期刊文献+
共找到1,993篇文章
< 1 2 100 >
每页显示 20 50 100
Numerical Investigation of Combined Production of Natural Gas Hydrate and Conventional Gas
1
作者 Hongzhi Xu Jian Wang +3 位作者 Shuxia Li Fengrui Zhao Chengwen Wang Yang Guo 《Fluid Dynamics & Materials Processing》 EI 2024年第3期505-523,共19页
Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effecti... Natural gas hydrate(NGH)is generally produced and accumulated together with the underlying conventional gas.Therefore,optimizing the production technology of these two gases should be seen as a relevant way to effectively reduce the exploitation cost of the gas hydrate.In this study,three types of models accounting for the coexistence of these gases are considered.Type A considers the upper hydrate-bearing layer(HBL)adjacent to the lower conventional gas layer(CGL);with the Type B a permeable interlayer exists between the upper HBL and the lower CGL;with the type C there is an impermeable interlayer between the upper HBL and the lower CGL.The production performances associated with the above three models are calculated under different conditions,including only a depressurized HBL(only HBL DP);only a depressurized CGL(only CGL DP);and both the HBL and the CGL being depressurized(HBL+CGL DP).The results show that for Type A and Type B coexistence accumulation models,when only HBL or CGL is depressurized,the gas from the other layer will flow into the production layer due to the pressure difference between the two layers.In the coexistence accumulation model of type C,the cumulative gas production is much lower than that of Type A and Type B,regardless of whether only HBL DP,only CGL DP,or HBL+CGL DP are considered.This indicates that the impermeable interlayer restricts the cross-flow of gas between HBL and CGL.For three different coexistence accumulation models,CGL DP has the largest gas-to-water ratio. 展开更多
关键词 Natural gas hydrate conventional gas coexistence accumulation DEPRESSURIZATION combined production
下载PDF
Optimization methods of production layer combination for coalbed methane development in multi-coal seams 被引量:2
2
作者 YANG Zhaobiao ZHANG Zhengguang +5 位作者 QIN Yong WU Congcong YI Tongsheng LI Yangyang TANG Jun CHEN Jie 《Petroleum Exploration and Development》 2018年第2期312-320,共9页
Based on the productivity equation of coalbed methane(CBM) wells, three indexes, main production layer optimization index, main production layer expansion index and capacity contribution index are proposed, with which... Based on the productivity equation of coalbed methane(CBM) wells, three indexes, main production layer optimization index, main production layer expansion index and capacity contribution index are proposed, with which the three-step optimization method of production-layer combination is established. In selecting main production layer, the coal seam thickness, CBM content, coal seam permeability, coal seam reservoir pressure and coal structure are considered comprehensively to evaluate the potential of the production layer. In selecting expansion of the main production layer combination, on the premise of ensuring full and slow desorption of the main production layer and non-exposure of the main production layer out of liquid surface, the degree of mutual interference between the main and non-main production layers is comprehensively evaluated by coupling the critical desorption pressure, layer spacing and reservoir pressure gradient difference. In optimizing production layer combination, the main concern is the economic efficiency of the combined layers. Only when the contribution coefficient of the main production layer is greater than 30% and the contribution index of the other production layers is more than 10%, the economic benefit of a CBM well after being put into production can be ensured. Based on the comparative analysis of the development effect of the development test wells in Songhe of Guizhou province, it is proved that the "three-step method" for the optimization of production-layer combination is scientific and practical, and can be used to design the multi-layer commingling scheme of coalbed methane. 展开更多
