Wear Resistance of CO_2 Corrosion Product Scale Formed at High Temperature

To investigate the correlation between structure characteristics and wear resistance of CO2 corrosion product scales at high temperature and high pressure, an autoclave was used to prepare CO2 corrosion product scales on N80 steel in carbon dioxide corrosion environment. The correlation between wear resistance of the scales and many other factors, such as temperature, pressure, morphology, structure, velocity of fluid medium, sand grain size, and so on, was comparatively analyzed by a self assembled wear device, and the scale morphologies before or after being worn were observed by scanning electron microscope （SEM）. And then the surface grain size and thickness of scale were measured. The results showed that the cross-section of the corrosion scale was of a double-layer structure, the outer layer of which was composed of regular crystals, whereas the inner layer was a thin scale of fine grains. The outer grain size and thickness of scale varied with temperature, and the initial wear loss was consistent with the surface grain size; at the same time, the total wear loss corresponded to the thickness of scale. Compared to wear resist- ance in different depths of the scale, it was found that the structure of scale was a double-layer structure in cross-section, and the wear resistance of inner layer was better than that of the outer layer; the closer the scale to the matrix, the greater was the wear resistance of scale; and the larger the size or the higher the rotary speed of solid grain in multiphase flowing medium, the more was the wear loss of scale.

Characterization of Small-Scale Farmers and Assessment of Their Access to Crop Production Information in Selected Counties of Kenya

Small-scale farming accounts for 78% of total agricultural production in Kenya and contributes to 23.5% of the country’s GDP. Their crop production activities are mostly rainfed subsistence with any surplus being sold to bring in some income. Timely decisions on farm practices such as farm preparation and planting are critical determinants of the seasonal outcomes. In Kenya, most small-scale farmers have no reliable source of information that would help them make timely and accurate decisions. County governments have extension officers who are mandated with giving farmers advisory services to farmers but they are not able to reach most farmers due to facilitation constraints. The mode and format of sharing information is also critical since it’s important to ensure that it’s timely, well-understood and usable. This study sought to assess access to geospatial derived and other crop production information by farmers in four selected counties of Kenya. Specific objectives were to determine the profile of small-scale farmers in terms of age, education and farm size;to determine the type of information that is made available to them by County and Sub-County extension officers including the format and mode of provision;and to determine if the information provided was useful in terms of accuracy, timeliness and adequacy. The results indicated that over 80% of the farmers were over 35 years of age and over 56% were male. Majority had attained primary education (34%) or secondary education (29%) and most farmers in all the counties grew maize (71%). Notably, fellow farmers were a source of information (71%) with the frequency of sharing information being mostly seasonal (37%) and when information was available (43%). Over 66% of interviewed farmers indicating that they faced challenges while using provided information. The results from the study are insightful and helpful in determining effective ways of providing farmers with useful information to ensure maximum benefits.

Multidisciplinary design optimization on production scale of underground metal mine

In order to ensure overall optimization of the underground metal mine production scale, multidisciplinary design optimization model of production scale which covers the subsystem objective function of income of production, safety and environmental impact in the underground metal mine was established by using multidisciplinary design optimization method. The coupling effects from various disciplines were fully considered, and adaptive mutative scale chaos immunization optimization algorithm was adopted to solve multidisciplinary design optimization model of underground metal mine production scale. Practical results show that multidisciplinary design optimization on production scale of an underground lead and zinc mine reflect the actual operating conditions more realistically, the production scale is about 1.25 Mt/a (Lead and zinc metal content of 160 000 t/a), the economic life is approximately 14 a, corresponding coefficient of production profits can be increased to 15.13%, safety factor can be increased to 5.4% and environmental impact coefficient can be reduced by 9.52%.

An intelligent system for calculating the scale of rational,enlarged production of an underground non-ferrous metal mine

The enlarged production scale of underground non-ferrous metal mines is affected by many uncertain factors difficult to describe mathematically with any level of accuracy.The problem can be solved by a synthesis of artificial intelligence.Based on the analysis of the major factors affecting the scale of enlarged production,we first interpreted in detail the design principles and structure of the intelligent system.Secondly,we introduced an ANN subsystem.In order to ensure technological and scale efficien- cies of the training samples for ANN,we filtrated the samples with a DEA method.Finally,we trained the intelligent system,which was proved to be very efficient.

Empirical Research on E-commerce to Increase the Scale of Agricultural Products Trade: Taking Guangxi Hezhou Zhengfeng Modern Agriculture Co.,Ltd. as an Example

Agriculture is the foundation of the national economy.The periodicity of agricultural product output and prices,the asymmetry of information between buyers and sellers,and the inherent characteristics of small scale,high cost,and low profit have caused slow sales,which greatly hurt the enthusiasm of farmers to develop production and endanger social stability.Constructing an informationized and commercialized trading platform and an information sharing platform through e-commerce and establishing related systems and supervision mechanisms will help to promote the rapid growth of agricultural product sales.Research has shown that in the field of agricultural circulation,e-commerce has a significant effect on increasing the scale of agricultural trade.

