Implication of Water-Rock Interaction for Enhancing Shale Gas Production

Horizontal well drilling and multi-stage hydraulic fracturing technologies are at the root of commercial shale gas development and exploitation.During these processes,typically,a large amount of working fluid enters the formation,resulting in widespread water-rock interaction.Deeply understanding such effects is required to optimize the production system.In this study,the mechanisms of water-rock interaction and the associated responses of shale fabric are systematically reviewed for working fluids such as neutral fluids,acid fluids,alkali fluids and oxidative fluids.It is shown that shale is generally rich in water-sensitive components such as clay minerals,acidsensitive components(like carbonate minerals),alkali-sensitive components(like quartz),oxidative-sensitive components(like organic matter and pyrite),which easily lead to change of rock fabric and mechanical properties owing to water-rock interaction.According to the results,oxidizing acid fluids and oxidizing fracturing fluids should be used to enhance shale gas recovery.This study also indicates that an aspect playing an important role in increasing cumulative gas production is the optimization of the maximum shut-in time based on the change point of the wellhead pressure drop rate.Another important influential factor to be considered is the control of the wellhead pressure considering the stress sensitivity and creep characteristics of the fracture network.

Effects of instantaneous shut-in of high production gas well on fluid flow in tubing

As the classical transient flow model cannot simulate the water hammer effect of gas well, a transient flow mathematical model of multiphase flow gas well is established based on the mechanism of water hammer effect and the theory of multiphase flow. With this model, the transient flow of gas well can be simulated by segmenting the curved part of tubing and calculating numerical solution with the method of characteristic curve. The results show that the higher the opening coefficient of the valve when closed, the larger the peak value of the wellhead pressure, the more gentle the pressure fluctuation, and the less obvious the pressure mutation area will be. On the premise of not exceeding the maximum shut-in pressure of the tubing, adopting large opening coefficient can reduce the impact of the pressure wave. The higher the cross-section liquid holdup, the greater the pressure wave speed, and the shorter the propagation period will be. The larger the liquid holdup, the larger the variation range of pressure, and the greater the pressure will be. In actual production, the production parameters can be adjusted to get the appropriate liquid holdup, control the magnitude and range of fluctuation pressure, and reduce the impact of water hammer effect. When the valve closing time increases, the maximum fluctuating pressure value of the wellhead decreases, the time of pressure peak delays, and the pressure mutation area gradually disappears. The shorter the valve closing time, the faster the pressure wave propagates. Case simulation proves that the transient flow model of gas well can optimize the reasonable valve opening coefficient and valve closing time, reduce the harm of water hammer impact on the wellhead device and tubing, and ensure the integrity of the wellbore.

Bacterial Groups Concerned with Maturing Process in Manure Production Analyzed by a Method Based on Restriction Fragment Length Polymorphism Analysis

Composting is a biological aerobic decomposition process consisted from different phases. Although the Japanese Standards for manure recommended that it took at least 6 months to complete the maturing phase, there was no reliable ground. In order to find out shortening method of the maturing phase, the microorganisms concerned with a progress of the maturing was determined by using the most probable number method (MPN) and PCR-RFLP of the 16S rDNA, which was found effective to provide numbers and taxonomy of polymyxin B resistant bacterial groups in the former paper [1]. Compared to the numbers after thermophilic phase, those of Actinobacteria, δ-proteobacteria, and the other gram negative bacteria increased to 50 times, 20 times, and 105 times, respectively, after maturing phase, while those of Bacillus spp., and α and β-proteobacteria decreased to 1/10, and 1/105 after maturing phase. Numbers of the other Fumicutes, and γ-proteobacteria remained in the same revel. Actinobacteria, δ-proteobacteria, and the other gram negative bacteria might be concerned with a progress of the maturing phase, because these bacterial groups were detected and enumerated due to their proliferation ability. Although number of Acitinobacteria might be underestimated because of a PCR bias, the method was found effective for the purpose to monitor bacteria actively proliferated in culture medium.