关键词 CBM MULTI-LAYER commingled productION selection of main productION LAYER combination optimization productION CONTRIBUTION
下载PDF
Natural product-induced oxidative stress-synergistic anti-tumor effects of chemotherapeutic agents
3
作者 Shu-Fan Wang Shi-Qi Dong +3 位作者 Quan Dong Wen-Xin Lin Mei Dong Duo Liu 《Traditional Medicine Research》 2024年第3期10-23,共14页
Reactive oxygen species are closely related to tumor development.In recent years,reactive oxygen species has become a hot spot in tumor therapy,and many natural substances in nature contain compound components with an... Reactive oxygen species are closely related to tumor development.In recent years,reactive oxygen species has become a hot spot in tumor therapy,and many natural substances in nature contain compound components with anti-tumor effects.However,there is a lack of discussion on the synergistic anti-tumor effects of natural products in combination with chemotherapeutic drugs through reactive oxygen species.The terms“natural products”,“reactive oxygen species”,“anti-tumor”,and“chemotherapy”were used to identify the synergistic effects of natural products.We conducted a systematic literature search in PubMed and Web of Science databases for relevant research articles and reviews published in recent years.We systematically summarized the studies related to anti-tumor active ingredients in natural compounds in the field of reactive oxygen species in recent years.A total of 77 relevant literatures were included.Among them,45 literatures containing various natural products such as terpenoids,flavonoids,alkaloids,etc.exert anti-tumor effects by regulating reactive oxygen species levels,and 32 literatures regarding adjunctive role of natural products in anti-tumor therapy.In this study,we found that natural products exert anti-tumor effects by elevating reactive oxygen species levels.It provides strong theoretical support for future clinical studies. 展开更多
关键词 nature products TUMOR reactive oxygen species combination chemotherapy oxidative stress
下载PDF
Influence of Combinations of Pesticides and Fertilizers on Aquatic Productivity
4
作者 Ganapati Hegde Mahesh Mandya +3 位作者 Sushma S. Gokarnakar Vinodbabu N. Babu Vijayakumar N. Shivaramaiah Sannanegunda V. Krishnamurthy 《Journal of Environmental Protection》 2014年第5期434-440,共7页
We have examined the effects of environmentally realistic concentrations of widely used pesticides and fertilizers for rice paddy in Western Ghats regions of India on chlorophyll and zooplankton production using a lab... We have examined the effects of environmentally realistic concentrations of widely used pesticides and fertilizers for rice paddy in Western Ghats regions of India on chlorophyll and zooplankton production using a laboratory mesocosm. Malathion (100 μg·L-1), Cypermethrin (25 μg·L-1), Nitrate-nitrogen (8 mg·L-1) and Phosphate-phosphorus (8 mg·L-1) in different combinations such as pesticide-pesticide and pesticide-fertilizer were tested in fully factorial manner for a period of 42 days. Study revealed that, chlorophyll production was supported by addition of fertilizers, while combinations of fertilizers with either one or two pesticides reduce the zooplankton density and diversity rendering chlorophyll concentration more than control groups. This could indicate the reason for eutrophication of ponds located in agro-ecosystems. Single application of combinations of pesticides (in spite of presence of fertilizers) even at low concentrations can produce severe negative effects on several taxonomic groups zooplankton living in small shallow water. 展开更多
