应用Catch-MSY模型评估印度洋蓝枪鱼资源

Catch-MSY模型可仅依靠渔获量数据进行渔业资源评估,在数据缺乏状况下能暂时替代标准资源评估模型。本研究以印度洋蓝枪鱼(Makaira nigricans)为例,根据有、无信息的内禀增长率r和环境容纳量K的先验分布,设立15组情景进行模型灵敏度分析、资源评估和预测。结果表明,参数r和K呈强烈的负相关,而最大可持续产量(Maximum Sustainable Yield,MSY)与参数r呈正相关;数据时间序列长度对评估结果影响有限,而模型对起止年渔获量较为敏感。资源状况评估表明,印度洋蓝枪鱼资源生物量状况良好,即B2015/BMSY大于1;而开发状况除其中两种情景外,均为过度捕捞,即F2015/FMSY大于1。资源预测表明,为使未来10年内B/BMSY>1的概率超过50%,需将渔获量缩减至当前渔获量的90%(13.86kt);考虑到该模型在数据缺乏状况下会更加保守,若将当前渔获量的100%~110%(15.40~16.94kt)设为管理目标,则未来5年内B/BMSY>1的概率超过50%。

N Cycle, N Flow Trends in Japan, and Strategies for Reducing N_2O Emission and NO_3^- Pollution

To feed an increasing population, large amounts of chemical nitrogen fertilizer have been used to produce much of our food, feed and fiber thereby increasing nitrogen levels in soils, natural waters, crop residues, livestock wastes,and municipal and agricultural wastes, with national and international concern about its potential adverse effects on environmental quality and public health. To understand these phenomena and problems, first the nitrogen cycle and the environment are described. Then recent trends for nitrogen cycling through the food and feed system, N2O emissions from fertilized upland and paddy soils, and NO-3 pollution in ground water in Japan are reported. Finally, mitigation strategies in Japan for reducing N2O emission and NO-3 pollution are proposed, including nitrification inhibitors, controlled release fertilizers, utilization of plant species that could suppress nitrification, utilizing the toposequence, government policy, and appropriate agricultural practices. Of all the technologies presented, use of nitrification inhibitors and controlled release fertilizers are deemed the most important with further development of these aspects of technologies being expected. These practices, if employed worldwide, could help reduce the load, or environmental deterioration, on the Earth's biosphere.

Development Strategies of E-commerce for Small and Medium - sized Enterprises

In the economic structure of our country, small and medium-sized enterprises （SMEs） are the most important part of the backbone, with the continuous popularization of the Internet, e-commerce has gradually become a business model that the current small and medium enterprises must face and accept, The development of enterprises is of great signifi cance. In this context, the article first introduced the importance of the development of e-commerce SMEs, and then based on the actual operation of the community put forward and analyzed the current e-commerce development under the existing problems, and finally based on the actual lack of effective Development Strategy of E - commerce for Small and Medium - sized Enterprises.

An Improved Binary Wolf Pack Algorithm Based on Adaptive Step Length and Improved Update Strategy for 0-1 Knapsack Problems

Binary wolf pack algorithm (BWPA) is a kind of intelligence algorithm which can solve combination optimization problems in discrete spaces.Based on BWPA, an improved binary wolf pack algorithm (AIBWPA) can be proposed by adopting adaptive step length and improved update strategy of wolf pack. AIBWPA is applied to 10 classic 0-1 knapsack problems and compared with BWPA, DPSO, which proves that AIBWPA has higher optimization accuracy and better computational robustness. AIBWPA makes the parameters simple, protects the population diversity and enhances the global convergence.

Appraisal of Existing HIV/AIDs Prevention and Control Measures and Presentation of Innovative Strategies to End HIV/AIDS Epidemic by 2030

