外文文献201136173
硬质合金圆锯片基体扩孔用珩磨条配方设计与试验
第32卷第5期㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀超㊀硬㊀材㊀料㊀工㊀程V o l.32 2020年10月S U P E R HA R D MA T E R I A LE N G I N E E R I N G O c t.2020ʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏʏ硬质合金圆锯片基体扩孔用珩磨条配方设计与试验曹彩婷,刘一波,徐燕军,尹㊀翔,刘㊀伟,李凤娟(北京安泰钢研超硬材料制品有限责任公司,北京㊀102200)摘㊀要:针对65M n㊁S K5㊁S A E1074等材质的硬质合金圆锯片基体扩孔用c B N珩磨条进行配方设计和性能验证,为解决珩磨条寿命短的问题,结合前期基础性试验,选择胎体主成分为C u S n㊁C u S n C o和磨料粒径为170/200㊁140/170镀钛c B N的3种配方制备成珩磨条样品进行性能测试,3种配方分别命名为A H1㊁A H3㊁A H5㊂经过测试3种配方珩磨条试样密度㊁硬度以及以65M n材质硬质合金圆锯片为例,锯片中孔29.7mm左右,珩磨扩孔加工量约0.2mm,珩磨加工中一次使用4根珩磨条,单次珩磨每组20片锯片㊂结果发现:A H1平均密度8.34g/c m3㊁平均硬度H R B104㊁测试寿命1003片锯片;A H3平均密度8.15g/c m3㊁平均硬度H R B98㊁测试寿命1400片锯片;A H5平均密度8.25g/c m3㊁平均硬度H R B112㊁测试寿命2990片锯片,3种配方珩磨条测试中效率相当,试验范围内可认为A H5配方最佳㊂关键词:硬质合金圆锯片基体;扩孔;珩磨条;c B N制品中图分类号:T Q164㊀㊀文献标识码:A㊀㊀文章编号:1673-1433(2020)05-0007-06F o r m u l aD e s i g n i n g a n dP e r f o r m a c eT e s t i n g o fH o n i n g S t o n e sf o rR e a m i ng C a r b i d eC i r c u l a r S a wB l a d eB a s e sC A O C a i t i n g,L I U Y i b o,X U Y a n j u n,Y I N X i a n g,L I U W e i,L IF e n g j u a n(B e i j i n g G a n g Y a nD i a m o n dP r o d u c t sC o m p a n y,B e i j i n g102200,C h i n a)A b s t r a c t:T h e f o r m u l ad e s i g na n d p e r f o r m a n c e v e r i f i c a t i o no f cB Nh o n i n g b a r,w h i c hw a sa p p l i e d f o r r e a m i n g t h e m a t r i xo fc a rb i d ec i r c u l a rs a w b l ade s m a d eo f65M n,S K5a n ds a e1074,w e r e c a r r i e do u t.I no r d e r t os o l v e t h e p r o b l e m o f s h o r t l i f e,a f t e r p r e l i m i n a r yb a s ic e x p e r i m e n t s,T h eh o n i n g s t o n e s a m p l e sw e r e p r e p a r e dw i t ht h e t h r e e f o r m u l a t i o n sr e s p e c t i v e l y n a m e dA H1,A H3,a n dA H5,w h i c hw e r ed e s i g n e dw i t ht h em a t r i xc o m p o-n e n t o fC u S n,C u S n C o,p a r t i c l e s i z e s o f170/200a n d140/170,a n d t h e a b r a s i v eo f t i t a n-i z e d c B N,a n d t h e n t h e p e r f o r m a n c eo f s a m p l e sw a s t e s t e d.T h ed e n s i t y a n dh a r d n e s so fh o n i n g s t o n e s a m p l e s A H1,A H3,a n dA H5w e r em e a s u r e d,a n d t h e h o n i n g s t o n e s a m p l e sw e r e a p p l i e d t o p r o c e s s65M n c a r b i d e c i r c u l a r s a wb l a d eb a s e a n d r e a mt h em i d d l eh o l eo ft h e s a wb l a d eb a s e f r o m29.7mmt o29.9mm.D u r i n g t h eh o n i n gp r o c e s s,4h o n i n g s t o n es a m p l e sw e r e i n s t a l l e d a n d20c a r b i d e c i r c u l a r s a wb l a d eb a s e sw e r e r e a m e da t o n e t i m e.T h e r e s u l t s s h o w e d t h a t t h e a v e r a g e d e n s i t y o fA H1s a m p l e sw a s8.34g/c m3,t h e a v e r-收稿日期:2020-07-24基金项目:北京安泰钢研超硬材料制品有限责任公司研发项目 精密磨削金刚石砂轮开发 (2020Z L05P C Y)作者简介:曹彩婷(1990-),女,硕士㊂研究方向:金属基超硬磨具㊂E-m a i l:c a o c a i t i n g@g a n g y a n-d i a m o n d.c o m㊂通讯作者:徐燕军(1971-),男,博士,正高级工程师,主要研究方向为超硬材料制品㊂E-m a i l:x u y a n j u n@g a n g y a n-d i a m o n d.c o m㊂引文格式:曹彩婷,刘一波,徐燕军,等.硬质合金圆锯片基体扩孔用珩磨条配方设计与试验[J].超硬材料工程,2020,32(5):7-12.a g e h a r d n e s sH R B104,a n d t h e s e r v i c e l i f e1003c a rb i d ec i r c u l a r s a wb l ade b a s e s.T h e a v-e r a g e d e n s i t y o fA H3s a m p l e sw a s8.15g/c m3,t h ea v e r a g eh a r d n e s sH R B98,a n dt h e s e r v i c e l if e1400c a r b i d e c i r c u l a r s a wb l a d eb a s e s.T h e a v e r ag ed e n s i t y o f A H5s a m p l e w a s8.25g/c m3,t h e a v e r a g e h a r d n e s sH R B112,a n d t h e s e r v i c e l i f e2990c a r b i d e c i r c u l a r s a wb l a d e b a s e s.T h e e f f ic i e n c y o f t h e t h r e e f o r m u l a s a m p l e sw a s e q u i v a l e n t,b u t t h e p e r f o r m-a n c e o fA H5f o r m u l a c o u l db e c o n s ide r e d a s t h eb e s t i n t h e t e s t r a n g e.K e y w o r d s:C a r b i d e c i r c u l a r s a wb l a d eb a s e;r e a m i n g;h o n i n g s t o n e1㊀引言硬质合金圆锯片是一种效率很高的切割刀具[1],因其切割锯路窄㊁效率高和切割面质量好而常被用于木材㊁塑料㊁铝型材㊁有机玻璃和家具等加工行业,是人们居家生活中不可或缺的一部分[2]㊂硬质合金圆锯片加工过程中,中孔冲完后公差和精度一般不能满足使用要求,这就需要珩磨加工㊂珩磨常用于孔的光整加工,珩磨切削力是周向力和轴向力的合成,珩磨头承受的扭矩是周向切削力的度量,珩磨作为一种磨削加工的特殊形式,是提高工件的尺寸㊁几何形状精度和表面质量的有效加工方法[3]㊂珩磨加工具有如下特点:(1)应用范围广,几乎所有的工件材料都可以珩磨加工;(2)加工工件表面质量好,由于珩磨速度是一般磨削速度的几十分之一,磨削力和热很小,工件表面不产生烧伤㊁裂纹等;(3)加工精度高,采用珩磨加工内孔时,表面粗糙度值R a可达0.05μm;(4)对机床精度要求低,珩磨加工除采用专用的珩磨机床外,在车床㊁镗床和钻床上也可进行[4]㊂从结合剂种类划分,珩磨条有树脂㊁陶瓷㊁金属等分类,磨料主要有金刚石㊁c B N超硬磨料和刚玉㊁S i C 等普通磨料,随着对加工工具性价比要求的提高,超硬磨料的珩磨条应用越来越广泛[5]㊂本文为解决胎体对c B N磨料的把持力㊁提高珩磨条使用寿命的问题,在控制成本的前提下实现寿命2500片以上的目标㊂结合前期基础试验,设计3种配方分别编号A H1㊁A H3㊁A H5,验证3种配方的密度㊁硬度和使用寿命等效果,确定试验范围内的最佳方案㊂2㊀配方设计思路㊁实验原材料与方法2.1㊀配方设计思路本文目标主要是解决珩磨条使用寿命短的问题,设计思路从影响寿命的三个方面入手:调整磨料的浓度或粒度㊁磨料表面镀覆处理提高胎体对磨料的把持力㊁胎体中添加耐磨性元素提高胎体耐磨性㊂经过前期基础试验积累及对客户样品分析后,确定A H1配方磨料c B N170/200~230,体积浓度35%,测试使用寿命1003片,未能达到寿命目标2500片;根据前期A H1的试验结果,在保证珩磨条锋利度以及珩磨的圆锯片表面精度满足要求的前提下,进行如下配方设计:(1)胎体和磨料粒度不变,提高磨料c B N体积浓度至60%,且c B N磨粒表面镀钛处理;(2)通过添加C o元素适度提高胎体耐磨性,调整磨料c B N体积浓度为45%㊁粒度为140/170,且c B N磨粒表面镀钛处理㊂通过以上试验对比,进一步了解磨料浓度㊁粒度变化和胎体成分变化对产品使用寿命的影响㊂2.2㊀实验原材料A H1主要成分及含量见表1,底粉为C u,磨料采用cB N170/200~230,粒径尺寸75~95μm,其颗粒形貌如图1所示:表1㊀A H1主要成分及含量T a b l e1㊀A H1m a i n c o m p o s i t i o na n d c o n t e n t编号C u S n其他c B N含量A H173.7%22.5%3.8%35%图1㊀A H1磨料颗粒表面形貌图F i g.1㊀T h e s u r f a c e t o p o g r a p h y o f a b r a s i v e p a r t i c l e sA H18超硬材料工程㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀2020年10月㊀㊀A H 3主要成分及含量见表2,底粉为C u ,磨料采用表面镀钛c B N 170/200~230T ,粒径尺寸75~95μm ,其颗粒形貌如图2所示:表2㊀A H 3主要成分及含量T a b l e 2㊀A H 3m a i n c o m po s i t i o na n d c o n t e n t 编号C u S n 其他c B N 含量A H 374.3%19.7%6%60%图2㊀A H 3磨料颗粒表面形貌图F i g .2㊀T h e s u r f a c e t o p o g r a p h y of a b r a s i v e p a r t i c l e sA H 3㊀㊀A H 5主要成分及含量见表3,底粉为C u ,磨料采用表面镀钛c B N 140/170~230T ,粒径尺寸90~106μm ,其颗粒形貌如图3所示:表3㊀A H 5主要成分及含量T a b l e 3㊀A H 5m a i n c o m po s i t i o na n d c o n t e n t 编号C u S n C o 其他c B N 含量A H 573%17.3%5.7%4%45%图3㊀A H 5磨料颗粒形貌图F i g .3㊀T h e s u r f a c e t o p o g r a p h y of a b r a s i v e p a r t i c l e sA H 52.3㊀实验方法将配方成分按比例配制好后,用三维混料机均匀混合1h ,加入c B N 磨料后再混合1h ㊂将混合好的粉末装入石墨模具进行热压烧结,制备50L-4W-2.8X-3.0T mm 3的试样,每组石墨模具中装有18个试样,三种配方的热压烧结工艺分别如图4~图6所示:图4㊀A H 1热压烧结工艺曲线图F i g .4㊀A H 1H o t p r e s s i n g s i n t e r i n gpr o c e s s c u r v e 9第32卷㊀第5期㊀㊀㊀㊀㊀㊀㊀㊀曹彩婷等:硬质合金圆锯片基体扩孔用珩磨条配方设计与试验图5㊀A H 3热压烧结工艺曲线图F i g .5㊀A H 3H o t p r e s s i n g s i n t e r i n gpr o c e s s c u r ve 图6㊀A H 5热压烧结工艺曲线图F i g .6㊀A H 5H o t p r e s s i n g s i n t e r i n gpr o c e s s c u r v e 3㊀实验结果与分析采用阿基米德排水法测量试样密度,每种配方选10个测量取平均值作为测试结果;利用H R-150A 型洛氏硬度计测量试样的硬度值,每种配方选5个试样每个测4个点,取平均值作为测量结果㊂三种配方试样密度和硬度测试结果见表4,对比柱形见图7㊂表4㊀三种配方试样密度和硬度测试结果T a b l e 4㊀T h e r e l u l t s o f d e n s i t y an dh a r d n e s s o f t h r e e s a m pl e s 配方编号密度(g/c m 3)硬度(H R B )A H 18.34104A H 38.1598A H 58.251121超硬材料工程㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀2020年10月图7㊀三种配方试样密度和硬度柱形图F i g.7㊀C o l u m n a r d i a g r a m s o f d e n s i t y a n dh a r d n e s s o f t h r e e f o r m u l a t i o n s㊀㊀珩磨验证时利用银焊片将试样(图8所示)焊接到基体(图9所示)上,以65M n材质锯片为例,锯片中孔29.7mm左右,珩磨扩孔加工量约0.2mm,珩磨加工中一次使用4根珩磨条,单次珩磨每组20片锯片㊂结果发现,珩磨过程中效率基本相当,A H1配方可加工1003片㊁A H3配方可加工1400片,A H5配方可加工2990片㊂图8㊀珩磨条试样图例F i g.8㊀T h eh o n i n g s t o n e s a m p l e f i g u re图9㊀珩磨条基体图例F i g.9㊀T h eh o n i n g s t o n e s u b s t r a t e f i g u r eF i g.10㊀T h e f r a c t u r em o r p h o l o g y o f s a m p l eA H 1F i g.11㊀T h e f r a c t u r em o r p h o l o g y o f s a m p l eA H311第32卷㊀第5期㊀㊀㊀㊀㊀㊀㊀㊀曹彩婷等:硬质合金圆锯片基体扩孔用珩磨条配方设计与试验F i g.12㊀T h e f r a c t u r em o r p h o l o g y o f s a m p l eA H5㊀㊀对于测试结果结合配方成分和磨料分析,发现A H3配方较A H1配方的主要差异是磨料c B N170/ 200~230体积浓度35%调整为镀钛c B N170/200~ 230T体积浓度60%,磨料体积浓度提高25%及磨料表面镀覆钛使珩磨条寿命提高约39%;A H5配方较A H3配方的主要差异是胎体中添加C o元素,以及磨料c B N粒度170/200~230T体积浓度60%调整为镀钛c B N粒度140/170~230T体积浓度45%,胎体配方增加耐磨性元素及磨料粒度调粗使珩磨条寿命实现翻倍增长,使用寿命完成2500片的目标㊂结合胎体断口形貌分析,从图10(a)断口显微照片中可以看出,A H1试样胎体对c B N有润湿性,胎体和c B N结合较好无缝隙,但图10(b)中显示胎体断裂为脆性断裂,断口无明显韧窝;从图11(a)可以看出,AH3试样胎体对c B N粘结不好,胎体对c B N润湿性不好,造成胎体和c B N间有较大缝隙,在使用中会造成c B N提前脱落,所以即使c B N体积浓度较高,试样表现出的寿命可能不会有很大提高,图11 (b)中显示胎体断裂为韧性断裂,韧窝状断口比较明显;从图12(a)中可以看出,胎体和c B N连结比较紧密,使用中胎体对c B N的把持力较好,图12(b)中显示胎体断裂为韧性断裂,断口表面有明显韧窝,该胎体配方比较合理㊂断口的理论推断效果与实际试验测试结果基本吻合,整体来看寿命测试结果与设计思路也基本一致㊂综合性能来看,试验范围内A H5配方使用效果最佳,可作为珩磨扩孔65M n等硬质合金圆锯片的最优方案㊂参考文献:[1]㊀刘勇.硬质合金木工圆锯片的C A D设计方法探究[J].现代制造技术与装备,2017(8):58-60.[2]㊀周富强.超薄硬质合金圆锯片在木材加工中的应用[J].南方农机,2015(5):35-36.[3]㊀谢国如.砂带内孔珩磨工艺研究及应用[J].工艺与装备,2005(1):105-106.[4]㊀孟璐,郑文虎.珩磨加工[J].金属加工(冷加工),2019(9):37-40.[5]㊀丁艳红,姚新改.淬火钢用c B N珩磨条的研制[J].制造技术与机床,2007(4):91-92.21超硬材料工程㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀㊀2020年10月。
美国化学家利用质谱分析法阅读遗传密码
美国化学家利用质谱分析法阅读遗传密码
佚名
【期刊名称】《世界经济科技》
【年(卷),期】1992(000)015
【总页数】2页(P47-48)
【正文语种】中文
【中图分类】Q349.55
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Asian Social Science; V ol. 9, No. 4; 2013ISSN 1911-2017 E-ISSN 1911-2025Published by Canadian Center of Science and Education Chinese Private Enterprises’ Management InnovationRi Nan11 Tianjin University of Commerce, Tianjin, ChinaCorrespondence: Ri Nan, Tianjin University of Commerce, Tianjin 300134, China. Tel: 86-136-8219-7910. E-mail: nanri0729@Received: January 11, 2013 Accepted: February 5, 2013 Online Published: March 28, 2013doi:10.5539/ass.v9n4p51 URL: /10.5539/ass.v9n4p51AbstractSince the reform and opening, private enterprises of China have got a rapid development, and have done a great contribution to the continual development of national economy. However, with the change of external and internal situations, private enterprise management appears to be defective, sometimes it even does harm to the development of the enterprises. This reports aims to present of the problem of private enterprises in China. In order to solve this problem, Chinese private enterprises should accelerate the management innovation.We analyzed the necessities of enterprises’ management innovation, the motivation of management innovation, obstacles to management innovation.Finally, it puts forward the countermeasures to solve the problems. Keywords: private enterprise, China, innovation1. IntroductionAfter more than three decades of rapid development, we see the emergence of a very strong private sector in China. Indeed, private enterprises have grown rapidly over the years and become an integral part of the Chinese economy. The Bank of Communications of China published a report regarding the wealth creation and management of China's private enterprises on May 16 2011. The report shows that while the private enterprises of China continue to make contributions to the GDP and create jobs, their wealth is also increasing rapidly. Private Chinese enterprises exported goods worth $481.3 billion in 2010, a jump of 223 percent compared with 2005, said a report by the All-China Federation of Industry & Commerce (ACFIC).The number of private enterprises in China exceeds 8.4 million after a yearly increase of 14.3 percent on average over the past five years. They account for more than 74 percent of China's total enterprises. However, China's private enterprises face increasing pressure from price hikes in raw materials, rising labor costs, financing difficulties, and a heavy tax burden. In order to do a good job, private enterprises have to implement management innovation. In this paper, we intend to discuss the necessities of implement management innovation, the motivation of management innovation, the obstacles to management innovation, and gave some suggestions on how to promote the management innovation.2. Relevant Literature ReviewThere is a considerable literature regarding the Chinese private enterprises. Most of the Chinese private enterprises are family business. Family business is generally viewed as the most common form of business structure. There is also a lack of the precise definition of private business. While some researchers avoid the use of clear definitions, others apply the definitions that most suit their researches. The definitional problem is compounded when the controversy emerges about whether it should include all blood relations and in-laws. Fahed-Sreh(2009) explains a family firm as any business that is controlled or influenced by a ‘single family’ and which is also intended to remain in family. Brrdthistle & Fleming (2005) and Birdthistle (2008) operate their studies on definition of family business, which regards it as ‘any form of business association that is classified as an SME (less than 250 employees)and where the majority ownership is held by the family/family members in the family business and/or the family is represented on the board of Directors’. This definition seems to ignore the succession issue, which is considered as a major focus of family business. But within the context of China, the family business is undeveloped compared to those in developed countries and exist only for a very short period. Most family businesses are still within the control of first-generation. The definition of family business here just emphasizes on the majority control of ownership held by the family/family members.In regard to the researches on family business, many people address the differences between family and non-family businesses. Harris et al. (2004) conclude that family-owed establishments are less likely to allowworkforce engagement via a range of communication approaches in comparison to non-family firms. Others also explore issues on family business in terms of varied perspectives and emphases. Birdthistle and Fleming (2005) investigate the creation of a learning organization within the framework of family SMEs and conclude that small and medium-sized family firms display some of the characteristics of a learning organization. In relation to the development of growth strategy, Kreiser et al. (2006) suggest that family firms typically apply conservative strategies in the very beginning and often maintain tight control of the strategic decision-making process within the family unit. Rather, researches into family business have noted the strategic advantages of being embedded within family relations. Spanos et al. (2008) treat family as a real source of competitive advantage for the firm since the owner (family) is usually involved in the key decision making process.3. China Has Grown Because of Private EnterprisesAfter more than three decades of rapid development, we see the emergence of a very strong private sector in China. Indeed, private enterprises have grown rapidly over the years and become an integral part of the Chinese economy.Today, entrepreneurship and the development of private enterprises continue to be at the forefront of economic development. They have not only contributed significantly to economic growth, employment, and tax revenue, but also played an increasingly dominant role in management, corporate social responsibility and compliance. These contributions help China achieve development in a more sustainable way.China's private enterprise reforms began first in agriculture in 1978 and spread from there. Agriculture accounted for most of Chinese output and most of the labor force when Mao died in 1976 and the reform period could begin. The freeing of agriculture from collective farms is the most important untold part of the Chinese growth story.Agricultural reforms began spontaneously from below, even before the "Reform" Party Congress of 1978 that installed reformer Deng Xiaping in power. A Chinese reform official later admitted: "In fact, reform wasn't discussed. Reform wasn't listed on the agenda, nor was it mentioned in the work reports."What became known as the "contract responsibility system" was sparked spontaneously by eighteen peasants from Xiaogang village in Anhui province. They secretly divided communal land in November 1978 and agreed to farm their plots individually, each contributing their share of the state quota. The state got its due and the peasants kept what was left over. The peasants' separation of their land from the collective farm was illegal, highly dangerous, and done without the approval of regional officials.As agricultural production soared, Deng Xiaping and his CPC realized that they should not resist something that was working. By 1982, more than 90 percent of rural dwellers worked under the contract responsibility system, but they were allowed only one- to three-year contracts on their land. It was only in 2003 that the state gave out longer-term leases.The spontaneous reforms in agriculture meant that new supplies of food products needed markets and that markets needed infrastructure. Rural dwellers created a private trade network, and, within one year, most state food stores were out of business. Rural entrepreneurs then created new businesses, such as hotels, services, private restaurants, and small-scale manufacturing, through the three Fs (friends, family and fools).They bribed local officials to register their companies as "township and village enterprises." They created fake "red hat" enterprises, that is, private companies masquerading as state companies, and sham collective enterprises, or they used state enterprises to issue receipts and open bank accounts. Large private manufacturing firms developed first in predominantly agricultural provinces. China's largest agribusiness was founded by brothers who left the city to found their company in rural Sichuan. Rural entrepreneurs built the largest refrigeration and air-conditioning companies in China.4. The Necessities of Chinese Enterprises’ Management InnovationMost of the Chinese private enterprises are family