PurposeIt is a complex and dynamic process to provide high-quality rural infrastructure. However, there lacks a holistic performance evaluation method for rural infrastructure provision that reflects changing rural social needs and takes a village as a whole. This study aims to develop a holistic and dynamic performance evaluation model for rural infrastructure in Mainland China.Design/methodology/approachThis study established an evaluation index system by combining the lifecycle theory and the economy, efficiency, effectiveness and equity (4E) theory. This study developed an evaluation model by using the analytic network process (ANP) and matter-element analysis theory (MEAT). The model was validated by two representative villages in Mainland China.FindingsThe developed model can reflect dynamic social needs and effectively evaluate the overall infrastructure provision performance of a village. The weight of indicators reflects the changes in Mainland China’s contemporary rural social needs, with particular emphasis on the impact and output performance. The evaluation result shows that the overall performance of the representative villages was excellent but had a tendency toward good. Although the output performance was excellent, different input, process and impact performances resulted in different downgrade trends.Originality/valueThis study provides a theoretical basis for disaggregating the complex issue of the performance of rural infrastructure provision. The results can be used by relevant authorities to make a holistic and dynamic evaluation of the performance of rural infrastructure provision and timely revise planning and management policies.

In the event of emergencies, inadequate emergency management in large-scale building construction projects can result in significant losses and adverse social impacts. Currently, there are still numerous problems in emergency management for these projects, and related research is insufficient. Therefore, this study aims to clarify the current state and improvement demands of emergency organization and resource management for large-scale building construction projects during the construction phase when handling unexpected emergencies. To achieve this aim, this study first identified potential problems and improvement demands in emergency organization and resource management for large-scale building construction projects through theoretical analysis and expert interviews. Then, this study developed a survey questionnaire and collected responses from 30 construction professionals in China who have participated in large-scale building construction projects. The analysis of the research results finalized the current state and notable improvement demands of emergency organization and resource management for large-scale building construction projects. The results first indicated that: (1) in terms of emergency organization management, work coordination among relevant parties and the quality of information communication have significant improvement demand; (2) in terms of emergency resource management, forecasting of emergency resource demand, acquisition channels, and reserve mechanisms show improvement demand. To address these demands, emergency organization management requires optimization from the perspectives of internal and external coordination mechanisms and information communication mechanisms; Emergency resource management requires improvement in both forecasting methods and reserve models. The results of this study first provide a foundation and direction for future research on emergency organization and resource management in large-scale building construction projects. Moreover, stakeholders in these projects can refer to the results of this study to identify their weaknesses in emergency organization and resource management and propose optimization strategies in a targeted manner.

This study investigated the effect of using nanofiber membrane composites containing Prussian blue-like compound nanoparticles (PNPs) with a stainless steel mesh as the carrier (NMCs) to relieve ammonia nitrogen inhibition of rural organic household waste during high-solid (total solid content of 15 %) anaerobic digestion (AD) and increase methane production. NMCs with different PNP contents were added to high-solid AD. When NMC with 15 % PNPs was added, the concentrations of volatile fatty acids and ammonia nitrogen were lower than those of the blank control group, and the methane yield was the highest (301.31 mL/g volatile solids [VS]), at 2.8 times higher than that of the blank control group. The R2 value of the modified Gompertz equation was 0.997. During digestion, the activities of extracellular protease and coenzyme F420 were higher than those of the control group. NMCs were successfully recovered at the end of the experiment, and confocal scanning three-dimensional electron micrographs indicated that NMC with 15 % PNPs of NMCs had stronger biological activity; microbial community structure analysis indicated increased abundance of hydrogenotrophic methanogens in this group. The study provides a new solution for improving the efficiency of biogas production and the recycling of exogenously added materials.

As a highly disruptive digital technology, blockchain provides new solutions for reshaping corporate governance mechanisms and improving resource allocation. We empirically examine the relationship between blockchain and corporate investment inefficiency. We find that blockchain can help improve corporate investment efficiency, and this result is valid after a series of robustness tests.Blockchain can not only significantly restrain overinvestment but also alleviate underinvestment. Reducing financing costs and alleviating agency conflicts are the two channels through which blockchain is associated with corporate investment efficiency, and financial reporting quality is the condition on which the channels depend. When the CEO holds few shares or the trade credit environment in the region where the company is located is poor, the effect of blockchain is more prominent than it is otherwise. Investment efficiency cannot be improved by blockchain for companies providing blockchain products or services to customers, only for those promoting their own operations and management with blockchain. Ultimately, blockchain can enhance companies’ value by alleviating inefficient investment. We reveal the role of blockchain in corporate investment efficiency, furnish microeconomic evidence for the integration of digital technology and the real economy and provide implications for China to promote digital technology to drive high-quality company development.