Dendritic cells derived from pluripotent stem cells:Potential of large scale production

Human pluripotent stem cells(hPSCs), including human embryonic stem cells and human induced pluripotent stem cells, are promising sources for hematopoietic cells due to their unlimited growth capacity and the pluripotency. Dendritic cells(DCs), the unique immune cells in the hematopoietic system, can be loaded with tumor specific antigen and used as vaccine for cancer immunotherapy. While autologous DCs from peripheral blood are limited in cell number, hPSC-derived DCs provide a novel alternative cell source which has the potential for large scale production. This review summarizes recent advances in differentiating hPSCs to DCs through the intermediate stage of hematopoietic stem cells. Step-wise growth factor induction has been used to derive DCs from hPSCs either in suspension cultureof embryoid bodies(EBs) or in co-culture with stromal cells. To fulfill the clinical potential of the DCs derived from hPSCs, the bioprocess needs to be scaled up to produce a large number of cells economically under tight quality control. This requires the development of novel bioreactor systems combining guided EB-based differentiation with engineered culture environment. Hence, recent progress in using bioreactors for hPSC lineage-specific differentiation is reviewed. In particular, the potential scale up strategies for the multistage DC differentiation and the effect of shear stress on hPSC differentiation in bioreactors are discussed in detail.

Robust Corner Detection Based on Multi-scale Curvature Product in B-spline Scale Space

这份报纸在 B 花键弯曲规模空间的框架论述一种多尺度的弯曲产品角落察觉技术。规模产品功能在不同规模从轮廓的弯曲产品被导出。角落被 thresholding 作为本地最大值构造越过几规模的弯曲产品结果。通过规模产品，本地化精确性和察觉表演能显著地以 CNN 标准被改进。实验也证明那个建议方法显示出坚韧性到高频率细节并且提供有希望的察觉结果。

An Empirical Study on the Moderate Scale of Food-production-based Family Farm in Guangxi

The moderate scale family farm is the future agricultural business entity in China,and the scale of family farm is a key factor affecting its development.With Guigang City in Guangxi as a point for the study,from the perspective of maximizing income of rural households,this paper uses production function model to calculate the moderate scale of food-production-based family farm at 5.7 ha,and makes policy recommendations.

Impact of Small-scale Production Mode on Citrus Industry of Hunan Province,China——Based on the Investigation on Citrus Industry in Shimen County

Small-scale farmer is defined by the domestic and foreign experts and scholars.They point out that since the fragmentation of production and the diseconomy of scale in small-scale farmer is inconsistent with the characteristics of scale and technology of modern agricultural production,it is necessary to eliminate the adverse effects of existing mode in order to provide theoretical references for the relevant researches.Citrus industry in Shimen County,Hunan Province,China is introduced from the aspects of natural geographical condition and socio-economic benefit.Impact of small-scale production mode on citrus production in Shimen County is discussed.Firstly,blindness of small-scale production is the main reason leading to overproduction of citrus.Secondly,small-scale production mode has limitation on the acceptance of new technologies,restricts the operation of geographical trademark,and constraints the enthusiasm of enterprises in entering the agricultural field.Finally,suggestions are put forward,such as encouraging the circulation of rural land,improving the organization degree of farmers,changing the work function of grass-roots government and perfecting the agricultural financial credit system.

Study on the Production Benefit of Large-scale Tobacco Growers

The tobacco growers with the growing area of greater than or equal to 100 mu,have become an important subject of tobacco production in Weng'an County of Guizhou Province. Regulating and developing the production and business activities of large-scale tobacco growers, plays an important role in stabilizing tobacco production,reducing costs and increasing efficiency in Weng'an County. Through the field survey of large-scale growers' production activities,this article analyzes the input and output levels,and explores the key factors influencing benefit, in order to provide a basis for further regulating the tobacco growing practices and improving the flue-cured tobacco production benefit.

Effects of the Produced Water from a Sour Oilfield in South Kuwait on the Production Tubing

Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.