Industrial Policy Analysis of Restricted Development Zones in Western China——A Study of State-level Main Producing Areas of Agricultural Products and Key Ecological Functional Areas

As one of the important policies of promoting the formation of main functional areas, the industrial policy directly determines the sustainable growth of space control ability of main functional areas. A restricted development zone is a type of main functional area which provides agricultural products and ecological products, assures the supply of national agricultural products and the stability of ecosystems, as well as safeguards the ecological functions and agricultural functions of wider regions by restricting its own development. Therefore scientific, complete and operable industrial policy support is needed. Restricted development zones are distributed widely in western China. With the restriction of their main functions, differential industrial policies should be implemented in the development of the restricted development zones: Dealing well with the relationship between industrial development and ecological protection, developing special industries which are friendly to resources and environment and appropriate for local conditions, guiding and encouraging industries to learn from regions with favorable development conditions, orderly withdrawing industries and enterprises adverse to main functions, facilitating industrial structure upgrading, optimizing industrial organization, improving industrial technological level and rationalizing industrial layout.

A Restriction Theorem on the Reduced Product Heisenberg Group

In this paper,we give the Plancherel formula on the reduced product Heisenberg group,and obtain a restriction theorem on this group.

The Leading Role of Governments in Promoting Chinese Agricultural Clean Production

On the basis of summarizing agricultural clean production,the theoretical basis of the leading role displayed by the government in promoting agricultural clean production is expounded.The characteristics of agricultural products,such as the hidden environment quality of agricultural production,spillover of profits and the benefits,make governments to display the leading role in promoting agricultural clean production at the primary stage in particular.The restrictive factors in promoting Chinese agricultural clean production are put forward,which include idea restriction,technology restriction,talent restriction,economic restriction and policy restriction.Countermeasures which should be adopted by governments on promoting Chinese agricultural clean production are put forward.Firstly,the laws and regulations for promoting agricultural clean production should be established and perfected gradually;secondly,the evaluation system for agricultural clean production should be established;thirdly,the promotion on agricultural clean production should be intensified;fourthly,the practical technologies and applications of agricultural clean production should be guided;fifthly,the industrialized operation of ecological agriculture should be vigorously promoted.

Monitoring and diagnosis of complex production process based on free energy of Gaussian–Bernoulli restricted Boltzmann machine

Online monitoring and diagnosis of production processes face great challenges due to the nonlinearity and multivariate of complex industrial processes.Traditional process monitoring methods employ kernel function or multilayer neural networks to solve the nonlinear mapping problem of data.However,the above methods increase the model complexity and are not interpretable,leading to difficulties in subsequent fault recognition/diagnosis/location.A process monitoring and diagnosis method based on the free energy of Gaussian-Bernoulli restricted Boltzmann machine(GBRBM-FE)was proposed.Firstly,a GBRBM network was established to make the probability distribution of the reconstructed data as close as possible to the probability distribution of the raw data.On this basis,the weights and biases in GBRBM network were used to construct F statistics,which represents the free energy of the sample.The smaller the energy of the sample is,the more normal the sample is.Therefore,F statistics can be used to monitor the production process.To diagnose fault variables,the F statistic for each sample was decomposed to obtain the Fv statistic for each variable.By analyzing the deviation degree between the corresponding variables of abnormal samples and normal samples,the cause of process abnormalities can be accurately located.The application of converter steelmaking process demonstrates that the proposed method outperforms the traditional methods,in terms of fault monitoring and diagnosis performance.

塑料食品包装中受限物质检测研究进展

食品安全问题关系国计民生,近年来食品安全质量有了明显提高,但容易忽视却现实存在的食品安全隐患即食品接触材料,尤其是大量使用的塑料食品包装材料中有害物质迁移到食品中对食用者造成的潜在危害无时不在。本文综述了塑料食品包装材料中4大类添加剂,包括增塑剂、紫外线吸收剂、抗氧化剂、荧光增白剂4类受限物质迁移至食品及食品模拟液中的风险及存在的安全问题、食品模拟物及迁移试验、受限物质检测研究现状,比较了我国与发达国家关于食品接触材料受限物质的法律法规及迁移限量,提出制备受限物质质控标准品对受限物质检测准确性和风险评估的重要性等。本文对加强我国塑料食品接触材料中受限物质的使用与监管、检测结果的方法学验证技术的开发,塑料食品接触材料添加剂的使用范围、使用限量及受限物质迁移限量值的制定,及对基于受限物质的食品安全风险评估等均具有明确的参考意义和数据支持。