Anaerobic digestion (AD) is an efficient technology that can efficiently convert organic waste into biofuel, but excessive ammonia nitrogen concentration will lead to failure of AD. In this study, a metal-organic framework (MOF)-derived porous metal oxide/graphene nanocomposite (FeMn-MOF/G) was first applied in AD to inves-tigate the mitigation effect of ammonia nitrogen inhibition. Five total solids (TS) concentrations of 8 %, 10 %, 12 %, 15 % and 20 % were set up for AD experiment to investigate the effect of FeMn-MOF/G on AD. The results showed that the average ammonia nitrogen adsorption capacity of FeMn-MOF/G in AD with different TS con-centrations was 102.68 mg/g, and the ammonia nitrogen adsorption effect decreased with the increase of TS. When FeMn-MOF/G was added to AD, the ammonia nitrogen concentration of the experimental group could be reduced to 2,086.00 mg/L, and the VFAs concentration was reduced to 1,510.34 mg/L. The methane production in each experimental group increased significantly, and the experimental group MOF-8 obtained the highest cumulative methane production of 321.35 mL/gVS, indicating that FeMn-MOF/G effectively mitigated the ammonia nitrogen inhibition,which promoteed the successful operation of AD. We characterized the prepared FeMn-MOF/G. The results of the vibrating sample magnetometer show that FeMn-MOF/G has excellent super -paramagnetic properties. Magnetic recycling is a promising method for the recycling of FeMn-MOF/G materials, which provides a broad prospect for the application of FeMn-MOF/G in AD.

During the rapid development of rural infrastructure in China, there are many important issues that have been overlooked, such as the real wishes of farmers and the management of the infrastructure, resulting in the farmers’ weak sense of gain. However, there is still a lack of research on the influence mechanism of the farmer’s sense of gain in the infrastructure development. To propose effective improvement strategies, this research aimed to explore the influence mechanism of the farmer’s sense of gain in the construction and operation of the rural infrastructure. To achieve the above aim, this study (1) proposed hypotheses for the influence mechanism from four perspectives which include the governance of the infrastructure, content of gain, way of gain, and sense of gain through theoretical analysis; (2) developed an evaluation index system for the above four constructs through a comprehensive literature review and rural field investigations; (3) conducted a questionnaire survey and received 107 effective responses from 7 tourism-oriented rural areas in Nanjing, Jiangsu Province, China; (4) used Structural Equation Modelling (SEM) and the software of AMOS to verify the proposed hypotheses. The results showed that content of gain and the way of gain directly affect the farmers’ sense of gain, and the governance indirectly affects the farmers’ sense of gain. And the way of gain has the greatest impact on the sense of gain, followed by access to the governance, and the content of gain has the least impact. The findings of this study first enriched the relevant theories of farmers’ sense of gain in the construction and operation of rural infrastructure. Moreover, the findings provided the theoretical supports for the government authorities to put forward effective governance strategies for the rural infrastructure from the perspective of the farmers’ sense of gain. Finally, the findings helped to identify the key points of the sustainable development of the infrastructure.

Anaerobic digestion is a beneficial way to convert organic waste resources, such as cow manure, into clean energy through microbial actions. However, when biochar was used as an additive to promote the efficiency of anaerobic digestion, there was a problem that the number of oxygen-containing functional groups was small, resulting in a limited effect on improving the electronic transport efficiency of the anaerobic digestion system. In this study, a high oxygen functional group containing humic acid biochar was prepared using ball milling technology to enhance reactivity and improve the anaerobic digestion performance of cow manure. The results showed that humic acid biochar had a more excellent performance in improving the gas production efficiency of cow manure AD. The addition of humic acid biochar did not significantly affect methane content. The humic acid biochar with a milling time of 8 h showed the best promotion effect in the anaerobic digestion system, and the methane yield reached 110.49 mL/gVS, which was 43.16% higher than that of the control group. The addition of humic acid biochar stimulated the secretion of extracellular polymers and enhanced interspecific electron transfer, leading to increased activity of key enzymes, including coenzyme F420. As a result, hydrogen-producing methanogens were enriched, methanogenic pathways were enhanced, and methane production was ultimately increased. Therefore, it improves intermediate product yield and utilization efficiency, thereby increasing methane production, and has great potential in the treatment of refractory organic waste.

