Size fractionated biomass and productivity of phytoplankton and new production in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1998/1999

The paper deals with the studies on the cell abundance, the composition of dominant species, size fractionated biomass and productivity of phytoplankton, new production, the environmentally restricted mechanism in the Prydz Bay and the adjacent Indian sector of the Southern Ocean during the austral summer 1998/1999. The results showed that there was marked feature of spatial zonation in the sea areas investigated. In the Prydz Bay and its adjacent continental shelf, the biomass and productivity of phytoplankton were high; those of continental slope and open ocean area were obviously low. The nutrient concentration had opposite distribution trend, due to the consumption of phytoplankton. It mainly affected by the vertical stability of water column, grazing pressure of zooplankton, temperature and light etc. The results of size-fractionation showed that the average contribution of netplankton to total chlorophyll a in studied sea areas was 52.2 %, those of nano- and picoplankton were 29.4 % and 18.4 %, respectively. The average contribution of netplankton to total primary production was 52.4 %, those of nano- and picoplankton were 28.7 % and 18.9 %, separately. It is same as previous conclusion that the contribution of picoplankton to productivity is slightly larger than that to biomass of phytoplankton communities. The average new production and f-ratio were 230.6 mg/ (m(2.)d) and 0.43, respectively.

MEASUREMENTS OF PARTICLE NUMBER SIZE DISTRIBUTIONS AND NEW PARTICLE FORMATION EVENTS DURING WINTER IN THE PEARL RIVER DELTA REGION,CHINA

Particle number size distribution(PNSD) between 10 nm and 20 μm were measured in the Pearl River Delta(PRD) region in winter 2011.The average particle number concentration of the nucleation mode(10-20 nm),Aitken mode(20-100 nm),accumulation mode(100 nm-1μm) and coarse mode(1-20 μm) particles were 1 552,7 470,4 012,and 19 cm-3,respectively.The volume concentration of accumulation mode particles with peak at 300 nm accounted for over 70% of the total volume concentration.Diurnal variations and dependencies on meteorological parameters of PNSD were investigated.The diurnal variation of nucleation mode particles was mainly influenced by new particle formation events,while the diurnal variation of Aitken mode particles correlated to the traffic emission and the growth process of nucleation mode particles.When the PRD region was controlled by a cold high pressure,conditions of low relative humidity,high wind speed and strong radiation are favorable for the occurrence of new particle formation(NPF) events.The frequency of occurrence of NPF events was 21.3% during the whole measurement period.Parameters describing NPF events,including growth rate(GR) and source rate of condensable vapor(Q),were slightly larger than those in previous literature.This suggests that intense photochemical and biological activities may be the source of condensable vapor for particle growth,even during winter in the PRD.

Distribution characteristics of size-fractionated chlorophyll a, primary production and new production in the Laizhou Bay, July 1997

The distributions of chlorophyll a concentration, primary production and new productionwere observed in the Laizhou Bay of the Bohai Sea in both spring and neap tides during July 1997. The results showed that there were marked features of spatial zonation in the surveyed area, due to the differences between the geographic environment and the hydrological conditions. Chlorophyll a, primary production and new production were all higher in spring tides than that in neap tides in the Laizhou Bay. The highest values of these parameters were encountered in the central regions of the bay. At most stations, chlorophyll a concentrations at the bottom were higher than that at the surface. The results of size-fractionated chlorophyll a and primary production showed that contributions of nanocombining pi-coplankton ( <20 μm) to total chlorophyll a and primary production were dominant in phytoplankton community biomass and production of the Laizhou Bay. The environmental factors, primary production and new production in the Laizhou Bay are compared with other sea areas.

Influence of MgO contents on silica supported nano-size gold catalyst for carbon monoxide total oxidation

A series of nano-size gold catalysts were prepared by deposition-precipitation method using silica material promoted with different amounts of MgO as the carrier. The influences of MgO addition on the structure and property of the nano-size gold catalysts were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, O2 temperature-programmed desorption （O2-TPD）, and inductively coupled with plasma atomic emission spectroscopy （ICP-AES） techniques. The total oxidation of CO was chosen as the probe reaction. The results suggest that for the gold catalysts supported on the silica material after MgO modification, the size of the gold particles is pronouncedly reduced, the oxygen mobility is enhanced, and the catalytic activity for low-temperature CO oxidation is greatly improved. The gold catalyst modified by 6 wt% MgO （Mg/SiO2 weight ratio） shows higher CO oxidation activity, over which the temperature of CO total oxidation is lower about 150 K than that over the silica directly supported gold catalyst.

