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Soluble triggering receptor expressed on myeloid cell-1 (sTREM- 1): a potential biomarker for the diagnosis of infectious diseases 被引量:65
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作者 Changlin Cao Jingxian Gu Jingyao Zhang 《Frontiers of Medicine》 SCIE CAS CSCD 2017年第2期169-177,共9页
Sensitive and useful biomarkers for the diagnosis and prognosis of infectious diseases have been widely developed. An example of these biomarkers is triggering receptor expressed on myeloid cell-1 (TREM-1), which is... Sensitive and useful biomarkers for the diagnosis and prognosis of infectious diseases have been widely developed. An example of these biomarkers is triggering receptor expressed on myeloid cell-1 (TREM-1), which is a cell surface receptor expressed on monocytes/macrophages and neutrophils. TREM-1 amplifies inflammation by activating the TREM-1/DAP12 pathway. This pathway is triggered by the interaction of TREM-1 with ligands or stimulation by bacterial lipopolysaccharide. Consequently, pro-inflammatory cytokines and chemokines are secreted. Soluble TREM-1 (sTREM-1) is a special form of TREM-1 that can be directly tested in human body fluids and well-known biomarker for infectious diseases, sTREM-1 level can be potentially used for the early diagnosis and prognosis prediction of some infectious diseases, including infectious pleural effusion, lung infections, sepsis, bacterial meningitis, viral infections (e.g., Crimean Congo hemorrhagic fever and dengue fever), fungal infections (e.g., Aspergillus infection), and burn-related infections, sTREM-1 is a more sensitive and specific biomarker than traditional indices, such as C-reactive protein and procalcitonin levels, for these infectious diseases. Therefore, sTREM-1 is a feasible biomarker for the targeted therapy and rapid and early diagnosis of infectious diseases. 展开更多
关键词 soluble triggering receptor expressed on myeloid cells-l infectious diseases diagnosis and prognosis BIOMARKER
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Change of hs-CRP,sVCAM-1,NT-proBNP levels in patients with pregnancy-induced hypertension after therapy with magnesium sulfate and nifudipine 被引量:46
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作者 Li Wang Zhi-Qiang Liu +3 位作者 Ying-Qian Huo Li-Juan Yao Xue-Gong Wei Yun-Fang Wang 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2013年第11期897-901,共5页
Objective:To investigate the change of the hs-CRP,sVC AM-1,NT-proBNP levels of the patients with pregnancy-induced hypertension(PIH) syndrome.Methods:A total of 200 patients with PIH were divided into mild,moderate an... Objective:To investigate the change of the hs-CRP,sVC AM-1,NT-proBNP levels of the patients with pregnancy-induced hypertension(PIH) syndrome.Methods:A total of 200 patients with PIH were divided into mild,moderate and severe group,and 50 healthy pregnancy patients served as the control group.The serum sVCAM-1 levels were detected by enzyme-linked immunosorbent assay,hs-CRP were detected by immunity transmission turbidity,and NT-proBNP levels were determined by the colloidal gold method.Patients were treated with magnesium sulfate and nifudipine and the contrastive analysis was performed before and after treatment.And the pathological changes in placental of PIH patients were delected by hematoxylin-eosin staining at the same time.Results:The hs-CRP,sVCAM-l,NT-proBNP levels of patients in the mild, moderate and severe PHI group were significantly higher than that in the control group(P<0.05). The hs-CKP,sVCAM-l,NT-proBNP levels in the severe group were significantly higher than the mild group and the moderate group,the difference was statistically significant(P<0.05).The hsCRP,sVCAM-l,NT-proBNP of the moderate group were significantly higher than the mild group(P<0.05).There was a positive correlation between hs-CRP,sVCAM-1,NT-proBNP expression levels and the degree of the PIH.The expression of hs-CRP,sVCAM-1,NT-proBNP levels of the moderate and the severe group were significantly decreased(P<0.05).The number of placental villi and interstitial blood vessel in the moderate and severe PIH group were significantly less than the control group(P<0.05).Conclusions:The increased levels of serum hs-CRP,sVCAM-1, NT-proBNP may be involved in the process of vascular endothelial cell injury of the PIH,and the hs-CRP,sVCAM-1,NT-proBNP can be used as the auxiliary index for diagnosis of PIH and determination of PIH severity. 展开更多
