This survey article illustrates many important current trends and perspectives for the field and their applications, of interest to researchers in modern algebra, mathematical logic and discrete mathematics. It covers...This survey article illustrates many important current trends and perspectives for the field and their applications, of interest to researchers in modern algebra, mathematical logic and discrete mathematics. It covers a number of directions, including completeness theorem and compactness theorem for hyperidentities;the characterizations of the Boolean algebra of n-ary Boolean functions and the bounded distributive lattice of n-ary monotone Boolean functions;the functional representations of finitely-generated free algebras of various varieties of lattices via generalized Boolean functions, etc.展开更多
Many specifications of paving asphalts are closely related to their colloidal stability, which is, however, determined by their exact chemical compositions. The Yumen vacuum residue (YVR), the bottoms of a paraffinic...Many specifications of paving asphalts are closely related to their colloidal stability, which is, however, determined by their exact chemical compositions. The Yumen vacuum residue (YVR), the bottoms of a paraffinic crude oil is unfit for the production of highway paving asphalts directly, Neither are the de-oiled asphalts of the YVR. In this research a blending method and an optimal process of solvent de-asphalts are adopted to investigate the feasibility of formulating highway-paving asphalts from YVR. Results show that highway paving asphalts are formulated by blending solvent de-oiled asphalts with one or more of the materials including YVR, decanted oil from FCC process, and furfural extracts from lubricating base stocks. Further investigations indicate that adding oil decanted from FCC process to the solvent de-asphalting process can increase the de-asphalted oil production, improve the de-oiled asphalts quality, and thus optimize the refinery processes. The methodology of this research can be extended even to refineries processing non-paraffinic crude oils.展开更多
For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates ...For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates being exceeded by molten steel production,affecting ULC steel surface quality.In this work,a carbon powder addition(CPA)process was proposed to reduce the dissolved oxygen content at the end of RH de-C through addition of carbon powder to molten steel in the vacuum vessel.Carbon and oxygen behavior during the CPA and conventional process was then studied.The results demonstrated that the de-C rate with CPA was lower compared to the conventional process,but the carbon content at the end of de-C presented no difference.The de-C reaction for CPA process took place in the four reaction sites:(1)within the bulk steel where the spontaneous CO bubbles form;(2)splashing area on the liquid steel surface;(3)Ar bubble surface;(4)molten steel surface.The CPA process could significantly reduce the dissolved oxygen content at the end of de-C,the sum content of FeO and MnO in the slag,the aluminum consumption,and the defect rate of rolled products.This was beneficial in improving ULC steel cleanliness.展开更多
Cornelia de Lange综合征(CdLS)是一种罕见的先天性畸形疾病,其典型特征包括生长受限、智力迟钝、颅面异常和多毛症等。本研究报道2例CdLS患者,对其临床表现和基因变异特点进行总结,并结合相关文献进行复习。患者1,女性,5岁,因生长发育...Cornelia de Lange综合征(CdLS)是一种罕见的先天性畸形疾病,其典型特征包括生长受限、智力迟钝、颅面异常和多毛症等。本研究报道2例CdLS患者,对其临床表现和基因变异特点进行总结,并结合相关文献进行复习。患者1,女性,5岁,因生长发育缓慢就诊。查体多毛,一字眉,牙齿小、稀疏,前胸、后背可见血管瘤(约2 cm×2 cm),语言发育迟缓,智力落后;身高98 cm [≤-2标准差(SD)],体质量15 kg (-2SD~-1SD),头围46 cm (-3SD~-2SD);脑核磁共振成像(MRI)平扫显示左侧侧脑室侧后角和双侧侧脑室三角略扩大,双侧上颌窦和筛窦黏膜轻度增厚,心脏彩超显示二、三尖瓣轻度反流。患者2,女性,1个月,生后气促,软腭裂,吞咽困难及三凹征阳性,双手小、左手通贯掌、右手第5指短小,右侧髋关节外展受限,双足内翻,右眼底白斑。1个月时超声显示三尖瓣轻度反流,房间隔卵圆孔未闭。2d时脑MRI平扫显示纵裂池及天幕可见少许斑片状低信号影,少量蛛网膜下腔出血,双侧上颌窦、筛窦和中耳乳突少量积液。染色体核型分析未见明显结构及数目异常。全外显子组测序检测,患者1存在NIPBL基因c.6653_6655del杂合变异,患者2存在NIPBL基因c.337C>T杂合变异,父母均未检测到该变异。NIPBL基因变异是CdLS患者的主要遗传学病因,基因变异c.337C>T的鉴定扩展了NIPBL基因的变异谱系,为研究CdLS患者致病性基因变异提供了新证据。展开更多
文摘This survey article illustrates many important current trends and perspectives for the field and their applications, of interest to researchers in modern algebra, mathematical logic and discrete mathematics. It covers a number of directions, including completeness theorem and compactness theorem for hyperidentities;the characterizations of the Boolean algebra of n-ary Boolean functions and the bounded distributive lattice of n-ary monotone Boolean functions;the functional representations of finitely-generated free algebras of various varieties of lattices via generalized Boolean functions, etc.