关键词 CHLOROPHYLL production ZOOPLANKTON PESTICIDE Fertilizers combinationS of PESTICIDES and Fertilizers
下载PDF
Production calculation of the second and tertiary recovery combination reservoirs under chemical flooding
5
作者 LIU Weidong WANG Gaofeng +4 位作者 LIAO Guangzhi WANG Hongzhuang WANG Zhengmao WANG Qiang WANG Zhengbo 《Petroleum Exploration and Development》 CSCD 2021年第6期1403-1410,共8页
Based on the analysis of the production composition of reservoirs developed by the second&tertiary recovery combination(STRC),the relationship between the overall output of the STRC project and the production leve... Based on the analysis of the production composition of reservoirs developed by the second&tertiary recovery combination(STRC),the relationship between the overall output of the STRC project and the production level during the blank water flooding stage is proposed.According to the basic principle of reservoir engineering that the“recovery factor is equal to sweeping coefficient multiplied by oil displacement efficiency”,the formula for calculating the ultimate oil recovery factor of chemical combination flooding reservoir was established.By dividing the reservoir into a series of grids according to differen-tial calculus thinking,the relationship between the ultimate recovery factor of a certain number of grids and the recovery de-gree of the reservoir was established,and then the variation law of oil production rate of the STRC reservoir was obtained.The concept of“oil rate enlargement factor of chemical combination flooding”was defined,and a production calculation method of reservoir developed by STRC was put forward based on practical oilfield development experience.The study shows that the oil production enhancing effect of STRC increases evenly with the in crease of the ratio of STRC displacement efficiency to water displacement efficiency,and increases rapidly with the increase of the ratio of recovery degree at flooding mode conversion to the water displacement efficiency.STRC is more effective in increasing oil production of reservoir with high recovery degree.Through practical tests of the alkali free binary flooding(polymer/surfactant)projects,the relative error of the oil production calculation method of STRC reservoir is about±10%,which meets the requirements of reservoir engineering. 展开更多
关键词 chemical combination flooding second&tertiary recovery combination oil displacement efficiency oil rate en-largement factor of chemical flooding oil production calculation
下载PDF
Research on the Combination Mode of Modem Product and Industrial Design under the Green Design Background
6
作者 Liying Wu 《International Journal of Technology Management》 2016年第3期57-59,共3页
In this paper, we conduct research on the combination mode of the modern product and the industrial design under the green design background. Our enterprises must set up the industrial design as the basis of the new m... In this paper, we conduct research on the combination mode of the modern product and the industrial design under the green design background. Our enterprises must set up the industrial design as the basis of the new mechanism, treatment of product, enterprise and market to trinity, cannot be indifferent to a certain aspect, to every aspect, to attach importance to technology, hard management talents, on the basis of industrial designers should play the role of soft energetically. Industrial design should have good adhesive property, product, enterprise and market more harmonious, more closely linked, creation of the technical performance, reasonable internal structure, a novel appearance, low production cost, a profound cultural products, for the enterprise to bring the most lucrative business profits, and make the market more prosperous more standardized. Under this background, we propose the novel combination pattern that holds special meaning. 展开更多