通过编写网络爬虫获取社交媒体上智慧城市话题的相关信息,基于提取学术论文关键词建立的智慧城市专业词库,运用文本挖掘法进行信息处理,发现公众对于智慧城市建设全局关注技术、服务、应用3方面.对智慧交通、智慧政务和智慧医疗3个关注度最高的应用领域进行关注热点分析,识别出各领域对应的公众需求及具体内容.

Stainless steel mesh, as the common cathode of microbial electrolytic cell-assisted anaerobic digestion (MEC-AD), has the disadvantages of low specific surface area, poor biocompatibility and low catalytic activity, which limits the production of methane. Metal-organic frameworks (MOFs) have attracted much attention due to their adjustable pores and specific catalytic properties. However, little attention was paid to the combination of MOF and stainless-steel mesh to improve the performance of MEC-AD cathode. In this study, we combined stainless steel mesh with bimetallic MOF catalyst (Fe/Ni-NH2BDC) to prepare a composite cathode, and verified its promoting effect on AD of swine wastewater. The experimental results showed that the reactor with the carbonized MOF composite cathode (FeNi2-PAN2) achieved the highest soluble chemical oxygen demand removal rate of 82.92% and a maximum cumulative methane yield of 213.47 mL CH4/g COD under an applied voltage of 0.8 V, which were 33.14% and 57.56% higher than those of an anaerobic digestion (AD) control reactor, respectively, and higher than those of a carbon paper (CP) cathode reactor. The enrichment of Meth-anobacterium and Methanoculleus on the surface of FeNi2-PAN2 cathode surface indicated that FeNi2-PAN2 cathode enhanced hydrogenotrophic methanogenesis and improved the stability of AD.

随着装配式建筑的不断发展,其质量问题越来越受到人们的重视.为提高装配式建筑质量的风险管理水平,以多个维度交叉分析装配式建筑全过程质量风险进行指标的识别,基于社会网络分析构建装配式建筑全过程质量风险评估模型,并以南京某中学校区建设项目为例论证此模型,结合质量风险指标风险值和质量风险指标的个体网络作用分析确定关键风险,并针对关键风险提出应对策略.

This paper examines the determinants of internal audit outsourcing from the macro perspective of financial ecological environment. We find that in regions with a poor financial ecological environment, firms are more likely to outsource internal audit and more inclined to outsource to other service providers than to accounting firms that provide financial report audit services for them. Furthermore, those firms with high financing constraints and non-state-owned firms are more likely to outsource internal audit in poor financial ecological environments. Firms outsourcing internal audit in poor financial ecological environments will have low debt financing costs. These results suggest firms in weak financial ecological environments tend to use internal audit outsourcing to enhance investor confidence and reduce financing costs. This paper helps expand the literature related to the determinants of internal audit outsourcing from a macro perspective, and provide a reference for improving the resource-allocation efficiency of the governance-oriented internal audit.

As a large agricultural country, China produces a large amount of wheat straw each year that needs to be treated harmlessly. Anaerobic digestion (AD) has a great potential to produce clean energy biogas while treating wheat straw. AD as a typical fermentation process, the regeneration of NAD(+) is achieved by fermentation using NADH to reduce metabolic intermediates and therefore there is a lack of reduction capacity in the metabolic process. The low reducing power of the digestion system and the low methane yield of wheat straw in the AD process have limited the further development of this technology. Cerium dioxide nanoparticles (CDNs) are known for their excellent reducing powers. At the same time the large amount of cerium contained in the earth provides the conditions for its large-scale use. In this study, we evaluated the effects of CDNs on the AD of wheat straw. The CDNs were successfully prepared via hydrothermal synthesis. The particle size of CDNs was about 5 nm, the measured specific surface area was 168.02 m(2)/g, and the zeta potential was 10.70 mV. Experiments involving volatile fatty acids (VFAs), cyclic voltammetry curves, electrochemical impedance spectroscopy, oxidation-reduction potential, and NADH/NAD(+) showed that CDNs effectively enhanced the reducing power and utilization of VFAs. Additionally, the cumulative methane production of the C10 group was 20.15% higher than CK group, reaching 367.78 mL CH4/g.VS. The cumulative methane production was well fitted using the modified Gompertz equation (R-2 = 0.99677). Analysis of microbial community structure showed that CDNs increased bacterial abundance in hydrolytic acidification. The reduction ability of CDNs is very important for the improvement of the methane production efficiency of AD, which is of great interest for the study of nanoparticles that promote AD.