Aerosol Spectra and New Particle Formation Observed in Various Seasons in Nanjing

The aerosol number spectrum and gas pollutants were measured and the new particle formation （NPF） events were discussed in Nanjing. The results showed that the size distributions of aerosol number concen- trations exhibited distinct seasonal variations, implying the relations of particle sizes and their sources and sinks. The number concentrations of particles in the nuclei mode （10-30 nm）, Aitken mode （30-100 nm）, accumulation mode （100 -1000 nm） and coarse mode （〉1μm） varied in the order of summer 〉 spring 〉 autumn, summer 〉 autumn 〉 spring, autumn 〉 summer 〉 spring, and spring 〉 autumn 〉summer, re- spectively. The diurnal variation of total aerosol number concentrations showed three peaks in all observed periods, which corresponded to two rush hours and the photochemistry period at noon. In general, the NPF in summer occurred under the conditions of east winds and dominant air masses originating from marine areas with high relative humidity （50%-70%） and strong solar radiations （400 -700 W m-2）. In spring, the NPF were generally accompanied by low relative humidity （14%-30%） and strong solar radiations （400-600 W m-2）. The new particle growth rates （GR） were higher in the summertime in the range of 10- 16 nm h-1. In spring, the GR were 6.8-8.3 nm h-1. Under polluted air conditions, NPF events were seldom captured in autumn in Nanjing. During NPF periods, positive correlations between 10- 30 nm particles and 03 were detected, particularly in spring, indicating that NPF can be attributed to photochemical reactions.

Computer Simulation of the Process of Quenching Large-Size Parts in Water and Aqueous Solutions

The article presents results of the computer simulation of quenching large-size parts in water and aqueous solutions. It has been shown that the main attention should be paid to eliminating film boiling and providing uniform cooling at the surface of the part to be quenched. Simplified formulas for calculating the optimal time of cooling large-size steel parts are presented.

长春市“专精特新”中小企业创新发展路径研究

“专精特新”中小企业作为创新发展的重要力量,在推动经济增长、提升产业链供应链竞争力方面发挥着关键作用。长春市作为中国东北地区重要的工业基地,积极响应国家关于“专精特新”中小企业的发展战略,致力于培育具有专业化、精细化、特色化和新颖化的中小企业。当前,长春市中小企业在发展过程中面临科技创新不足、高水平人才短缺、融资困难以及服务体系不健全等问题。为促进长春市“专精特新”中小企业创新发展,应加大科技创新投入、推动产学研合作、优化金融服务体系,并完善“专精特新”中小企业服务体系建设。

IN718高温合金的新型热控凝固工艺优化

针对高温合金复杂薄壁铸件易出现欠铸、晶粒粗大和疏松等问题,开发了一种以“低温浇注、高温充型、顺序凝固”为特征的新型热控凝固工艺,研究了在1 380℃浇注温度下模壳温度(1 260~1 350℃)和抽拉速度(6~48 mm·min^(-1))等工艺参数对IN718高温合金圆柱试样组织的影响,并在优化工艺下进行了复杂薄壁特征结构件的成形试验。结果表明:随着模壳温度升高,试样的晶粒尺寸从2.33 mm增加到7.46 mm,且组织均匀性变差,断面等轴晶比例由98%降低到41%,疏松数量减少,尺寸减小。随着抽拉速度增大,晶粒尺寸从3.66 mm减小到2.69 mm,疏松数量增加,尺寸增大;当抽拉速度不小于24 mm·min^(-1)时,组织均匀性较好。最优工艺为模壳温度1 290℃、抽拉速度24 mm·min^(-1),采用该工艺可制备得到晶粒尺寸为0.81 mm、疏松面积分数仅为0.2%、最小壁厚为1.8 mm的IN718高温合金大面积薄壁特征结构件。

新零售业态下中小型网店运营策略

新零售背景下,当下网店运营与服务模式均迎来了新的转变,各种企业的信息更加透明化,通过对无形资源价值动态的把握来创造更多的有形、无形资源的抓取。另外新零售模式也使得以前对于不对称、信息差认知的可能逐步降低。新零售模式下整体的行业信息透明化、对策化幅度逐渐升高,从以前的单纯成交的关系逐步转化成现在以客户关系为中心的管理模式。当下针对零售企业提高创新服务模式,做好创新服务模式的绩效,以服务创新驱动力模型将内部和外部因素进行总体把握问题,从经济价值,功能价值,情感价值三方面充分考虑到顾客的主张,希望通过理论综述结合案例分析对于新零售背景下的服务模式以及营销方式背后的作用机理开展进一步的研究,以期对于理论和实践具有一定的指导价值。

