应《网络安全法》要求，自2017年10月1日起，未进行实名认证将不得使用互联网跟帖服务。为保障您的帐号能够正常使用，请尽快对帐号进行手机号验证，感谢您的理解与支持！

24小时热门版块排行榜    

小木虫论坛-学术科研互动平台 » 科研生活区 » English Cafe » Diary » SCI writing diary
1543/16返回列表上一页123456下一页末页
查看: 5266  |  回复: 153
只看楼主@他人 存档 新回复提醒 (忽略) 收藏    在APP中查看
本帖产生 2 个 ESEPI ，点击这里进行查看

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:01:38
on Friday, June 10th, 2022,
Mechanical properties of Fractions
stress-strain curves were measured for fraction specimen at a drawing rate of 50 mm/min at 25C, and the extension ratio was determined from the distance between the points on the specimen which was originally 0.5cm <apart >from each other. tensile impact test was carried out following ASTM 1822 at -70C ,-30C and 25C.  Sample specimens of sheets of 1mm<thickness>(tensile test) or 0.5mm<thickness>(tensile impact test ) were prepared by compress moulding <compression-mold>at 160C.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
21楼2022-06-10 08:35:46
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:01:45
on sunday, june 12th, 2022,
results and discussion
as reported in previous papers and as shown in table 3, fractions of lldpe by molecular weight (sgef fractions) have a wide molecular weight distribution(mwd) of mwd=1.1-1.3 and a wide intermolecular ccd which are characterized  with sec and cross-fractions, respectively. this wide ccd results in wide distributions of lamella thickness and crystallinity(xc).
transmission electron microscopy (tem) revealed that sgef fractions exhibited clearly two different types of lamellae, i.e., thick, long and straight lamella like those of high density polyethylene, and thin, short, curved lamellae which grew among the former ones. it was found from tem observations, dsc measurements and x-ray diffractions of cross-fractions that thick lamellae of about 140-180a thickness arise from highly crystalline components(xc>75%) of a few comonomer content which shows melting temperature of 《at》above 120c, and thinner ones of about 100a consist of the component having the average comonomer content, tm at about<around> 100-110c, <and the>crystallinity of about 60%. on the basis of these results, the author proposed <the>dsc index as a structure parameter using the multimodal (usually bimodal) broad endothermic curve of sgef fraction
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
22楼2022-06-12 15:19:34
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:01:51
On Monday, June 13th, 2022
As shown in Figure 1, DSC index is defined as SR/SA, where SR is the area of the second broad peak<around 100-110C>, and SA is that of the sharp peak around 120C, which is common to a commercial LLDPE of the density about 0.920. Consequently, DSC index indicates the degree of concentration of components having the average composition, <the> average crystallinity(ca. 60%), and the  lamella thickness of about 100A. In other words, it expresses CCD and <the distribution of the crystallinity and the lamella thickness>crystallinity and lamella thickness distribution. Therefore, as shown in Figure 2, it is <quite >reasonable <that a remarked correlation was observed > between DSC index and the coefficient variation for CCD for ethylene-butene-1 fractions <as shown in Figure 2>, because a narrow CCD <should> lead to a narrow lamella thickness distribution. Figure 2 also indicates the higer-a olefin copolymers have the narrower lamella thickness distribution than that of ethylene-butene-1 copolymer of the same <level of >CCD  <the reason for>This point will be discussed latter.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
23楼2022-06-13 21:57:59
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:01:58
on Thursday, June 16th, 2022
Figure 6 shows the endothermic curves of the SGEF fractions having molecular weight of 104,  Though samples have almost the same level of molecular weight, MWD, crystallinity and the heat of fusion as shown in figure 4, the DSC curve is remarkably different with each other and the feature of DSC index<indices> is reflected in table 4. DSC index was calculated for other SGEF fractions of the molecular weight range from 3 to 4 10^, and shown as a function of molecular weight in Figure 4. The molecular molecular weight dependence of DSC index is remarkably <significantly>different with each other among samples. sampels A, A' and B exhibited a flat or a little bit concave dependence of molecular weight. on the contrary, samples D, F and G clearly show a convex one. this situation results in a big difference in DSC index at the molecular weight range form a to b, suggesting a considerably difference in the distribution of crystallinity and<the >lamellae thickness for the fractions of this molecular weight range. To put it  concretely, for instance, lamella thickness distribution is judged to be narrow in order of A>a>B.......  The centralization of DSC index onto a small value at the high molecular weight region might be due to the decrease of the comonomer<content>at  high molecular weight  region which is a tendency common to all kinds of LLDPE
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
24楼2022-06-16 10:16:15
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:02:04
on Friday, June 17th, 2022