Various externalities caused by highway infrastructures, such as promoting economic development, traffic congestion, and air pollution, are becoming more and more important. Currently, there is no multi-dimensional quantitative evaluation of the externalities of highway infrastructures, hindering the sustainable planning and development of highway infrastructures. Therefore, this study aims to develop a three-dimensional evaluation model of the externalities of highway infrastructures. To achieve the above objective, this study: (1) developed a three-dimensional evaluation index system through a comprehensive literature review and interviews with experts; (2) weighted the evaluation indexes using the entropy weight method; (3) developed the comprehensive evaluation model using the grey correlation analysis method; (4) validated the developed model by using statistical data of Jiangsu province, China. The analysis results showed that the developed model is feasible and effective in evaluating the externalities of highway infrastructures as the analysis results are consistent with reality. In addition, the model can capture the value of externality-related information, the distance to the optimal state of the externalities of highway infrastructures, and the temporal and spatial trends of the externalities of highway infrastructures for a region. The results of this study for the first time set a basis for investigating the influential mechanism of the multi-dimensional externalities of highway infrastructures. Moreover, the results provide theoretical support for the scientific formulation of relevant policies and decision-making for the government.

Trace metals are essential constituents of cofactors and enzymes and that their addition to anaerobic digesters increases methane production. Many trace elements are contained in herbal-extraction process residues (HPR). The present study concerns the effect of six kinds of HPR [Danshen root (Dr), Astragalus membranaceus (Am), Isatis root (Ir), Angelica sinensis (As), and Pseudo-ginseng (Pg)] that were used as additives, respectively, in the anaerobic digestion of wheat straw on biogas and methane production. The ratios of HPR residues/wheat straw [based on total solids (TS), of wheat straw] were 3, 5, and 10%, respectively. The digesters were at 37 ± 1°C of water bath during 30 days of anaerobic digestion. The results showed that HPR had significant effects on the anaerobic co-digestion. The highest biogas productivity was achieved when treated with 10% Pseudo-ginseng residues (PGR), which yielded 337 ml/g TS of biogas and 178 ml/g TS of methane. Cumulative production of biogas and methane increased by 28 and 37% compared to the production achieved in the control. These results suggest that PGR is an effective HPR to enhance the production of methane.

The application of Prussian blue analogue nanoparticles in anaerobic digestion was firstly used to evaluate the removal effect of ammonia nitrogen inhibition in anaerobic digestion. We have successfully prepared Prussian blue analogue nanoparticles, which has a high adsorption capacity of ammonia nitrogen in anaerobic digestion is 71.09 mg/g. The high concentration anaerobic digestion of rural organic household waste was not successful because of the serious inhibition of ammonia nitrogen. After adding Prussian blue analogue nanoparticles, the methane production of each group increased greatly, up to 302.22 ml/gVS. The concentration of ammonia nitrogen in anaerobic digestion decreased to 1700.77 mg/l. Prussian blue analogue nanoparticles have a good application prospect in high concentration anaerobic digestion of rural organic household waste enriched with a high concentration of ammonia nitrogen.

Anaerobic digestion (AD) is an effective measure to deal with organic waste, and biogas can be recovered from waste as clean energy. China is mainly an agricultural country, and a large amount of wheat straw is produced every year, which needs to be treated innocuously and resourcefully. In this context, the purpose of this study was to evaluate the effect of exogenous conductive material Fe3O4 nanoparticles on AD of wheat straw and to further evaluate the effect of the charge of nanoparticles on AD. The effects of different charged Fe3O4 nanoparticles on AD of wheat straw were studied. Fe3O4 nanoparticles with positive, negative, and no charge were successfully prepared and used them in the AD of wheat straw. The experiments were carried out in a 500-mL glass bottle with an effective volume of 350 mL and a total solid (TS) concentration of 6%. The results showed that Fe3O4 nanoparticles with positive, negative, and no charge could increase the cumulative methane production of AD, and the pure ligands used to modify Fe3O4 nanoparticles had no considerable effect on AD of wheat straw. The negatively charged nanoparticles (NNPs) had the greatest positive effects on the AD of wheat straw, which was 51.33% higher than that of the blank control group and reached 333.14 mL CH4/g.TS. The peak concentration of volatile fatty acids (VFAs) in the negative experiment was 31.65% higher than that of the blank control group at the beginning of the experiment and 30.57% lower than that of the blank control group at the end of the experiment. The cyclic voltammetry curve showed that the NNPs improved the redox performance in the AD process, and the maximum value was reflected in the methane production. NNPs can increase the metabolic rate of VFAs and the content of active substances catalyzing biochemical reactions. The charge properties of Fe3O4 nanoparticles play an important role in improving the efficiency of AD, which is of great significance for nano-electron transfer mediators to improve the efficiency of AD. These results show that NNPs have the most significant effect on AD. The addition of this material is helpful in regulating the indices in the process of AD and can be applied to the AD of more substrates.