business, highly centralized managed.This model can save costs, and maintain the flexibility of operation.However, this kind of management model also has a lot of problems, and it caused more problems with the change of environments and out of the enterprises, sometimes these shortcomings even constrain the development of private enterprises.Private enterprises have to improve their management model if they want to be strong in the future.4.1 Expand the Operate and Assets ScaleThe process and function of the enterprise will become more and more complicated as the Chinese enterprises’ assets increased. If we still use the old information management, internal and external information of the enterprises will both become confusing. This will hinder the rapid development of the enterprises. Many Chineseprivate businesses have such problems. Some private enterprises’ employees behave against the enterprises’ regulations and will be discovered only when such behavior is causing serious consequences. Therefore, private enterprises should take new management methods before expanding. The primary task is to create a new organization structure, in which the corporations’ internal information will be transmitted in time, and the leader of the enterprises can get more suggestions for the enterprises’ operation.4.2 Enter into Capital-Intensive and Technology Intensive IndustriesAs China's reform and opening up process, some of the best private enterprises enter into capital-intensive industries and technology intensive industries in which strategic management is very important to enterprises’ survival and development. Sorry to private enterprises, most of them haven’t even thought of strategic management. They don’t have a clear idea of their market orientation, competitors or competitive environment. Affected by experiences which they got at the process of starting business, executives still take the development of enterprises as a kind of speculation. To those private enterprises which have entered into technology intensive industries, competitive edge have to be won by create self-owned core technologies. Those private enterprises are kind of technology based businesses or higher level knowledge-based enterprises, in which the research of knowledge management and technical research and development has become the key to enterprises’ development. Therefore, both the organization and its operating system have to change to get along well with the need of knowledge management. This is a great reform to management idea, management technology and management method.4.3 Make Best Use of Human ResourcesAt the beginning of starting a business, the entrepreneurs’ social capital and ability to find opportunities are very important. Owing to these good entrepreneurs, private enterprises grew up fast in the past years when there were not enough products in the market. However, the market is now full of products and with fierce competition. Private enterprises will end in disaster if they still depend on the entrepreneurs’ social capital and ability to develop. Private enterprises’ owners should change the idea that developing is the job of themselves, welcome workers with great abilities to join the enterprises, and let the human resources become the engine of enterprises’ development. In order to do this, private enterprises have to change their human resource management, which are not attractive to workers. They should pay more attention to the need of workers, to attract good workers to join in, to train old workers to make them more talent, and to give more inspiration to the employees to keep them.4.4 DevelopThe process of private enterprises’ develop is a strategic process, which needs a long-term development strategy. The strategy should change as the situations of the enterprises change. That is to say, the strategy should change with the market competition, enterprises’ competitive edge, etc.5. Innovative Power of Private Enterprises’ ManagementInnovative power is the main reason to conduct and sustained the innovation in enterprise’s development. The power of innovation is complicated. Private enterprise’s management innovative power comes mainly from the following aspects:5.1 InterestsPeople play a very important part in enterprises. It is one of the key factors to enterprises’ survival and development. Different people have different positions, thus their power, responsibility and interests are also different. The main task of management innovation is to abolish the existing power, responsibility, interests and establish a new pattern according to the environmental requirements. Everyone in the enterprise wants to gain more interests according to the innovation. Investors care about the enterprise’s development and capital value, seeking for maximize investment returns. On one hand, they want to further enhance enterprise’s vitality and sustain the growth with the help of management innovation; on the other hand, they hope that by implementing management innovation, they can strengthen the supervision and control of the enterprise so as to protect their rights. Proprietors want maximize their utility through innovation. That is to say, they want secure more power, more income, subsidies, and to promote their positions. A common worker may want to secure more income, better treatment, and effectively protect the legitimate rights and interests. Other stakeholders, such as the government, banks, the community, the creditors, partners, all want to protect their own interests and gain a higher income through management system innovation. The desire to gain more interests can become the engine of management innovation.5.2 Psychological PowerInnovation is promoted not only by interests, but also by psychology. It is one of the most important human needs. The fulfillment of innovation on success, personal values and responsibilities often become the power of innovation. Both the investors and proprietors want to show their abilities and values from successful management innovation. For professional managers, they have to responsible for the enterprise according to professional and ethical requirements. Therefore, they have a strong will to lead the enterprise to success through innovation. Besides, there is still someone who wants to take greater social responsibilities for society to make more contributions and become a noble man through management innovation. All these wishes and believes are psychological power which will promote management innovation.5.3 Enterprises ThemselvesAs an organism, enterprises have demand to innovating in certain condition. As the environment inside and outside the enterprises change, the existing management model doesn’t conform to the new situation, thus the development of the enterprises will stop. In such case, managers will have to change the exiting management model. This kind of innovation is forced by the enterprises themselves. If the managers fail to notice the problem and take no action, the enterprise will have great trouble, some even will bankrupt. Besides, changes of the society, policy and law can also force the enterprises to improve their management.6. Obstacles to Private Enterprises’ Management Innovation6.1 The Low Quality of ManagerOwing to historical reasons, most of the private enterprises’ owners haven’t received the formal education, not to mention comprehensive and systematic business administration training. Thus they don’t have enough management theories, methods and skills. Some of them even don’t know English and computers. These problems may hamper their work. What’s more, some of the owners are easy to be content and not aggressive. These may not be good for the enterprises’ development.6.2 Inefficient Management ModelAt present most of the private enterprises use the family management model. The distinct characteristic of this management model is that owners or their relatives run the enterprises and control the whole production and operation process all by themselves. It is proved that this kind of management model is good for starting a business but bad for developing a business. At the beginning of starting a business, this kind of model can collect talents and capital at a very low cost. For most of the talents belong to a single family, their interests are the same. So these talents will devote all they have to fight for the enterprise together. This hard work sometimes really works. It can help the enterprise grow up into a bigger scale enterprise with competitive advantage. However, as the enterprises’ scales grow, the old family management model becomes more and more inefficient. First, owners treat their relatives and exotic workers differently make the exotic workers unhappy. Second, the owners just follow their feelings to make decisions for the enterprises without listen to others. Third, the managerial authority will be passed on to their descents. All these factors make the enterprises hard to develop.6.3 Management BeliefPrivate enterprises choose family management model indicate that they take the family interests as the most important thing. This can be explained by Chinese traditional culture. First, in Chinese traditional culture, family is the basic economic unit. The chief function of family is the ownership of enterprises’ wealth. Second, “obey” is very important in a family which means that people have to follow their parents’ decisions. These factors give the owners absolute decision-making rights. All the descents have to follow these decisions to defend the family’s interests. Followed by these believes, many private enterprises seeking for the maximum family interests at the cost of social interests. For example, some private enterprises defraud tax, produce counterfeited products. All these bad behavior not only caused bad effects on the social economic order and marketing order but also damaged the social image of the private enterprises. And these effects damaged the living environment of the private enterprises in return.6.4 Human Resources Management6.4.1 The Unfair Hiring SystemMost of Chinese private enterprises choose family management model, that is to say, they hire workers according to relationships. If the workers are close to the owner, like the owner’s relatives, students, friends and so on, they will be considered important and trustworthy. On the contrary, if the relationship between workers and the owners is just employees and employers, the workers will be ignored and distrusted. What’s more, theowners give different treatments to the workers according to relationships, too. Those who are close to the owners will get better pay. This kind of human resource management makes the common workers very unhappy, they find the system unfair, have no security and have no sense of belonging. Therefore, many workers quit their jobs in the private enterprises. When talents are gone, the private enterprises will end in disaster.6.4.2 Ignore Talent: It Is True That the Owners Are Very CleverWhen starting a business, all decisions are made by the owners themselves. And these decisions really works, the enterprises grow from infants to sizable enterprises. In some ways, there will be no private enterprises if there were no such excellent owners. However, these legends also have some bad effects. Some of the owners will become conceit and opinionated. They don’t pay much attention to the talents. They believe that their own intelligence can handle all the troubles. Many owners hire talents just for decorating the enterprise. This is very dangerous for an enterprise to live in nowadays.6.4.3 Little Training for the Employees: In Order to PromoteThe enterprise’s development, some private enterprises try many ways to attract excellent graduates to join in. However, most of the enterprises site in middle and small city. Even some of the graduates want to work there, they don’t want to take their registered permanent residence there. In this case, the enterprises will have no security on keeping these graduates. They fear that these graduates will leave after a few years. So they have no incentive to train these graduates. On the other hand, no training for the graduates makes the graduates very worry about the future. How to solve this vicious circle is very important for private enterprises’ development. 6.4.4 The Lack of Effective Incentive MechanismsEffective incentive mechanisms can arouse the employees’ potential abilities, create a homegrown innovation environment, attract talents in and out of the enterprise. However, most of the Chinese private enterprises ignore the talents management, ignore employees’ needs, and lack effective incentive mechanisms. In the long term, these problems will become the bottle-neck which obstructs stable development of an enterprise.7. The Ways to Enforce Administrative CreationWith the implementation of China’s economic system reform, the external environment of the management innovation will be better and better. Enterprises should also take actions to promote innovation.7.1 Pay Attention to Management InnovationManagement is not only a kind of science but also productive forces. Good management is an important factor to enterprises’ long-term development. The workers, especially the managers should pay attention to enterprises’ management, and make it an engine to management innovation.7.2 Improve the Quality of the EntrepreneurEntrepreneurs are the soul of enterprises. Their qualities determine the management qualities and enterprises’ development in the future. Therefore, the improvement of their qualities is the key factor to enterprises’ development. Generally speaking, a successful entrepreneur should have the following qualities: first, he must have a wide range of knowledge and skilled management techniques. Second, he must be good at communicating with others. Third, he must be very aggressive. Forth, he must have a strong sense of responsibilities. Only when an entrepreneur has these characteristics can he promise the enterprise a bright future while do no harm to the society.7.3 Improve the Property Rights SystemThe property rights structure of most private enterprises is single and closed. It is limited to personal property rights. The problem of this kind of property rights system is that enterprises may have difficulties in getting rid of personal and family control system, departing the ownership and management power, changing the investor’s model into managerial management model, and accepting social capital. These problems will set back the enterprises’ development. Therefore, if the private enterprises want to grow bigger and stronger, they have to get rid of the family management model and welcome other investors to join in. In this way, the shortcomings of closed property rights will be solved, more capital can be used for the enterprises’ expansion.7.4 Change the Management ModelNowadays the property rights are belonging to a single family. The leader of the family makes decisions for the enterprise. When the leader quit, the management power will be passed on to his descents. However, not all descents are as clever as their ancestors. Sometimes, they are not good at operating an enterprise and this will bring disaster to the enterprise. To avoid this tragedy, the owner should choose the most suitable successor to bethe manager, either he is the descent or not, and let the unsuitable descents be shareholders. “Most suitable” means he is best at manage an enterprise.7.5 Form an Environment of Management Innovation CultureFor enterprises, the most important value of management innovation is that the enterprises’ problems can be solved much better. The characteristics and practices of management innovation show that management innovation often appears when workers have different ideas in solving a same problem. That is to say, the workers get stuck, hold different opinions in solving them, discuss advantages and disadvantages of these solutions, and finally create a best solution. This best solution may be considered as part of the enterprises’ management innovations. So enterprises can pay more attention to cultivate management innovation environment. Call for the workers to join in the management innovation so as to create more solutions.7.6 Try to Make the Enterprises and Social Live in HarmonyEnterprises are profit-making organizations, and seeking for the maximum interests is one of their duties. However, enterprises’ interests can’t be counted only by profits at present. They must consider interests both at present and in the future. If they only seek for profits at present, and smuggling, cheating, producing fake products and so on, their social image will be very bad. In the long run, people wouldn’t buy their products. And this will finally ruin the enterprises’ future. So enterprises should put the future interests and present interests together,form a good social image so as to live in harmony with the society.7.7 Improve the Human Resource Management SystemIn order to break the bottlenecks of lacking talents, private enterprises have to pay more attention to their employees, select employees by their abilities instead of by relationships. Besides, enterprises should accept all kinds of talents, especially those who are good at research, development and management. Furthermore, private enterprises should give different employees different incentives. That means enterprises should give employees prizes which they need most. For example, if an employee wants to promote himself, enterprises should give him more opportunities to study and give him a promotion when he deserves it. Finally, private enterprises should create a good, comfortable environment so that employees can do their best.8. ConclusionThe main purpose of this paper is to give some suggestions on how to innovate private enterprises’ management. We analyze the necessities of private enterprises’ management innovation, the motivation of management innovation, the obstacles to management innovation, and finally we come to the solution. We think that, in order to develop, the private enterprise should pay attention to management innovation, improve the quality of the entrepreneur, improve the property rights system, change the management model, form an environment of management innovation culture, try to make the enterprises and social live in harmony, and improve the human resource management system.ReferencesBirdthistle, N. (2008). Family SMEs in Ireland as learning organizations. The Learning Organization, 15(5)./10.1108/09696470810898393Birdthistle, N., & Fleming, P. (2005). Creating a learning organization within the family business: an Irish perspective. Journal of European Industrial Training, 29(9)./10.1108/03090590510629858 Chua, J. H., James, J. C., & Lloyd, P. (2006, Summer). Steier. Extending the theoretical horizons of family business research. Entrepreneurship Theory and Practice.Fahed-Sreih, J. (2009). An exploratory study on a new corporate governance mechanism: Evidence from small family firms. Management Research News, 32(1)./10.1108/01409170910922023Gu, B. R. (2006). Culture obstacles to private enterprises’ management innovation. Enterprise Development Forum, (12).Harris, M., & Raviv, A. (1991). The Theory of Capital Structure. Journal of Finance, 46(1)./10.1111/j.1540-6261.1991.tb03753.xHong, S. (2003). Modern Institutional Economics. Beijing: Peking University Press.Klyver, K. (2007). Shifting family involvement during the entrepreneurial process. International Journal of Entrepreneurial Behaviour &Research, 13(5). /10.1108/13552550710780867Kreiser, P. M., Ojala, J., Lamberg, J. A., & Melander, A. (2006). A historical investigation of the strategic process。