噬菌体临床应用监管法规的现状及展望

抗生素的广泛使用使得耐药和泛耐药病原菌不断涌现,对全球公共卫生造成了巨大威胁。目前,噬菌体治疗已成为抗击多重耐药菌的重要手段之一,在欧美国家和中国已经进行了临床应用。然而,中国目前尚未形成针对噬菌体治疗的专项监管法规,研究者发起的临床研究成为我国开展噬菌体治疗的主要形式,这制约了我国噬菌体治疗的进一步发展和广泛应用,亟需在当前的药品监管框架下,制定适当的噬菌体监管法规。因此,本文回顾了格鲁吉亚、美国、英国、比利时和中国的噬菌体治疗现状和监管法规框架,旨在为噬菌体临床治疗的监管提供参考。完善的噬菌体临床应用监管法规将极大促进噬菌体治疗在中国的推广和应用,也必将有效地遏制细菌耐药危机,更好地维护人民群众的生命健康安全。

汽车涂装亚光色批量生产方法研究

亚光色光泽度低,给人典雅、柔和目视效果,越来越受消费者喜爱,但亚光漆面无法使用常规亮光色漆面缺陷处理方法,因此本文对喷涂前准备、喷涂过程中工艺问题、漆渣控制、生产组织进行探究,梳理控制漆面缺陷方法,为同行实现汽车涂装亚光色批量生产提供思路。

肉种鸡生产过程中的能量限饲

由于肉种鸡较强的采食能力,生产过程中需要通过限制饲喂控制其体重,以防增重过快导致生长期生殖系统发育不平衡和后期脂肪积累导致繁殖性能快速下降。该文主要从动物营养与饲料加工和肉种鸡生产饲喂程序方面对肉种鸡生产过程中的能量摄入限制进行综述,其中动物营养方向主要是降低单位重量饲料中营养物质含量尤其是代谢能水平,饲料加工方向主要是颗粒料的使用保障各种营养物质均衡摄入,肉种鸡生产饲喂程序方向主要是改变肉种鸡日常饲喂模式和周饲喂总量。在种母鸡产蛋过程中,综合鸡群产蛋率与每天每只鸡饲喂量来执行能量限饲,以充分发挥种鸡产蛋性能和繁殖性能。

高效液相色谱法用于氧化型染发产品中42种限用染发剂的筛查和定量分析

建立了一种利用高效液相色谱筛查和定量分析氧化型染发产品中42种限用染发剂的方法。染发产品经亚硫酸氢钠水溶液-乙醇超声提取后,以0.02 mol/L乙酸铵水溶液-乙腈为流动相,在TechMate AQUA-STIII色谱柱上进行梯度洗脱和分离,选择235和280 nm作为检测波长,对42种染发剂进行一次性定性筛查,同时实现其中35种染发剂的定量分析,当筛查结果表明产品中含有2,6-二甲氧基-3,5-吡啶二胺盐酸盐、2-甲基-5-羟乙氨基苯酚等7种染发剂时,以0.02 mol/L乙酸铵水溶液-乙腈为流动相,在Waters Symmetry C_(18)色谱柱上进行等度洗脱,选择235 nm作为检测波长进行定量分析。结果表明:42种染发剂的方法检出限为10~101μg/g,定量限为33~337μg/g。在相应的线性范围内,42种染发剂色谱峰面积与质量浓度线性关系良好,相关系数(r)均大于0.9998。在4个不同含量水平下,各目标化合物的平均回收率在81.3%~119.6%之间,RSD不大于5%。

On restricted edge-connectivity of replacement product graphs

This paper considers the edge-connectivity and the restricted edge-connectivity of replacement product graphs, gives some bounds on edge-connectivity and restricted edge-connectivity of replacement product graphs and determines the exact values for some special graphs. In particular, the authors further confirm that under certain conditions, the replacement product of two Cayley graphs is also a Cayley graph, and give a necessary and sufficient condition for such Cayley graphs to have maximum restricted edge-connectivity. Based on these results, we construct a Cayley graph with degree d whose restricted edge-connectivity is equal to d + s for given odd integer d and integer s with d 5 and 1 s d- 3, which answers a problem proposed ten years ago.