关键词 combination Mode product and Industrial Design Green Design Trend.
下载PDF
Rationale for Treatment of Common Cold and Flu with Multi-Ingredient Combination Products for Multi-Symptom Relief in Adults
7
作者 Ron Eccles Ingo Fietze Uwe-Bernd Rose 《Open Journal of Respiratory Diseases》 2014年第3期73-82,共10页
This up-to-date overview will look at the rationale for the recommendation of combination products for multi-symptom relief of common cold and flu. Common cold and flu are defined by their multi-symptom nature with da... This up-to-date overview will look at the rationale for the recommendation of combination products for multi-symptom relief of common cold and flu. Common cold and flu are defined by their multi-symptom nature with data showing a variety of symptoms reported simultaneously each day over the first six days of illness. Multi-ingredient combination products for multi-symptom relief are formulated to safely, simply, and simultaneously treat multiple symptoms when used as directed. The rationale for the formulation combination products for common cold and flu is therefore practical, logical and reasonable. No evidence has been found that multi-symptom relief medicines are inherently less safe than single-active ingredient medicines. Multi-symptom relief combination products containing several active ingredients provide a safe, effective, cost-effective, and convenient way of treating the multiple symptoms of common cold and flu, when used as directed. This therapy requires some special information for the patient to be provided by the physician and the pharmacist. 展开更多
关键词 combination products Multi-Symptom Relief Multi-Ingredient Common Cold FLU
下载PDF
Combination strategies for first-line treatment of patients with unresectable hepatocellular carcinoma:prospect of natural products 被引量:1
8
作者 ZHANG Lele LU Jinjian 《Chinese Journal of Natural Medicines》 SCIE CAS CSCD 2024年第1期1-3,共3页
Liver cancer stands as a significant global health concern,contributing substantially to cancer incidence and mortality,particularly in Asian countries[1].Hepatocellular carcinoma(HCC)accounts for approximately 90%of ... Liver cancer stands as a significant global health concern,contributing substantially to cancer incidence and mortality,particularly in Asian countries[1].Hepatocellular carcinoma(HCC)accounts for approximately 90%of all liver cancer cases and is characterized by a high-risk profile and a generally poor prognosis[2].To address advanced HCC,systemic therapy has been recommended,leading to the approval of a range of treatment regimens in clinical practice.Traditionally,first-line therapy involved the use of multitargeted tyrosine kinase inhibitors(TKIs)such as sorafenib or lenvatinib,while cabozantinib,ramucirumab. 展开更多
关键词 Unresectable hepatocellular carcinoma combination strategies IMMUNOTHERAPY PD-1/PD-L1 Natural products
原文传递
Tuning combined steam and dry reforming of methane for “metgas”production: A thermodynamic approach and state-of-the-art catalysts 被引量:5
9
作者 Karam Jabbour 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2020年第9期54-91,I0003,共39页