以大学为依托的农业科技推广新模式分析_农业科技专家大院的调查与思考
中国农业科技导报,2007,9(1):64~68Review of China Agricultural Science and Technol ogy 收稿日期:2006207213;修回日期:2006208225。
作者简介:聂海(1971-),男,副研究员,博士研究生;主要从事农业推广、农业教育管理等方面的研究工作。
E -mail:niehai@n wsuaf .edu .cn【农业科技推广】以大学为依托的农业科技推广新模式分析———农业科技专家大院的调查与思考聂 海, 郝 利(西北农林科技大学经济管理学院,陕西杨凌712100)摘要:农业院校拥有人才优势、科研优势、农业科技信息优势,是我国农业科技推广的重要力量。
但受传统体制壁垒制约,农业院校有组织的技术推广与服务长期游离于政府主导型的农业科技推广体系之外,其优势发挥缺乏长效机制。
西北农林科技大学与宝鸡市人民政府探索推进农业科技推广体系改革过程中,创建了以大学为依托的农业科技推广新模式———农业科技专家大院。
农业科技专家大院以大学科技力量为依托,布局在农产品集中产区,在一定程度上突破了传统体制壁垒,实现了农业科技供给与需求之间的直接对接,效果明显。
通过分析农业科技专家大院形成的背景、运行机制模式及效果、存在问题等,揭示其中的规律和值得汲取的经验与教训。
关键词:农业大学;科技推广模式;专家大院中图分类号:S3233,F306 文献标识码:A 文章编号:100820864(2007)0120064205A new m ode l fo r a g ricu ltu ra l extens i on ba sed on un ive rs iti es———I nve s ti ga ti ng a nd th i nki ng a bou t a g ri cu ltu ra l e xp e rt w o rkshopN I E Ha i ,HAO Li(Co ll ege of E conom i cs a nd M a na gem en t ,N o rthw es t A&F U n i ve rs ity,Y a ng li ng Sha nxi 712100,Ch i na )Abs tra ct :Ag ri cu ltu ra l un i ve rs iti e s,w h i ch ha ve the a dva n ta ges i n b ra i ns,re sea rch a nd sci 2te ch i nfo r m a ti on i n the fi e l d of a g ri cu ltu re,i s a n i m p o rta n t p a rt of a g ri cu ltu ra l extens i on.How eve r ,the exte ns i on sys tem ba se d on the a g 2ri cu ltu ra l un i ve rs iti e s ha s no e ffecti ve i n teg ra ti on w ith the tra d iti ona l sys tem be l ongs to gove rnm en t a t e ve ry l e ve l .N o rthw es t A &F U n i ve rs ity a nd the gove rnm en t of Ba o ji city exp l o re d the a g ri cu ltu ra lw o rkshop s fo r exp e rts,w h i ch i s a new m ode l fo r a g ri cu ltu ra l e xte ns i on ba sed on sci 2te ch re sou rces of un i ve rs ity .T he a g ri cu ltu ra lw o rkshop s l oca 2te d i n the m a j o r a rea s of m a i n a g ri 2p roduct p roducti on,a nd m a de va li d li nka ges be t w ee n the un i ve rs ity a nd fa r m 2e rs.T h i s p ap e r a na l yse s the fo r m i ng ba ckg round,the op e ra ti ng m echa n i sm a nd effe cts of a g ri cu ltu ra l exp e rtw o rk 2shop.K e y w o rds:a g ri cu ltu ra l un i ve rs ity ;exte ns i on m ode l ;a g ri cu ltu ra l e xp e rt w o rkshop 农业科技专家大院是西北农林科技大学与宝鸡市政府在农业发展新阶段,探索建立新型农业科技推广模式过程中的重要成果。
木质饰面胶合板的视觉物理量与视觉心理量的相关性分析
西北林学院学报2009,24(5):147~151Journal o f No rthw est F or est ry U niversit y木质饰面胶合板的视觉物理量与视觉心理量的相关性分析收稿日期:2008 11 06 修回日期:2009 03 22基金项目:安徽省教育厅教学研究项目(2008JYXM 367);安徽农业大学教学团队资助项目。
作者简介:武恒,男,讲师,硕士,主要从事木质品加工研究。
武 恒,徐 斌(安徽农业大学林学与园林学院,安徽合肥230036)摘 要:在对市场具代表性的51个不同材种饰面胶合板表面视觉物理量系统分析的基础上,抽取27个典型材种饰面胶合板,采用数字图像处理技术测量并分析得出表面材色参数,以7个视觉心理变量为基本依据,探讨木材视觉物理量与心理量之间的联系,建立木质饰面胶合板色彩情感模式,为创造更舒适、健康的生活环境以及提高生活质量提供科学依据。
关键词:饰面胶合板;视觉物理量;视觉心理量;色彩情感模式中图分类号:T S664.1 文献标识码:A 文章编号:1001 7461(2009)05 0147 05Analysis on t he Relat ion betw een Visual Physical M ag nitude and V isualPsychological M agnitude of Veneer Overlaid Plyw oodW U Heng,XU Bin(S chool of Fore stry &L an dscap e Ar chite cture ,Anhu i A g ricultur al Unive rsity ,H ef ei,A nhui 230036,China)Abstract:Based on sy stematic analysis o f v isual physical parameters o f 51different representative species veneer overlaid plyw ood at w o od products market,27typical species veneer overlaid plyw oo d w ere selected fo r m easuring and analyzing surface color parameters by dig ital imag e processing.Co rrelation betw een vis ual physical parameters and visual psycho logical mag nitudes w as discussed accor ding to 7different data sources o f visual psycholog ical magnitudes,and emo tional ex pression of colo r of veneer overlaid plyw ood w as induced.Key words:v eneer o verlaid ply w ood;visual physical parameter;visual psycholo gical mag nitudes;emotional ex pression o f co lor饰面胶合板视觉特性和调节特性的研究工作,使木材与木质材料在建筑和室内装饰过程中更充分地发挥其特有的优良环境学特性[1 3],饰面胶合板表面视觉物理量由所覆木材的材色参数、光泽度参数及纹理参数等与人类视觉相关并可定量测量表征的物理量组成,是木材表面性质中的重要特征,木材表面视觉物理量直接与木制品以及室内环境的质量评定密切相关,国外学者较早开始了木材材色定量测量的研究。
Method and apparatus for computer modeling of the
专利名称:Method and apparatus for computermodeling of the interaction between andamong cortical and subcortical areas in thehuman brain for the purpose of predictingthe effect of drugs in psychiatric andcognitive diseases发明人:Hugo Geerts,Athan Spiros申请号:US13412626申请日:20120306公开号:US08332158B2公开日:20121211专利内容由知识产权出版社提供专利附图:摘要:A computer model of a diseased human brain includes inputs representing a drug and outputs representing the clinical effect of that drug on psychiatric and cognitive diseases. Diseases that can be modeled include psychiatric disorders, such as schizophrenia, bipolar disorder, major depression, ADHD, autism, obsessive-compulsive disorder, substance abuse and cognitive deficits therein and neurological disorders such as Alzheimer's disease, Mild Cognitive impairment, Parkinson's disease, stroke, vascular dementia, Huntington's disease, epilepsy and Down syndrome. The computer model preferably uses the biological state of interactions between and among cortico and subcortical areas of the human brain, to define the biological processes related to the biological state of the generic synapse model, the striatum, Locus Coeruleus, Dorsal raphe, hippocampus, amygdala and cortex, as well as certain mathematical relationships related to interactions among biological variables associated with the biological processes and to correlations between the biological variables and clinical effects on a clinical scale.申请人:Hugo Geerts,Athan Spiros地址:Berwyn PA US,Portland OR US 国籍:US,US代理机构:Berliner & Associates更多信息请下载全文后查看。
丹红注射液联合依达拉奉治疗急性脑梗死的临床疗效
实用心脑肺血管病杂志2017年11月第25卷第11期投稿网址:http: //www. ■83 ■•中医•中西医结合•丹红注射液联合依达拉奉治疗急性脑梗死的临床疗效杨迎伟1张爱民1李亚梅1郭大志2【摘要】目的观察丹红注射液联合依达拉奉治疗急性脑梗死的临床疗效。
方法选取北京市顺义区医院2015—2016年收治的急性脑梗死患者84例,根据治疗方法分为对照组与观察组,每组42例。
在常规治疗基础上,对照组患者予以依达拉奉治疗,观察组患者予以依达拉奉联合丹红注射液治疗;两组患者均连续治疗14 d。
比较两组患者临床疗效,治疗前及治疗14 d美国国立卫生研究院卒中量表(NIHSS)评分、血脂指标、超敏C反应蛋白(hs-CRP)水平、纤维蛋白原(FIB)水平,观察两组患者治疗期间不良反应发生情况。
结果观察组患者临床疗效优于对照组(尸<0.05)。
治疗前两组患者NIHSS评分比较,差异无统计学意义(尸>0.05);治疗14 d观察组患者 NIHSS评分低于对照组(P<0.05)。
治疗前两组患者低密度脂蛋白(LDL)、高密度脂蛋白(HDL)、总胆固醇(TC)、hs-CRP、FIB水平比较,差异无统计学意义(尸>0.05);治疗14d观察组患者LDL、TC、hs-CRP、FIB水平低于对照组,HDL水平高于对照组(尸<0.05)。
两组患者治疗期间均未发生严重不良反应。
结论丹红注射液联合依达拉奉治疗急性脑梗死的临床疗效确切,可有效改善患者神经功能,调节血脂代谢,减轻炎性反应并降低FIB水平,且安全性较高。
【关键词】脑梗死;丹红注射液;依达拉奉;治疗结果【中图分类号】R743. 33 【文献标识码】B DOI:10.3969// issn. 1008 -5971. 2017. 11. 023杨迎伟,张爱民,李亚梅,等.丹红注射液联合依达拉奉治疗急性脑梗死的临床疗效[J].实用心脑肺血管病杂志,2017,25 (11) :83 - 85. []YANGY W,ZHANG A M,LI Y M,et al.Clinical effect of danhong injection combined with edaravone in patients with acute cerebral i nfarction[J].Practical Journal of Cardiac Cerebral Pneumal and Vascular Disease, 2017, 25(11) :83 -85.Clinical Effect of Danhong Injection C ombined witli Edaravone in Treating Patients witli Acute Cerebral InfarctionYANG Ying- wei ,ZHANG Ai- min1,LI Ya- mei ,GUO Da- zhi21.The Second Department of Neurology,Shunyi District Hospital of Beijing,Beijing101300, China2.Department of Hyperbaric Oxygenation,Navy General Hospital,Beijing 100048, China【Abstract】Objective To observe the clinical effect of danhong injection combined with edaravone in treating patientswith acute cerebral i nfarction.M ethods A total of84 patients with acute cerebral infarction were selected in Shunyi District Hospital of Beijing from2015 to2016, and they were divided into control group and obs methods,each of42 cases.Based on conventional treatment,patients of control group received edaravone,while patients of observation group received danhong injection combined with edaravone;both groups continuously treated for 14 days.Clinical effect,NIHSS score,blood lipids index,hs-CRP and FIB before treatment and after 14 days of treatment were compared between the two groups,and incidence of adverse reactions was observed during the treatment.Results Clinical effect of observation group was statistically significantly better than that of control group(P <0.05 ).No statistically significant differences of NIHSS score was found between the two groups before treatment(P> 0.05 ),while NIHSS score of observationgroup was statistically significantly lower than that of control group after treatment(P < 0.05 ).No statistically significant differences of LDL,HDL,TC,hs-CRP or FIB was found between the two groups before treatment(P> 0.05 ); aft treatment,LDL,TC,hs-CRP and FIB of observation group were statistically significantly lower than those of control group,while HDL of observation group was statistically significantly higher than that of control group(P < 0.05 ).No one of the twogroups occurred any serious a dverse reactions during the treatment.Conclusion Danhong injection combined with edaravone onhas certain clinical effect in treating patients with acute cerebral infarction,can effectively improve the neurological function,adjust the blood lipid metabolism,relieve the inflammatory reaction and reduce the FIE>,with relatively high safety.【K eyw ords】Brain infarction;Danhong injection;Edaravone;Treatment outcome1 101300北京市顺义区医院神经内二科2 100048北京市,海军总医院高压氧科• 84 •PJCCPVD November 2017, Vol, 25 No. 11 http://w w 急性脑梗死是由于脑供血动脉出现粥样硬化和血栓形成, 导致管腔狭窄甚至闭塞,造成脑供血不足、缺血、缺氧,进而 引发脑组织坏死,高血压、冠心病、糖尿病、高脂血症、吸 烟、饮酒、肥胖等是其主要影响因素。
磷酸氧化铜无机胶疲劳寿命的试验研究
收稿日期:2000-04-03 3云南省教委基金资助项目(N o.9612023)作者简介:赵希英(1956-),男,沈阳市人,工程师,研究方向是非金属胶粘剂研制与应用。
磷酸氧化铜无机胶疲劳寿命的试验研究3赵希英, 王时越(昆明理工大学粘接研究所,云南昆明 650051) 摘要: 本文对磷酸氧化铜无机胶进行了套接抗拉疲劳寿命的试验研究,测出了该胶的S -N 曲线及疲劳极限。
结果表明:磷酸氧化铜无机胶的抗拉疲劳特性与金属材料的特性较相似,该无机胶的抗拉疲劳极限为其静拉伸剪切强度的41125%。
本研究结果为将该无机胶更有效地应用于疲劳构件的粘接提供了理论依据。
关键词: 粘接强度;疲劳寿命;试验条件 中图分类号:T Q 43017+75 文献标识码:A 文章编号:1001-0017(2001)02-0058-02Experimental lnvestigation on F atigue Life of Copper oxide -Phosphate lnorganic AdhesiveZH AO X i -ying and W ANG Shi -yue(Bonding Technology Research lnstitute ,Kunming Polytechnic University ,Kunming 650051,China ) Abstract :Experimental investigation on fatigue life of the Y W -1copper oxide -phosphate inorganic adhesive with 45steel specimen was conducted.The S-N curve was obtained.Results showed that the fatigue behavior of the Y W -1adhesive beared a resemblance to that of the metal material and the fatigue limit value of the copper oxide -phosphate inorganic adhesive was equal to 41125%of the static strength value.The research result was very useful for applying the cop 2per oxide -phosphate inorganic adhesive to fatigue com ponents. K ey w ords :adhesive strength ;fatigue life ;testing condition引 言疲劳是机械零部件破坏的主要形式,约占机械零部件破断事故中的50%~90%[1]。
染色体文献
染色体文献(中英文版)英文文档:Chromosome LiteratureChromosomes are structures found in the nucleus of animal and plant cells that contain genetic information.They are composed of DNA and proteins and are responsible for carrying genes, which are the hereditary units that determine an organism"s traits.The study of chromosomes and their composition, organization, and behavior is known as cytogenetics.Over the years, numerous scientific studies have been conducted to explore the fascinating world of chromosomes.These studies have led to a better understanding of how genetic information is inherited, how chromosomes evolve, and how they can be affected by various factors such as radiation and chemicals.One of the most significant findings in the field of cytogenetics is the discovery of the structure of chromosomes.In 1953, James Watson and Francis Crick proposed the double-helix model of DNA, which revolutionized the way scientists thought about chromosomes and genetics.Their discovery laid the foundation for modern molecular biology and has been instrumental in unraveling the mysteries of life.Another important area of research in chromosome literature is thestudy of chromosomal abnormalities.Errors in the replication or division of chromosomes can lead to genetic disorders such as Down syndrome, cystic fibrosis, and many others.Understanding these abnormalities has crucial implications for the diagnosis, treatment, and prevention of genetic diseases.In recent years, advancements in technology have allowed scientists to study chromosomes at the atomic level.Techniques such as chromosome microscopy, fluorescence in situ hybridization (FISH), and polymerase chain reaction (PCR) have enabled researchers to explore the intricate details of chromosome structure and function.The field of chromosome literature is constantly evolving, with new discoveries and insights being published every day.Scientists around the world continue to delve into the complex world of chromosomes, seeking to unravel the remaining mysteries of genetics and improve our understanding of life itself.中文文档:染色体文献染色体是存在于动物和植物细胞核中的结构,负责携带遗传信息。
CPD4 光动力学治疗诱导人卵巢癌细胞凋亡的实验研究Ξ
・论著・CPD4光动力学治疗诱导人卵巢癌细胞凋亡的实验研究Ξ魏 薇,孔北华,张友忠,马道新,江 森(山东大学齐鲁医院,济南 250012) 【摘要】 目的:探讨叶绿素衍生物CPD4光动力学治疗杀伤体外培养卵巢癌细胞的作用机制。
方法:应用不同浓度CPD4、不同能量激光对人卵巢癌细胞株3AO进行光动力学治疗,在光镜和电镜下观察其形态变化;做DNA片段分析;并用流式细胞仪分析细胞DNA含量的改变和细胞凋亡率。
结果:CPD4光动力学治疗明显抑制体外培养人卵巢癌细胞株3AO的生长,细胞分裂阻滞于G0~G1期,并诱导细胞发生凋亡。
凋亡细胞表现为细胞固缩,染色质聚集或断裂;DNA凝胶电泳显示梯形条带。
结论:凋亡为叶绿素衍生物CPD4光动力学治疗杀伤体外培养细胞的主要作用机制。
【关键词】 光动力学治疗;卵巢肿瘤;体外研究;叶绿素衍生物中图分类号:R737.31 文献标识码:A 文章编号:1004-7379(2003)06-0410-03Experimental study on apoptosis induced by CPD4photodynamic therapy of hum an ovariancancer cells.Wei Wei,K ong Beihua,Zhang Youzhong,et al.Department o f Obstetrics and Gynecol2ogy,Qilu Hospital o f Shandong Univer sity,Jinan250012【Abstract】 Objective:T o investigate the mechanism of chlorophyll derivative CPD4photody2namic therapy of cultured ovarian cancer cells.Methods:The human ovarian cancer cells3AO weretreated by photodynamic therapy with different CPD4concentration and different laser energy.M or2phologic changes were examined by light and electron microscopes.DNA fragment were analyzed.Changes of nuclear DNA contents and percent of cell apoptosis were detected by flow cytometry.R e2sults:The growth of human ovarian cancer cells3AO was inhibited after CPD4photodynamic thera2py.Cell cycle arrested at G02G1phase and apoptosis was induced.The m orphology of3AO showednuclear chromatine condensation and fragmentation.T ypical ladder pattern of DNA fragmentation wasobserved.Conclusion:Apoptosis is the main mechanism of chlorophyll derivative CPD4photodynam2ic therapy to kill culture cells in vitro. 【K ey w ords】 Photodynamic therapy;Ovarian neoplasms;In vitro study;Chlorophyll deriva2tive 光动力学治疗(Ph otodynamic therapy,PDT)是利用光敏剂在恶性肿瘤组织内积聚,然后通过合适波长的激光照射产生光化学效应而导致组织损伤。
Analytical methods and the use of annexin V in the
摘要:Analytical method and analytical reagent of annexin V which can easily measure annexin V without requiring the addition of a drug for suppressing the binding of various proteins and calcium ions and adjustments of analyte solutions, etc. in the measurement stage An anti annexin V monoclonal antibody and antigenic antibody antigens against urinary anisinin V in contact with anti annexin V monoclonal antibody In order to form an annexin V antigen anti annexin V monoclonal antibody complex, it is possible to determine the concentration of annexin V in urine by quantifying the annexin V antigen anti annexin V monoclonal antibody complex By the analysis value of annexin V in the measured urine, diagnosis of organ damage such as disseminated intravascular coagulation syndrome and diagnosis of acute nephritis can be performed.