多向加权Tsallis熵最大化导向的自动阈值分割方法

受噪声或随机细节、目标和背景的大小比例、成像时的点扩散等不同因素的影响,许多图像的灰度直方图呈现为无模态、单模态、双模态或者多模态样式.为了在统一框架内处理这4种不同模态情形下的自动阈值选择问题,本文提出了一种多向加权Tsallis熵最大化导向的自动阈值分割方法(Multi-directional Weighted Tsallis Entropy,MWTE).基于新设计的反正切方向性卷积核的多尺度乘积效应,该方法将不同模态的灰度直方图转化为统一的单模态右偏灰度直方图.在4个不同方向上提取出这种特殊的单模态右偏灰度直方图后,通过多向加权策略构建出与原始图像灰度值紧密相关的加权Tsallis熵目标函数,并以该目标函数取最大值时对应的灰度值作为最终分割阈值.本文将提出的方法和3个阈值分割方法、1个软分割方法、1个活动轮廓分割方法以及1个自动聚类分割方法进行了比较.在4种不同模态情形下的4幅合成图像和50幅真实世界图像上的实验结果表明,本文提出的方法虽然在计算效率方面不占有优势,但它对不同模态的测试图像具有更稳健的分割适应性,且在量化分割精度所用的马修斯相关系数方面优于其他6个分割方法.

Sustainable Potato Production in the Mountain Area of Ecuador, an Approach to Increase Productivity with Small Scale Farmers

Ecuador potato crop is family based production system. Potato production has two roles in their economy, the first is providing food for their families and the second is a source of income for the household. However small scale farmers have limited access to local markets and most of the sales are through intermediates’ who purchase directly in the field at the lowest price possible. Potato production challenges for the small-scale farmers are among others availability of quality potato seed, direct sales, purchase of agrochemical inputs to maintain their crops and lack of education. In 2021, only 4% of potato farmers used certified seed. Potato yield is still low around 16.1 t·ha-1, in the last 10 years the total potato cultivated area was reduced by at least 50%. The farmers produce “Bokashi” and other organic fertilizer and these are effective to improve soil fertility and plant health. Homemade bio-pesticides reduce agrochemical pesticides. The Decision Support System (DSS) is a handheld device to control late blight, minimizes fungicide applications and improve fungicide rotation. In 2018 Candidatus Liberibacter solanacearum (Lso), the causal agent of zebra chip, and its vector, the potato psyllid Bactericera cockerelli, together created havoc for farmers and researchers. Promotion of early potato varieties INIAP—Libertad is an alternative to lower the impact of this newest pest.

我国青贮玉米生产的集聚演变及其作用机制——基于动态空间杜宾模型

为观测青贮玉米生产的动态变化,研究基于2001—2021年我国30个省面板数据,选用重心模型分析青贮玉米生产集聚区域变动。在此基础上,借助动态空间杜宾模型剖析要素投入、社会经济、政策支持对中国青贮玉米生产区域变动的影响。结果表明,我国青贮玉米存在空间聚集现象,即2001—2021年间我国青贮玉米生产量的莫兰指数总体上呈“先降再升再降再升”的发展态势。生产重心演变轨迹结果显示,我国青贮玉米生产区域重心呈现“先东北后西北、西南”的演变趋势。机制结果表明,粮食优势、财政扶持、务工收入增加是推进青贮玉米生产的主要驱动因素;生产基础设备、化肥施用、农业收益对本省份青贮玉米生产具有正向影响,但对相邻省份青贮玉米生产的影响不显著。

生产标准化与农业规模生产的范围选择

农业规模化经营是我国实现农业现代化的重要途径,而规模化生产过程中雇佣劳动力的监督问题,使得规模化经营者在选择雇佣经营或外包经营时常常陷入两难境地。在监督困境不可避免且当下规模化经营势在必行之时,经营者可以将雇佣劳动力的监督成本视为其经营成本的一部分,通过对比成本创新与质量创新的成本收益,进行农业规模生产的范围选择。在成本-质量创新的双目标任务下,生产单位受农作物标准化生产程度的影响,标准化程度较高时,经营者有成本创新的偏好,其生产呈现出规模效应;反之,经营者更愿意追求质量创新,将生产范围缩小到农户家庭等较小的生产单位中去。

我国肉羊养殖生产全程机械化现状及发展建议

通过国家肉羊产业技术体系、地方畜牧主管部门等组织,对全国13个省市、自治区的113家规模化羊场全程机械化养殖情况进行调研,结果存(出)栏羊规模1万只以上的有20家,占比17.70%,其中3万只以上大型养羊企业8家,仅占7.08%;中小规模羊场(5 000只以下)75家,占比66.37%。按照羊场养殖规模分别对饲草料加工、饲喂、饮水、清粪、消毒、装卸羊等各生产环节机械化水平进行统计分析,自动化饮水占比最高为63.9%,其次为机械化清粪(62.9%)、消毒机械化(42.4%)和TMR饲喂(41.3%),舍内有害气体检测占比最低,仅为8.3%。养殖各生产环节机械化水平随着养殖规模的扩大而提高。影响养殖各生产环节机械化水平的因素主要是肉羊生产本身效率和效益较低,标准化、产业化生产水平低等,表现在不同地域、不同养殖环节机械化水平差异大,肉羊机械装备基础研究薄弱、科技创新能力差,产品标准化程度低,售后维修配套服务差等,建议加强宣传和示范推广工作,加强行业监管,逐步建立与养殖机械化发展水平相适应的监督服务体系,加大基础研究,增强科技创新能力,研究制定相关行业标准,推动行业标准化生产。

