科技创新、供应链金融与跨境电子商务产业政策的耦合研究——以河南省为例

“一带一路”建设的背景下,供应链金融与跨境电子商务产业深度融合、各类资源和要素高效整合、产业发展与集成高效协同的贸易体系发展路径愈发清晰。推动科技创新、供应链金融与产业政策工具的协同发展尤为重要。基于河南省数据,通过建立耦合模型,研究科技创新、供应链金融与跨境电子商务产业政策的耦合关系,分析比较三者之间耦合度,再根据现存问题和不足提出可行策略,以此加强三者之间互通互动,最终促进三者实现正向匹配和协调发展,从而推动河南省跨境电子商务产业的持续发展。

Analysis on Spatial Pattern of Land Use Based on Fractal Theory:A Case Study of a Southwest Town

Based on GIS,RS technology and fractal theory,this paper analyzes land use type of a southwest town in 2010. It obtains fractal model,fractal dimension and stability index of land use types,which will provide favorable reference for healthy social and economic development of this town and scientific decision making for rational control of land resource.

An Analysis of Government Interventions in Addressing Market Failures Caused by Non- Excludable and Non-Rivalrous Public Goods Based on COVID-19 Vaccination Cases

The non-excludable and non-rivalrous characteristics of public goods distinguish them from private goods.The existence of these two characteristics leads to the<cfree rider problem^^and the variation problem,making the market supply less than the actual demand,thus causing market failure.The government should therefore intervene against this impact.At the beginning of 2020,the global outbreak of the novel COVID-19 brought significant harm to various countries,races,and groups of people.In the second half of 2020,several companies developed vaccines,which are able to fundamentally block the transmission of the virus.However,as vaccines have been reducing the severity of the epidemic in certain regions,the situation somewhat reflects non-excludability and non-rivalry,in which before officially being listed in vaccination programs,the society may have the thought of"vaccination would reduce the risk of transmission;thus,I can enjoy the reduced risk of everyone being vaccinated without paying for it."For this reason,most countries have been purchasing vaccines for the public through government appropriations to solve the free-rider problem.It can be said that in the face of market failure caused by public goods,the government should carry out timely intervention measures,including taxation and government appropriation,to avoid negative impacts from the characteristics of public goods.

Synergistic oxidation-reforming of biomass for high quality syngas production based on a bifunctional catalyst

Conventional O_(2)gasification for low-rank biomass/sludge conversion is prone to high CO_(2)concentrations in the syngas because of its high O content and low calorific value.This study establishes a synergistic oxidationreforming reaction route for the conversion of low-rank carbon-containing resources into high-quality syngas.The efficient oxidation-reforming reaction is based on the bifunctional catalyst NiO-Fe_(2)O_(3)/Al_(2)O_(3),which includes Fe_(2)O_(3) oxidation sites and NiO reforming sites.Hydrogen temperature-programmed reduction,together with X-ray diffraction and X-ray photoelectron spectroscopy experiments,demonstrated that the two functional active sites have strong interactions with the support,leading to efficient cooperation between the oxidation reaction and reforming reaction with regards to both the reaction sequence and C/H/O element balance.Syngas produced from biomass/sludge based on oxidation-reforming reactions has an extremely low CO_(2)concentration of approximately 3%,and the valid gas(CO,H_(2))concentration exceeds 95%.The valid gas yield of walnut shell reached 1452.9 mL/g,the total gas yield was 1507.2 mL/g,and the H_(2)/CO ratio was 1.02,which are all very close to the theoretical maximum values of 1553.1 mL/g and 1.01,respectively,demonstrating that the inherent CO_(2)/H_(2)O along with CH4/tar species were efficiently converted to H_(2)and CO through oxidation-reforming reactions.During a 60-cycle test,NiO-Fe_(2)O_(3)/Al_(2)O_(3) exhibited good redox stability.

An unusual UMP C-5 methylase in nucleoside antibiotic polyoxin biosynthesis

Polyoxin is a group of structurally-related peptidyl nucleoside antibiotics bearing C-5 modifications on the nucleoside skeleton. Although the structural diversity and bioactivity preference of polyoxin are, to some extent, affected by such modifications, the biosynthetic logic for their occurence remains obscure. Here we report the identification of PolB in polyoxin pathway as an unusual UMP C-5 methylase with thymidylate syn- thase activity which is responsible for the C-5 methyla- tion of the nucleoside skeleton. To probe its molecular mechanism, we determined the crystal structures of PolB alone and in complexes with 5-Br UMP and 5-Br dUMP at 2.15 A, 1.76 A and 2.28 A resolutions, respec- tively. Loop 1 （residues 117-131）, Loop 2 （residues 192- 201） and the substrate recognition peptide （residues 94- 102） of PolB exhibit considerable conformational flexi-bility and adopt distinct structures upon binding to different substrate analogs. Consistent with the structural findings, a PolB homolog that harbors an identical function from Streptomyces viridochromogenes DSM 40736 was identified. The discovery of UMP C5-methy-lase opens the way to rational pathway engineering for polyoxin component optimization, and will also enrich the toolbox for natural nucleotide chemistry.