牛食道阻塞及病毒性腹泻防治
Veterinary clinical science | 兽医临床科学118 ·2020.230 引言在牛类养殖中食道阻塞通常是由于牛类食用的干草或饲料中有较大的固体导致阻塞时。
出现阻塞后,牛不会呈现出特别痛苦的症状,仅会呈现出吞咽困难。
一般情况下,牛养殖中的食道阻塞问题主要分为2种,分别是完全阻塞及不完全阻塞。
对于2种食道阻塞有不同的处理方式。
此外,还可观察牛食道阻塞的部位进行分类,分为咽部食道阻塞、颈部食道阻塞及胸部食道阻塞。
文中主要论述牛养殖中出现食道阻塞的原因,且介绍相应的治疗方法。
此外,在研究对牛病毒性腹泻的成因及治疗方法进行分析。
1 牛食道阻塞成因养殖中牛食道阻塞出现问题的原因通常较为复杂,如喂养中喂养方式不正确、负责草料出现问题等,都会导致牛类出现食道阻塞。
此外,在养殖中如果养殖人员没有给予牛类规律的饮食,会造成牛类过于饥渴,饮食过程会较为急躁,因此也易出现食道阻塞。
喂养中牛类吃下体积较大的食物,如土豆、地瓜、植物根茎等。
在喂养中,养殖人员如果养殖方法不正确,都会导致牛出现食道阻塞的情况。
对于有经验的养殖人员,如果牛类食用体积较大的食物,会造成食道完全阻塞。
而一些不应被牛类食用的物体,被牛类误食,会造成不完全阻塞[1]。
2 牛食道阻塞治疗方法2.1 胃导管推送法胃导管推送法比较适合牛食道轻微阻塞的情况,造成这种情况时,一般导致牛出现食道阻塞的物体体积较小。
同时经过观察发现该物体位于头颈部或胸部食道,针对于这种情况,在治疗中比较适合使用胃导管推送法,这种方法详细需要将牛的头部固定,使用胃部导管,从口部或者鼻腔推送进牛食道中。
如果推送中,感受到胃部导管的推动较为困难,此时情况为在导管已经开始接触阻塞位置,因此出现推动困难,禁止直接大力推动。
此时需要在导管的另一端灌入1%普鲁卡因溶液35~55 mL ,随后等待5 min 左右,再灌注200 mL 左右的石蜡油等待15~20 min 后,在缓缓推动胃部导管,此时缓慢推动,解除牛食道阻塞症状。
西方行政改革的理论溯源、逻辑及启示
陕西行政学院学报Journai of Shaanxi Academy of Governace 2021年5月第35卷第2期Mas ,, 2021Voi. 35 , No. 2文章编号:1673 - 9973 (2021) 02 - 0029 - 04公共行政0方行政改革的理论溯源、逻辑及启示杨国栋%大连海事大学公共管理与人文艺术学院,辽宁大连116026)摘要:西方行政改革理论源于行政的基;理论及其实践发展中所关注和探讨的一系列主题,包括组织理论、制度分析、管理主义和治理理论。
理论在应用的 中,形成 、 影响的逻辑线索,表现为“环境-理念”的配、“织-制度”的协同,以及“体制-管理”的调适。
改革的理论逻辑能够为实践 示,如探索国家治理视 化协同的 政府治理结构,构建多元协调的 制度形式,提升动合作的韧性治理能力等。
关键词: 改革; ;制度;治理中图分类号:D630文献标识码:A D0I :10.13411/ki.sxsx.2021.02.006The Theoretical Source , Logic and Revelations of Western Administrative ReformYANG Guo-dong% Dalian Maritimr University , School 时 Public Administration and Humaniths , Dalian 116026, China )Abstract : The administrative reform theory of Western countries originates from the basic theoiy of administration and a series of topics which are concerned and discussed in the development of its practice , including oraanizationai theora, institutional analysis, mana-geeiayism and goeeenanceiheoes.An ihepeoce s oeappyicaiion ! iheseiheoeieseoem iheeeinieedependeniand inieeaciionayyogicaycyues !which are the adaptation of “ environment-idea" , the coordination of “ oraanizations-institutions" and the adjustment of “ system -manage -ment". The theoreticai loeie of administrative reform provides enlightenment for reform practice , it is necessara te explore an optimizedand cooedinaied goeeenmenigoeeenancesieuciueeeeom ihepeespeciieeoenaiionaygoeeenance , buiyd adieeesieied and cooedinaied oegani-aaiionaysssiem , and enhanceiheeesiyienigoeeenancecapaciisoeinieeaciion and coopeeaiion.Key wo C s : administration reform ; organization ; institution ; governance 行政改革是一种政府治理关系调整、边界界定,及政策选择的 调试和动衡的活动,它通过对行政体制、机构、运行方 等方面的改革创新,"在 行政结构的更新、行政功能的调整,以此 动经济社会的 "*1+( 上世纪70年 ,于"英 "国家,随后扩大到西方大部分发达国家,出 大 的政府再造运动,推动 世界性的行政浪潮。
木本植物生长发育及繁殖过程中DNA甲基化模式重建
木本植物生长发育及繁殖过程中DNA甲基化模式重建中国摩亏c亟擅2010,26(24):35—41ChineseAgriculturalScienceBulletin木本植物生长发育及繁殖过程中DNA甲基化模式重建骆薇,曾凡锁,詹亚光(东北林业大学生命科学学院,哈尔滨150040)摘要:DNA甲基化是重要的表观遗传修饰之一,在基因表达调控,植物生长发育和进化中起重要的调节作用.笔者主要对木本植物生长发育及无性,有性繁殖过程的DNA甲基化模式重建的相关研究进展进行综述.结合当前研究进展讨论了与木本植物年龄,花期,休眠,育性等相关的不同生长发育阶段的DNA甲基化模式重建,以及愈伤组织继代,再生植株形成,体胚发生等无性繁殖过程中的DNA甲基化模式重建,最后讨论杂交过程中的DNA甲基化模式重建,并对当前研究进行展望. 关键词:DNA甲基化;表观遗传;微繁;木本植物中图分类号:O3文献标志码:A论文编号:2010.2371 InvolvementofDNAMethylationinTreeDevelopmentandMicropropagation LuoWei,ZengFansuo,ZhanY aguang(CollegeoilScience,NortheastForestryUniversity,Harbin150040)Abstract:DNAmethylationisthemostimpo~antwayofepigeneties,whichplaysanimporta ntroleingeneexpression,plantdevelopmentandmicropropagation.Thispaperintroducedtheprogressof DNAmethylationintreedevelopmentandmicropropagation,includingtheDNAmethylationpatternsreconstr uctionbetweendifferentdevelopmentstages,suchasage,flowering,dormancy,educationandsexofwoody plants,andthe DNAmethylationpatternsreconstructioninthecallussubculture,theformationofregenerat edplantsandst,therelationshipbetweenhybridizationandDNAmethylation wasreviewed,andthenprospectedthecurrentresearch.Keywords:DNAmethylation;epigeneticchanges;micropropagation;woodyplant0引言DNA甲基化作为最重要的表观遗传修饰方式,与植物生长发育,无性和有性繁殖过程密切联系.即DNA甲基化是植物季节性变化的重要标志,是植物感受外界的窗口.植物DNA甲基化具有其自身的特性,在不同的物种,植株,部位甚至不同时期都可能存在差异『1】.木本植物相对1年生草本植物,具有生长发育周期长,基因组庞大等特点,其表观遗传学的研究相对滞后.越来越多的研究也表明,在树木生长发育阶段的转变以及无性和有性的繁殖过程伴随着广泛的表观遗传变异.,因此对树木生长发育过程及繁殖过程中DNA甲基化水平和模式变化的研究十分必要.目前,对植物表观遗传的研究主要集中在水稻,高粱等草本植物,而对木本植物的研究相对较少,尤其是无性繁殖及有性繁殖过程.因此,笔者就此方面的研究进展进行综述.1木本植物不同发育阶段DNA甲基化模式重建树木胚后生长一般分3个阶段:幼年营养生长阶段,成年营养阶段和成年生殖生长阶段.每个发育阶段由独立调节而又相互交错的发育程序控制.特定发育阶段的保持是由后生细胞的状态和DNA甲基化等细胞内因调节,而发育阶段的转变取决于某些特定的基因是否转录表达.随着发育生物学研究的深入,人们发现植物发育过程中原始DNA序列并未改基金项目:国家自然科学基金(30872045);教育部博士点新教师基金(200802251038).第一作者简介:骆薇,女,1985年出生,黑龙江哈尔滨人,硕士,研究方向:植物生物技术.Tel:0451—82191752,E—mail:******************.通讯作者:詹亚光,女,1963年出生,黑龙江人,博士生导师,教授,博士.通信地址:150040黑龙江省哈尔滨市香坊区和兴路26号东北林业大学生命科学学院,Tel:0451—82191752,Email:*******************.收稿日期:201008—09,修回日期:2010—09—03.36'中国农学通报变,而是基因组DNA序列以外的因素调控特定基因的表达,这种能通过有丝分裂或减数分裂来传递非DNA序列遗传信息的现象称为表观遗传.其中,DNA甲基化作为重要的表观遗传修饰,在基因表达,细胞分化,系统发育及调节基闪组功能中起重要作用.DNA甲基化通过影响特定基因的时空性表达,在转录水平上调控植物个体发育的阶段转变.DNA甲基化,去甲基化及组蛋白修饰直接制约基因的活化状态.当基因处于表达水平时,甲基化状态一一般较低,而生长发育需要关闭时,就会发生重新甲基化,抑制转录并终止其表达.Ishfaq等研究表明,重复序列的甲基化可以导致不同发育阶段基因的表达,基因组DNA序列某些位点的甲基化修饰控制着幼苗F}1营养牛长向生殖牛长的转变.1.1DNA甲基化与木本植物的年龄关系大量研究表明,植物不同发育阶段的植物激素,多胺含量,特异蛋白质和DNA甲基化水平都有筹异'.".近年来,针对不同植物不同发育阶段基闪组DNA甲基化水平和模式变化的研究较多.一般来说,无论是被子植物还是裸子植物,随着年龄增加,DNA甲基化水平呈上升趋势,小本植物也是如此.幼年植株通过改变特定基因的甲基化状态,调控基因表达而逐渐成熟,幼年植株全能性更高,更易在试管内无性繁殖并生根,因此成年植株需要通过去甲基化处理复壮才更利于离体再生,如图1.Fraga等对辐射松(PinIISradiateD.Don.)不同发育阶段甲基化程度进行研究发现,幼年的DNA甲基化水平为30%~50%,而成年是60%.Fraga等又重复嫁接成年组织使其复壮,发现DNA总甲基化水平降低,经过4次连续嫁接后,胞嘧啶甲基化含量下降35%.Baurens等对桃树的研究发现,幼年叶片的DNA甲基化水平(22.4%)高于成熟叶片.』二述试验均表咧,DNA甲基化水平可能与幼年的形态建成相关,随着年龄增加,DNA甲基化水平呈上升趋势.4,JCLONAL^ULI"t.JCAWOC矗PACyCOMPLEXARc辑rT瑟8琶0R0o啊枣|G0,:MORPHOGE嘲eA尉L盯V0VITROESTABLISHMENTREPROOUC~VE嘲吁H幼年植株通过特定基因的甲基化逐渐成熟,幼年柏株全能性较高,更易在试管内无性繁殖并生根,而成熟植株=.f'=易无性繁殖.因此可以通过去甲基化处理使成年植株复壮.图1DNA甲基化与木本生长发育的关系1.2DNA甲基化与木本植物的花期,休眠和育性DNA甲基化水平和模式与木本植物的花期,休眠,育性等密切相l关.研究表明,甲基化程度的降低和春化作用可以促进植物提早开花,且两者具有加成作用】.Bum等"通过试验证明,加入去甲基化试剂5.氮胞苷(5azaC)可以使沉默的rRNA基因恢复功能,促使植物提早开花,说明DNA甲基化抑制了rRNA基因的表达,正是诱导开花的相关基因或其启动子的甲基化状态改变,促使植物提早开花.Hasbun等发现,栗树幼根的DNA甲基化水平最低为13.7%,而成骆薇等:木本植物生长发育及繁殖过程中DNA甲基化模式重建?37? 熟根是15%,休眠状态的根甲基化水平最高(23%).Luis等也报道了休眠的芽中包含甲基化的组织最多,说明休眠也可以促使DNA甲基化程度的升高或降低.Manning等对番茄进行研究发现,控制果实发育基因的Crtr位点(Colorlessnon—ripening)发生DNA超甲基化会抑制果实成熟,产生一系列表观变异,如果实无色,果皮缺乏.Teyssier等也发现在番茄果实成熟过程中,成熟叶片的甲基化水平为22.3%.而从果实的裂开期到成熟红色过程中,果皮中C含量从29.9%降iLgWU20.1%,又对CG位点和CNG位点的甲基化水平进行研究发现CG位点和CNG位点甲基化水平有所增加,进而又研究番茄甲基转移酶相关基因的表达变化,发现SLMETI在所有植物器官和果实中都表达,在幼嫩器官中优先表达.CMT基因存在差异表达,在番茄茎,花和幼叶中优先表达.SLCMT3的mRNA在所有植物组织都检测到,但水平较低.SLCMT2和SLCM在小室组织和果皮组织主要表达.因此,DMT基因在不同果实组织中表达复杂,但甲基转移酶CMT和DRM基因家族在果皮中优先表达,说明DNA甲基化水平影响果实的发育和成熟.2木本植物离体繁殖过程中的DNA甲基化模式重建植物组织培养技术是通过植物的细胞,原生质体,胚,组织或器官等作为外植体,在人工控制的条件下进行培养,获得再生的完整植株的技术.植物的快繁主要包括:诱导具有器官发生潜力的愈伤组织和胚性愈伤组织,然后再分化形成再生植株,如图2所示-zo.一一图一_竹鲈州斡(greenhou~;e;p牲姆(G掰vilro-grown(proiferatng{shoots(嘲undiffecentiatedc~IIuse)豫gen0墒蹦0f『.morganogenicc~liusorganO~eniccailu瀚0e{=.e,温室植物(greenhousep1am)作为母本,转入试管内无性繁殖植株(pmliferatingshoots),经脱分化形成愈伤组织(undi髓remiatiatedcallus),通过诱导具有器官发生潜力的愈伤组织(o曜anogenicca11us)和胚性愈伤组织(embryogeniccallus),然后再分化形成再生植株,达到快速获得再生植株的目的.图2玫瑰再生植株形成过程理论上由供体植株诱导出的再生植株应与供体完全相同.但大量研究表明,植物组织培养过程中伴随广泛的表观遗传变异,如甘蔗",黑麦口,大麦,玉l马铃薯,番茄,甜菜,豌豆,菊花[21等.植物的老化可能是由胞嘧啶和组织形态学状态的改变引起删,而组织培养可以减缓很多物种的年龄老化并影响其发育,离体培养对于细胞来说算是一种非生物胁迫,而植物在应对环境胁迫时多数会发生基因型和表现型的改变.这种改变是通过对某些特定的DNA,组蛋白进行修饰或染色质重塑来调控植物的生长发育.其中,DNA甲基化水平和模式的改变起很重要的作用.2.1组织培养植株与野生植株的DNA甲基化水平和模式差异木本植物组织培养过程中也伴随着DNA甲基化模式的重建.一般情况,木本植物再生植株的DNA甲基化水平低于正常生长的植株.如Kubis等对油椰子(Elaeisguineensis)的研究发现,组织培养的植株其_黑圈f■38?中国农学通报.CD甲基化水平低_J:种子生长的植株,而转座DNA元件的序列组成上有很小的差异.说明特异表型不是由转座元件的重排造成,而与基因组甲基化类型的改变有关.Miroslav对葡萄树的研究发现,试管内培养的植株在CCGG位点的甲基化水平(8.75%)低于温室培养的植株(9.86%).然而也有研究得出相反结论,如李丽琴等对红豆杉植株及其愈伤组织甲基化水平研究发现,红杉植株嫩苹和愈伤组织DNA总体甲基化水分别为12.4%和16.2%,其中伞甲基化水平分别为9.3%和l1.9%,说明红豆杉脱分化后无论是总r『1基化水平还是仝甲基化牢都着升高.Monteuuis等对巨杉的研究也发现【{1成熟杉木诱导的再生植株DNA 甲基化水平(23%)高于野生植株(13.4%).Li等研究发现,苹果组织培养和野生型2种的nr片DNA甲基化水半相似,但组织培养中的根有特异性DNA甲基化条带.这些研究都证明组织培养过程确实发牛DNA甲基化水平或模式的改变.2.2再生过程,体胚发生,继代培养以及外植体状态与甲基化模式重建仅组织培养的植株与野生植株相比发生了DNA甲基化重建,无性繁殖过程中愈伤组织的继代,冉牛植株形成,外植体状态以及体胚发生对DNA甲基化水平和模式都有影响M.大量研究结果表明,愈伤组织或再生植株的DNA甲基化总体水平多数呈降低趋势.例如玉米,油棕,水稻和玫瑰[201等.孟海军等叫对柑橘胚胎发生过程中DNA甲基化进行研究也发现,DNA甲基化水平在新鲜愈伤中最低,继代和再生过程都会上升.也有研究得出相反的结论,Smykal等对豌进行研究发现,长期组织培养的豌豆植株DNA甲基化水j(11.2%)高于野生植株(4.8%),说明组织培养过程可能导致DNA甲基化程度增加的变异.番茄的愈伤组织长期组织培养也发现DNA甲基化程度有升高趋势.这些都说明植物无性繁殖过程中发生DNA甲基化重建.笔者通过对转基因白桦(Betulaplatyphylla)研究发现,转入外源基因并且表达的无性系植株随继代次数的增加出现转基沉默的现象,并通过添加去甲基化试剂5-azac恢复表达,证实继代次数增多导致DNA 甲基化状态的改变,造成转基因的沉默.目前,对转基白桦无性系再生过程的研究得出的初步结论,也说明愈伤组织的继代及再生植株形成的过程中确实伴随着DNA甲基化水平和模式的改变.同时发现,再生过程中DNA甲基化水平与很多生理指标旱正相关. Causevic等也得出类似结果,通过对甜菜无性系进行研究发现,再生过程中的DNA甲基化水平和模式发生改变并且和活性氧,反应底物,谷胱甘肽,抗坏血酸,脱氢抗坏血酸等16个生理指标呈正相关.体胚发生过程巾也伴随DNA甲基化水平的改变.Klimaszewska对松树体胚发生的研究发现,不同年龄的体胚DNA甲基化水平在17.8%~19.%1之间, 无明显差异.然而,老化体胚伴有5'-CCGG一3'位点序列的DNA甲基化.不仅是最高频的CC,还有CC和CC内部的DNA甲基化,说明体胚发生过程中甲基化的类型发生改变.Hao和Deng[4对具有体细胞发生能力和失去体细胞发生能力的两种脐橙的愈伤组织进行研究,发现具有体细胞胚发生能力的愈伤组织的甲基化水平较失去体细胞胚发生能力的要低.除了再生过程中及体胚发生过程中存在甲基化模式的熏建,不同的外植体也影响DNA甲基化模式.如Baurens等分析了金合欢树(AcaciamangiumWilld.)幼嫩和成熟外植体离体繁殖基因组DNA甲基化的关系,发现幼嫩叶为外植体诱导的徽芽DNA甲基化程度(22.4%)高于成熟叶状柄形态型(20.7%),说明不同外植体诱导的冉牛植株DNA甲基化水平不同.3杂交与DNA甲基化模式重建种内或种问杂交是生物界最广泛的繁殖方式,对促进基因组进化和新种形成有重要意义.因此,对杂交诱导的DNA甲基化变异进行研究,可为植物遗传改良和杂种优势的形成机制提供新思路.同时种内或种问杂交也是一种诱发变异的主要因素,能够引起杂交代发生广泛的表观遗传变异,如DNA甲基化,组蛋白乙酰化等,从而获得新的可遗传性状H.研究表明,动物和植物有着截然不同的甲基化遗传传递模式.动物胞嘧啶甲基化在每一代都要经历消除和重建,而植物亲本的甲基化状态通常可以稳定遗传并影响后续的几个世代",并且在杂种优势形成过程中起重要作用.然而目前对于木本植物的相关报道较少,研究主要集中在水稻,高粱等农作物.洪舟等对杉木研究发现,杂交自带的甲基化百分率相对于亲本的自交系呈降低趋势;同一组合正反交组合后代之间在CCGG位点胞嘧啶的甲基化水平上无明显差异;6个杂交组合在CCGG的位点上的甲基化位点数明显低丁它们的亲本自交子代.杉木基因组外侧胞嘧啶半甲基化程度越低,内侧胞嘧啶甲基化位点越少,3个生长性状的杂种优势愈明显.仪治本等也得出类似的结果,采用MSAP方法检测了高粱亲本及杂种子代5-CCGG位点的胞嘧啶甲基化水平,发现亲本杂交形成的杂交种全甲基化和半甲基化比率均低于双亲,说骆薇等:木本植物生长发育及繁殖过程中DNA甲基化模式重建?39? 明形成杂交种过程中,DNA的某些位点可能发生去甲基化.Zhang等[54也发现,高粱亲本自交系的大部分胞嘧啶甲基化位点能够稳定遗传给其F1杂交种,然而有1.69%~3.22%的位点发生变异,不能从亲本遗传给杂交种,又对与胚乳特异性相关的6个基因进行反转录和MSAP分析,发现胚乳比叶片的表达水平高,说明导致杂交种的甲基化水平低于其亲本(尤其在叶片中差异显着),证明DNA甲基化模式的改变和杂种优势相关.Xiong等与以上的结果有所不同,对水稻进行研究发现,亲本的DNA甲基化水平(16.3%)低于杂交种(18%).虽然DNA甲基化总体水平与杂种优势无明显相关,但某些特异位点上的甲基化增强或减弱对杂种优势有显着效应,不同位点的甲基化增强或降低都有可能对杂种优势有利.说明杂种优势不仅与某些基因的表达增强有关,可能与某些基因受到抑制有关.这些都说明杂交过程中确实伴随着表观遗传变异.4结论通过对木本植物生长发育及繁殖过程中DNA甲基化模式变化相关研究的综合分析,笔者发现木本植物不同发育阶段,无性及有性繁殖过程中确实伴随着广泛表观遗传变异,表现在以下几点:(1)一般来说,无论是被子植物还是裸子植物,随着年龄增加,DNA甲基化水平呈上升趋势.因此,可通过改变甲基化状态使植物复壮;(2)根据不同物种的甲基化水平的变化趋势,可通过降低DNA甲基化程度,促使植物提早开花或打破休眠;(3)组织培养技术可快速高效的繁殖木本植物,然而其对木本植物DNA甲基化状态的影响并不相同.一般情况,再生过程中,愈伤组织或再生植株的DNA甲基化水平与野生植株相比多数呈降低趋势. 然而随即带次数的增加,DNA甲基化水平提高;(4)有性繁殖过程中存在DNA甲基化模式重建的现象,其表观模式重建与杂种优势的形成密切相关.5问题与展望木本植物基因组大,生长周期长,表观遗传的研究相对落后.MSAP和高效液相色谱等技术的应用为表观遗传变异的研究提供了新思路,但是也存在一些问题,MSAP使用的同裂酶只能识别CCGG位点的胞嘧啶甲基化,而不能识别CAG和CTG等位点的胞嘧啶的甲基化,获得的结果对于基因组中实际的甲基化水平可能估计不准.因此,在植物高度可塑性结合表型变化和定量的表观遗传参数上可能很少的数据是有效的,而且对于DNA甲基化多数研究只能定性分析,缺少定量的数据,并且对组蛋白乙酰化,染色质重塑,基因组印迹,siRNA等的研究比较有限.今后的工作应进一步着眼于这些方面,随着表观遗传学及功能基因组的不断深入,木本植物表观遗传的分子机制会更加明确.参考文献[1】南楠,曾凡锁,詹亚光.植物DNA甲基化及其研究策略[J].植物学通报,2008.25(1):102—111.[2]MonteuuisO.Maturationconceptandpossiblerejuvenationof arborescentspecies.Limitsandpromisesofshootapicalmeristems toensuresuccessfulcloning.In:Breedingtropicaltrees:population structureandgeneticimprovementstrategiesinclonalandseedling forestry.ProcConferenceIUFRO,1989,106—118.[3】FragaMF,CanalMJ,RodriguezR.Phase?changerelatedepigenetic andphysiologicalchangesinPinusradiataD.Don[J].Planta,2002,215(4):672—678.[4]ClemensJ,HenriodRE,BaileyDG,eta1.V egetativephasechange inmetrosideros:shootandrootrestrictiopn[J].PlantGroRegul,1999,28:207—214.[5]AderkasPV,BongaJM.Influencingmicropropagationandsomatic embryogenesisinmaturetreesbymanipulationofphasechange, stressandcultureenvironment[J].TreePhysiol,2000,20(14):921-928.[6】郭长花,康向阳.树木发育中的阶段转变研究进展【JJ.生物技术通讯,2008,19(5):784—786.【7]WasseneggerM.RNA—directedDNAmethylation[J].PlantMolBiol, 2004,43(2-3):203?220.[8】IshfaqAH,LiAL,ZhangSL.DNA—Methylationvariationatsome loxiintransitionfromjuveniletomaturephaseofcrabapple[J]-JAgricRes,2000,38(1):43—52.[9]FordYTaylorJM,BlakePS,eta1.Stimulatesadventitious rootingofcuttingsfromcherry(n~ium)[J】.PlantGrowthRegul,2002,37:127—133.【10】An&esH,FemandezB,RodriguezR,eta1.Phytohormonecontents inCorylusavellanaandtheirrelationshiptoageandother develomengtalprocesses[J].PlantCellTissOrganCult,2002,70:l73—180.[11】TanimotoE.Regulationofrootgrowthbyplanthormones—rolesfor auxinandgibberllin[J].CritRevPlantSci,2005,24(4):249?265.[12】Luis,'RodrigoH,MonieaM,eta1.InvolvementofDNA methylationintreedevelopmentandmicropropagation[J].PlantCell TissOrganCult,2007,91(2):75?86.【13]FragaMF,RodriguezCanalMJ./nl,qtromorphogenicpotential ofdifferentlyagedPinusradiatetreescorrelateswithpolyamines andDNAmethylationlevels[J].PlantCellTissOrgCult,2002,70(2): 139—145.【14]BaurcnsFC,NicolleauJ,Legavreeta1.GenomicDNA methylationofjuvenileandmatureAcaciamangiummicropropagated面vitrowithreferencetoleafmorphologyasa40?中国农学通报phasechangemarker[J].TreePhysiol,2004,24(4):401-407【l5]侯雷l',梅兰.DNAIIj基化与植物的生长发[JJl植物i学通,2001,37(6):584.588[16]BumJE,BagnallDJ,MetzgerJD,etalDNAmethylation, vernalization,andtheinitiationofflowering[J].ProcNatlAcadSciUSA,1993,90(1):287—291.[17]HasbunR,V alledorL,BerdascoM,etal/nvitroproliferationand GenomeDNAmethylationinadultchestuts[J].ActHort,2005,693: 333—339[18]ManningK,TotM,PooleM,eta1.Anaturallyoccurringepigenetic mutationinageneencodinganSBP—boxtranscriptionfactor inhibitstomatofruitripening[J].NatuGenet,2006,38(8):948—952. 【19]TeyssierE,BernacchiaG,MauryS,eta1.Tissuedependent variationsofDNAmethylationandendoreduplicationlevelsduring tomatofruitdevelopmentandripening[J].Planta,2008,228(3): 391—399.[20】XuMI,LjXQ,KorbanSS.DNA—methylationalterationsand exchangesduring抽vitrocellulardifferentiationinrosefRosa hybridaL)[JIlTheorApplGenet,2004,109(5):899-910[21]HeinzDJ,MeeGWP.Plantdiferentiationfromcallustissueof Saccharumspecies[J].CropSci1969,9:346—348.[22]AhloowaliaBS,SheringtonJ.Transmissionofsomadonalvariation inwheat[J].Euphitca,1989,34(2):525—537.[23]DevauxKilianA,KleinhofsA.Anthercultureandhordeum bulbosum—derivedbarleydoublehaploids:mutationsandmethylation[J].Mole&GenerGenet:MGG,1993,24l(5-6):674—679. 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基于风洞模拟试验的典型机械防沙工程防护效益对比