地理标志正当使用的重释

实务认为《商标法实施条例》第4条第2款“正当使用地理标志”是指使用地理标志地名的说明产地,并衍生出产地规范使用和产地宽松使用两种观点。然而,当地名和特定产品相联系时,特定产品上使用特定地名就必然暗含对地理标志商业声誉的利用。因此,“正当使用地理标志”实际是立法者利益衡量后对地理标志商标权所作的权利限缩,而非《商标法》第59条重述。在符合地理标志使用条件时,生产者可以通过在产品上使用地理标志的“地名和商品名称”,合法利用地理标志的品质声誉,地理标志行业协会应当尊重生产者的合理使用行为。

房地产限购、企业税负与企业全要素生产率

在“房住不炒”的政策导向下,限购措施已成为各地政府调控房地产市场的重要手段。然而,该项政策在稳定房市的同时,可能会降低地方“土地财政”收入。基于稳定和扩大财政收入的动机,地方政府可能会增加企业的税负压力,进而对企业生产造成负面影响。本文深入探讨了房地产限购政策如何通过企业税负变动影响企业的全要素生产率,并对其作用机制进行了细致剖析。研究结果显示,限购政策显著降低了企业的全要素生产率。机制分析表明,税负压力的增加是其中的关键机制。因此,如何在保障居民住房需求的同时,减轻企业税负压力,提高生产效率,成为政府亟待解决的现实问题。本文进一步分析了限购政策导致土地财政压力上升后,地方政府对企业进行的策略性税费执法现象。这不仅有助于深入理解当前经济现状,也为政府制定更为合理的政策措施提供了重要参考。

电子电气产品有害物质限制及其国际标准化研究

主要介绍了欧洲、日本、韩国和印度等国家和地区的电子电气产品中有害物质限制使用相关的市场准入要求,包括相关法律法规、标准及其相关合格评定程序要求。同时介绍国际电工委员会电子电气产品有害物质限制最新国际标准化进展和发展趋势。为促进我国各行业和社会实现循环经济可持续发展以及碳达峰和碳中和的“双碳”目标,结合国内实际情况,为国内电子电气产品制造商及其供应链从建立产品符合性管理系统角度提出建议。

气象观测场在汽车试验场中的应用研究

汽车试验场作为汽车开展道路测试的重要场所,用于验证汽车产品的品质以及可靠性。除了场地道路外,气象条件作为汽车道路测试的重要一环,在《GB/T12534-1990汽车道路试验方法通则》中也有明确要求,如:试验时应是无雨无雾天气,相对湿度小于95%,气温0-40℃,风速不大于3m/s。同时气象条件也作为试验场道路管控的重要依据,实时风速、雨量、能见度等信息为场地管理者发布限速、限行、封场等通知提供必要参考依据,直接影响道路测试安全管控的及时性。因此,文章从气象观测场的建设、气象服务、异常天气道路管控等方面开展气象观测场在汽车试验场中的应用研究。

福建粮食生产能力预测与粮食安全保障对策研究

分析了福建省粮食生产能力制约因素和宏观约束因素,结合福建粮食综合生产能力及其影响因子的计量分析和粮食生产潜力预测,根据省情,从资源保护、耕地利用、技术支撑、市场机制、预警机制、粮食政策、防灾减灾等方面,提出保障福建粮食安全的具体对策。

基于小网格的北京山区植物气候生产力及其限制因子分析

利用北京山区 1km2 网格的气候资料 ,应用桑斯维特纪念模型与迈阿密模型对各网格点的植物气候生产力进行了估算 ,并利用地理信息系统软件ArcGis与ArcView对估算结果进行了可视化处理。结果显示 ,北京山区植物气候生产力总体分布趋势由东向西递减 ,高值区集中在东北部山区的平谷中部及密云南部 ;低值区主要集中在西部山区包括门头沟西部、延庆、怀柔北部地区。除部分海拔较高的中山区以外 ,水分条件是北京山区植物气候生产力的主要限制因子 ,大部地区水分亏缺量在 130～ 2 6 0mm。用遥感方法对 2种模型的估算结果进行了验证 ,模型估算结果与北京山区植被指数 (NDVI)的相关性均达到了 0 0 1的显著性水平 ,且桑斯维特纪念模型的估算结果好于迈阿密模型。

社会功能在限制性产品设计和引导性产品设计中的体现

从限制性设计和引导性设计两个方面论述了产品设计中的社会作用,并期望能通过对"限制"和"引导"设计方法的理解和运用,树立设计师的社会责任感。