新旧混凝土界面双面直剪性能尺寸效应试验研究

以界面处理方式、横向约束形式、混凝土强度、界面尺寸为变量,开展了8组50个新旧混凝土界面试件双面直剪试验研究,得到界面受剪破坏形态和抗剪强度-滑移曲线,分析界面抗剪强度的尺寸效应规律,拟合得到新旧混凝土双面直剪试件极限应力尺寸效应的换算系数,建立受剪承载力计算表达式。结果表明:在剪力作用方向上,新旧混凝土界面受剪极限应力存在明显的随界面高度增加而降低的尺寸效应现象;开裂应力、裂通应力以及滑移的尺寸效应不明显;施加横向约束可提升界面裂通应力和极限应力;施加预压应力可显著提升试件的裂通应力,并有效限制试件的极限滑移。无横向约束条件下,凿毛形式对极限应力影响显著,相比整浇混凝土试件,机械凿毛的同强度新旧混凝土双面直剪极限应力减少至整浇试件的0.22以下,而人工凿毛试件的折减系数在0.34~0.37之间。有横向约束条件下,同凿毛粗糙界面相比,规则齿槽试件的开裂应力、裂通应力以及滑移表现优势突出;约束下强度折减系数提高到无约束同等条件试件的2~2.5倍以上,最大可达到整浇试件强度的0.97倍。新旧混凝土强度提高可增加试件裂通应力和极限应力,但提升幅度有限。

广西中小微企业转型升级打造“专精特新”小巨人企业障碍分析

中小微企业是国民经济和社会发展的生力军,是扩大就业、改善民生、促进创新创业的重要力量。文章以广西中小微企业为样本,研究中小微企业转型升级打造“专精特新”小巨人企业的现状,探讨中小微企业转型升级打造“专精特新”小巨人企业的障碍,并提出相应的解构策略。

本土市场规模与制造业出口复杂度——基于国内国际市场协同的视角

在“双循环”新发展格局下,利用我国超大规模市场优势提升出口产品的复杂度显得尤为重要。通过构建本土市场规模影响出口复杂度的理论模型,采用147个国家(地区)205种制造业产品的出口数据进行实证检验,研究结果表明:本土市场规模对制造业出口复杂度呈显著促进效应,且这种作用在数字基础设施高水平国家、非毗邻大国国家以及发展中国家中表现得更为突出。渠道检验显示,本土市场规模可以通过提高技术创新水平进而影响出口复杂度。此外,基于国内、国际两个市场协同的视角,发现发展中国家进口依存度与本土市场规模具有协同效应,能够促进出口复杂度的提高,其出口依存度则存在负向作用,而发达国家则相反。

金融支持先进制造业的国际经验及借鉴

加快发展先进制造业,是我国加快形成新质生产力、建设现代化产业体系、加快构建国内国际双循环新发展格局的重中之重。文章以德国和日本为例,梳理总结了发达国家金融支持先进制造业发展的经验,剖析了我国金融支持先进制造业发展面临的技术识别专业度受限、科创类贷款与企业研发资金需求不匹配、产业链配套中小企业信用资源不足、部分行业产能过剩风险加大等方面问题。在此基础上,本文提出金融支持先进制造业的对策建议:坚持顶层设计,完善产业创新支持体系;坚持深化研判,强化对先进制造业产业链的认识;坚持放权赋能,提升产业链综合金融服务能力;坚持系统协同,加大配套中小企业“链式”支持;坚持底线思维,保障金融支持可持续性。

新型基础设施投资对区域经济差距的影响

从新型基础设施角度出发采用动态面板的研究方法,以中国2003—2020年30个省份为样本,探讨新型基础设施投资对区域经济差距的影响。研究结果表明:新型基础设施投资与区域经济差距呈倒“U”型关系,这一结果经过一系列的稳健性检验后仍然成立;进一步分析表明,新型基础设施投资会缩小东部地区经济差距,但是会扩大中部、西部地区经济差距;将新型基础设施分为融合基础设施、信息基础设施、创新基础设施后,发现融合基础设施对于区域经济差距的扩大效应弱于信息基础设施、创新基础设施;新型基础设施投资会通过劳动效率、技术创新渠道影响区域经济差距。