第37卷第6期2023年12月水土保持学报J o u r n a l o f S o i l a n d W a t e rC o n s e r v a t i o nV o l .37N o .6D e c .,2023收稿日期:2023-03-31资助项目:国家重点研发项目(2020Y F A 0608403-1);国家自然科学基金项目(42171083);甘肃省自然科学基金项目(22J R 5R A 066) 第一作者:潘加朋(1999 ),男,硕士研究生,主要从事风沙灾害与防沙工程研究㊂E -m a i l :p a n j i a p e n g @n i e e r .a c .c n 通信作者:张克存(1978 ),男,博士,研究员,主要从事风沙灾害与风沙工程研究㊂E -m a i l :k e c u n z h @l z b .a c .c n基于风洞模拟试验的典型机械防沙工程防护效益对比潘加朋1,2,3,张克存1,安志山1,2,张宏雪1,2,3,薛承杰1,2,3(1.中国科学院西北生态环境资源研究院敦煌戈壁荒漠生态与环境研究站,甘肃敦煌736200;2.中国科学院西北生态环境资源研究院沙漠与沙漠化重点试验室,兰州730000;3.中国科学院大学,北京100049)摘要:为探究3种典型机械防沙工程措施实施后所体现的防护效益,通过风洞模拟试验,以敦煌黑山嘴地区的典型机械防沙工程为参考,对草方格与尼龙网格状沙障及阻沙栅栏的防风㊁固阻沙效益进行系统的对比分析㊂结果表明:草方格与尼龙网格状沙障的布设均能有效降低风速,当指示风速为20m /s 时,1.5c m 高度的风速降低率分别达到82.5%与80.9%,同时极大地增加流沙地表粗糙度,显著影响当地的风速变化;此外,两者在不同高度对风速削弱能力差异明显;草方格与尼龙网格状沙障也深刻影响当地风沙流结构,其中草方格沙障的固沙能力主要体现在近地表;阻沙栅栏前后平均输沙率降低44.2%,同时对当地流场结构影响深刻㊂综合分析可知,草方格与尼龙网格状沙障防风㊁固沙效益良好,阻沙栅栏阻沙效益显著㊂研究结果可为当地机械防沙工程建设提供指导,同时对其他地区防沙工程布设予以借鉴㊂关键词:风洞试验;风沙治理;防护效益;敦煌中图分类号:X 171 文献标识码:A 文章编号:1009-2242(2023)06-0104-07D O I :10.13870/j.c n k i .s t b c x b .2023.06.014C o m p a r a t i v eA n a l y s i s o fP r o t e c t i v eB e n e f i t s o fT y pi c a lM e c h a n i c a l S a n d C o n t r o l P r o j e c t sB a s e do n W i n dT u n n e l S i m u l a t i o nE x pe r i m e n t P A NJ i a p e n g 1,2,3,Z H A N G K e c u n 1,A NZ h i s h a n 1,2,Z HA N G H o n g x u e 1,2,3,X U EC h e n g ji e 1,2,3(1.D u n h u a n g G o b i a n dD e s e r tE c o l o gi c a l a n dE n v i r o n m e n t a lR e s e a r c hS t a t i o n ,N o r t h w e s t I n s t i t u t e o f E c o -E n v i r o n m e n t a n dR e s o u r c e s ,C h i n e s eA c a d e m y o f S c i e n c e s ,D u n h u a n g ,G a n s u 736200;2.K e y L a b o r a t o r y o f D e s e r t a n dD e s e r t i f i c a t i o n ,N o r t h w e s t I n s t i t u t e o f Ec o -E n v i r o n m e n t a n dR e s o u r c e s ,C h i n e s eA c ade m y of S c i e n c e s ,L a n z h o u 730000;3.U n i v e r s i t y o f C h i n e s eA c a d e m y o f S c i e n c e s ,B e i j i ng 100049)A b s t r a c t :I no r d e rt oe x p l o r et h e p r o t e c t i o nb e n e f i t so f t h r e et y p i c a lm e c h a n i c a l s a n dc o n t r o le n g i n e e r i n gm e a s u r e s a f t e r i m p l e m e n t a t i o n ,t h r o u g hw i n d t u n n e l s i m u l a t i o ne x p e r i m e n t s ,t a k i n g t h e t y pi c a lm e c h a n i c a l s a n d c o n t r o l e n g i n e e r i n g i nH e i s h a n z u i a r e ao fD u n h u a n g a s a r e f e r e n c e ,t h ew i n da n ds o l i ds a n dr e s i s t a n c e b e n e f i t s o f g r a s s g r i d a n dn y l o n g r i d s a n db a r r i e r a n ds a n d -b l o c k i n g f e n c ew e r e s y s t e m a t i c a l l y c o m pa r e da n d a n a l y z e d .T h e r e s u l t s s h o wt h a tb o t h g r a s s g r i da n dn y l o n g r i ds a n db a r r i e rc a ne f f e c t i v e l y r ed u ce t h ew i n d s p e e d ,w h e n t h e i n d i c a t ew i n d s p e e d i s 20m /s ,t h ew i n d r e d u c t i o nr a t e s a t 1.5c m h e i gh t r e a c h82.5%a n d 80.9%,m e a n w h i l e ,t h e s u r f a c e r o u g h n e s so f q u i c k s a n d i s g r e a t l y i n c r e a s e d ,w h i c hs i g n i f i c a n t l y a f f e c t s t h e l o c a lw i n ds p e e d .I na d d i t i o n ,t h e s e t w os a n db a r r i e r sh a v eo b v i o u sd i f f e r e n c e s i nt h ea b i l i t y t ow a k e nt h e w i n d s p e e d i nd i f f e r e n t h e i g h t s .T h e g r a s s g r i d a n dn y l o n g r i d s a n db a r r i e r a l s oh a v e s i g n i f i c a n t i n f l u e n c eo n t h e l o c a l w i n d -s a n d f l o ws t r u c t u r e ,t h e s a n d -f i x i n g a b i l i t y o f g r a s s g r i d s a n d b a r r i e r s i sm a i n l y r e f l e c t e d i n t h e n e a r s u r f a c e .T h e a v e r a g e s e d i m e n t t r a n s p o r t r a t e b e f o r e a n d a f t e r t h e s a n d b a r r i e r i s r e d u c e d b y 44.2%,a n d i t h a s a p r o f o u n d i m p a c t o n t h e l o c a l f l o wf i e l ds t r u c t u r e .C o m p r e h e n s i v e a n a l y s i s s h o w s t h a t t h e g r a s s g r i d a n dn y l o n g r i ds a n db a r r i e rh a v e g o o dw i n d p r o o f a n ds a n d -f i x i n g b e n e f i t s ,a n dt h es a n d -b l o c k i n g f e n c eh a s s i g n i f i c a n t s a n d -b l o c k i n g be n ef i t s .T h er e s e a r c hr e s u l t sc a n p r o v i d eg u i d a n c ef o rth ec o n s t r u c ti o no f l o c a l m e c h a n i c a l s a n d c o n t r o l p r oj e c t s ,a n d p r o v i d e r e f e r e n c e f o r t h e l a y o u t o f s a n d c o n t r o l p r o je c t s i no t h e r a r e a s .K e yw o r d s :w i n d t u n n e l t e s t ;s a n d y e r o s i o n c o n t r o l ;p r o t e c t i n g e f f i c i e n c y ;D u n h u a n g风沙活动主要指风沙地貌发育中的侵蚀㊁搬运和堆积过程,在此过程中造成的人畜伤亡㊁沙埋农田及牧场㊁大气环境恶化等直接导致区域风沙灾害[1]㊂风沙灾害一直以来都是影响我国生态文明建设及社会经济发展的重要因素,近年来,随着全球气候变化与人类活动影响,我国风沙灾害风险显著提升,风沙治理工程也面临着严峻考验[2-4]㊂风沙治理工程中的机械防沙工程,由于其防护效益较好㊁施工速度快且价格低廉,已在实际工程中得到广泛普及[5-7]㊂现有研究已在机械防沙工程的防护特征㊁效益评价等方面有较为深入的了解,席成等[8]对乌兰布和沙漠穿沙公路所布设的高立式尼龙网格状沙障防护特征研究发现,在不同风能环境下其有效防护距离差异显著;石涛等[9]对库布齐沙漠光伏电站内芦苇沙障研究发现,其有效降低近地表风速,对风沙流拦截作用明显;董智等[10]通过风洞模拟试验研究发现,不同规格的土工格栅沙障积沙效应随孔隙度增大而减小;张帅等[11]利用风洞试验对硬质地H D P E沙障防风效益研究表明,其防风效果与高度呈正相关,而孔隙度则与之相反㊂上述研究中,对机械沙障防护效益评价主要通过野外观测与风洞试验来实现,但目前野外观测局限性较大,易受环境影响[8-9,12],而传统的风洞试验设计仅考虑机械沙障自身性质,未以具体工程为参考[10-11],模拟结果缺少针对性㊂故以敦煌黑山嘴地区典型机械防沙工程为参考设计风洞试验,从而对3种典型机械防沙工程防护效益进行系统的对比分析㊂黑山嘴位于敦煌绿洲的西南角,南接鸣沙山,北邻党河,为典型的沙漠 绿洲过渡带,也是敦煌绿洲南缘重要的风沙口[13]㊂其地表类型以流沙为主,盾状沙丘和沙饼零星分布其间,区域南侧沙漠腹地金字塔沙丘广布,为风沙灾害的发育提供丰富沙源㊂由于黑山嘴境内大风天气频繁且风沙活动强烈,当地生态环境遭到严重破坏㊂为遏制当地风沙灾害发展,黑山嘴进行大规模风沙治理,主要措施包括草方格与尼龙网格状沙障㊁阻沙栅栏及人工种植植被,植被以梭梭(H a l o x y l o na mm o d e n d r o n)㊁骆驼刺(A l h a g i s p a r-s i f o l i a)为主㊂具体布设方式为在区域南侧流动沙丘设置草方格与尼龙网格状沙障,中部平坦流沙地以人工种植梭梭为主,区域北侧设置6道60c m高度阻沙栅栏,中间阻沙带宽为18m,同时在阻沙带内撒播骆驼刺种子㊂经过多年治理后,黑山嘴的生态环境得到一定恢复,各类机械沙障防护效益显著㊂基于此,依据黑山嘴自然条件及机械防沙工程,通过风洞模拟试验对3种典型机械防沙工程措施(即草方格㊁尼龙网格状沙障与阻沙栅栏)的防风㊁固阻沙效益进行对比分析,以期为当地机械防沙工程建设提供指导,同时为其他地区防沙工程的布设予以借鉴㊂1材料与方法试验在中国科学院西北生态环境资源研究院沙漠与沙漠化重点实验室的野外环境风洞进行,该风洞试验段长21m,横断面为1.2mˑ1.2m(图1)㊂试验模型参考敦煌黑山嘴地区野外机械防沙工程,根据研究区环境条件,当地主要通过布设草方格㊁尼龙网格状沙障及阻沙栅栏以实现风沙灾害防治㊂为确保沙障模型在风洞中能再现黑山嘴地区大气边界层与风沙流的运动特征,试验需满足几何相似与动力相似,其中,几何相似指模型与原型间保持一定缩尺比,动力相似指两者对应点上表征力的物理参数相同[14]㊂试验中沙障模型采用原型材料,将1.0mˑ1.0m草方格㊁尼龙网格状沙障以1ʒ1的缩尺比在流沙地表依次设置7个网格,间距为1.0m;孔隙度为40%,高度为0.6m阻沙栅栏则按1ʒ5的缩尺比进行布设㊂同时,根据各沙障间差异对草方格及尼龙网格状沙障分别选取8,12,16,20m/s的4组指示风速,对阻沙栅栏选取8,10,12,14,16,18,20m/s的7组指示风速进行分析,最大程度满足试验相似条件,确保试验结果能准确反映黑山嘴实际工况的防风及固阻沙效益㊂为保证试验所采集数据准确可靠,依据试验当时气象条件,使用数字式微压差计系统对进出口风速进行调节,并通过 X 型防沙毕托管对风速进行观测,其中,风速观测点则依次设置在距试验床面1.0,1.5, 3.0,6.0,12.0,20.0,35.0,50.0c m的8个高度且采样间隔时间为2s,测量时,将其与压力传感器相连,利用数据采集仪直接储存到微机上;输沙量则采用集沙仪进行量测,布设在洞体中央距一侧60c m处,同时,对草方格沙障㊁尼龙网格状沙障与阻沙栅栏的输沙量采用不同规格的集沙仪进行量测,2种集沙仪入口断面分别为1.0c mˑ0.5c m和2.0c mˑ2.0c m㊂试验使用外来风沙进行供给,为保证试验结果能准确模拟各工程在敦煌黑山嘴当地的防护效益,试验沙样选取当地所采集的天然沙样,并在每次更换试验材料时,保证各仪器位置不变;不同沙障在各风速下试验结束后,重新对沙面进行布置,确保沙源充足㊂对草方格㊁尼龙网格状沙障2种措施防风效益的评价通过风速廓线及其参数㊁防风效能来反映,而草方格㊁尼龙网格状沙障与阻沙栅栏3种措施的固阻沙效益则通过其输沙量㊁输沙率在不同高度分布情况来判断㊂其中,防风效能指在相同条件下对环境及其在工程措施作用下进行风洞模拟试验后所测得的风速,通过环境风速与工程措施下风速的差值与环境风速的比值进行计算,具体公式为:501第6期潘加朋等:基于风洞模拟试验的典型机械防沙工程防护效益对比K =U 环境-U 工程U 环境ˑ100%(1)式中:K 为防风效能(%);U 环境㊁U 工程为同一高度流沙地表与工程措施下风洞试验所测得的平均风速(m /s)㊂图1 风洞试验布设示意2 结果与分析2.1 2种措施的防风效益2.1.1 草方格沙障 风速廓线变化趋势与沙障防风效益高度相关,对各指示风速下流沙地表及其在草方格沙障作用下各高度风速测量值进行拟合,拟合系数均>0.8,表明两者风速沿高度变化均符合对数分布规律(图2)㊂不同指示风速下同一高度层草方格沙障作用下的风速明显小于流沙地表,当指示风速为8m /s 时,1.5c m 高度流沙地表风速为4.155m /s ,而在草方格沙障作用下其风速仅为0.631m /s ,降低84.8%;当指示风速为20m /s 时,1.5c m 高度风速降低率达82.5%,其布设有效降低流沙地表风速㊂进一步对风速廓线方程分析(表1)可知,流沙地表在草方格沙障作用下风速增长率明显下降,可见草方格沙障布设不仅有效削弱下垫面风速,同时也对风速变化产生显著影响㊂根据风速廓线方程l n Z =a +b U ,通过Z 0=e x p (a )与U *=k/b (k 为冯卡门常数,一般取0.4)可求得各指示风速下流沙地表及其在草方格沙障作用下地表粗糙度(Z 0)与摩阻速度(U *)㊂结果表明,在草方格沙障作用下,地表粗糙度随指示风速增加呈先上升后下降趋势,当指示风速为12m /s 时,地表粗糙度最大,为1.944c m ,相同条件下流沙地表粗糙度仅为0.072c m ,增长率高达2600%;而草方格沙障作用下摩阻速度表现为随指示风速增加呈上升趋势,当指示风速为20m /s 时,其上升至1.878m /s ,相较于流沙地表增加近0.48倍,大幅降低风沙流对地表的侵蚀能力,有效提升流沙地表抗风蚀能力㊂综上分析,草方格沙障布设深刻影响流沙地表气流场,导致其风速显著降低,风速增长率明显下降㊂同时,其大规模布设也大大提高流沙地表粗糙度,使其风沙活动量远低于流沙地表,进而在黑山嘴表现出良好的防风效益[15]㊂图2 流沙与草方格沙障近地表风速廓线表1 流沙地表及其在草方格沙障作用下拟合的风速廓线方程、粗糙度及摩阻速度风速/(m ㊃s-1)流沙风速廓线拟合方程(R 2)Z 0/c m U */(m ㊃s-1)草方格沙障风速廓线拟合方程(R 2)Z 0/c m U */(m ㊃s-1)8l n Z =-3.494+0.947U (0.976)0.0300.422l n Z =0.495+0.442U (0.826)1.6400.90512l n Z =-2.634+0.629U (0.988)0.0720.636l n Z =0.665+0.304U (0.881)1.9441.31616l n Z =-1.220+0.347U (0.984)0.2951.153l n Z =0.639+0.236U (0.917)1.8951.69520l n Z =-1.440+0.314U (0.989)0.2371.247l n Z =0.401+0.213U (0.943)1.4931.878注:R 2为风速廓线拟合方程的拟合系数;Z 0为地表粗糙度(c m );U *为摩阻速度(m /s)㊂下同㊂2.1.2 尼龙网格状沙障 对各指示风速下流沙地表及其在尼龙网格状沙障作用下的风速廓线分析(图3)可知,在一定指示风速下其风速测量值随高度变化存在明显差异,且拟合系数均>0.85,表明两者在各高度内风速变化均符合对数分布规律㊂两者风速均随指示风速增加而呈上升趋势,且流沙地表在尼龙网格状沙障作用下同一高度层风速均明显降低㊂当指示风速为8m /s 时,1.5c m 高度流沙地表风速为601水土保持学报 第37卷4.155m/s,而其在尼龙网格状沙障作用下风速仅为1.631m/s;当指示风速为20m/s时,1.5c m高度风速则降低80.9%,尼龙网格状沙障布设有效阻挡风沙流运移过程,大幅降低地表的风速,但相较于草方格沙障,其对地表风速削弱作用较低,对风速大小及变化幅度影响也均小于草方格沙障㊂根据两者风速廓线方程求出其地表粗糙度与摩阻速度(表2),结果表明,当指示风速逐渐增加时,尼龙网格状沙障作用下地表粗糙度变化趋势波动幅度较大,在指示风速为8m/s时达到最大值0.79c m;而其摩阻速度则随指示风速增加明显上升,在指示风速为20m/s时达到最大值1.556m/s,相较于流沙地表增加0.25倍㊂与草方格沙障作用下地表粗糙度与摩阻速度相比,尼龙网格状沙障作用下两者增加幅度均较小,但仍能对流沙地表风速大小及其变化产生显著影响㊂由此可见,尼龙网格状沙障的布设能有效增大下垫面地表粗糙度与摩阻速度,进而增强其对风速的削弱作用,防风效益显著[16]㊂但相较于草方格沙障,其粗糙度增大幅度较小且成本较高,应根据环境适当调整布设规模,与草方格沙障综合使用以达到最佳防风效益㊂图3流沙与尼龙网格状沙障近地表风速表2流沙地表及其在尼龙网格状沙障作用下拟合的风速廓线方程、粗糙度及摩阻速度风速/ (m㊃s-1)流沙风速廓线拟合方程(R2)Z0/c m U*/(m㊃s-1)尼龙网格状沙障风速廓线拟合方程(R2)Z0/c m U*/(m㊃s-1)8l n Z=-3.494+0.947U(0.976)0.0300.422l n Z=-0.236+0.587U(0.894)0.7900.681 12l n Z=-2.634+0.629U(0.988)0.0720.636l n Z=-0.422+0.427U(0.930)0.6560.937 16l n Z=-1.220+0.347U(0.984)0.2951.153l n Z=-0.354+0.302U(0.944)0.7021.325 20l n Z=-1.440+0.314U(0.989)0.2371.247l n Z=-0.552+0.257U(0.935)0.5761.5562.1.32种措施的防风效能防风效能是评估机械防沙工程防风效益的重要指标,对草方格与尼龙网格状沙障的防风效能分析(表3)可知,2种措施均能有效降低地表风速,当指示风速为8m/s时,1.5c m 高度草方格沙障防风效能达到84.82%,除此高度外,其余高度防风效能均随着指示风速增大而逐渐降低,当高度达到50c m时,草方格沙障防风效能已减小至-7.42%,无法有效降低地表风速;当指示风速为8m/s时,1.5c m高度尼龙网格状沙障防风效能为60.75%,随着高度增加,防风效能均随着指示风速增大呈递减趋势㊂总体来说,2种措施防风效能均表现为在一定指示风速下随高度增加而降低,但当高度一定时,两者防风效能则随指示风速变化表现出明显差异,1.5c m 高度草方格沙障防风效能先上升后下降,而50c m高度尼龙网格状沙障在各指示风速下其防风效能则明显优于草方格沙障;草方格沙障在近地表对风速的削弱能力显著,而尼龙网格状沙障在距地表50c m及以上降低风速能力已明显强于草方格沙障㊂两者布设虽均能体现良好的防风效能,但其对风速大小削弱高度及程度仍存在较大差异,使得草方格沙障在黑山嘴的防风效益整体上优于尼龙网格状沙障㊂表3不同机械防沙工程的防风效能指示风速/ (m㊃s-1)1.5c m高度防风效能/%草方格沙障尼龙网格状沙障6c m高度防风效能/%草方格沙障尼龙网格状沙障20c m高度防风效能/%草方格沙障尼龙网格状沙障50c m高度防风效能/%草方格沙障尼龙网格状沙障884.8260.7573.7251.1230.3323.57-11.981.11 1293.5251.1566.9040.8923.6212.74-17.31-3.03 1684.7129.0161.2234.2223.8611.87-7.42-6.06 2082.4827.7349.6323.5419.343.43-6.96-8.57701第6期潘加朋等:基于风洞模拟试验的典型机械防沙工程防护效益对比2.23种措施的固阻沙效益在典型机械防沙工程中,固沙㊁阻沙是遏制风沙灾害发展的主要途径,前者指对流沙进行固定,后者则表示对过境的风沙流进行阻滞㊁拦截,两者差异明显㊂故根据3种措施自身特征,本研究分别对草方格㊁尼龙网格状沙障及阻沙栅栏的固阻沙效益进行对比分析[14,17]㊂2.2.1草方格沙障图4a㊁图4b为流沙地表及其在草方格沙障作用下输沙率沿高度的变化,对其分析可知,当指示风速低于12m/s时,两者输沙率随高度变化并无明显差异,固沙效益不明显;当指示风速高于16m/s时,流沙地表各高度输沙率在草方格沙障作用下差异显著,流沙地表输沙率主要集中在距地表10c m高度内,且随高度上升迅速减小,而在草方格沙障作用下,输沙率在距地表20c m高度迅速增加后基本保持不变㊂整体来看,草方格沙障作用下输沙率变化随指示风速增加变化剧烈,波动明显,20m/s时其输沙率减小27.89g/(c m2㊃m i n),固沙效益明显㊂进一步对两者输沙量累计百分含量分析(图5)可知,各指示风速下流沙地表输沙量均集中分布在20c m高度后保持不变;在草方格沙障作用下,除指示风速为8m/s时,输沙量均匀分布在各高度,其余各指示风速下输沙量均在距地表20c m高度内保持不变,而后迅速增加,表明其对风沙流阻碍作用均集中在近地表,在距地表20c m高度内固沙能力显著,对当地风沙流结构影响深刻㊂而草方格沙障主要是通过增大地表粗糙度以降低风速,从而削弱气流挟沙能力,使其与流沙地表输沙率㊁输沙量随高度变化均出现明显差异[18-19]㊂由此可知,大规模布设草方格沙障能有效减少流沙地表输沙率与输沙量,使其分布特征差异明显,同时,对风沙流运移过程起到良好抑制作用㊂2.2.2尼龙网格状沙障分析流沙地表及其在尼龙网格状沙障作用下输沙率沿高度变化(图4)可知,各指示风速下流沙地表在尼龙网格状沙障作用下平均输沙率明显降低,当指示风速为20m/s时其变化最为明显,输沙率范围从0.64~40.57g/(c m2㊃m i n)减少至1.44~ 5.30g/(c m2㊃m i n)㊂从输沙率变化曲线来看,两者均表现为先上升后下降趋势,且其变化幅度随指示风速增加而增大㊂当指示风速为20m/s时差异最为显著,表现为流沙地表输沙率主要在距地表10c m高度内呈上升趋势,而其在尼龙网格状沙障作用下此高度增加至20 c m,但输沙率却大幅降低,极大地阻碍风沙流对沙粒运移过程并深刻影响流沙地表输沙率的变化情况㊂图4各指示风速下流沙地表及沙障作用下输沙率沿高度变化图5流沙地表及沙障作用下输沙量累计百分含量同样,两者输沙量累计百分含量也表现出较为明显差异(图5a,图5c):除指示风速8m/s时尼龙网格状沙障作用下输沙量在距地表10c m高度内迅速上升,其余指示风速下均表现为随高度增加近似均匀分布,而流沙地表输沙量主要集中在距地表30c m高度内,表明尼龙网格状沙障布设使流沙地表风沙流结构发生较大改变,分布特征出现明显差异,深刻影响一定高度内风沙流结构,很大程度上削弱风沙流对流沙地表侵蚀能力,固沙效益显著㊂2.2.3阻沙栅栏对阻沙栅栏前后输沙率沿高度变801水土保持学报第37卷化分析(图6)可知,其变化趋势在各指示风速范围内差异明显,当指示风速低于12m/s时,栅栏前后输沙率随高度变化差异较小;而当指示风速高于12m/s 时,栅栏前后输沙率差异明显,栅栏前输沙率整体呈下降趋势,栅栏后则与之相反㊂随着指示风速增大,两者间差异更加显著;当指示风速为12m/s时,栅栏前输沙率在2~4c m高度迅速下降后保持不变,栅栏后输沙率则在14~20c m高度迅速上升;当指示风速为20m/s时,栅栏前输沙率在2~20c m高度表现为随高度减少,而同高度栅栏后输沙率变化则呈完全相反趋势,但其输沙率大小也明显下降,相较于阻沙栅栏前平均输沙率从126.42g/(c m2㊃m i n)降低至70.57g/(c m2㊃m i n),降低44.2%,阻沙效益显著㊂由图7可知,各指示风速下阻沙栅栏前输沙量累计百分含量也表现出明显差异,栅栏前输沙量累计百分含量随高度上升而增加,且随指示风速变化而在近地表差异明显,当指示风速为8m/s时,2c m高度栅栏前输沙量累计百分含量为66.58%,而其在同高度㊁指示风速为20m/s时,仅为28.7%,整体呈随风速增加而减小趋势㊂而栅栏后的输沙量累计百分含量在各高度㊁各指示风速下均无明显差异,表明阻沙栅栏对当地风沙流阻碍作用明显,对当地风沙流结构影响深刻㊂因此,黑山嘴北侧所布设的阻沙栅栏能有效阻碍风沙流运移过程,加之在其阻沙带间撒播骆驼刺,阻沙效益更为显著㊂图6阻沙栅栏前㊁后输沙率沿高度的变化图7阻沙栅栏前㊁后的输沙量累计百分含量3讨论机械防沙工程是风沙治理的主要措施之一,其主要通过影响当地流场特性㊁风沙流结构等以实现良好的防风及固阻沙效益[20-21]㊂敦煌黑山嘴机械防沙措施以草方格与尼龙网格状沙障㊁阻沙栅栏以及人工种植植被为主㊂通过风洞试验发现,草方格与尼龙网格状沙障均通过增大地表粗糙度以降低风速,从而对当地风沙流结构产生深刻影响,使得流沙地表在两者作用下其输沙率明显降低,与黎小娟等[22]研究结果一致㊂尼龙网格状沙障的布设使得研究区当地近地表输沙率垂直分布特征明显改变,并表现出先增后减趋势㊂此外,由于2种沙障自身材料等差异,草方格沙障防风固沙效益主要体现在近地表,而尼龙网格状沙障则在较高处防护效益优于草方格沙障,故在机械防沙工程建设中应结合当地地形按一定间距交错布设,地形起伏同样对其防护效益产生重要影响[23]㊂本研究中,阻沙栅栏对风沙流阻碍明显,栅栏前后输沙率㊁输沙量在各指示风速下的分布均差异显著㊂张克存等[24]在对青藏铁路沿线阻沙栅栏流场结构分析后发现,布设阻沙栅栏能有效阻截沙源,成效良好㊂而本试验中,阻沙栅栏后输沙率㊁输沙量分布均符合风沙流在其集流加速区与减速沉降区的运移特征,表明其阻沙效益良好,有效遏制当地的风沙活动㊂风洞试验是评价机械防沙工程防护效益的重要途径之一,其对实际防沙工程的设计㊁建设有着重要的参考意义㊂当前,对机械沙障防护效益评价的方式仍以野外观测与风洞试验为主,但野外观测易受环境条件限制,风洞试验又多集中于研究机械沙障自身性质对其防901第6期潘加朋等:基于风洞模拟试验的典型机械防沙工程防护效益对比护效益的影响,忽视其布设环境㊁合理配置等因素,且存在与野外实际情况不一致的风险㊂本研究以敦煌黑山嘴布设机械防沙工程为参考设计风洞试验,根据当地环境控制试验参数,对其布设3种典型机械防沙措施进行系统的对比分析,研究结果均与野外观测相一致[22,24],表明风洞试验可有效模拟黑山嘴环境,结论可信㊂本研究在对研究区内机械防沙措施防护效益进行系统对比分析的基础上,不仅针对性地为当地机械防沙工程建设提供数据基础㊁设计参考及评价模式,同时也为其他地区防沙工程建设予以借鉴㊂4结论(1)草方格与尼龙网格状沙障布设大大增加流沙地表粗糙度,对风速削弱作用显著,当指示风速为20 m/s时,两者作用下1.5c m高度风速降低率分别达82.5%,80.9%;在对两者防风效能进行分析后发现,其在不同高度对风速削弱能力差异明显,在不同高度防风效益差异显著㊂草方格与尼龙网格状沙障布设也导致地表输沙率及输沙量沿高度分布差异明显㊂当指示风速为20m/s时,两者输沙率主要在距地表20c m高度内先增加后稳定不变或呈下降趋势,而流沙地表则表现为在距地表10c m高度内先增加后迅速减小;两者输沙量分布也出现明显分异,其中,草方格沙障固沙能力集中体现在近地表,而尼龙网格状沙障则在各高度固沙效益均较为显著㊂此外,阻沙栅栏前后输沙率㊁输沙量差异明显,当指示风速为20m/s 时,其平均输沙率降低44.2%,深刻影响当地的流场结构,阻沙效益良好㊂(2)草方格与尼龙网格状沙障及阻沙栅栏的布设虽均起到良好的防风及固阻沙效益,但3种机械防沙措施间防护效益仍存在明显差异㊂风洞试验表明,草方格㊁尼龙网格状沙障以防风㊁固沙为主,且前者近地表防护效益明显优于后者,而阻沙栅栏则以阻截风沙流运移过程为主㊂对今后风沙治理工程设计与调整具有重要指导意义,其布设模式等亦可直接应用于敦煌黑山嘴机械防沙工程建设中㊂参考文献:[1]史培军,严平,袁艺.中国北方风沙活动的驱动力分析[J].第四纪研究,2001,21(1):41-47.[2]刘燕燕,孙桂丽,吉小敏,等.2000 2020年博尔塔拉蒙古自治州沙漠化风险评价[J].水土保持通报,2022,42(3):66-73.[3]王旭,王昀,陈宝欣,等.塔里木盆地风沙灾害强度和频次的时空分布特征[J].干旱区地理,2021,44(6):1590-1600. 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致密砂岩气藏自支撑裂缝损伤机理及导流能力研究
