Results 61 to 70 of about 1,259,370 (186)
四川大学学报. 自然科学版, 1980 前言天然气中含有少量的有机硫与无机硫.其有机硫的基本组分多半为低沸点的硫醇、硫茂、气态的硫羰和二硫化碳.无机硫主要是硫化氢与二氧化硫.由于天然气在井中,因温度高,各组分均有可能存在,但经过输气管配气后,将有一部冷凝,一部分则以蒸气状态残留,故含量较微。此等硫化物在天然气催化过程中,常引起催化剂中毒,因此生产控制要求测定总硫量.据文献介绍气体中总硫量的测定,常用燃烧一氧化法与燃烧一氢化法 ...
顾永祚, 张万福, 李芳林
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Scientists’ warning on the global destruction of rock outcrop ecosystems
Conservation Biology, Volume 40, Issue 5, October 2026.Abstract Rock outcrops are geological formations that harbor a highly specialized biota adapted to harsh environmental conditions that differ from their surrounding landscapes. They are globally distributed, especially in old, highly weathered landscapes, and can function as habitat islands containing high levels of endemism and distinct evolutionary ...
Luiza F. A. de Paula +19 more
wiley +1 more source
, 2006 一种液化气和汽油同时进料的催化转化方法，原料油与液化气从提升管/流化床的下部进入，与催化剂接触，反应后的油气进入冰水冷凝器进行气液分离，反应条件为：反应温度300-500℃，重量空速为0.2-4h-1，液化气与原料油的重量比80∶20-3∶97，具有液体收率高，明显降低原料汽油烯烃含量和产物汽油中芳烃大幅度提高的特点 ...
安 杰 +6 more
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Conservation Biology, Volume 40, Issue 5, October 2026.Abstract Ecological niche models (ENMs) are used to assess the abiotic preferences of species by linking their occurrences to the environmental conditions in which they live. We developed a fossil‐informed ENM framework that integrates mid‐Holocene and modern occurrences to test niche stability and reconstruct abiotic niche characteristics for four ...
Claire. M. Williams +3 more
wiley +1 more source
, 2001 采用常规浸渍法制备了经镧和镁改性的镍基催化剂，以铜锌铝甲醇合成催化剂和HZSM－5分子筛通过机械混合制造了二甲醚合成催化剂，采用固定床流动反应色谱装置研究了甲烷空气催化部分氧化制合成气的催化性能，同时开展了以含氮合成气制备二甲醚的研究，结果说明，镍基催化剂对甲烷空气部分氧化制合成气在常压下具有高的转化率，随压力升高，随压力升高，转化率明显下降，并且催伦剂严重积炭，通过向反应体系添加H2O和CO2可以提高加压条件下的CH4转化率并抑制催化剂积炭，还可获得n(H2)/n(CO)接近2的合成气 ...
侯守福 +9 more
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Shiyou jixie, 2014 为使煤层气排采生命周期更长、煤层气产出量最大化，对地面直驱螺杆泵在煤层气排采中的生产参数进行了优化研究。综合考虑煤层气排采制度及井、泵之间的供排协调的实际约束条件，建立以生命周期内煤层气产气量最大为优化目标的数学模型。引入煤层气井生产数值模拟结果，将其作为优化过程中的参数，将煤层气井生产排采制度这一较难表征的约束条件恰当转化，以适当的时间段内压降值作为计算排水量的依据，编制优化流程图，按照优化流程及其他各约束条件对生产参数进行优化。通过具体实例验证了优化方法的有效性。
孙艳萍, 赵, 宁, 屈文涛, 刘, 庆
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Modeling seed germination data to meet biodiversity conservation needs in the Mediterranean
Conservation Biology, Volume 40, Issue 5, October 2026.Workflow to assess the availability and quality of germination data and assign species' thermal risk in the Mediterranean. (a) Assessment of data availability, including the phylogenetic distribution of the number of records (i.e. available germination data); (b) data quality assessment; and (c) assignment of climate risk categories for species that ...
Diana María Cruz‐Tejada +2 more
wiley +1 more source
, 1991 一种内燃机排气催化净化器由上、下壳体，前置催化床层，主体催化床层和导流散热板组成，催化剂床层用无机隔热材料包绕后装填到壳体内。由于采用无机隔热包层，使催化剂床层与壳体间不必固紧或加密封件，使其结构简单，加工精度下降，组装容易。该净化器加有导流散热板可防止地面可燃物被引燃，同时增加前置净化催化剂床层，可有利于气流分布的改善，防止了汽车不正常运行时喷油所引起的主体催化剂床层被烧坏，既提高净化率又延长了净化器的使用寿命 ...
李北芦 +3 more
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Predictive evolutionary genomics: principles, validation, and practice
New Phytologist, Volume 252, Issue 1, Page 36-48, October 2026.Summary Climate change and habitat loss are driving rapid evolutionary responses in populations world‐wide, which creates an urgent need for evolutionary forecasting in conservation and agriculture. Such forecasting can be categorized into three time scales: trait‐based models that use multivariate quantitative genetic equations to project correlated ...
Daniel Ortiz‐Barrientos +5 more
wiley +1 more source
, 2009 描述了用于转化氢气与一种或多种碳氧化物的催化剂和方法，其中该催化剂含有含单质碳的载体。同样描述了降低碳纳米管中附聚的方法，其中碳纳米管悬浮在液体中，并同时通过超声和搅拌处理。该方法可用于制备碳纳米管负载的催化剂，该催化剂对含有氢气与一种或多种碳氧化物的原料的转化显示出高活性 ...
X潘, W陈, Y丁, Z范, X包, H罗
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