Comparing the DSC index among<the> samples of different kinds of comonomer, Figure 4 also shows <suggest> that  higher-a-olefin copolymers have narrower lamella thickness <distribution >than those of butene--1 compolymers<of the same of molecular weight>.  Judging from the result shown in Figure 2. this  would <not>be not because of the difference in CCD but in the<a> kind of SCB.
the authors <already> have reported that butene-1 compolymer has  a tendency to form <make >thicker lamella compared to<than> higher a-olefin of the same level of molecular weight and  comonomer content from the DSC measurement and TEM observation<of cross-fractions >. we consider that this is because of the difference in the degree of the inclusion of the SCB into lamella crystals, judging from the the results of NMR spectrum measurements for the residue after the fuming nitric acid etching of various kinds of a-olefin copolymers. for instance, twice larger amount of ethylene branching was found to be included in the crystal compared to the iso -butyl branching <for melting-quenching samples>., suggesting that butene- copolymers could make thicker lamella compared to 4-methyl-pentene-1 of the same degree of comonomer content.  consequently, more inclusion of SCB should lead to a wider lamella thickness distribution as shown in Figure 5, turning out to be a small DSC index <as seen> in Figure 2-4.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
25楼2022-06-17 09:15:14
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2 2022-07-01 14:02:10
On Saturday, June 18th, 2022
From the discussed above, it would be concluded that
1)        SGEF fraction has wide intermolecular distributions of the chemical composition, the crystallinity and the lamella thickness,
2)        For copolymers of the same kind of comonomers, narrow CCD leads to narrow structure distribution on the crystalline level, and
3)        Higher a-olefin copolymers exhibit narrow lamella thickness distribution than that of butene-1 copolymer even if CCD is on a level with each other.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
26楼2022-06-18 21:17:59
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:02:15
On Sunday, June 19th, 2022,
Mechanical properties
<The >Tensile test and <the> tensile impact test were carried out for SGEF fractions of molecular weight range from <of >A to B. Typical stress-strain curves for buten-1 copolymer fractions was  <are>shown in Figure 6. Fractions of molecular weight less than C were brittle and elongation is<was> impossible<not possible>. As for the critical molecular weight above which the mechanical properties of PE can be experimentally measured, Huang et, al. investigated the effect of molecular weight and of branching density on<the> slow crack growth for a series of ethylene homopolymers and ethylene-hexene-1 copolymers. The reported critical molecular weight seems to be in accordance with the value described here at which the tensile strength can<could> be observed.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
27楼2022-06-19 21:14:29
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:02:20
on June 20th, 2022
Necking was observed during elongation for the fractions of molecular weight above 3*104. <Further>FT type elongation (elongation with stress increase )was observed for the fractions of molecular weight above 5*104 as shown in Figure 6. This type elongation occurred for molecular weight range above 3*104 in<the> case of high<higher> a-olefin copolymer fractions. A and B increased with increasing molecular weight. molecular weight dependences of A  at break(A), B and the slope of stress increase after necking  were shown in Figure 7 a-c. here, A was calculated using the true stress, considering the decrease of the cross-section <of sample specimen>with elongation. B increased discretely at 3*104 for butene-1 copolymer and 2*104 for higher- a-olefin copolymer, and above this critical molecular weight, B ididnot show <a> significant dependence both on molecular weight and a kind of comonomer. on the other hand,both  A and B increased <gradually>with increasing molecular weight. higher a-olefin copolymer showed higher values of A and B in the molecular weight region from C to D. Further, there appeared a difference in A <among> butene-1 copolymers  of the same molecular weight range.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
28楼2022-06-20 20:39:49
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, good job 2022-07-01 14:02:27
on Tuesday, June 21th, 2022
Molecular weight dependence of the tensile impact strength measured at 25C for LLDPE fractions and ethylene homopolymer is shown in Figure 8. A for LLDPE fractions increased with the increasing molecular weight, reached a maximum at molecular weight range of about 1-2*105, and then decreased slightly approaching <the line of> ethylene homopolymer fractions. Molecular weight above which A could be measured is 2*104 for higher-a olefin copolymer, 4*104 for butene-1 copolymer and 8*104 for ethylene homopolymer fractions. the decrease of A at high molecular weight <region> seems to be corresponding to the increase of density. in the case of HP-LDPE(whole polymer), A is known to increase linearly with Mw^3.3. the difference in molecular weight dependence of A between LDPE and LLDPE is <would be> mainly due to the difference in CCD and molecular weight dependence of the density.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
29楼2022-06-21 08:39:10
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖

236839923

铁杆木虫 (正式写手)
★ ★
ksq887: 金币+2, thanks for sharing~ 2022-07-01 14:02:37
on Wednesday, June 22th, 2022,
Comparing A among fractions having the same molecular weight, there appear great differences for the molecular weight range from A to B  as shown in Figure 8.  Since fractions of the same of molecular weight have the same level of crystallinity and sharp MWD., the differences in A are considered to be due to the differences in CCD and structure distribution on the crystalline level. thus, A <of the fractions >are <was>  plotted as functions of C and DSC index. C increaseed with narrowing CCD as shown in Figure 9. However this relationship could not be expressed by a single line but a double one, i.e., higher a-olefin copolymer showed higher C than that of butene-1 compolymers at the same degreee of CCD.  on the other hand, A of fractions exhibits definitive relationship with DSC index regardless of the type of comonomer.(Figure 10a and b), suggesting C is essentially governed structure distribution on the crystalline level, and the narrower distribution of crystallinity and the lamella thickness give higher impact strength.
赞一下 回复此楼
十四万人齐解甲，竟无一个是男儿
30楼2022-06-22 08:34:45
 已阅   回复此楼   关注TA 给TA发消息 送TA红花 TA的回帖
相关版块跳转 我要订阅楼主 236839923 的主题更新
1543/16返回列表上一页123456下一页末页
普通表情 龙 兔 虎 猫 高级回复(可上传附件) SCI英文润色翻译-EnPapers美团队-先修改后付款
最具人气热帖推荐 [查看全部] 作者 回/看 最后发表
[论文投稿] 求助大神，Fe和Al离子对MOF都有淬灭，当两种离子共存时，怎么区分两种离子？ 10+3 maoxiao 2024-06-02 3/150 2024-06-03 01:43 by nono2009
[硕博家园] 实验室太吵闹，无法安静学习，怎么办？ +8 utahh 2024-05-31 15/750 2024-06-03 00:40 by utahh
[基金申请] 为什么美国要封锁华为而不封锁丘C同呢？ +8 zju2000 2024-06-02 9/450 2024-06-03 00:08 by 瞬息宇宙
[硕博家园] 又想换工作 +15 brightmj 2024-05-27 25/1250 2024-06-02 23:57 by brightmj
[论文投稿] Scientific reports 投稿 +4 chencome12 2024-06-02 4/200 2024-06-02 21:39 by lizhengke06
[基金申请] 入职高校3年发表10+SCI，尽人事听天命 +33 kaoyan250 2024-05-27 48/2400 2024-06-02 19:17 by kaoyan250
[基金申请] 离职后国自然项目不能变更单位，在新单位还能申请新的国自然项目吗 5+3 宜兰 2024-05-31 10/500 2024-06-02 17:50 by 月五年子庚
[基金申请] 化学B02口青基 代表作都是什么水平的？向大佬求助 +12 arthas_007 2024-06-01 14/700 2024-06-02 16:18 by 夏木荫浓
[基金申请] 讨论贴：好本子一定会被打招呼的淘汰吗 +40 ioe3937 2024-05-27 51/2550 2024-06-02 13:52 by Howard28
[论文投稿] 选期刊 5+3 jfdhj 2024-05-29 4/200 2024-06-02 13:30 by bobvan
[论文投稿] 没收到邮件 10+4 荣小撇 2024-05-31 9/450 2024-06-02 13:25 by bobvan
[考博] 导师不让硕转博，让我去国外读博，能理解吗？ +12 萧山幽谷 2024-05-29 20/1000 2024-06-02 12:01 by yuan0806
[硕博家园] 讨厌酒桌文化 +7 hahamyid 2024-05-31 7/350 2024-06-02 10:01 by 御龙老大
[考博] 申请2024或2025年博士研究生 +5 嘟噜嘟1 2024-05-29 12/600 2024-06-01 22:36 by 嘟噜嘟1
[教师之家] 研究生在毕业答辩时挂了，遗憾 +10 spacr2022 2024-05-27 13/650 2024-06-01 17:45 by keyaner23
[基金申请] B口人才项目 +9 WOWO159357 2024-05-29 19/950 2024-06-01 14:24 by linxuhuizj
[教师之家] 中年 (金币+3) +18 459582015 2024-05-28 19/950 2024-06-01 00:41 by 沈婉婷.Girl
[基金申请] 信息学部函评结束了吗？ +6 ducan21 2024-05-28 7/350 2024-05-29 12:10 by WORLD0256
[有机交流] 奇怪的物质 100+4 桃桃PXS 2024-05-27 7/350 2024-05-28 10:22 by 091602
[硕博家园] 课题做到一半担心做不出来怎么办 +4 mkpooooo 2024-05-27 7/350 2024-05-27 11:56 by kanmiaolucky
信息提示
关闭
请填处理意见
关闭