㊀㊀收稿日期:20220410;改回日期:20230310㊀㊀基金项目:国家重点研发计划项目 油/水/固界面浸润调控智能流体提高采收率关键材料与机理研究 (2019YFA0708700)㊀㊀作者简介:孙永鹏(1985 ),男,副教授,2007年毕业于西南石油大学石油工程专业,2014年毕业于美国密苏里科技大学石油工程专业,获博士学位,现从事非常规油气开发工作㊂㊀㊀通讯作者:戴彩丽(1971 ),女,教授,博士生导师,1993年毕业于石油大学(华东)采油工程专业,2006年毕业于中国石油大学(华东)油气田开发工程专业,现主要从事提高采收率与采油化学㊁非常规能源高效开发研究与应用工作㊂DOI :10.3969/j.issn.1006-6535.2023.02.010致密砂岩气藏自支撑裂缝损伤机理及导流能力研究孙永鹏1,2,王传熙1,2,戴彩丽1,2,魏利南1,2,陈㊀超1,2,谢孟珂3(1.中国石油大学(华东),山东㊀青岛㊀266580;2.非常规油气开发教育部重点实验室,山东㊀青岛㊀266580;3.中国石油西南油气田分公司,四川㊀成都㊀610051)摘要:针对致密砂岩气藏压裂后自支撑裂缝导流能力发生变化的问题,建立了裂缝壁面仿真自支撑裂缝导流能力的实验评价方法,从裂缝壁面微观形貌㊁粗糙度㊁强度等方面探究导流能力损伤机理,明确了裂缝导流能力变化规律㊂研究表明:裂缝遇水后壁面黏土水化,并在应力作用下压实,壁面平均高度下降了8.5%;同时,裂缝壁面软化,平均硬度降低了34.3%㊂生产油嘴尺寸变化越密集,高应力时自支撑裂缝导流能力越高;第3次开井生产时的裂缝导流能力比首次开井下降91.7%~98.5%;错位裂缝的导流能力为无错位裂缝的18.1~140.4倍;随着压裂后地层水驱替压裂液产出,最终裂缝导流能力为原始裂缝导流能力的3.45倍㊂该文明确了致密气藏生产过程导流能力损伤机理,阐明了不同因素作用下自支撑裂缝导流能力变化规律,为致密砂岩气藏自支撑裂缝保护提供了基础理论依据㊂关键词:致密砂岩气藏;自支撑裂缝;导流能力;损伤机理;裂缝壁面特征中图分类号:TE357㊀㊀文献标识码:A ㊀㊀文章编号:1006-6535(2023)02-0081-07Study on Damage Mechanism and Conductivity of Unpropped Fractures in Tight Sandstone Gas ReservoirsSun Yongpeng 1,2,Wang Chuanxi 1,2,Dai Caili 1,2,Wei Linan 1,2,Chen Chao 1,2,Xie Mengke 3(1.China University of Petroleum (East China ),Qingdao ,Shandong 266580,China ;2.Key Laboratory of Unconventional Oil and Gas Development ,Ministry of Education ,Qingdao ,Shandong 266580,China ;3.PetroChina Southwest Oil &Gas Field Company ,Chengdu ,Sichuan 610051,China )Abstract :For the change in unpropped fracture conductivity after fracturing in tight sandstone gas reservoirs ,an ex-perimental method for unpropped fracture conductivity evaluation with fracture wall simulation was established to in-vestigate the damage mechanism of conductivity in terms of the microscopic morphology ,roughness ,strength andother aspects of the fracture wall ,and to clarify the variation law of fracture conductivity.The study shows that after the fracture was exposed to water ,the wall clay was hydrated and compacted under stress ,and the average height ofthe wall was decreased by 8.5%;meanwhile ,the fracture wall was softened and the average hardness decreased by 34.3%.The more frequent the change in production nozzle size ,the higher the conductivity of the unpropped frac-ture under high stress ;the fracture conductivity of the third well opening was 91.7%-98.5%lower than that of the first well opening ;the conductivity of misaligned fractures was 18.1-140.4times that of non -misaligned fractures.With the formation water displacing fracturing fluid after fracturing ,the conductivity of the final fracture was 3.45times that of the original fracture.In this paper ,the conductivity damage mechanism in the production of tight gas reservoirs was defined ,and the variation law of unpropped fracture conductivity under the action of different factors was clarified ,which provides a basic theoretical basis for the protection of unpropped fractures in tight sandstonegas reservoirs.Key words :tight sandstone gas reservoir ;unpropped fracture ;conductivity ;damage mechanism ;fracture wallcharacteristics㊀82㊀特种油气藏第30卷㊀0㊀引㊀言致密气储层具有低孔低渗的特点,水力压裂是致密气藏高效开发的必要手段[1-2]㊂水力压裂形成的裂缝包括颗粒支撑裂缝和自支撑裂缝[3],泵入的支撑剂一般在裂缝底部沉积,在裂缝中上部则存在大量没有支撑剂的自支撑裂缝[4-5]㊂由于缝网压裂的广泛应用,自支撑裂缝面存在滑移,使得裂缝表面存在自支撑结构,从而产生导流空间[6-7]㊂在一定滑移范围内,自支撑裂缝的导流能力与相对滑移量成正比,当相对滑移量达到10mm 以上时,裂缝导流能力不再增加[8-10]㊂同时,在低闭合应力下裂缝表面以点状支撑为主,具有较强应力敏感性,而在高闭合应力下裂缝表面大量微凸起被压碎,裂缝几乎完全闭合[11-12]㊂然而,目前针对气藏生产过程中致密砂岩气藏自支撑裂缝的导流能力变化机理及影响规律尚不明确[13]㊂因此,通过制备人工劈裂岩心模型,建立了裂缝壁面特征仿真自支撑裂缝导流能力实验评价方法,明确了岩心矿物组成;通过观察导流实验前后裂缝壁面微观形貌变化特征,测量裂缝壁面粗糙度和表面硬度变化情况,分析了自支撑裂缝导流能力损伤机理;考察净应力变化梯度㊁应力循环次数㊁裂缝错位距离和流体矿化度等因素对裂缝导流能力的影响规律[14-16],为致密气藏压裂及生产工艺改进提供了基础理论依据㊂1㊀实验部分1.1㊀实验材料实验用岩心选自四川西部致密砂岩露头,岩心均加工为长度为5.0cm㊁直径为2.5cm 的标准岩心,岩心上下两端面平行度小于ʃ20μm㊂利用岩心气相渗透率自动测定仪测得岩心渗透率为0.27~0.32mD,利用氦气孔隙度测量仪测得岩心孔隙度为11.2%~13.2%㊂地层水选自四川西部坳陷高庙构造南侧的高庙32井,地层水各成分质量浓度如表1所示,总矿化度为25076.70mg /L㊂表1㊀地层水各成分质量浓度㊀㊀向地层水中加入质量分数分别为0.025%和0.250%的减阻剂和助排剂配制压裂液㊂利用Haake MARS 60流变仪测试其流变性能㊂在170s -1时,压裂液黏度为1.99mPa㊃s,满足行业标准(小于5.00mPa㊃s);压裂液在储层温度(78ħ)下表面张力为26.6mN /m,满足行业标准(小于28.0mN /m)㊂1.2㊀实验方法1.2.1㊀裂缝壁面微观形貌观测从实验岩心样品上敲取约1cm 3的小块,采用GB /T 16594 2008‘微米级长度的扫描电镜测量方法通则“[17],通过上桩㊁去尘㊁干燥㊁喷镀等步骤制备样品㊂用扫描电镜扫描平整裂缝表面,对比分析导流实验前后的裂缝表面变化㊂1.2.2㊀裂缝壁面粗糙度测定采用ISO 25178 600‘几何产品规格“[18],利用激光共聚焦显微镜分别扫描实验前后岩心裂缝表面㊂通过软件重构三维图像并使其数值化,为砂岩裂缝表面粗糙度表征参数提供计算基础㊂1.2.3㊀裂缝壁面强度测试为定量表征液体及应力作用下裂缝壁面强度变化,采用GB /T 4340.4 2022‘金属材料维氏硬度试验“[19],利用维氏硬度计测试实验前后相邻位置的裂缝壁面硬度㊂样品表面干燥后,测量区域使用1200目砂纸轻轻打磨再开展测试,加载压力为9.8N㊂1.2.4㊀导流能力测试传统导流能力测试是在API 导流室中采用2块相互平行的光滑岩板模拟地层裂缝,无法模拟自支撑裂缝壁面特征㊂因此,此次实验利用巴西劈裂造缝装置,制作缝面粗糙的人工裂缝,实验装置如图1所示㊂主要步骤为(以油嘴更换频率为例):①基于巴西劈裂法,将岩心沿轴向劈裂形成人工裂缝,设置好错位距离;②驱替流量固定为1mL /min,围压固定为43MPa;③调整回压为预设压力值,待注入压力稳定后,依次调整回压至下一压力值;④实验过程中,软件持续记录流压㊁围压和回压㊀第2期孙永鹏等:致密砂岩气藏自支撑裂缝损伤机理及导流能力研究83㊀㊀数据,待最后一个回压下的压力稳定后,视为此次导流实验结束;更换岩心,开展实验测试其他实验参数(如净应力变化梯度㊁应力加载次数㊁自支撑裂缝错位距离㊁地层水矿化度等)㊂图1㊀裂缝导流能力实验装置示意图Fig.1㊀The schematic diagram of fracture conductivity test device2㊀自支撑裂缝导流能力损伤机理分析2.1㊀矿物成分分析将实验用岩心加工成粉末状,使用X 射线衍射仪测定其中矿物成分含量[20-24]㊂结果表明:岩心中矿物以石英(33.6%)㊁斜长石(17.8%)和钾长石(12.0%)为主,含有少量的方解石(0.4%);黏土矿物含量为36.2%,主要以伊利石和绿泥石为主㊂绿泥石和伊利石是强水敏矿物,遇水后,水分子会进入矿物晶层之间,引起晶层间距扩大,矿物内部黏结力变小,发生软化㊁泥化㊁崩解,同时,矿物残渣进入缝面凹陷部位,填充裂缝壁面空间,减小渗流通道㊂在壁面软化㊁矿物运移和净应力共同作用下,加速了裂缝壁面的平整化,裂缝等效宽度减小,进而减小裂缝空间,降低裂缝导流能力㊂2.2㊀裂缝壁面微观形貌特征为直观观察裂缝壁面形貌变化特征,利用扫描电镜观察了实验前后裂缝壁面的微观形貌(图2)㊂由图2可知:实验前裂缝壁面形貌较为复杂,矿物棱角清晰,矿物分离产生的凹坑和不规则凸起明显;实验中裂缝壁面矿物在水化㊁冲刷和应力作用下发生膨胀㊁破碎㊁运移㊁填充㊁压实㊁胶结等物化作用,裂缝壁面逐渐趋于光滑而致密;实验后缝面原有的碎屑和凸起大量减少,壁面比较光滑,导致自支撑裂缝岩心支撑能力降低,可供流体通过的渗流通道减少,从而导致其导流能力降低㊂a b图2㊀实验前后裂缝壁面形态(50倍)Fig.2㊀The fracture wall morphology beforeand after the test (50times)2.3㊀裂缝壁面粗糙度变化为定量表征岩心裂缝壁面的粗糙度,利用激光共聚焦显微镜测量实验前后裂缝壁面粗糙度情况㊂导流实验前,裂缝壁面各峰算术平均高度和最大高度分别为34.3㊁543.9μm㊂导流实验后,二者分别下降了8.50%和13.20%(表2)㊂实验后的裂缝壁面粗糙度较实验前有一定程度下降㊂壁面在滑溜水压裂液的持续冲刷下,表面原本不规则的凸起在一定程度上趋于沿岩心轴向规则排列,即壁面松散的黏土颗粒发生水化膨胀并在应力作用下形成碎屑,沿滑溜水的冲刷方向被带出裂缝㊂同时,壁面原本起到支撑作用的尖锐凸起被逐渐压平,其支撑能力不断降低导致缝宽减小,供流体通过的渗流通道随之减小㊂㊀84㊀特种油气藏第30卷㊀表2㊀壁面粗糙度测试结果2.4㊀裂缝壁面强度变化特征利用维氏硬度计定量表征实验前后裂缝壁面强度变化,结果如图3所示㊂a b1805 m .μ1816 m .μ2223 m .μ2243 m .μ图3㊀实验前后裂缝表面微米压痕图Fig.3㊀The micrometer indentation image of fracturesurface before and after the test导流实验前,裂缝壁面硬度为56.6HV㊂经过裂缝导流实验,裂缝壁面硬度降至37.2HV,降幅为34.3%㊂由于岩心的黏土矿物含量较高,而黏土矿物容易发生水化膨胀㊁软化,导致壁面硬度降低,抗压强度降低㊂一方面矿物在应力和滑溜水冲刷作用下破碎㊁运移,堵塞渗流通道;另一方面错位裂缝壁面中起到支撑作用的不规则凸起因强度降低,更容易在高应力下被压平或破碎,导致支撑能力越来越小,裂缝两面咬合程度越来越高,裂缝趋于闭合㊂3㊀致密气藏自支撑裂缝导流能力影响因素致密气藏通过大规模水力压裂形成复杂缝网,增大改造体积,提高单井控制程度㊂支撑剂一般在裂缝底部沉积,在裂缝中上部及裂缝远端形成大量没有支撑剂的自支撑裂缝,裂缝错位距离是自支撑裂缝的关键特征㊂压裂后生产过程中,通过改变油嘴更换频率㊁关井等手段可恢复井底压力,而储层液体返排产生盐度变化等因素均影响致密气藏自支撑裂缝导流能力㊂3.1㊀油嘴更换频率现场生产过程中,通常会采用不同尺寸的油嘴进行生产以控制生产过程中的井底压力,调节生产速度㊂不同的油嘴更换频率会导致地层净应力变化梯度不同,进而影响裂缝的导流能力㊂采用错位距离为0.5mm 的自支撑裂缝岩心模型,设置了3种不同的净应力递减梯度:梯度1为10㊁15㊁20㊁25㊁30㊁35㊁40MPa;梯度2为10㊁20㊁30㊁40MPa;梯度3为10㊁25㊁40MPa,模拟不同的油嘴更换频率,通过式(1)计算导流能力,结果如图4所示㊂F =F iF max (1)式中:F 为无因次裂缝导流能力;F i 为初始裂缝导流能力,D ㊃cm;F max 为最大裂缝导流能力,D ㊃图4㊀净应力变化梯度对裂缝导流能力的影响Fig.4㊀The influence of net stress gradient on fracture conductivity由图4可知:随净应力增大,无因次裂缝导流能力逐渐下降,降幅为80.2%~88.1%;低净应力时,不同应力变化梯度对导流能力的影响差别不大,在高净应力下,油嘴更换6次比更换2次时裂缝无因次导流能力提高了7.9%㊂分析表明:净应力较低时,裂缝两侧壁面因滑移而形成的不规则凸起能够较好支撑裂缝,形成较大的渗流空间;随着净应力逐渐增大和滑溜水压裂液的持续冲刷,由于岩心黏土矿物含量较高,遇水膨胀㊁水化,其抗压强度逐渐降低,而当净应力增大至缝面凸起部分的抗压强度时,矿物发生破碎,降低了裂缝宽度,引起裂缝导流能力降低㊂因此,致密气藏压裂后生产过程中,增加生产油嘴尺寸更换频率,可使裂缝受到的净应力变化较为缓慢,自支撑裂缝的导流能力下降幅度较低,更有利于为致密气提供高渗流动空间㊂3.2㊀开关井次数气藏生产过程中近井压力逐渐降低,会在生产㊀第2期孙永鹏等:致密砂岩气藏自支撑裂缝损伤机理及导流能力研究85㊀㊀一段时间后关井,待井底压力恢复后再次开井生产㊂采用错位距离为0.5mm 的自支撑裂缝岩心模型,模拟了开井 关井 再开井共4次开关井过程,考察地层净应力循环次数对裂缝导流能力的影响,结果如图5所示㊂图5㊀开关井次数对裂缝导流能力的影响Fig.5㊀The influence of well opening and closingtimes on fracture conductivity由图5可知:随开关井次数增加,相同净应力下裂缝导流能力有所减小,尤其第3次比第1次下降了91.7%~98.5%,第3㊁4次开井时在高净应力下裂缝导流能力极低,几乎为0D㊃cm㊂分析表明:实验用致密砂岩岩心黏土矿物含量较高,抗压强度较低,随着净应力的增加,其逐渐超过裂缝表面抗压强度,裂缝表面凸起破碎程度逐渐加剧,原本错位的裂缝出现闭合现象,导致缝宽减小,裂缝导流能力减小;而随着净应力循环加载,破碎后的矿物残渣等细小颗粒不断增多,逐渐堵塞裂缝凹陷壁面,减小了裂缝空间,造成裂缝导流能力降低㊂因此,在致密气藏生产过程中,压裂形成的大量自支撑裂缝,在多次开关井后存在闭合的可能性,不再贡献渗流通道㊂为保持自支撑裂缝导流能力,应尽量控制生产速度,减缓近井压力下降速度,减少关井恢复压力次数㊂3.3㊀自支撑裂缝错位距离在水力压裂造缝过程中,裂缝通常会受到不同程度的剪切应力,产生滑移错位㊂由于裂缝表面凹凸不平,虽然部分裂缝中未充填支撑剂,裂缝表面不均匀结构也可以相互支撑,为气体导流贡献能力㊂实验采用0.5㊁1.0mm 厚的铜片固定在岩心裂缝两端,实现对裂缝不同错位距离的精准控制㊂不同净应力条件下的导流能力见图6㊂由图6可知:随裂缝错位距离的增大,其导流能力有明显提高,可达18.1~140.4倍,低净应力下图6㊀错位距离对裂缝导流能力的影响Fig.6㊀The influence of dislocation distance on fracture conductivity提升效果尤为明显;错位距离为1.0mm 的裂缝导流能力略高于错位距离为0.5mm 的裂缝,且均远大于无错位的裂缝;无错位裂缝在低净应力时存在一定的导流能力,当净应力增至8MPa 以上,裂缝接近闭合,基本无导流能力㊂分析表明:错位距离对裂缝导流能力的影响与储层骨架颗粒性质(矿物类型㊁尺寸㊁形状㊁硬度等)㊁胶结物性质(成分㊁含量㊁排布等)以及外来水与胶结物的作用等影响密切相关㊂在裂缝开裂过程中,裂缝一侧壁面产生的凸起或凹陷部分未被对侧壁面包裹时,则在裂缝中间形成较大的渗流空间,大幅度改善流动通道,裂缝导流能力则呈现倍数增长㊂因此,错位距离对裂缝导流能力的影响主要体现在有无错位的区别上㊂当裂缝产生一定错位后,其导流能力并非线性增长,而是在一定范围内波动并呈现一定的随机性;当裂缝没有错位时,高净应力下裂缝两侧壁面容易恢复至未开裂时的紧密咬合状态,裂缝中的流动空间极其有限,导流能力极差,裂缝不能贡献气体流动的空间㊂因此,在致密气藏压裂造缝过程中,裂缝形成一定的错位距离,可大幅度改善自支撑裂缝导流能力,提高气井产能㊂3.4㊀压裂后返排液矿化度在现场压裂过程中,使用地表水配置的压裂液矿化度较低(一般为100~1000mg /L),而致密气储层地层水矿化度较高㊂向地层中注入低矿化度水会造成裂缝壁面黏土矿物发生水化膨胀,导致黏土矿物和骨架颗粒发生运移,进而影响裂缝导流能力㊂利用0.5mm 错位裂缝岩心模型,配制矿化度㊀86㊀特种油气藏第30卷㊀分别为0㊁5000㊁10000㊁15000㊁20000㊁25000mg /L 的滑溜水压裂液,研究不同矿化度压裂液对裂缝导流能力的影响,结果如图7所示㊂图7㊀压裂液矿化度对裂缝导流能力的影响Fig.7㊀The influence of fracturing fluid salinity on fracture conductivity由图7可知:随压裂液矿化度逐渐上升,裂缝的导流能力随之升高,当矿化度从0mg /L 提升至25000mg /L,裂缝导流能力提升3.45D㊃cm㊂分析认为:储层中含有一定量的黏土等胶结物,低矿化度下水对黏土矿物水化抑制作用较差,此时产出液中有细小矿物颗粒和胶结物碎屑排出;在高矿化度下,水溶液中的静电斥力较强,抑制黏土矿物晶层间的斥力,进而抑制了水化作用,有助于保留裂缝空间,进而使得裂缝导流能力得到提升㊂因此,致密气储层水力压裂后,低矿化度压裂液大量赋存于地层,此时自支撑裂缝导流能力较低,随着后续高矿化度地层水驱替压裂液排出,地层流体矿化度逐渐升高,自支撑裂缝导流能力相较刚开井时会有一定程度的提升㊂4㊀结论和建议(1)致密砂岩储层矿物水化膨胀㊁分散㊁运移,结合应力作用,自支撑裂缝闭合后壁面更平整,壁面硬度平均降低了34.3%㊂水化结合应力作用加速了裂缝壁面平整化,减小裂缝空间,进而降低自支撑裂缝导流能力㊂针对储层沉积及矿物特征,可考虑加入黏土稳定剂保护自支撑裂缝导流能力㊂(2)致密气藏生产制度对自支撑裂缝导流能力影响巨大㊂生产油嘴尺寸变化越频繁,自支撑裂缝导流能力下降幅度越低,油嘴更换6次比更换2次时裂缝无因次导流能力提高了7.9%㊂在前几次开井生产过程中自支撑裂缝可贡献导流能力,多次关井恢复压力后,裂缝存在闭合的可能,因此,在现场生产过程中应尽量提高生产油嘴尺寸更换频率并减少开关井次数㊂(3)合理设计压裂及返排工艺可提高自支撑裂缝导流能力㊂相比无错位裂缝,错位自支撑裂缝导流能力可提高18.1~140.4倍㊂现场压裂施工造缝时应尽量使裂缝形成一定程度的错位,可极大增加裂缝导流能力㊂如果压裂液矿化度低于地层水矿化度,致密气储层压裂后,当地层水驱替压裂液逐渐排出后,自支撑裂缝导流能力可得到一定程度的恢复㊂参考文献:[1]李国欣,朱如凯.中国石油非常规油气发展现状㊁挑战与关注问题[J].中国石油勘探,2020,25(2):1-13.LI Guoxin,ZHU Rukai.Progress,challenges and key issues of un-conventional oil and gas development of CNPC[J].China Petrole-um Exploration,2020,25(2):1-13.[2]熊俊雅,杨兆中,杨磊,等.压裂填砂裂缝导流能力室内研究进展与展望[J].特种油气藏,2020,27(3):1-7.XIONG 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Testing,2020,29(1):7-12.[12]张阳.致密储层人工裂缝导流能力及影响因素实验研究[D].西安:西安石油大学,2015.ZHANG Yang.Experimental study on artificial fracture conductiv-ity and influencing factors in tight reservoirs [D].Xiᶄan:Xiᶄan Shiyou University,2015.[13]刘学伟.页岩储层水力压裂支撑裂缝导流能力影响因素[J].断块油气田,2020,27(3):394-398.LIU Xuewei.Influencing factors of hydraulic propped fractureconductivity in shale reservoir[J].Fault -Block Oil &Gas Field,2020,27(3):394-398.[14]LI N,ZHANG S,MA X,et al.Thermal effect on the evolution ofhydraulic fracture conductivity:an experimental study of enhancedgeothermal system [J].Journal of Petroleum Science and Engi-neering,2020,187:106814.[15]DESOUKY M,ALJAWAD M S,SOLLING T,et al.Improving long -term hydraulic fracture conductivity by alteration of rock minerals [J].Journal of Petroleum Science and Engineering,2021,196:108046.[16]FAN M,MCCLURE J,HAN Y,et ing an experiment /simu-lation -integrated approach to investigate fracture -conductivity e-volution and non -Darcy flow in a proppant -supported hydraulic fracture[J].SPE Journal,2019,24(4):1912-1928.[17]国家质量监督检验检疫总局.微米级长度的扫描电镜测量方法通则:GB /T 16594 2008[S].北京:中国标准出版社,2008:1-15.General Administration of Quality Supervision,Inspection andQuarantine of the Peopleᶄs Republic of China.General rules for measurement of length in micron scale by SEM:GB /T 16594-2008[S].Beijing:Standards Press of China,2008:1-15.[18]Geometrical product specifications(GPS)-surface texture:areal -part600:metrological characteristics for areal topography measuring meth-ods:ISO 25178-600:2019[S /OL].https:// /standard /67651.html.[19]国家质量监督检验检疫总局.金属材料维氏硬度试验:第1部分试验方法:GB /T 4340.1 2009[S].北京:中国标准出版社,2009:1-16.General Administration of Quality Supervision,Inspection andQuarantine of the Peopleᶄs Republic of China.Metallic materials -vickers hardness test -part 1:test method:GB /T 4340.1-2009[S].Beijing:Standards Press of China,2009:1-16.[20]徐正辉.页岩裂缝液体损害机理研究[D].北京:中国石油大学(北京),2016.XU Zhenghui.Research on the mechanism of shale fracture fluiddamage[D].Beijing:China University of Petroleum (Beijing),2016.[21]郭红鑫,程林松,王鹏,等.碳酸盐岩油藏不同裂缝产状岩心水驱油实验及水驱规律[J].油气地质与采收率,2022,29(6):105-112.GUO Hongxin,CHENG Linsong,WANG Peng,et al.Water flood-ing experiment and law of carbonate reservoir cores with different fracture occurrences[J].Petroleum Geology and Recovery Effi-ciency,2022,29(6):105-112.[22]林魂,宋西翔,罗超,等.致密砂岩油藏裂缝与基质间渗吸特征及主控因素[J].油气地质与采收率,2022,29(5):133-140.LIN Hun,SONG Xixiang,LUO Chao,et al.Dynamic imbibition characteristics between fractures and matrix in tight sandstone res-ervoirs and main controlling factor [J].Petroleum Geology and Recovery Efficiency,2022,29(5):133-140.[23]马承杰.多尺度边缘检测技术在断层识别及裂缝发育带预测中的应用 以车排子地区排691井区为例[J].油气地质与采收率,2021,28(2):85-90.MA Chengjie.Application of multi -scale edge detection technolo-gy to fault recognition and fracture zone prediction:a case study of Block Well P691,Chepaizi Area[J].Petroleum Geology and Re-covery Efficiency,2021,28(2):85-90.[24]孙福亭,何娟,王龙,等.伊拉克A 油田Asmari 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软骨下骨的病理改变及其在骨关节炎发病机制中的作用