Background: Globally, UNAIDS report 2022 shows, there are 84.2 million people affected by HIV/AIDS and 40.1 million deaths from AIDS since the start of epidemic. In sub-Saharan Africa, women and girls accounted for 63% of all new HIV infections in 2021 with, six in seven new HIV infections among adolescents aged 15 - 19 years being girls. Key populations accounted for 70% of HIV infections globally in 2021, with 51% of these new HIV infections in sub-Saharan Africa. Reflecting on the 4 decades’ journey of HIV epidemic amidst local, national and international efforts, the UN target of ending AIDS as a public health threat by 2030 remains questionable unless new innovative ways are used. This study aimed at analyzing existing HIV/AIDS interventions, discuss UN interventions in line with ending HIV/AIDS by 2030 then, suggest and discuss new innovative ways of ending HIV scourge by 2030. Methods: Systematic literature review methodology was used to extract existing published information on HIV prevention strategies from 1981 to 2023. The articles were previewed by 2 experts for quality and grouped by intervention. Of the 637 articles accessed, on HIV prevention/control only 45 met the inclusion criteria. Data were synthesized using a narrative synthesis approach following standard guidelines on synthesis without meta-analysis. Descriptive analysis was done, strength and limitations were identified. UNAIDS recommendations for ending HIV/AIDS by 2030 identified and analyzed. New Innovations in HIV/AIDS were presented and discussed. The scope of the reviewed literature was limited to HIV preventive strategies practiced between 1981 and 2023. Results: Findings show that, Uganda’s HIV prevalence was at a peak in 1991 of 15% (30% among pregnant women in urban areas). ABC strategy is claimed to have turned sharply downward the prevalence through the mid-1990s and reached 5% (14% for pregnant urban women) by 2001. Analysis of the strategy showed that the achievements of the strategy could not be sustained, subsequently HIV prevalence rose again. This is because none of the ABC components can independently reduce HIV problem. In the real world, 100% abstinence has failed, condom use only reduces infection by 90% (WHO), and lifelong monogamy is impractical. Such limitations weaken ABC strategy. The study established that Post-exposure prophylaxis (PEP) i.e. taking HIV medicines within 72 hours (3 days) after a possible exposure to HIV infection is a safe, effective and a globally practiced HIV preventive intervention in emergency situations of HIV exposure. However, PEP is limited to care sought within 72 hours after exposure and yet timely access especially in rural areas and for key populations remains a big challenge. Oral PrEP was also identified as effective HIV preventive measure that can reduce HIV risk from sex by about 99% and from injection drug users by 74%. However, like PEP, timely access especially in rural areas and for key populations remains a big challenge. The UNAIDS 95-95-95 strategy (i.e. 95% of people know their HIV status, 95% with +HIV status be on sustained ART and 95% on ART get viral load suppression) formed the basis for setting the target of ending HIV/AIDS epidemic by 2030. However, our analysis shows that this target is unrealistic given the above highlighted limitations/ barriers in preventive measures and the unlikely perfect adherence (100%) to ART by all enrolled HIV positive persons. Conclusion: Ending HIV/AIDS by 2030 cannot be achieved by implementing the current preventing strategies and control measures. This study established that most of the existing HIV preventive strategies and control measures have a number of limitations. However, with sustained UN 95-95-95 strategy supplemented with additional innovative ways, there is hope that the UN dream of ending HIV/AIDS though not necessarily by 2030, can in the long run be achieved.

The Characteristics of Putaohua Reservoir and Development Strategies in Xujiaweizi Baxin Oilfield

With the using of new full 3 - D interpretative technology, the carefully interpretation of the micro - amplitude structures and faults by the reprocessed 3 -D seismic data in IES (Interactive Exploration System) interpretative system of Sun workstation is obtained. Because of the application of the well - advanced predictive technique for reservoir lithological changes, the predictive accuracy rate of drilling for 31 wells drilled in 1996 achieved 100 % and the economic and social benefits are desirable.

Stator Winding Turn Faults Diagnosis for Induction Motor by Immune Memory Dynamic Clonal Strategy Algorithm

Quick detection of a small initial fault is important for an induction motor to prevent a consequent large fault.The mathematical model with basic motor equations among voltages,currents,and fluxes is analyzed and the motor model equations are described.The fault related features are extracted.An immune memory dynamic clonal strategy(IMDCS)system is applied to detecting the stator faults of induction motor.Four features are obtained from the induction motor,and then these features are given to the IMDCS system.After the motor condition has been learned by the IMDCS system,the memory set obtained in the training stage can be used to detect any fault.The proposed method is experimentally implemented on the induction motor,and the experimental results show the applicability and effectiveness of the proposed method to the diagnosis of stator winding turn faults in induction motors.

