力,既是新课改的出发点和归宿,也是生物教学提升学生学科核心素养的根本要求。就如何把这一重要学习思想巧妙地运用到高中生物教学实践中,将浅层学习优化为深度学习,为生物学科新课改理念的落实,找到突破口和切合点,进行了积极探索与思考,并从深度学习的内涵与特点、促进深度学习的策略构想、实施等方面展开论述。

导学案“行为导向”式教学模式在高中生物教学中的构建与思考

行为导向教学主要是以行动来导向驱动,在教学过程中以发挥学生的主体作用与教师的主导作用为主,通过行为的引导使学生在活动中提高学习兴趣、培养创新思维、形成关键能力,目前广泛地应用在职业教育领域。将此方法创造性地以导学案为载体,借鉴案例教学法的模式,提出了适用于高中生物教学新的实践模式——导学案'行为导向'式教学模式。同时,对该模式在实践过程中取得的成效和实际操作中应注意的问题进行了分析总结。论文主要阐述了导学案'行为导向'式教学模式的构建背景、理论依据、实施目的、教学环节,并以案例的形式对实践价值进行了探讨。

Role of non-coding RNAs in pancreatic cancer: The bane of the microworld

Our understanding of the mechanisms underlying the development of pancreatic cancer has been greatly advanced. However, the molecular events involved in the initiation and development of pancreatic cancer remain inscrutable. None of the present medical technologies have been proven to be effective in significantly improving early detection or reducing the mortality/morbidity of this disease. Thus, a better understanding of the molecular basis of pancreatic cancer is required for the identification of more effective diagnostic markers and therapeutic targets. Non-coding RNAs (ncRNAs), generally including microRNAs and long non-coding RNAs, have recently been found to be deregulated in many human cancers, which provides new opportunities for identifying both functional drivers and specific biomarkers of pancreatic cancer. In this article, we review the existing literature in the field documenting the significance of aberrantly expressed and functional ncRNAs in human pancreatic cancer, and discuss how oncogenic ncRNAs may be involved in the genetic and epigenetic networks regulating functional pathways that are deregulated in this malignancy, particularly of the ncRNAs&#x02019; role in drug resistance and epithelial-mesenchymal transition biological phenotype, with the aim of analyzing the feasibility of clinical application of ncRNAs in the diagnosis and treatment of pancreatic cancer.

A Model for Conducting Strategy Training

Effective learning is not merely a matter of an individual having a high IQ. What appears to be important is the learners＇ ability to respond to the particular learning situation and to manage their learning in an appropriate way. Studies of successful and unsuccessful learners show that people who succeed in learning have developed a range of strategies from which they are able to select those that are most appropriate for a particular problem, to adapt them flexibly for the needs of the specific situation, and to monitor their level of success. Based on the assumption that integrating strategies into foreign language teaching is both valuable and achievable and that their accomplishment can enhance independent foreign language learning, this paper offered a model of strategy-based instruction, which includes both explicit and implicit integration of strategies into classroom instruction.

On the Modular Erdos-Burgess Constant

Let n be a positive integer. For any integer a, we say that is idempotent modulo n if a2≡a(mod n). The n-modular Erd&#246;s-Burgess constant is the smallest positive integer l such that any l integers contain one or more integers, whose product is idempotent modulo n. We gave a sharp lower bound of the n-modular Erd&#246;s-Burgess constant, in particular, we determined the n-modular Erd&#246;s-Burgess constant in the case when n was a prime power or a product of pairwise distinct primes.

Calculation method for the formation time of dynamic filter cake in slurry shield tunneling

In slurry shield tunneling,the stability of tunnel face is closely related to the filter cake.The cutting of the cutterhead has negative impact on the formation of filter cake.This study focuses on the formation time of dynamic filter cake considering the filtration effect and rotation of cutterhead.Filtration effect is the key factor for slurry infiltration.A multilayer slurry infiltration experiment system is designed to investigate the variation of filtrate rheological property in infiltration process.Slurry mass concentration C_(L),soil permeability coefficient k,the particle diameter ratio between soil equivalent grain size and representative diameter of slurry particles d_(10)/D_(85) are selected as independent design variables to fit the computational formula of filtration coefficient.Based on the relative relation between the mass of deposited particles in soil pores and infiltration time,a mathematical model for calculating the formation time of dynamic filter cake is proposed by combining the formation criteria and formation rate of external filter cake.The accuracy of the proposed model is verified through existing experiment data.Analysis results show that filtration coefficient is positively correlated with slurry mass concentration,while negatively correlated with the soil permeability coefficient and the particle diameter ratio between soil and slurry.As infiltration distance increases,the adsorption capacity of soil skeleton to slurry particles gradually decreases.The formation time of external filter cake is significantly lower than internal filter cake and the ratio is approximately 3.9.Under the dynamic cutting of the cutterhead,the formation time is positively associated with the rotation speed of cutter head,while negatively with the phase angle difference between adjacent cutter arm.The formation rate of external filter cake is greater than 98%when d_(10)/D_(85)≤6.1.Properly increasing the content or decreasing the diameter size of solid-phase particles in slurry can promote the formation of filter cake.

Review on photonic method for generating optical triangular pulses

In this paper, several photonic generating methods for optical triangular pulses were reviewed. Four frontier research methods for generating optical triangular pulses were introduced, these four methods are respectively based on the frequency-to-time conversion, using normally dispersive fiber, by single-stage dual-drive Mach-Zehnder modulator （MZM）, and using dual-parallel MZM. These four methods can be classified into two categories in terms of the optical source employed, such as mode-lock laser （MLL） and continuous-wave （CW） respectively. Compared with the methods based on MLL, those based on CW have many advantages, such as simpler structure, lower price, higher stability, more flexible and wider tunability. Besides, the method using single-stage drive MZM can generate versatile waveform optical pulses, which has better performance than the first two methods in tunable capability of both repetition rate and center wavelength. With the same driving signal applied, the optical source using the dual-parallel MZM can generate signal with higher frequency than that of using the single-stage MZM.