文摘Many specifications of paving asphalts are closely related to their colloidal stability, which is, however, determined by their exact chemical compositions. The Yumen vacuum residue (YVR), the bottoms of a paraffinic crude oil is unfit for the production of highway paving asphalts directly, Neither are the de-oiled asphalts of the YVR. In this research a blending method and an optimal process of solvent de-asphalts are adopted to investigate the feasibility of formulating highway-paving asphalts from YVR. Results show that highway paving asphalts are formulated by blending solvent de-oiled asphalts with one or more of the materials including YVR, decanted oil from FCC process, and furfural extracts from lubricating base stocks. Further investigations indicate that adding oil decanted from FCC process to the solvent de-asphalting process can increase the de-asphalted oil production, improve the de-oiled asphalts quality, and thus optimize the refinery processes. The methodology of this research can be extended even to refineries processing non-paraffinic crude oils.
基金financially supported by the National Natural Science Foundation of China(No.51874021)Fundamental Research Funds for the Central Universities of China(No.FRF-IC-18-002)State Key Laboratory of Advanced Metallurgy Foundation of China(No.41618019)
文摘For ultra-low-carbon(ULC)steel production,the higher oxygen content before Ruhrstahl-Heraeus(RH)decarburization(de-C)treatment could shorten the de-C time in the RH degasser.However,this would lead to oxidation rates being exceeded by molten steel production,affecting ULC steel surface quality.In this work,a carbon powder addition(CPA)process was proposed to reduce the dissolved oxygen content at the end of RH de-C through addition of carbon powder to molten steel in the vacuum vessel.Carbon and oxygen behavior during the CPA and conventional process was then studied.The results demonstrated that the de-C rate with CPA was lower compared to the conventional process,but the carbon content at the end of de-C presented no difference.The de-C reaction for CPA process took place in the four reaction sites:(1)within the bulk steel where the spontaneous CO bubbles form;(2)splashing area on the liquid steel surface;(3)Ar bubble surface;(4)molten steel surface.The CPA process could significantly reduce the dissolved oxygen content at the end of de-C,the sum content of FeO and MnO in the slag,the aluminum consumption,and the defect rate of rolled products.This was beneficial in improving ULC steel cleanliness.
文摘Cornelia de Lange综合征(CdLS)是一种罕见的先天性畸形疾病,其典型特征包括生长受限、智力迟钝、颅面异常和多毛症等。本研究报道2例CdLS患者,对其临床表现和基因变异特点进行总结,并结合相关文献进行复习。患者1,女性,5岁,因生长发育缓慢就诊。查体多毛,一字眉,牙齿小、稀疏,前胸、后背可见血管瘤(约2 cm×2 cm),语言发育迟缓,智力落后;身高98 cm [≤-2标准差(SD)],体质量15 kg (-2SD~-1SD),头围46 cm (-3SD~-2SD);脑核磁共振成像(MRI)平扫显示左侧侧脑室侧后角和双侧侧脑室三角略扩大,双侧上颌窦和筛窦黏膜轻度增厚,心脏彩超显示二、三尖瓣轻度反流。患者2,女性,1个月,生后气促,软腭裂,吞咽困难及三凹征阳性,双手小、左手通贯掌、右手第5指短小,右侧髋关节外展受限,双足内翻,右眼底白斑。1个月时超声显示三尖瓣轻度反流,房间隔卵圆孔未闭。2d时脑MRI平扫显示纵裂池及天幕可见少许斑片状低信号影,少量蛛网膜下腔出血,双侧上颌窦、筛窦和中耳乳突少量积液。染色体核型分析未见明显结构及数目异常。全外显子组测序检测,患者1存在NIPBL基因c.6653_6655del杂合变异,患者2存在NIPBL基因c.337C>T杂合变异,父母均未检测到该变异。NIPBL基因变异是CdLS患者的主要遗传学病因,基因变异c.337C>T的鉴定扩展了NIPBL基因的变异谱系,为研究CdLS患者致病性基因变异提供了新证据。