Nowadays,combined steam and dry reforming of methane(CSDRM)is viewed as a new alternative for the production of high-quality syngas(termed as"metgas",H2:CO of 2.0)suitable for subsequent synthesis of methano... Nowadays,combined steam and dry reforming of methane(CSDRM)is viewed as a new alternative for the production of high-quality syngas(termed as"metgas",H2:CO of 2.0)suitable for subsequent synthesis of methanol,considered as a promising renewable energy vector to substitute fossil fuel resources.Adequate operation conditions(molar feed composition,temperature and pressure)are required for the sole production of"metgas"while achieving high CH4,CO2 and H2O conversion levels.In this work,thermodynamic equilibrium analysis of CSDRM has been performed using Gibbs free energy minimization where;(i)the effect of temperature(range:200-1000℃),(ii)feed composition(stoichiometric ratio as compared to a feed under excess steam or excess carbon dioxide),(iii)pressure(range:1-20 bar)and,(iv)the presence of a gaseous diluent on coke yields,reactivity levels and selectivity towards"metgas"were investigated.Running CSDRM at a temperature of at least 800℃,a pressure of 1 bar and under a feed composition where CO2-H2O/CH4 is around 1.0,are optimum conditions for the theoretical production of"metgas"while minimizing C(S)formation for longer experimental catalytic runs.A second part of this work presents a review of the recent progresses in the design of(principally)Ni-based catalysts along with some mechanistic and kinetic modeling aspects for the targeted CSDRM reaction.As compared to noble metals,their high availability,low cost and good intrinsic activity levels are main reasons for increasing research dedications in understanding deactivation potentials and providing amelioration strategies for further development.Deactivation causes and main orientations towards designing deactivationresistant supported Ni nanoparticles are clearly addressed and analyzed.Reported procedures based on salient catalytic features(i.e.,acidity/basicity character,redox properties,oxygen mobility,metal-support interaction)and recently employed innovative tactics(such as confinement within mesoporous systems,stabilization through core shell structures or on carbide surfaces)are highlighted and their impact on Ni0reactivity and stability are discussed.The final aspect of this review encloses the major directions and trends for improving synthesis/preparation designs of Ni-based catalysts for the sake of upgrading their usage into industrially oriented combined reforming operations. 展开更多
关键词 combined steam and dry reforming of methane Thermodynamic equilibrium analysis "Metgas"production Nickel-based catalysts Heterogeneous catalysis Structure-activity relationship
下载PDF
Therapeutic potential of thymoquinone in combination therapy against cancer and cancer stem cells 被引量:1
10
作者 Zaynab Fatfat Maamoun Fatfat Hala Gali-Muhtasib 《World Journal of Clinical Oncology》 CAS 2021年第7期522-543,共22页
The long-term success of standard anticancer monotherapeutic strategies has been hampered by intolerable side effects,resistance to treatment and cancer relapse.These monotherapeutic strategies shrink the tumor bulk b... The long-term success of standard anticancer monotherapeutic strategies has been hampered by intolerable side effects,resistance to treatment and cancer relapse.These monotherapeutic strategies shrink the tumor bulk but do not effectively eliminate the population of self-renewing cancer stem cells(CSCs)that are normally present within the tumor.These surviving CSCs develop mechanisms of resistance to treatment and refuel the tumor,thus causing cancer relapse.To ensure durable tumor control,research has moved away from adopting the monotreatment paradigm towards developing and using combination therapy.Combining different therapeutic