关键词 Pregnancy-induced hypertension soluble vascular cell adhesion MOLECULE-1 Ultra-sensitivity C-reactive protein Amino-terminal pro-brain NATRIURETIC peptide
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可溶性ST2对心力衰竭患者死亡的预测价值 被引量:46
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作者 张荣成 张宇辉 +7 位作者 张健 黄燕 郭潇 王运红 安涛 周琼 吕荣 季诗明 《中华心血管病杂志》 CAS CSCD 北大核心 2014年第9期726-730,共5页
目的 观察住院心力衰竭(心衰)患者血浆可溶性ST2(sST2)水平与其他指标的相关性,探讨其对心衰患者死亡的预测价值.方法 入选2009年3月至2012年7月阜外心血管病医院心力衰竭中心以心衰为主要原因住院的患者1 244例.采用酶联免疫吸附... 目的 观察住院心力衰竭(心衰)患者血浆可溶性ST2(sST2)水平与其他指标的相关性,探讨其对心衰患者死亡的预测价值.方法 入选2009年3月至2012年7月阜外心血管病医院心力衰竭中心以心衰为主要原因住院的患者1 244例.采用酶联免疫吸附法测定患者入院时血浆sST2水平.随访1年,终点事件为全因死亡.结果 1 244例心衰患者死亡193例.患者入院时血浆sST2水平与N末端B型利钠肽原(NT-proBNP)、纽约心脏病协会(NYHA)心功能分级以及心率呈正相关,与左心室射血分数(LVEF)、收缩压、血钠、总胆固醇、肾小球滤过率呈负相关.1年内死亡患者血浆sST2水平明显高于未死亡者(P<0.01).多因素Cox回归模型分析显示,患者基线sST2水平与死亡明显相关,LnsST2每变化1个单位风险增加1.87倍.sST2对预后判断的ROC曲线下面积(AUC=0.776)与NT-proBNP(AUC=0.775)近似,将二者联合应用预测效果(AUC =0.813)明显提高.结论 住院心衰患者基线sST2水平与临床及生化变量相关.sST2可以独立预测心衰患者的全因死亡,且与NT-proBNP联合应用可增加预测能力. 展开更多
关键词 心力衰竭 充血性 死亡 ST2 可溶性
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Mesoporous silica nanoparticles for drug and gene delivery 被引量:38
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作者 Yixian Zhou Guilan Quan +6 位作者 Qiaoli Wu Xiaoxu Zhang Boyi Niua Biyuan Wu Ying Huang Xin Pan Chuanbin Wu 《Acta Pharmaceutica Sinica B》 SCIE CAS CSCD 2018年第2期165-177,共13页
Mesoporous silica nanoparticles(MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume,selective surface functionality, as... Mesoporous silica nanoparticles(MSNs) are attracting increasing interest for potential biomedical applications. With tailored mesoporous structure, huge surface area and pore volume,selective surface functionality, as well as morphology control, MSNs exhibit high loading capacity for therapeutic agents and controlled release properties if modified with stimuli-responsive groups, polymers or proteins. In this review article, the applications of MSNs in pharmaceutics to improve drug bioavailability, reduce drug toxicity, and deliver with cellular targetability are summarized. Particularly,the exciting progress in the development of MSNs-based effective delivery systems for poorly soluble drugs, anticancer agents, and therapeutic genes are highlighted. 展开更多
关键词 Mesoporous silica nanoparticles Poorly soluble drug Cancer therapy Multidrug resistance Gene delivery
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Map-based cloning of the ALK gene,which controls the gelatinization temperature of rice 被引量:33
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作者 高振宇 曾大力 +5 位作者 崔霞 周奕华 颜美仙 黄大年 李家洋 钱前 《Science China(Life Sciences)》 SCIE CAS 2003年第6期661-668,共8页
Gelatinization temperature (GT) is an important parameter for evaluating the cooking and eating quality of rice besides amylose content (AC). The inheritance of the genes affecting GT has been widely studied and is co... Gelatinization temperature (GT) is an important parameter for evaluating the cooking and eating quality of rice besides amylose content (AC). The inheritance of the genes affecting GT has been widely studied and is considered to be controlled by a major gene. Here, we report the map-based cloning of rice ALK that encodes the soluble starch synthase II (SSSII). Comparison between the DNA sequences from different rice varieties, together with the results obtained with digestion of the rice seeds in alkali solution, indicates that the base substitutions in coding se-quence of ALK may cause the alteration in GT. 展开更多
关键词 rice (Oryza sativa L.) ALK soluble starch synthase II gelatinization temperature map-based cloning.