Efficient Early Termination Strategy for LDPC Codes in GPS Systems

By exploiting the structural features of L1C messages,a novel Early Termination( ET) strategy is proposed to speed up the decoding of low-density parity-check( LDPC) codes in the GPS system. The proposed strategy is based on the cyclic redundancy check( CRC) of the messages in the subframes 2 and 3. The simulation results show that average number of iterations of the proposed strategy is less than that of the standard ET strategy,with nearly no degradation in decoding performance. Besides,the proposed ET strategy can be efficiently implemented in a sequential or parallel manner. Thus,the proposed ET strategy is attractive for practical purposes.

技术赶超导向下的军民科技创新网络:重大使命、耦合模式与发展路径

大国竞争正成为中国乃至全世界发展面临的新形势。在关键技术与产业面临限制和打压的环境中,面向军民两用的高新技术融合创新是双循环新发展格局中的重要一环,是推动我国高水平科技自立自强发展的关键。高新技术的“卡脖子”特征主要发生在面向国家安全、经济发展和应对重大社会挑战三个层面,是军民科技创新实现技术赶超的重大使命。因此,军民科技创新网络需要进一步明确创新网络的耦合关系和网络组织中利益相关者的职能分配,充分发挥政府的干预作用;结合关键技术与产业的创新特征,围绕技术赶超的“原路模仿型”“弯道超车型”和两者相结合的“双元交叉型”三种发展路径进行设计,推动一体化国家战略体系与能力建设。

Vitamin A supplement: a key strategy to prevent vitamin A deficiency among young children in Afghanistan

Background:Vitamin A deficiency is the main problem of public health worldwide demonstrated that 190 million population of preschool children and 122 countries(in Africa and South-East Asia)have vitamin A deficiency,according to recent estimated research.In Afghanistan,vitamin A supplementation is a key strategy to prevent vitamin A deficiency among young children.Children receive vitamin A supplements as part of National Immunization Days(NID)campaigns.Methods:In this case study,the data was collected from June 15/2015 to February 23/2016,and the final report of the Afghanistan Demographic Health Survey(AfDHS)2015 was released on February 15/2017.All 27,209 children aged 6-59 months who are living with their mothers were included in this study.Who consumed foods rich in vitamin A was not included in this study.Results:The percentages who were given vitamin A supplements in the last 6 months among all children 6-59 months aged.A total of 1,572 children aged among 6-8 months were given vitamin A supplements 670(42.6%)children and comparison with the total community of the study(27,209)children(2.46%).A total of 1,148 children aged among 9-11 months were given vitamin A supplements to 465(40.5%)children and comparison with the total community of the study(27,209)children(1.70%).Conclusion:After following up on more studies,we found that vitamin A deficiency is a public problem,thus it is better to use wheat flour fortification,vitamin A capsule(VAC)supplementation,nutrition education,source of vitamin A,and training of primary healthcare workers on the clinical to prevent and treat the vitamin A deficiency among children.Therefore,we aimed to determine the given vitamin A supplementation among children aged 6-59 months in 33 provinces in Afghanistan,in 2015.

Synergetic Alkoxy Side-Chain and Chlorine-Contained End Group Strategy toward High Performance Ultra-Narrow Bandgap Small Molecule Acceptors

Ultra-narrow bandgap(ultra-NBG)small molecule acceptors(SMAs)show great potential in organic solar cells(OSCs)due to the extended near-infrared(NIR)absorption.In this work,a synergetic alkoxy side-chain and chlorine-contained end group strategy is employed to achieve A-DA'D-A type ultra-NBG SMAs by introducing alkoxy chains with oxygen atom at the second position into the thiopheneβposition as well as replacing the F atoms with Cl atoms in the end group.As a result,the heptacyclic BZO-4F shows a redshifted absorption onset(960 nm)compared with Y11(932 nm)without oxygen atoms in the side chains.Then,the fluorinated end groups are substituted with the chlorinated ones to synthesize BZO-4Cl.The absorption onset of BZO-4Cl is further redshifted to 990 nm,corresponding to an optical ultra-NBG of 1.25 eV.When blending with the polymer donor PBDB-T,the binary devices based on PBDB-T:BZO-4F and PBDB-T:BZO-4Cl deliver power conversion efficiencies(PCEs)over 12%.Furthermore,ternary devices with the addition of BZ4F-O-1 into PBDB-T:BZO-4Cl system achieve the optimal PCE of 15.51%.This work proposes a synergetic alkoxy side-chain and chlorine-contained end group strategy to achieve A-DA'D-A type ultra-NBG SMAs,which is important for future molecular design.