modalities has demonstrated significant therapeutic outcomes by strengthening the anti-tumor potential of monotreatment against cancer and cancer stem cells,mitigating their toxic adverse effects,and ultimately overcoming resistance.Recently,there has been growing interest in combining natural products from different sources or with clinically used chemotherapeutics to further improve treatment efficacy and tolerability.Thymoquinone(TQ),the main bioactive constituent of Nigella sativa,has gained great attention in combination therapy research after demonstrating its low toxicity to normal cells and remarkable anticancer efficacy in extensive preclinical studies in addition to its ability to target chemoresistant CSCs.Here,we provide an overview of the therapeutic responses resulting from combining TQ with conventional therapeutic agents such as alkylating agents,antimetabolites and antimicrotubules as well as with topoisomerase inhibitors and non-coding RNA.We also review data on anticancer effects of TQ when combined with ionizing radiation and several natural products such as vitamin D3,melatonin and other compounds derived from Chinese medicinal plants.The focus of this review is on two outcomes of TQ combination therapy,namely eradicating CSCs and treating various types of cancers.In conclusion,the ability of TQ to potentiate the anticancer activity of many chemotherapeutic agents and sensitize cancer cells to radiotherapy makes it a promising molecule that could be used in combination therapy to overcome resistance to standard chemotherapeutic agents and reduce their associated toxicities. 展开更多
关键词 THYMOQUINONE combination therapy Cancer cells Cancer stem cells Conventional cancer therapy Natural products
下载PDF
Produced-water treatment: Application and research of combined fiber coalescence technique in offshore oilfield 被引量:2
11
作者 Pin-Yi Dai Yi-Qian Liu +2 位作者 Hao Lu Yu-Dong Li Qiang Yang 《Petroleum Science》 SCIE EI CAS CSCD 2023年第1期569-576,共8页
When the process of extraction of oil from an offshore oilfield enters the advanced stages,the water content in the extracted fluid can be above 90%.The water quality is complex with many types of pollutants and highl... When the process of extraction of oil from an offshore oilfield enters the advanced stages,the water content in the extracted fluid can be above 90%.The water quality is complex with many types of pollutants and highly emulsified water.Therefore,a key consideration in the production process of offshore oilfields is the efficient and economical treatment of the oil-containing produced water to make it suitable for discharge and recover oil pollutants.In this study,we developed a hydrophilic and hydrophobic combined fiber coalescence separator with composite fiber shapes using fiber induction and X/Uweaving.The separator is designed based on experimental observations of the mechanism of structure coalescence in the physical oil removal method.A pilot test was performed on an oil exploration platform in the Bohai Sea.At the designed flow rate,the separator reduced the total concentration of petroleum in the produced water from 2000 to 3000 mg/L to below 60 mg/L,with an average oil removal efficiency of 98.24%.Furthermore,it effectively reduced the number of organic compounds present in the water from 120 to 17 and removed 70% of the SS.The test results show that the proposed device can be used fr produced-water treatment on offshore platforms. 展开更多
关键词 combined fiber coalescence production water Oil-water separation X/U weaving
下载PDF
Individual and Combined Effects of Food Components in Attenuating the Formation of Advanced Glycation End Products (AGEs) 被引量:1
12