劳动生产率与社会生产规模对利润引致需求的作用——马克思经济理论视阈下的函数与分析

以马克思经济理论为基础,分析劳动生产率和社会生产规模对利润引致需求的作用、数量关系及其本质所在,社会生产规模可以用劳动者人数和资本数量两个方面来衡量。当劳动生产率提高和资本数量扩张时,利润引致需求不一定增长;如果资本有机构成的增长率高于劳动生产率和资本数量的增长率时,利润引致需求会下降,这就是经济增长中的总需求下降或总需求不足加剧现象。预期的不稳定性和投资在形成市场供给和需求上的时间差,会导致利润引致需求具有内在的不稳定性,从而导致宏观经济内在的不稳定性和周期性。在宏观经济政策制定中,特别关注这两点,具有至关重要的意义。在马克思经济理论基础上构建利润引致需求函数关系及其数量分析,并由此出发解决宏观经济运行中的现实问题,也证明了马克思主义理论的生命力。

Kenyan Counties Geospatial Data Knowledge to Monitor Crop Production

Climate change effects have had negative effects on most farmers, both small and large-scale, with weather patterns increasingly becoming unpredictable, such that farmers are unable to plan well for their farming, resulting in reduced harvests and sometimes losses for farmers. Better availability of information such as weather patterns, suitable crops, nutrient requirements based on soil types and conditions would greatly alleviate these challenges. While geospatial information is being developed and improved continuously by researchers, its accessibility and use by the counties has not been established and cannot be identified as contributing to better crop production outcomes. The aim of this study, therefore, was to assess the awareness and status of geospatial data availability and use for crop production, and the level of the relevant capacities, both human and infrastructural, in selected Counties of Kenya. A survey was conducted in the four counties of Vihiga, Kilifi, Wajir and Nyeri and key informant interviews were conducted with both management and technical County Agricultural Officers, as well as sub-county agricultural extension officers. From the results of the survey, out of the four counties, only one has adequate infrastructure in terms of hard-ware, software and connectivity to conduct useful geospatial data acquisition and processing. While most indicated awareness of the existence of geospatial data, limited resources, low skills and knowledge have restricted any meaningful sourcing of and access to data, with only 38% moderately or highly skilled in acquisition, 48% in processing and 57% in interpretation and use of geospatial data. The study concludes that moderate skills and capacities available within the counties have considerable potential to make use the available geospatial data to inform farmers accordingly and improve their farming outcomes.

城市创新创业活力与新兴产业核心技术:空间极化、规模门槛与中介效应

城市新企业、新资本和新发明涌现是孕育新兴产业核心技术的活力源泉,对加快形成新质生产力具有重要意义。利用中国城市面板数据考察创新创业活力对新兴产业核心技术的影响及作用机制。研究发现:(1)城市创新创业活力显著促进新兴产业核心技术数量提升,在考虑一系列稳健性检验后结论仍然成立。(2)创新创业活力对新兴产业核心技术活动的影响存在“边际递增”的城市规模门槛特征,而对邻近城市产生显著的抑制作用,存在“马太效应”和“虹吸效应”。(3)城市创新创业活力对新兴产业核心技术活动的影响存在区域和梯度异质性,不同地理位置和文化区的城市存在显著差异,而资源型城市、智慧城市和创新型城市的分组回归体现了梯度性特征。(4)创新创业活力通过提升城市多样性,特别是专业化部门的多样性程度,促进新兴产业核心技术数量增长。

农业保险对农户种植业收入的影响研究——基于中国土地经济调查(CLES)数据的实证分析

基于2020年中国土地经济调查(CLES)数据,采用中介效应及门槛效应模型,实证考察农户购买农业保险对其自身种植业收入的影响。研究结果显示:第一,农业保险能够增加农户种植业收入,其增收效应通过种植规模的扩大得以实现,且在影响过程中存在遮掩效应。第二,农业保险的增收效应存在三重门槛,即农业保险、种植业规模与农户种植业收入之间存在非线性关系,当农户种植面积达到一定规模后,农业保险的增收效果显著提升。这有利于各级政府规范农村土地流转制度,鼓励农户通过土地流转合理规划种植规模,并推行差异化农业保险政策,同时为保险机构完善农业保险服务体系、扩大保障范围、丰富农业保险种类提供新的经验证据。