Self-assembled supramolecular immunomagnetic nanoparticles throughπ-πstacking strategy for the enrichment of circulating tumor cells

Owing to their high-specific binding toward targets as well as fast and convenient separation operations,immunomagnetic beads(IMBs)are widely used in the capture and detection of circulating tumor cells(CTCs).To construct the IMBs,surface modifications are generally performed to functionalize the magnetic cores(e.g.Fe_(3)O_(4)nanoparticles),and the employed surface modification strategies normally influence the structure and functions of the prepared IMBs in return.Different from the existing work,we proposed the use of supramolecular layer-by-layer(LBL)self-assembly strategy to construct the IMBs.In general,owing to theπ-πstacking interactions,the polydopamine,graphene oxide and‘molecular glue’γ-oxo-1-pyrenebutyric acid were self-assembled on Fe_(3)O_(4)nanoparticles sequentially,thereby accomplishing the integration of different functional components onto magnetic cores to prepare the self-assembled supramolecular immunomagnetic beads(ASIMBs).The ASIMBs showed high sensitivity,specificity and good biocompatibility to the model CTCs and low nonspecific adsorption to the negative cells(∼93%for MCF-7 cells and 17%for Jurkat cells).Meanwhile,ASIMBs possessed a remarkable potential to screen the rare MCF-7 cells out of large amounts of interfering Jurkat cells with the capture efficiency of 75-100%or out of mouse whole blood with the capture efficiency of 20-90%.The captured cells can be further recultured directly without any more treatment,which showed huge applicability of the ASIMBs for in vitro detection in clinical practices.

文化是如何影响消费的制度安排的?——消费认知与政策选择偏好的文化根源分析

多年来,我国消费率和平均消费倾向偏低,居民消费在经济增长中的作用难以充分发挥。经济学界对此问题进行了深入的研究,但较少触及该问题的文化根源。从文化视角对此问题进行分析,本文认为:一方面,消费政策是基于国家对消费的认知而形成的,不同阶段的消费政策对应不同的消费认知;另一方面,国家的消费认知决定了消费政策的选择偏好。市场化改革以后,消费政策更多地呈现为增长型政策,而不是发展型政策。居民消费领域发展型政策的供给不足,是我国消费率和平均消费倾向偏低的原因。而消费认知和政策选择偏好的背后,均有着文化根源。本文对消费认知与政策选择偏好如何受文化影响进行了分析。

创新方式与柔性战略对后发企业追赶路径的影响——基于fsQCA的实证分析

后发企业追赶的以往研究主要集中于技术追赶、商业模式。不同于以往研究,从企业创新和战略层面探讨其对后发企业追赶行为的影响,并引入消费者接受程度和领先企业对后发企业追赶行为的态度来衡量后发企业是否采用柔性战略,同时衡量后发企业新产品是否具有市场优势以及追赶超越的难度;基于20个典型案例,通过模糊集定性分析法和二分法进行编码、赋值和校准处理,最终得到后发企业实现追赶甚至超越领先企业的6条路径。结果表明:颠覆性创新在后发企业追赶过程中起到了重要影响作用,后发企业往往通过边缘市场培植新技术发展直至符合主流市场需求,但后发企业要善于采取颠覆性创新方式;柔性战略可以避免追赶过程中不必要的竞争,弥补后发企业在技术和市场等方面的不足,发挥企业创新优势;多元化创新方式有利于企业内部形成综合性、立体性和多维度的创新能力,且与柔性策略交互作用可以提高后发企业核心竞争力,有助于后发企业的追赶。据此提出在多元化创新能力和柔性战略的交互作用下,后发企业要注重培养自身的多元创新能力,并充分结合自身创新能力和柔性战略提高竞争力。