专科护理主导的多学科协作模式在主动脉夹层术后早期ICU高压氧救治中的应用

目的:总结专科护理主导的多学科协作(MDT)模式应用于Stanford A型主动脉夹层(AD)术后脑部并发症患者早期ICU高压氧(ICU-HBO)的治疗效果。方法:2018年1月至2020年12月在18例AD术后出现脑部并发症的患者行ICU-HBO治疗中运用MDT模式,观察其呼吸机耐受及撤机时间、转归、医疗(安全)不良事件发生次数及护理满意度。结果:15例机械通气患者经1~5次ICU-HBO治疗顺利撤机。16例患者接受2~13次ICU-HBO治疗,意识恢复正常,总有效率88.89%;2例深度昏迷患者经2次ICU-HBO治疗后患者家属放弃。随访6个月至2年,临床痊愈11例,有效1例,失访4例,放弃治疗的2例患者并发感染死亡。ICU-HBO治疗期间未发生医疗(安全)不良事件。护理满意度100%。结论:Stanford A型AD术后脑部并发症患者早期ICU-HBO治疗时,运用专科护理主导的MDT模式有利于控制治疗风险,保障治疗有效性,改善AD患者的长期预后及生活质量。

Characterization of the tunicamycin gene cluster unveiling unique steps involved in its biosynthesis

Tunicamycin,a potent reversible translocase I inhibitor,is produced by several Actinomycetes species.The tunicamycin structure is highly unusual,and contains an 11-carbon dialdose sugar and anα,β-1″,11′-glycosidic linkage.Here we report the identification of a gene cluster essential for tunicamycin biosynthesis by high-throughput heterologous expression(HHE)strategy combined with a bioassay.Introduction of the genes into heterologous non-producing Streptomyces hosts results in production of tunicamycin by these strains,demonstrating the role of the genes for the biosynthesis of tunicamycins.Gene disruption experiments coupled with bioinformatic analysis revealed that the tunicamycin gene cluster is minimally composed of 12 genes(tunA–tunL).Amongst these is a putative radical SAM enzyme(Tun B)with a potentially unique role in biosynthetic carbon-carbon bond formation.Hence,a seven-step novel pathway is proposed for tunicamycin biosynthesis.Moreover,two gene clusters for the potential biosynthesis of tunicamycin-like antibiotics were also identified in Streptomyces clavuligerus ATCC 27064 and Actinosynnema mirums DSM 43827.These data provide clarification of the novel mechanisms for tunicamycin biosynthesis,and for the generation of new-designer tunicamycin analogs with selective/enhanced bioactivity via combinatorial biosynthesis strategies.

Stabilization of hexavalent chromium with pretreatment and high temperature sintering in highly contaminated soil

This study explored the effectiveness and mechanisms of high temperature sintering following prereduction with ferric sulfate(FeSO_(4)),sodium sulfide(Na_(2)S),or citric acid(C_(6)H_(8)O_(7))in stabilizing hexavalent chromium(Cr(VI))in highly contaminated soil.The soil samples had an initial total Cr leaching of 1768.83 mg/L,and Cr(VI)leaching of 1745.13 mg/L.When FeSO_(4)or C_(6)H_(8)O_(7)reduction was followed by sintering at 1000℃,the Cr leaching was reduced enough to meet the Safety Landfill Standards regarding general industrial solid waste.This combined treatment greatly improved the stabilization efficiency of chromium because the reduction of Cr(VI)into Cr(III)decreased the mobility of chromium and made it more easily encapsulated in minerals during sintering.SEM,XRD,TG-DSC,and speciation analysis indicated that when the sintering temperature reached 1000℃,almost all the chromium in soils that had the pre-reduction treatment was transformed into the residual form.At 1000℃,the soil melted and promoted the mineralization of Cr and the formation of new Cr-containing compounds,which significantly decreased subsequent leaching of chromium from the soil.However,without reduction treatment,chromium continued to leach from the soil even after being sintered at 1000℃,possibly because the soil did not fully fuse and because Cr(VI)does not bind with soil as easily as Cr(III).

Construction and Application of Interfacial Inorganic Nanostructures

Interfacial nanostructured materials have stimulated extensive interests in the research areas of green energy production and conversion due to their unique structures and performance.These interfacial crystalline structures with rich intrinsic defects,such as oxygen vacancies,adatoms,grain bounda-ries,and substitutional impurities,have led to unique activities in a variety of catalytic reactions.The rational design and engineering development of the interfaces provide an attractive way to optimize the catalytic performance and finally improve the efficiency of energy conversion and storage.Herein,a comprehensive overview of interfacial inorganic nanostructures and their electrocatalytic applications are summarized,and some future challenge and opportunity have also been proposed.