软骨下骨的病理改变及其在骨关节炎发病机制中的作用陈文杰,李益军,郑小飞,王华军【摘要】骨关节炎是一种常见的慢性退行性病变。
现有研究表明,软骨下骨病变在骨关节炎的发生发展过程中起着重要作用。
本文阐述骨关节炎软骨下骨的病理改变及其在骨关节炎发病机制中的作用,同时对以软骨下骨为治疗靶点的相关研究进展进行综述,从而为研究骨关节炎发病机制、开发治疗药物提供参考依据。
【关键词】骨关节炎;软骨,关节;软骨下骨;微结构;骨髓水肿样病变;骨囊肿;钙质沉着症;二磷酸盐类;甲状旁腺素;降钙素中图分类号:R684.3,R364.3文献标识码:A 文章编号:1674-666X(2020)04-234-08Pathological changes of subchondral bone and their roles in pathogenesis of osteoarthritisCHEN Wenjie*,LI Yijun,ZHENG Xiaofei,WANG Huajun.*Joint and Sports Medicine Center,the First Clinical Medical College of Jinan University,the First Affiliated Hospital of Jinan University,Guangzhou,Guangdong 510630,ChinaCorresponding author:WANG Huajun,E-mail:**************【Abstract 】Osteoarthritis is a most common chronic degenerative disease.Current studies have shown that subchondral bone lesions play important roles in the occurrence and development of osteoarthritis.In this paper,the pathological changes of subchondral bone and theirs roles in pathogenesis of osteoarthritis were discussed,the related research progress of subchondral bone as a therapeutic target were reviewed,so as to provide references for exploring the pathogenesis of osteoarthritis and developing treatment drugs.【Keywords 】Osteoarthritis;Cartilage,articular;Subchondral bone;Microstructure;Bone marrow edema-like lesions;Bone cysts;Calcinosis;Diphosphonates;Parathyroid hormone;CalcitoninDOI :10.3969/j.issn.1674–666X.2020.04.007基金项目:广东省医学科学技术研究基金项目(A2019100);广州市科技计划(3345464565);东莞市社会科技发展(重点)项目(202050715011167)作者单位:510630广州,暨南大学第一临床医学院/暨南大学附属第一医院骨关节与运动医学中心(陈文杰,郑小飞,王华军);523290广东,东莞市石碣医院康复医学科(李益军)通信作者:王华军,E-mail :**************综述骨关节炎是一种以关节软骨退变为主要特征的慢性疾病,是导致成年人群残疾的主要原因。
稀土离子掺杂铝酸盐长余辉发光材料的研究进展_武秀兰
稀土离子掺杂铝酸盐长余辉发光材料的研究进展Ξ武秀兰,任 强,王 莹(陕西科技大学材料科学与工程学院,陕西 咸阳 712081)摘要:综述了长余辉发光材料的国内外研究进展,并以稀土离子激活的铝酸盐体系为例,从发光机理、合成方法和研究现状等方面进行了全面的分析。
特别对飞秒激光诱导下的长余辉发光玻璃的研究情况进行了详细介绍,对发展前景和研究方向进行了展望。
关键词:长余辉;稀土离子;发光机理;飞秒激光;诱导结构中图分类号:T Q171.73+9 文献标识码:A 文章编号:1000-2871(2003)06-0053-05Progress in Study on R are-E arth Ion Doped Aluminate Long-Lasting Phosphorescent MaterialWU Xiuνlan,REN Qiang,WANG Ying(Material Science and Engineering C ollege,Shaanxi Universityof Science&T echnology,X ianyang712081,China)Abstract:This paper reviews progress in study on long-lasting phosphorescent material at home andabroad.A detailed analysis of the phosphorescence mechanism,methods of synthesis and current status ofresearch is given by taking the aluminates activated by rare-earth ion as an exam ple,especially for theresearch of the femtosecond laser-induced long-lasting phosphorescent material.The further researchitems and developmental prospects of the materials were proposed.K ey w ords:Long-lasting;Rare-earth ion;Phosphorescence mechanism;Femtosecond laser;Induced-structure1 前言长余辉发光是指当激发光源切断后能持续发光的现象。
海洋硫酸多糖类药物聚甘古酯单克隆抗体的制备及其特性研究_cropped
海洋硫酸多糖类药物聚甘古酯单克隆抗体的制备及其特性研究1, 辛现良1 , 耿美玉1 3, 朱建春2 , 杨 明2 , 李 勇2陈(1. 青岛海洋大学 药物与食品研究所 , 山东 青岛 266003 ; 2. 长春生物制品研究所 血液制品研究室 , 吉林 长春 130012)摘要 : 目的 制备和纯化聚甘古酯 (911) 单克隆抗体 ,为 911 药代动力学的免疫学方法的建立提供依据 。
方法用还原胺化法 ,制备 9112BS A 和 9112HS A 复合物 ,间接 E L I S A 法检测抗体生成 。
以 Isostrip T M试剂盒测定抗体亚型 ,流式细胞仪测定 DNA 含量 。
结果 获得了一株阳性杂交瘤细胞 DD3 ,腹水效价可达 1 ×105,其抗体亚型为 IgG 2a (κ) , 细胞株的 DNA 含量约为脾细胞和 NS 21 细胞之和 ,亲和力常数为 210 ×108 L 〃m ol - 1。
结论 本实验制备了特异性针 对 911 的单克隆抗体 DD3 ,且与内源性多糖和褐藻酸无交叉反应 ,为 911 药代动力学的免疫学检测提供了依据 。
关键词 : 海洋硫酸多糖 ; 聚甘古酯 ; 单克隆抗体 ; 抗艾滋病药物 文章编号 : 0513 - 4870 (2003) 01 - 0023 - 04中图分类号 : R 967文献标识码 : APrep aration and characterization of m onoclonal antibody aga i nst m arinesulfated polysaccharid e d rug poly 2m annaguluronic acidCHE N Kun 1, XI N X ian 2liang 1, GEN G Mei 2yu 1, ZH U J ian 2chun 2, Y AN G Ming 2, L I Y ong2( 1 . Marine Drug and F ood Institute , Ocean University o f Qingdao , Qingdao 266003 , C hina ;2 . Biologics Institute o f Changchun , Changchun 130012 , C hina )Abstract : Aim T o prepare and characteriz e the m onocl onal antibody against poly 2m annaguluronic acid(911) . M ethod s A hybridom a cell line was obtained by cl oning for 3 tim es those cells that secret antibody against 911 after the fusi on of NS 21 m yel om e cells with spleen cells from Balb Πc m ice imm unized with a 9112 bovine serum albumin conjugate , prepared by reductive aminati on. Hybridom a was inoculated to Balb Πc m ouse to induce ascites. The antibody was puri fied by amm onium sul fate and Protein A - Sepharose C L 24B . DD3 was confirm ed to be fusi on cells after determinati on of DNA content with fl ow cytom etry. C om petitive inhibitory test and Biacore confirmed the cross 2reactivity of the antibody with other endogenous polysaccharides or with alginic acid sodium. Igs ′classes and subclasses were identi fied by Isostrip TMm ethod. The affinity of DD3 was verified by E L IS A. Results A hybridom a cell line secreting m onocl onal antibody against 911 (m arine sul fate polysaccharide ) named DD3 was obtained. The DD3 ascites contained speci fic antibody with titer over 110 × 105. There was no cross 2reactivity of these antibodies with other endogenous polysaccharides or with alginic acid sodium. The imm unogl obulin subclass of DD3 was IgG 2a ,κ type . The affinity of DD3 was 210 ×108L 〃m ol - 1. Conclusion One hybirdom a line (DD3) secreting m onocl onal antibody against 911 was established to provide a potential m ethod for the pharm acokinetic study of 911 .K ey w or ds : m arine sul fated polysaccharide ; poly 2m annaguluronic acid ; m onocl onal antibody ; anti 2AIDs agent多糖有抗凝血 、抗病毒 、抗氧化 、神经营养和保护等多种生物学活性 。
iSpartan软件在有机波谱解析教学中的应用
iSpartan软件在有机波谱解析教学中的应用
李继贞;郭玉鹏
【期刊名称】《化学教育》
【年(卷),期】2016(037)016
【摘要】介绍了iSpartan软件的特点及其在有机波谱解析教学中的具体应用.分子红外振动模型和红外与核磁波谱的吸收峰归属是波谱教学中的实践难点.通过iSpartan软件的简单可视化操作,使教学内容形象生动,有助于学生感性认知和深刻理解此部分内容,提高了波谱解析课程的教学效果.
【总页数】3页(P70-72)
【作者】李继贞;郭玉鹏
【作者单位】吉林大学化学学院长春130023;吉林大学化学学院长春130023【正文语种】中文
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本科毕业设计(论文)外文翻译题目家具企业对外贸易现状及其对策—以宜家为例姓名徐晶莹专业班级11级国际经济与贸易六班学号201136173指导教师楚明钦财经学院二零一五年三月Furniture remains the largest home furnishings and housewares sector.Bulgaria’s furniture industry is a dynamically developing sector in the past few years. It is well known that most furniture companies in the country are based on strong traditions and good correlation between price and quality, but (as in many other countries), although the major part of the customers on the inner market prefer Bulgarian-made furniture, high prices are seen as a sign of high quality, so most furniture pieces produced by the companies are considered high priced and hardly affordable for the majority of people.IKEA was founded in 1943 by Ingvar Kamprad. It started as a place where a person can buy pens, picture frames, watches, etc. and with the time turned to be the world’s largest furniture retailer. One of the main aims of the organisation include: keeping costs low and assist customers and products combining good quality, durability and functionality and this replies to the needs of the Bulgarian customer. Trough analyzing the situation within the country and IKEA the decision to open an IKEA store in Sofia was taken.A PEST analysis was held to recognize all the factors that might have an effect on the company entering the Bulgarian market. The current situation of the furniture industry was analyzed and trough that the target market and the positioning of IKEA were identified. The competitors’ and customers’ analyzes that were made show what IKEA has to adapt to when entering the market of the country. The Internal and SWOT analysis show why IKEA has the opportunity to enter, develop and gain a market share in the Bulgarian furniture sector. The Market was researched and based on all that the marketing mix strategies were developed. And a PERT analysis was also held to show how the decisions made will be implemented.PEST AnalysisPolitical Factors: -The political environment in Bulgaria is constantly changing due to financial instability and changes in lows and regulations that are closely related to the economic development and trade policy in the country. -Lately the Bulgarian government is famous with its inadequate decisions which directly reflect on the business environment in the country. The furniture industry as well as many others is handicapped by the high value added tax (20% V AT); -An official code of ethics is conducted by the government; however it is not widely adopted by the companies and organizations in the country. The Bulgarian government does not force the companies within the country to follow the ethic code; -The government policy’s on the economy is changing constantly due to the fact that Bulgariajoined EU in 2007. the reason for this is that our economy is striving to reach the level of other European countries’ economie s; -The government is trying to remain neutral when considering and religious issues in the country. It is striving to protect the official religion in Bulgaria which is Orthodox Christianity. Nonetheless, the government allows the existence of other religions in the country and it is trying to keep the tolerance between religions. There is lack of government’s involvement in the protection and development of the cultureBulgaria is a member of the European Union and a member of WTO ( World Trade Organization); Economic Factors:- According to the European commission statement, the real annual GDP per capita is accelerating for the past two years. In 2006, the GDP was 6.1% which was almost double the GDP of EU. In 2007 it reached 6.5% and for 2008 it is expected to top 7%. The level of employment has been rising also for the past two years. In 2007 it reached 9% per capita and it is expected to reach 7% in thefirst half of 2009. In 2007, the level of inflation has dropt dawn to 4.1%. However, according to the data gathered by the National Statistic Institute (NSI), the shrinking of the labor market and the rising of salaries will be the main reason for high inflation in 2008 and 2009. In 2006 the interest rates were 3.9%, in 2007; it has increased to 4.8%. Presently, the interest rates are 4.78%. Socio-cultural Factors: -The dominant one is Orthodox Christianity. The average age of the Bulgarian population is 75 years. The older generations are not wealthy. Women and men share equal rights. However, it is still noticeable the fact that greater percentage of the women are still being only housewives. A positive attitude towards foreign products occurs on first place. The average Bulgarian person cannot allow to himself long time for leisure. Only a small percentage of the population has time for leisure. According to a research done by the National Statistical Institute, the annual income per capita is 2831 BGN.Technological Factors: -the adoption of new technologies in Bulgaria opens new markets for the Bulgarian products and services and also increases their quality; -distribution has also changed due to technological development (online distribution); -New technologies also reflected on the communication with consumers by making them better and more intensive (including online marketing);Current Situation AnalysisMarket Definition and Market SizeThe furniture industry in Bulgaria is well developed and there is a number ofcompanies