数字金融对专精特新中小企业研发创新的影响

基于我国2018—2022年专精特新中小企业上市公司的面板数据,实证分析数字金融对专精特新中小企业研发创新的影响机制。结果表明,数字金融通过缓解融资约束、降低市场风险、加快IPO进程,从而推动专精特新中小企业研发创新。因此,相关金融机构应加大数字金融技术投入与建设力度,拓展数字金融服务边界,以支持专精特新中小企业高质量发展,创造优渥的金融空间。

连续研发联盟新伙伴规模对企业突破性创新绩效的影响

选取中国医药制造行业2008—2017年80家上市公司的502个研发联盟样本,基于动态视角,探讨连续研发联盟新伙伴规模均值和新伙伴规模波动两个维度对企业突破性创新绩效的影响.实证结果表明:前者对企业突破性创新绩效有显著的负向作用;后者对企业突破性创新绩效有显著的正向作用,当新伙伴规模均值较大时,其波动增加显著正向增强企业突破性创新绩效.

江西省专精特新企业发展困境及培育路径研究

中小企业在经济社会发展中具有十分重要的地位和作用。专精特新企业是中小企业的“排头兵”,是未来产业链的重要支撑,具有较强的创新能力和抗风险能力。本文探究了江西省专精特新企业发展的背景与现状,分析了影响专精特新企业发展的制约因素,有针对性地提出了推动专精特新企业发展的建议,希望能为加快培育专精特新企业,特别是推动中西部地区中小企业发展提供参考。

中国大都市区范围新近发展与演化研究——基于全国人口普查数据

大都市区是中国城镇化的重要空间载体,是推动城市群发展和新型城镇化进程的主要空间形态。基于已有“五普”“六普”相关研究,利用“七普”数据,采用城镇化率、人口密度、人口数量等指标,选择位序-规模法则、首位度指数等方法,识别大都市区空间范围,分析大都市区新近发展及演化特征。结果表明:(1)总体来看,2020年全国有174个大都市区,总人口为5.8亿。2020年大都市区数量较2000年增加57个,较2010年增加46个;人口比2000年增加3.81亿,比2010年增加2.61亿。(2)从规模来看,2000—2020年不同规模大都市区数量逐渐由金字塔型向橄榄型演变,但人口数量倒金字塔结构愈发增强。大都市区首位分布不明显,更加符合位序-规模分布。(3)从空间分布特征来看,2000—2020年大都市区东多西少的空间梯度分异格局基本稳定,并逐渐形成“两横三纵”的空间分布格局,且基本包含于城市群规划空间范围内。

数字经济发展如何助推共同富裕?

数字经济作为经济增长的新动能,对推动共同富裕具有重要作用。结合城市层面数据,检验数字经济发展目标是否与共同富裕实现目标高度吻合;进一步探究人力资本结构高级化和产业结构高级化的传导机制作用,以及城市规模的影响作用。研究结果表明:(1)在共同富裕实现进程中,数字经济在发展性、共享性和可持续性三方面均能够发挥正向驱动作用,而且在生产、流通和交换三个领域均能够发挥正外部性作用,扎实推进共同富裕。(2)提高当地人力资本结构高级化水平和产业结构高级化水平是数字经济助推共同富裕的有效传导渠道;城市规模存在倒U型影响作用,并表现出区域数字鸿沟的存在性。(3)无论按照东部和中西部地区划分,还是按照中心城市和外围城市划分,数字经济发展均正向影响共同富裕进程。为此,各地区应加快培育高数字素养的复合型人才,加速融合数据要素与高质量劳动者形成新质生产力,合理推进新型城镇化进程。

某新建水闸结构设计与施工导截流方法

拟新建中型水闸代替月亮湾流域内现状井头村5孔水闸,并与规划截洪工程、现状七一水闸、规划中的拟建泵站联合调度,形成月亮湾流域内完整的防洪排涝系统。从水闸选址、工程总体布置出发,对水闸结构型式、水闸孔数以及水闸基础处理等方面进行详细的方案比较,选择出适合该水闸的工程设计方案,并对选定水闸结构及主要建筑物进行工程布置,为工程水闸设计施工提供技术支撑。