Background Enzymatic hydrolysis is a key step in the conversion of lignocellulosic polysaccharides to fermentable sugars for the production of biofuels and high-value chemicals. However, current enzyme preparations from mesophilic fungi are deficient in their thermostability and biomass-hydrolyzing efficiency at high temperatures. Thermophilic fungi represent promising sources of thermostable and highly active enzymes for improving the biomass-to-sugar conversion process. Here we present a comprehensive study on the lignocellulosic biomass-degrading ability and enzyme system of thermophilic fungus Malbranchea cinnamomea N12 and the application of its enzymes in the synergistic hydrolysis of lignocellulosic biomass. Results Malbranchea cinnamomea N12 was capable of utilizing untreated wheat straw to produce high levels of xylanases and efficiently degrading lignocellulose under thermophilic conditions. Temporal analysis of the wheat straw-induced secretome revealed that M. cinnamomea N12 successively degraded the lignocellulosic polysaccharides through sequential secretion of enzymes targeting xylan and cellulose. Xylanase-enriched cocktail from M. cinnamomea N12 was more active on native and alkali‑pretreated wheat straw than the commercial xylanases from Trichoderma reesei over temperatures ranging from 40 to 75 °C. Integration of M. cinnamomea N12 enzymes with the commercial cellulase preparation increased the glucose and xylose yields of alkali‑pretreated wheat straw by 32 and 166%, respectively, with pronounced effects at elevated temperature. Conclusions This study demonstrated the remarkable xylanase-producing ability and strategy of sequential lignocellulose breakdown of M. cinnamomea N12. A new process for the hydrolysis of lignocellulosic biomass was proposed, comprising thermophilic enzymolysis by enzymes of M. cinnamomea N12 followed with mesophilic enzymolysis by commercial cellulases. Developing M. cinnamomea N12 as platforms for thermophilic enzyme mixture production will provide new perspectives for improved conversion yields for current biomass saccharification schemes.

采用中温批式发酵方式,研究人粪分别与稻秸、 尾菜、 牛粪按1:1、2:1、3:1的干物质质量比混合发酵的产沼气效果和无害化处理效果.结果表明,纯人粪发酵40 d的产气率仅140.64 mL·g-1(以总固体计),而通过添加其他有机废弃物进行混合发酵能较好地提高其产气效率,且对产气效率的提升效果表现为稻秸>牛粪≈尾菜.纯人粪经37℃发酵40 d后对粪大肠菌群和蛔虫卵的杀灭率分别达98.18％和100％,混合发酵有利于进一步提高其无害化处理效果,但发酵结束后的粪大肠菌群数值接近于NY/T 2596—2014《沼肥》 限值要求,故后续需强化人粪无害化的热处理关键参数研究.

旨在对农村有机生活垃圾厌氧发酵产沼气的潜力进行研究.对江苏省徐州市沛县大屯街道王庄村生活垃圾分类处置中心每月1次采集样品,并对一周年十二个月份的生活垃圾样品进行批式中温厌氧发酵产气潜力研究,考察农村生活垃圾作为发酵原料周年沼气产量和甲烷产量的变化,各月份试验组的累积沼气产气量范围为447～1398 mL、累积甲烷产气量范围为215～865 mL.并用SPSS数据分析发现农村生活垃圾含水率、总磷TP、总钾TK、总氮TN、有机质、C/N、半纤维素、纤维素、木质素的含量均对产沼气潜力有影响,其中纤维素含量会对产沼气潜力有显著的正向影响关系,而TP会对产气潜力产生显著的负向影响关系,最后,该研究根据生活垃圾理化性质数据基础上建立了多元线性逐步回归最优方程,可根据农村有机生活垃圾的含水率、纤维素和木质素的含量预测其厌氧发酵产沼气潜力.

工程质量潜在缺陷保险(IDI)有助于提升住宅建筑质量,维护业主合理权益.为推进IDI在我国规范有效发展,在明确IDI相关概念特征的基础上,分析和总结了国外的典型发展经验及我国的探索现状.运用文献研究和鱼刺图分析方法,从政府、保险公司、风险管理机构、建设单位、消费者等五大主体角度梳理当前我国IDI发展中存在的问题.并结合国情指出相关方积极参与、多措并举,实现多方共赢是推动我国IDI发展,改善房屋质量,保障业主权益的关键.