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共缩聚型可溶性聚酰亚胺的合成与性能研究(1) 被引量:18
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作者 房建华 印杰 +3 位作者 徐宏杰 刘娜 蔡志云 朱子康 《高分子材料科学与工程》 EI CAS CSCD 北大核心 1998年第2期28-30,共3页
采用3,3′-二甲基-4,4′-二氨基二苯甲烷,4,4′-二氨基二苯醚或4,4′-二氨基二苯甲烷为共缩聚二胺单体与二苯醚3,3′-,4,4′-四酸二酐进行缩聚制备共缩聚型聚酰亚胺。当3,3′-二甲基-4,4′-二氨基... 采用3,3′-二甲基-4,4′-二氨基二苯甲烷,4,4′-二氨基二苯醚或4,4′-二氨基二苯甲烷为共缩聚二胺单体与二苯醚3,3′-,4,4′-四酸二酐进行缩聚制备共缩聚型聚酰亚胺。当3,3′-二甲基-4,4′-二氨基二苯甲烷与4,4′-二氨基二苯醚的摩尔比为10∶0~4∶6或3,3′-二甲基-4,4′-二氨基二苯甲烷与4,4′-二氨基二苯甲烷的摩尔比在10∶0~5∶5时,所得聚酰亚胺可溶解于强极性有机溶剂。所得可溶性聚酰亚胺在NMP中的特性粘度在0.87~1.45dL/g.它们在氮气中的热降解起始温度在504℃以上,并且在研究范围内与共聚二胺的结构及比例无明显关系。 展开更多
关键词 聚酰亚胺 可溶性 共缩聚 性能 合成
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Long-term follow-up of the effects of fecal microbiota transplantation in combination with soluble dietary fiber as a therapeutic regimen in slow transit constipation 被引量:33
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作者 Xueying Zhang Hongliang Tian +6 位作者 Lili Gu Yongzhan Nie Chao Ding Xiaolong Ge Bo Yang Jianfeng Gong Ning Li 《Science China(Life Sciences)》 SCIE CAS CSCD 2018年第7期779-786,共8页
As some studies have reported that strategies targeting the gut microbiota such as fecal microbiota transplantation(FMT) with or without other microecological therapy might have efficacy in treating slow transit const... As some studies have reported that strategies targeting the gut microbiota such as fecal microbiota transplantation(FMT) with or without other microecological therapy might have efficacy in treating slow transit constipation(STC), we conducted a singlecenter, open-label trial to study the long-term effect of FMT combined with soluble dietary fiber(pectin) on STC. Thirty-one adult patients with STC were enrolled into the trial. Patients received 6-day FMT procedures repeatedly for the first 3 months and soluble dietary fiber(pectin) daily during the follow-up. The rate of clinical remission and improvement, stool consistency, the Wexner constipation scale, and assessment of constipation-related symptoms were evaluated at week 4 and 1 year later. The clinical remission and improvement rates at week 4 were 69.0%(20/29) and 75.9%(22/29), respectively. At the end of the study,48.3%(14/29) of patients continued to have at least three complete spontaneous bowel movements per week and 58.6%(17/29)of patients showed clinical improvements. Stool consistency, the Wexner constipation scale, and constipation symptoms improved both at short-term and long-term follow-up. The results indicated that FMT in combination with soluble dietary fiber(pectin) had both short-term and long-term efficacy in treating STC. 展开更多
关键词 fecal microbiota transplantation soluble dietary fiber slow transit constipation long-term efficacy
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Anti-tumor Effect and Protective Effect on Chemotherapeutic Damage of Water Soluble Extracts from Hedyotis diffusa 被引量:24
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作者 李瑞 赵浩如 林以宁 《Journal of Chinese Pharmaceutical Sciences》 CAS 2002年第2期54-58,共5页
Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic mater... Bai-Hua-She-She-Cao Hedyotis diffusa Willd. (Ru-biaceae) is a medicinal herbwidely distributed in northeast Asian countries. In traditional Chinese medicine, it has the effectof 'clearing away heat and toxic material, promoting blood circulation and removing blood stasis'.It is a well known Chinese folk-medicine used for the treatment of appendicitis, sore throat, mumps,acne, sebo-rheic dermatitis and various kinds of tumors, such as tumors of digestive tract,carcinoma of liver. It was reported that the MeOH extract of H. diffusa demonstrated a significantantitumor activity and ursolic acid succeeded in being isolated from the MeOH extract as an activecomponent . Shan BN, et al suggested that the direct aqueous extract of H. diffusa hadimmuno-modulating activity and antitumor activity in vitro through stimulating the immune system tokill or engulf tumor cells. But regarding anti-tumor activity in vivo of water soluble extracts fromH. diffusa, no detail was reported. Therefore, we prepared water soluble extracts (H_1 and H_2)from H. diffusa and evaluated their anti-tumor property in vivo experiments as well as protectiveeffect on chemo-therapeutic damage. 展开更多
关键词 hedyotis diffusa water soluble extracts ANTI-TUMOR CHEMOTHERAPY
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Serum leptin and soluble leptin receptor in non-alcoholic fatty liver disease 被引量:26
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作者 Xiao-Dong Huang Yan Fan +4 位作者 Hen Zhang Ping Wang Jing Ping Yuan Ming-Jie Li Xi-Yan Zhan 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第18期2888-2893,共6页
AIM: To determine the role of leptin system in non-al- coholic fatty liver disease (NAFLD) development by deli- neating the changes in serum levels of leptin and soluble leptin receptor (sOB-R). METHODS: Blood samples... AIM: To determine the role of leptin system in non-al- coholic fatty liver disease (NAFLD) development by deli- neating the changes in serum levels of leptin and soluble leptin receptor (sOB-R). METHODS: Blood samples were collected from 30 consecutive patients with liver-biopsy-proven NAFLD and 30 patients with cholecystolithiasis (stationary phase) as controls. Serum leptin levels were determined by radio- immunoassay and concentration of sOB-R was measured by ELISA. Body mass index (BMI) was calculated for all subjects, and serum insulin, C-peptide, and lipoprotein levels were also detected. RESULTS: Mean serum leptin level and BMI in the NAFLD group were significantly higher than in the con- trols (both P < 0.001), but mean sOB-R level was lower in the NAFLD group when compared to the controls. Both men and women in the NAFLD group had higher mean serum leptin levels and lower sOB-R levels than did the men and women in the control group (all P < 0.001). The- re was a significant negative correlation between serum leptin and sOB-R levels (r = -0.725, P < 0.001). Multiva- riate analysis showed that the percentage of hepatocyte steatosis, sex, BMI, and homeostasis model assessment of insulin resistance (HOMA IR) were independently rela- ted to serum leptin levels. CONCLUSION: Elevated serum leptin seems to be afeature of steatosis, and serum leptin seems to increase as hepatocyte steatosis develops. An enhanced release of leptin is accompanied by an decrease in sOB-R con- centration, which suggests higher resistance of periphe- ral tissues towards the action of leptin. 展开更多
关键词 LEPTIN soluble leptin receptor Non-alcoholic fatty liver disease
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Size distribution, characteristics and sources of heavy metals in haze episod in Beijing 被引量:27
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作者 Jingchun Duan Jihua Tan +1 位作者 Jiming Hao Fahe Chai 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2014年第1期189-196,共8页
Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and ... Size segragated samples were collected during high polluted winter haze days in 2006 in Beijing, China. Twenty nine elements and 9 water soluble ions were determined. Heavy metals of Zn, Pb, Mn, Cu, As, Cr, Ni, V and Cd were deeply studied considering their toxic effect on human being. Among these heavy metals, the levels of Mn, As and Cd exceeded the reference values of National Ambient Air Quality Standard (GB3095-2012) and guidelines of World Health Organization. By estimation, high percentage of atmospheric heavy metals in PM2.5 indicates it is an effective way to control atmospheric heavy metals by PM2.5 controlling. Pb, Cd, and Zn show mostly in accumulation mode, V, Mn and Cu exist mostly in both coarse and accumulation modes, and Ni and Cr exist in all of the three modes. Considering the health effect, the breakthrough rates of atmospheric heavy metals into pulmonary alveoli are: Pb (62.1%) 〉 As (58.1%) 〉 Cd (57.9%) 〉 Zn (57.7%) 〉 Cu (55.8%) 〉 Ni (53.5%) 〉 Cr (52.2%) 〉 Mn (49.2%) 〉 V (43.5%). Positive matrix factorization method was applied for source apportionment of studied heavy metals combined with some marker elements and ions such as K, As, SO42- etc., and four factors (dust, vehicle, aged and transportation, unknown) are identified and the size distribution contribution of them to atmospheric heavy metals are discussed. 展开更多
关键词 source apportionment positive matrix factorization PM2.5 water soluble ion health effect
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Predicting value of serum soluble ST2 and interleukin-33 for risk stratification and prognosis in patients with acute myocardial infarction 被引量:27
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作者 ZHANG Kun ZHANG Xin-chao +1 位作者 MI Yu-hong LIU Juan 《Chinese Medical Journal》 SCIE CAS CSCD 2013年第19期3628-3631,共4页
Background Acute myocardial infarction (AMI) is a common cardiac emergency with high mortality.Serum soluble ST2 (sST2) is a new emerging biomarker of cardiac diseases.The present study is to investigate the predi... Background Acute myocardial infarction (AMI) is a common cardiac emergency with high mortality.Serum soluble ST2 (sST2) is a new emerging biomarker of cardiac diseases.The present study is to investigate the predictive value of sST2 and interleukin-33 (IL-33) for risk stratification and prognosis in patients with AMI.Methods Fifty-nine patients with AMI,whose chief complaint was chest pain or dyspnea,were selected for our study.Physical examination,chest radiograph,electrocardiograph (ECG),biomarkers of myocardial infarction,NT-proBNP,echocardiography and other relevant examinations were performed to confirm the diagnosis of AMI.Thirty-six healthy people were chosen as the control group.Serum samples from these subjects (patients within 24 hours after acute attack) were collected and the levels of sST2 and IL-33 were assayed by enzyme-linked immuno-sorbent assay (ELISA) kit.The follow-up was performed on the 7th day,28th day,3rd month and 6th month after acute attack.According to the follow-up results we defined the end of observation as recurrence of AMI or any causes of death.Results Median sST2 level of the control group was 9.38ng/ml and that of AMI patients was 29.06ng/ml.Compared with the control group,sST2 expression in the AMI group was significantly different (P〈0.001).In contrast,the IL-33 level showed no significant difference between the two