作者 Monisha Pradeep Filmon Kiflezghi Kiflemariam Eden Tareke 《Food and Nutrition Sciences》 2022年第1期17-25,共9页
Advanced Glycation End Products (AGEs) have been associated as a possible <span>cause in inflammation-mediated chronic diseases such as diabetes, Alzhei</span>mer’s and cardiovascular disorders. Thus, inh... Advanced Glycation End Products (AGEs) have been associated as a possible <span>cause in inflammation-mediated chronic diseases such as diabetes, Alzhei</span>mer’s and cardiovascular disorders. Thus, inhibition of AGE formation repre<span>sents a prospective therapeutic target for the prevention and treatment of</span> these complications. This study investigated the individual and combined effect</span><span style="font-size:10.0pt;font-family:"">s</span><span style="font-size:10.0pt;font-family:""> of dietary ingredients, spices, on lowering AGEs formation in meat pat<span>ties. In the study, Carboxymethyllysine (CML), a well-investigated AGE is</span> used as a marker for AGEs and malondialdehyde (MDA) as an indicator for <span>lipid peroxidation. Nine spices were selected based on their ability to inhibit </span>the formation of AGEs at different stages of Maillard reactions. Individually, all the 9 selected spices significantly inhibited the formation of AGEs. Among <span>the 33 combinations of spices, 26 combinations significantly inhibited the</span> formation of AGEs. The highest reduction (84%) was found by the combination <span>of Black Pepper</span></span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">Rose</span><span style="font-size:10.0pt;font-family:"">-</span><span style="font-size:10.0pt;font-family:"">Cumin. The individual spices failed to significantly </span><span style="font-size:10.0pt;font-family:"">lower the MDA </span><span style="font-size:10.0pt;font-family:"">concentration</span><span style="font-size:10.0pt;font-family:"">;however, all 33 combinations were able to signifi<span>cantly reduce MDA </span></span><span style="font-size:10.0pt;font-family:"">concentration</span><span style="font-size:10.0pt;font-family:"">. The results of this study showed that</span><span style="font-size:10.0pt;font-family:""> </span><span style="font-size:10.0pt;font-family:"">spices when supplemented in combinations are more effective in inhibiting <span>the formation of AGEs and in decreasing MDA </span></span><span style="font-size:10.0pt;font-family:"">concentration</span><span style="font-size:10.0pt;font-family:""> in meat patties. 展开更多
关键词 Advanced Glycation End-products CML Spice combinations MALONDIALDEHYDE
下载PDF
RESEARCH ON COMBINATION AND PLANNING OF PROCESSING UNITS UNDER CIMS CONDITION
13
作者 Qi Ershi Yao Gang +2 位作者 Xue Mei Zhang Tong (Tianjin University) 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 1996年第3期234-241,共1页
A method of the rational combinging and planning of the given processing machines into units under the condition of computer integrated manufacturing systems is presented. Here the modelling method is a kind of queuin... A method of the rational combinging and planning of the given processing machines into units under the condition of computer integrated manufacturing systems is presented. Here the modelling method is a kind of queuing network model with the change of productivity, which has been checked in the reality and effectivencss by a manufacturing case in China 展开更多
关键词 CIMS combination Planning Queuing network productivity
全文增补中
我国设施生态农业主要模式及配套技术的研究与实践 被引量:1
14
作者 李萍萍 韩建刚 +1 位作者 陈欣 高丽红 《浙江大学学报(农业与生命科学版)》 CAS CSCD 北大核心 2024年第2期149-160,共12页