with high reputation that serve the market. The furniture manufacturing in Bulgaria is growing rapidly and a proof for this is the 30% increase since 2007. The rise in sales is also very noticeable. According to the Analysis on development, manufacturing and sales of furniture inBulgaria done by the National Statistical Institute, the level of sales is twice higher in 2007 compared to the sales performed in 2006. The import of furniture is becoming more and more intensive during the last two years. In 2006, the imported furniture increased with 38% in the second half of the year and in 2007 it reached 44%. The export of furniture is rising slower. Only 15.8% growth in the export is noticed for the last two years.Market Segmentation AnalysisAnalysis has been carried out in order to outline the target markets. Several segments have been examined. These are: -Households with average income 500-1000 BGN; -Offices; -Public Institutions such as schools, universities, hospitals; -Hospitality businesses;1.Households segmentThe approximate number of households in Bulgaria is 2 369 100 according to a research done by the National Statistical Institute in 2007. According to the results, 70% of all Bulgarian households would be interested in theproducts offered by the company, but could not afford them. However, only 35% of them or 829 185 households are potential consumers, as their average annual income is higher than the Bulgarian standards.2.Offices segmentThe approximate number of middle and large-sized companies in Bulgaria is 80 000. The following graphic presents the number of potential consumers among them. Approximately 48% of these companies will be interested in the products provided by the company. The reason for this is the company’s policy of self-assembling furniture and unwillingness of large businesses to purchase this type of products. However, 25% of all companies or 20 000 firms are considered as potential customers, because middle sized businesses will buy the products in order to reduce their expenses.3.Public InstitutionsAs already explained above, this market segment consists of educational institutions and hospitals. At the moment the secondary schools performing in the country are 2843 according to the National Statistical Institute. Only 30% of them would be interested in the products available, as they are private secondary schools and they are not subsidized by the government. However 8% of them or 227 schools are able to afford it and are considered to be potential consumers.The reason stated above considering the secondary schools applies on the other two segments and explains the percentages mentioned below. The approximate number of universities and colleges in Bulgaria is 48. 60% of them will be interested in the products, however, only 6% of them orapproximately 3 higher educational institutions are potential consumers.The approximate number of health care institutions in Bulgaria is 7500. Very smallpercentage of them will be interested in the products provided by IKEA-only 30%. 5% of them or approximately 112 are considered to be potential customers.4.Hospitality BusinessThis market segment consists of all hotels and motels that are presently performing in the country. The approximate number of hotels and other types of tourist accommodation places is 3 300. Almost 80% of them will show interest in the products of the company, because the products are lower priced. 45% of them or 1200 are considered to be potential customers, because they will have the budget needed to afford them.TargetingAccording to the segmentation analysis carried out, the segments that are appropriate for targeting are the households, offices and hospitality market segments. The main target segment will be the households due to the large number of potential customers. Public institutions are not considered as a target segment due to the lack of government subsidies which may allow the institutions to purchase IKEA’s products.Competitors AnalysisIn Bulgaria there are more than 1200 competitors. The main competitors of IKEA in Bulgaria are Mebel Style, Astra, Diva Style and Metron. These of them are large companies with stores in the large Bulgarian cities and their main offices are situated in Sofia. These companies have already built strong brand and high image and the majority of Bulgarians have good awareness of their products. The price lists of Diva Style and Mebel Style cannot be afforded it by great percentage of the Bulgarian population. Metron and Astra have lower priced products. However, their quality could not be compared with IKEA’s products. The import of Chinese furniture also outlines several major competitors for IKEA. The very low prices of the imported goods undercut the business of the Bulgarian furniture industry and a number of companies suffer the lost of customers and therefore the lost of profit.SWOT AnalysisStrengths-A global organization with good reputation built in the past 64 years. -It offers a wide range of home furnishing items with good design and function, excellent quality and durability, at low and affordable (for the majority of people) prices. -Within the company everyone can distribute to its development with their specialist knowledge. -Products are developed in close cooperation with suppliers and often only one supplier is appointed to supply all stores around the world which makes it easy to control the whole process. -The company has a good marketing strategy of attracting the customer through catalogues, but keeping them and giving them a reason to come back through good service. -IKEA uses leading-edge technology and the company has developed its own global distribution network. -It adapts easily to the demands customers might have . -Relies on simplicity and common sense when it comes to planning and strategic direction. -All design teams have complete autonomy in their work and are expected to design new and appealing products regularly.The company does not believe that quality comes with high prices and that allows them to concentrate on creating quality products rather than on competing with their competitors.-Long term relationship with suppliers. -Approaches unknown, relatively small and risk markets by franchising.Weaknesses-Having only one supplier dealing with supplies all over the world can be hard on first place for the supplier, and on second for the company because if some problems occur with that supplier the whole distribution process of the company is at threat and may cause serious problems. -IKEA does not have its own manufacturing facilities but uses subordinated manufacturers all over the world.Opportunities-The company has the opportunity to expand to even more countries and earn more customers. -Through deciding to target a new country for distributing their products and because the company uses subordinated manufacturers all over the world rather than having their own manufacturing facilities, IKEA has the opportunity to create new work placement for the local community and in terms increase the level of loyalty towards the company. -Working towards the total customer satisfaction as a result it might beexpected that customers will come back and buy again and if really satisfied they will advertise IKEA among other possible clients. -To meet all challenges that might occur, the company has the opportunity to find the properbalance between country level autonomy and centralized intervention.Threats- Expanding overseas equals: -increase in complexity of the logistic systems -more difficulties when responding to national needs and culturalsensitivity issues - Franchisees may demand more control over operations -Emerging demographic trends may force the organization to broaden its focus strategy to respond to varying nation-level groups - Design teams have complete autonomy in their work which might lead to losing control over them at some point during the working process. - When entering new international markets the company faces a risk of political, legal, cultural, financial, etc. issues. - Approaches unknown, relatively small and risk markets by franchising.Marketing Mix StrategiesProduct MixThe products available in IKEA are not going to be altered. The company’s policy of self-assembling is one of the winning points for the Bulgarian market. However, augmented products will be offered together with the main goods of the company. These products will be sold with the furniture and will be used for maintaining it. Augmented products will be provided by Bulgarian companies with good reputation. Such kind of products are varnishes, polishers and other preparations used for maintaining, the surfaces of the furniture.The furniture will also be available with repair kits. These will include the tools necessary for assembling and additional parts of the furniture, which in case of damage of the furniture will be used for replacement. When purchasing greater amount of products, a team of the company’s employees will perform the assembling of the products instead of the customer. This applies to the hospitality segment in particularly.Price MixIKEA’s products target the mass ma rket in Bulgaria. The main target segment is the households. Therefore, the prices will be decided in order to be affordable for them on the basis of their average annual income.In order to eliminate the competitors, the company will under-price them, by introducing slow growth of the prices of its products. Discounts will be available, when purchasing a certain amount of the products. Also when the company launches new product lines. This type of discounts will be available for short period of time. The augmented products will be free, when a greater amount of furniture products is purchased. The store will work together with several credit firms, which will allow the customers, to purchase the desired product by paying in installments. Certain discounts will be available for the use of the assembling team on the basisof the amount of furniture purchased. Applies mainly to the hospitality segment. The seasonal collections of IKEA will be available with discounts after the end of the active season. The summer collection will be sold during the winter and vice versa.Promotion MixThe company will be presented and promoted in national trade fairs for furniture design and solutions. Advertising campaign will be carried out by using billboards, and by having the company’s catalogues in the most popular daily newspapers and by posting them when the customers require. Advertisements will be included in specialized magazines for furniture and design such as “My Home” magazine. Advertisements will be placed in the mass media such as radio and television, such as the national TV channels BTV, BNT and NOV ATV. The company’s website will provide on-line catalogue and shopping in Bulgarian language. Advertising will be performed by using Google AdWords, Yahoo Search Engine Marketing and through various SEO optimizations of the official Bulgarian IKEA web site.Place/Distribution MixThe store will be placed in Sofia. The transportation costs of products (when the amount of them is big and special transport is n eeded) will be covered by the company, when it’s locally-within the city. Products will be distributed to big stores in the country, where they will be sold together with the products of other furniture companies. It is also considered to open offices in the big malls around the country, where products will be available for purchase.Implementation of strategiesBy carrying out PERT analysis and critical path analysis, the time needed for the implementation of the strategies has been estimated. The different activities to be performed have been distributed among the departments in the company. The overall time needed for the implementation of the plan is two months. Delays are also considered by using critical path analysis. These are shown below: PERT is a method to analyze the tasks involved in completing a given project, especially the time needed to complete each task, and identifying the minimum time needed to complete the total project.Optimistic time is the minimum possible time required to accomplish a task, assuming everything proceeds better than is normally expected.Pessimistic time is the maximum possible time required to accomplish a task, assuming everything goes wrong (but excluding major catastrophes).Most Likely Time is the best estimate of the time required to accomplish a task, assuming everything proceeds as normal.Expected time is the best estimate of the time required to accomplish a task, assuming everything proceeds as normal (the implication being that the expected time is the average time the task would require if the task were repeated on a number of occasions over an extended period of time).家具仍然是最大的家居用品和家居用品部门。