赶超战略的阶段变化与粤港澳大湾区制造业高质量发展

随着中国制造业发展从赶超阶段前期进入中后期,中国企业市场地位变化引起发达国家及其跨国公司竞争战略深度调整,而这势必需要中国制造业发展方向和战略作出适应性调整。粤港澳大湾区制造业具有强大的规模优势,同时也面临突出的结构性挑战。下一步,粤港澳大湾区制造业高质量发展既要强调发挥规模经济优势以推动量的合理增长,又要贯彻创新驱动发展战略以实现质的有效提升。这要求相应的机制设计和政策选择有效回应更为复杂的信息问题和激励问题。为此,粤港澳大湾区需要进一步明确未来制造业高质量发展的重点方向,并在“一国两制”框架下推动体制机制改革和政策设计探索。

从城市偏向到城乡协调发展的政治经济逻辑

城市偏向是新中国成立以来中国政府的主导性政策选择。本文基于新中国60年经济发展史,把政府行为置于研究的中心,理解城市偏向经济政策演变的内生机制。研究表明,计划经济体制下的城市偏向是政府赶超的必然结果,而转型经济下的城市偏向则是政府主导的经济发展模式下,政治集权和经济分权的必然产物。持续的城市偏向导致累进的社会成本,从而为政府的政策调整提供契机。一个简单的两部门模型用于刻画政府主导下城市偏向的内生演变机制。

北极海域渔业资源开发现状及对策

随着全球变暖,北极海冰覆盖面积逐年减少。在全球海洋渔业资源衰退的大背景下,北极渔业资源的开发和合理利用备受世界各国关注,越来越多的国际组织和科学家开始对北极渔业进行探索研究。由于北极地区环境恶劣,海洋鱼类的种类和资源量相比其他地区较少,但随着北极海冰的融化,北极渔业资源开发和利用成为可能,北极潜在的未充分开发利用的渔业资源正吸引着有关国家的高度关注。为此,本文通过收集国内外相关文献,对北极渔业种类、资源状况及其开发现状进行了分析,同时提出了中国参与北极渔业资源开发和利用的对策与建议。

我国集成电路设备的全球竞争力、赶超困境与政策建议

作为集成电路制造的“母机”,设备在集成电路产业发展中至关重要。提升设备领域的可控力,是破解集成电路产业“卡脖子”问题的关键之一。总体来看,我国已成为集成电路设备的最大消费国,但在关键设备和先进制程设备上面临美国、日本和欧洲厂商的垄断控制甚至是打压。为推动产业自主发展,近年来我国在集成电路产业设备领域涌现出一大批开拓者,在一定程度上实现部分设备的有效替代。但是,在美国对华政策日趋紧张的大背景下,集成电路设备本身行业规模不大和超长的产业链特征,降低了后发者进入的吸引力,且难以突破领先者形塑的技术路线,在后发赶超过程中还会面临领先企业依托自身优势构筑的“进入壁垒”以及可能实施的“定向狙击”。为此,需进一步保持战略定力,推动设备领域的国产化和赶超发展,不仅要着眼于长期发展目标以加大政策支持力度和创新政策工具,还要把握技术、市场等机会窗口期推动产业跃迁,强化国际合作尤其是与韩国等处于类似市场地位的国家合作,完善我国在设备领域的供应链体系。

我国制造业与主要制造国家的差距与追赶战略

我国制造业已经进入全球市场的竞争 ,美、德、日、韩等全球的主要制造国家是主要的竞争对手。明确我国制造业与主要制造国家的差距 ,并根据差距制定对策 ,具有重要意义。本文先从出口额和制造业增加值两个方面考察我国制造业总量水平与主要制造国的差距 ,发现 :从总量上来看 ,我国制造业成长的空间还很大 ,只要努力 ,还可以取得非常大的发展。然后 ,文章从制造业增加值率、劳动生产率、出口产品技术水平和专利等方面考察我国制造业质量水平与主要制造国的差距 ,发现 :从质量上看 ,我国制造业与主要制造国差距很大 ,这个差距比制造业总量上的差距还要大。最后 ,文章提出一些追赶战略 ,期望我国制造业在实现总量赶超的同时。

我国自主创新技术赶超战略与路径研究

我国已经进入可以更多地依靠创新推动经济发展的新阶段,但与西方先进国家和一些工业化进程较为发达国家和地区之间的差距仍然偏大。我国技术发展在创新性上不足,企业尚未真正成为技术创新的主体,缺乏创新的动力和机制。同时,我国开始关注技术赶超战略的制定。我国已经决定大力推进市场经济体制改革,因此,必须着重自主创新技术赶超战略与路径的研究,早日实现振兴中华的民族目标。