设施生态农业是指在设施种植和设施养殖中采用清洁、绿色、健康生产方式,以提高资源利用效率、农产品产量与质量、环境效益为目标的生态农业模式。2002年农业部重点推广的设施生态农业模式主要有两大类:一类是种养沼三结合的“四位一体... 设施生态农业是指在设施种植和设施养殖中采用清洁、绿色、健康生产方式,以提高资源利用效率、农产品产量与质量、环境效益为目标的生态农业模式。2002年农业部重点推广的设施生态农业模式主要有两大类:一类是种养沼三结合的“四位一体”生态模式,从最初以农户为单位的单体日光温室到以村庄为单位的种养结合生态温室群模式,拓展到在一个大区域内将大型猪场的粪污进行工业化沼气并网发电,沼液通过管道输送到农田来减少化肥施用和改良土壤的宏观生态农业模式,相关的结构配置、配套的种养殖技术和装备也在不断研发和提升中。另一类是采用综合性生态农业技术的设施生态农业模式,包括:采用各类立体/垂直栽培技术提高土地资源利用率;通过各种轮作栽培技术减少设施蔬菜土壤连作障碍和降低农药使用量;采用土壤健康栽培技术,通过有机肥的合理施用改善土壤性状;采用有机基质栽培技术,用农林废弃物发酵后的物料作为栽培基质为作物提供养分;采用覆盖防虫网、色板诱杀、灯光诱杀、高温封棚、蒸气消毒、有色膜覆盖土壤、天敌昆虫生物防治等病虫草害生态防治技术来减少有害生物发生。期望通过相关配套装备技术的进一步研发提高设施生态农业的信息化、自动化水平,实现设施农业的可持续发展。 展开更多
关键词 设施生态农业 “四位一体”生态模式 种养沼结合 立体栽培 轮作栽培 有机基质栽培 生态防治
下载PDF
甘肃西部地区肉羊与湖羊杂交组合效果研究
15
作者 冯玲霞 杨军祥 +3 位作者 董和 梁金花 王胜明 高梓越 《饲料研究》 CAS 北大核心 2024年第6期100-105,共6页
试验旨在研究甘肃西部地区杂交一代羊与湖羊纯繁组的生产性能及肉用性能,筛选适宜该区域生态条件的肉羊杂交组合模式。以杜泊羊、澳洲白、萨福克羊为父本,以湖羊为母本开展杂交试验,按照体重、年龄相近的原则,随机选择90只杂交羔羊,分... 试验旨在研究甘肃西部地区杂交一代羊与湖羊纯繁组的生产性能及肉用性能,筛选适宜该区域生态条件的肉羊杂交组合模式。以杜泊羊、澳洲白、萨福克羊为父本,以湖羊为母本开展杂交试验,按照体重、年龄相近的原则,随机选择90只杂交羔羊,分成杜湖组(DHF1组)、澳湖组(AHF1组)和萨湖组(SHF1组),每组3个重复,每个重复10只羊;以30只湖羊纯繁(HHF1组)作为对照组,比较各组F1代羔羊的生长性能、产肉性能及肉品质。结果显示,各试验组F1代羔羊的5月龄体重和平均日增重均显著高于对照组(P<0.05),以DHF1组最高。各试验组F1代羔羊的宰前活重、胴体重、屠宰率、眼肌面积、GR值均高于对照组,其中DHF1组显著高于对照组(P<0.05)。各组羊肉中必需氨基酸占总氨基酸的40%以上,必需氨基酸占非必需氨基酸的70%以上,均高于FAO/WHO的推荐值。综合比较,DHF1组肉用性能较好。研究表明,DHF1组羊生长发育快、屠宰性能高、肉品质相对较好,可作为甘肃西部地区商品肉羊生产的二元杂交模式优先推广应用。 展开更多
关键词 肉羊 杂交组合 生产性能 屠宰性能 肉品质
下载PDF
基于产教融合理念的化工生产实习运行机制探索
16
作者 鞠志宇 张艳鸽 +1 位作者 谢智宇 吴长增 《化工管理》 2024年第23期25-29,共5页
生产实习是应用型本科专业技术人才培养过程中一个关键环节。文章结合化工发展的新形势,分析了化工生产实习与行业融合的必要性。鉴于当前产教融合面临的实际问题,从产教共同体、学生实习价值观、专业化师资、运行监控与反馈机制等方面... 生产实习是应用型本科专业技术人才培养过程中一个关键环节。文章结合化工发展的新形势,分析了化工生产实习与行业融合的必要性。鉴于当前产教融合面临的实际问题,从产教共同体、学生实习价值观、专业化师资、运行监控与反馈机制等方面构建了产教融合型生产实习运行的新机制。初步实践探索表明,共同体是产业和学校融合的突破口,正确的劳动观是调动学生积极性的良药、专业化师资是实习质量的关键,运行监控与反馈机制是实习质量调控的有效手段,对于生产实习课程建设具有指导与借鉴意义。 展开更多
关键词 产教融合 生产实习 运行机制 化工
下载PDF
气体封隔器密封单元的增强方法与安全分析
17
作者 程文佳 李越 +3 位作者 徐凤祥 魏瑞涛 葛垣 王雷鹏 《石油机械》 北大核心 2024年第3期79-85,共7页
气体封隔器胶筒是实现气井分层分段开采的关键部件。常规三胶筒结构在坐封时易发生初始破坏,导致胶筒整体应力水平降低,密封安全性储备不足。为此,提出一种多材料组合式密封单元的增强方法,用于HPHT105-232-V0型含硫化氢高温高压气体封... 气体封隔器胶筒是实现气井分层分段开采的关键部件。常规三胶筒结构在坐封时易发生初始破坏,导致胶筒整体应力水平降低,密封安全性储备不足。为此,提出一种多材料组合式密封单元的增强方法,用于HPHT105-232-V0型含硫化氢高温高压气体封隔器密封单元的设计;基于拉伸试验和Yeoh理论获得橡胶的本构模型参数;在温度204℃、坐封力200 kN和环空压力70 MPa下,分析了胶筒的应力和变形规律;试验测试了增强单元的密封安全性。分析结果表明:HPHT105-232-V0型封隔器密封单元胶筒的最大变形量为94.785 mm,最大接触应力为240 MPa,位于金属护环与套管接触区域。根据API标准,对HPHT105-232-V0型封隔器实物进行测试试验,坐封时胶筒未发生初始破坏,密封单元的整体应力水平提高;稳压过程胶筒压降幅度小于1%;整个试验测试过程中,密封单元无气泡溢出,封隔器卸载后胶筒结构无明显的塑性变形。研究结果表明,采用该增强方法所设计的多材料组合式密封单元具有良好的密封性能,满足极端环境下的密封安全性要求。 展开更多
关键词 气井开采 气体封隔器 多材料组合式密封单元 安全性试验 高温高压 增强方法
下载PDF
基于在线评论的服装供应链的生产努力投入策略
18
作者 许菱 万艳红 +1 位作者 张克 钟少君 《现代纺织技术》 北大核心 2024年第6期97-107,共11页
考虑消费者购买意愿受在线评论与生产努力的共同影响,构建了由服装制造商、电商平台和消费者组成的服装供应链模型,重点探讨了集中决策模型和分散决策模型下在线评论和生产努力等因素对各参与方利润的影响,并引入“成本分担+收益共享”... 考虑消费者购买意愿受在线评论与生产努力的共同影响,构建了由服装制造商、电商平台和消费者组成的服装供应链模型,重点探讨了集中决策模型和分散决策模型下在线评论和生产努力等因素对各参与方利润的影响,并引入“成本分担+收益共享”组合契约来实现供应链的协调。结果表明:集中决策和分散决策的最优解均与生产努力偏好系数呈正相关;受利益驱使,分散决策时的生产努力往往低于集中决策时的生产努力;组合契约模式下,契约参数的取值与批发价格的取值范围有关,在契约参数取值范围内,“成本分担+收益共享”组合契约能实现供应链的协调。研究结果为服装制造商和电商平台销售决策提供借鉴,可提高消费者满意度和市场竞争力。 展开更多
关键词 生产努力 服装供应链 在线评论 组合契约
下载PDF
大力培育新质生产力提升饲料工业高质量发展水平
19
作者 王卫国 《饲料工业》 CAS 北大核心 2024年第12期1-4,共4页
我国饲料工业已进入转型升级和高质量发展时期。要实现饲料工业的高质量发展和全生产要素生产效率的显著提升,就必须大力培育和发展新质生产力。文章介绍了新质生产力的概念和发展的四个维度,详细介绍了饲料工业高质量发展所需新质生产... 我国饲料工业已进入转型升级和高质量发展时期。要实现饲料工业的高质量发展和全生产要素生产效率的显著提升,就必须大力培育和发展新质生产力。文章介绍了新质生产力的概念和发展的四个维度,详细介绍了饲料工业高质量发展所需新质生产力的四个组成部分及其优化组合,包括新型劳动者、新劳动对象、新劳动工具、公益性新型基础设施平台建设,并对新型劳动者-饲料工程技术人才培养提出了建议。 展开更多
关键词 新质生产力 高质量发展 优化组合 饲料工业 人才培养
下载PDF
新工科大学生创新创业教育发展路径研究——以安徽工程大学机械工程学院为例
20
作者 钟相强 王春亭 杨怀安 《吉林农业科技学院学报》 2024年第3期45-49,共5页
提高新工科大学生创新创业教育水平,是应用型本科大学高素质人才培养的重要途径之一。通过开展创新型、实用性教育,实施校企合作和创客教育模式,结合社团培养、“学校+老生”、多学科联合培养教育模式,探索新工科大学生创新创业独特且... 提高新工科大学生创新创业教育水平,是应用型本科大学高素质人才培养的重要途径之一。通过开展创新型、实用性教育,实施校企合作和创客教育模式,结合社团培养、“学校+老生”、多学科联合培养教育模式,探索新工科大学生创新创业独特且高效的培养模式,实现创新创业教育与专业教育的深度融合,为新时代下高校大学生教育改革提供新的模式参考。 展开更多
关键词 创新创业 专业培养 产学结合 人才培养
下载PDF
上一页 1 2 100 下一页 到第
使用帮助 返回顶部