groups.Serum sST2 was a predictive factor independent of other variables and may provide complementary information to NT-proBNP or GRACE risk score.IL-33 had no relationship to recurrence of AMI.Both sST2 and the IL-33/sST2 ratio were correlated with the 6-month prognosis; areas under the ROC curve were 0.938 and 0.920 respectively.Conclusions Early in the course (〈24 hours) of AMI,sST2 usually increases markedly.The increase of sST2 has an independent predictive value for the prognosis in AMI patients and provides complementary information to NT-proBNP or GRACE risk score.The IL-33/sST2 ratio correlates with the 6-month prognos 展开更多
关键词 serum soluble ST2 interleukin-3 3 acute myocardial infarction risk stratification PROGNOSIS
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共聚态聚苯胺的合成及性能 被引量:17
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作者 马利 汤琪 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2003年第6期76-79,共4页
在不同的单体浓度和摩尔分率条件下,合成了聚苯胺-邻氨基苯甲酸、聚苯胺-邻甲氧基苯胺、聚苯胺-邻甲基苯胺和聚苯胺。用红外光谱表征了各聚合物的结构。对其溶解性、电致变色性进行了较详细的研究。结果表明:通过苯胺与带有极性或可溶... 在不同的单体浓度和摩尔分率条件下,合成了聚苯胺-邻氨基苯甲酸、聚苯胺-邻甲氧基苯胺、聚苯胺-邻甲基苯胺和聚苯胺。用红外光谱表征了各聚合物的结构。对其溶解性、电致变色性进行了较详细的研究。结果表明:通过苯胺与带有极性或可溶性基团的苯胺衍生物共聚可有效提高聚苯胺的溶解性和可加工性,溶解性好的共聚态聚苯胺可制得稳定性和电致变色性好的膜。聚苯胺-邻甲氧基苯胺不但具有较高的溶解性而且具有很好的电致变色特性,很容易加工制得电致变色性膜。 展开更多
关键词 共聚态 聚苯胺 合成 性能 电致变色 红外光谱 溶解性
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脂环族聚酰亚胺的性能研究 被引量:24
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作者 王宏远 印杰 +4 位作者 王晓瑞 孙立民 房建华 徐宏杰 朱子康 《高分子材料科学与工程》 EI CAS CSCD 北大核心 1997年第1期83-88,共6页
以脂环族酸酐-3,5,6-三羧基-2-乙酸基-二环[2,2,1]庚烷2∶3,5∶6二酸酐为二酐单体,二氨基二苯醚为二胺单体,在强极性有机溶剂中缩聚,并以乙酸酐进行化学亚胺化制得了脂环族聚酰亚胺,并对它的性能进行了测试... 以脂环族酸酐-3,5,6-三羧基-2-乙酸基-二环[2,2,1]庚烷2∶3,5∶6二酸酐为二酐单体,二氨基二苯醚为二胺单体,在强极性有机溶剂中缩聚,并以乙酸酐进行化学亚胺化制得了脂环族聚酰亚胺,并对它的性能进行了测试研究。此聚酰亚胺为无色透明,可溶于强极性有机溶剂,氮气保护下的热分解温度为460℃,玻璃化转变温度为217℃。 展开更多
关键词 聚酰亚胺 脂环族 可溶性 性能
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电感耦合等离子体质谱法测定食品接触材料中可溶性铅、镉、砷、汞 被引量:26
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作者 朱桃玉 郑艳明 +3 位作者 罗海英 彭荣飞 郭新东 吴玉銮 《现代食品科技》 EI CAS 2008年第8期842-844,共3页
建立了食品用粘合剂、塑料瓶等高分子食品接触材料中可溶性铅、镉、砷、汞和含量的电感耦合等离子体质谱检测方法。样品中铅、镉、砷、汞的可溶部分溶解在0.07mol/L的盐酸(模拟人体胃酸)中,用电感耦合等离子体质谱检测,内标法定量。在0.... 建立了食品用粘合剂、塑料瓶等高分子食品接触材料中可溶性铅、镉、砷、汞和含量的电感耦合等离子体质谱检测方法。样品中铅、镉、砷、汞的可溶部分溶解在0.07mol/L的盐酸(模拟人体胃酸)中,用电感耦合等离子体质谱检测,内标法定量。在0.5μg/L~100μg/L添加水平,回收率在88.6%~98.3%之间,精密度在1.8%~5.1%之间。 展开更多
关键词 电感耦合等离子体质谱法 食品接触材料 可溶性
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可溶性聚酰亚胺的合成与性能研究 被引量:15
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作者 李庆华 印杰 朱子康 《高分子材料科学与工程》 EI CAS CSCD 北大核心 1996年第2期38-42,共5页
采用“柔顺性”二胺单体4,4'-二(4-氨基苯氧基)二苯砜与二氨基二苯砜及二苯甲酮四甲酸酐进行共缩聚并在高温溶液亚胺化合成了可溶于NMP、DMAc、DMF等强极性溶剂的可溶性聚酰亚胺,并发现在本研究体系中,单纯提高分... 采用“柔顺性”二胺单体4,4'-二(4-氨基苯氧基)二苯砜与二氨基二苯砜及二苯甲酮四甲酸酐进行共缩聚并在高温溶液亚胺化合成了可溶于NMP、DMAc、DMF等强极性溶剂的可溶性聚酰亚胺,并发现在本研究体系中,单纯提高分子链柔顺性并不能很好地提高PI的可溶性,必须结合共缩聚方法以破坏分子链规整性,所得PI只有在4,4’-二(4-氨基苯氧基)二苯砜与二氨基二苯砜的摩尔比在3:7~6:4时才可溶。所得可溶性PI的特性粘度为0.21~0.38dl/g(NMP为溶剂,T=30℃),以DSC测得的玻璃化转变温度在250~290℃,氮气中热分解温度在500℃以上。 展开更多
关键词 聚酰亚胺 可溶性 共缩聚 合成 力学性能
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Chemical characteristics and source apportionment of PM_(2.5) between heavily polluted days and other days in Zhengzhou, China 被引量:24
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作者 Nan Jiang Qiang Li +5 位作者 Fangcheng Su Qun Wang Xue Yu Panru Kang Ruiqin Zhang Xiaoyan Tang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第4期188-198,共11页
PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual avera... PM(2.5) samples were collected in Zhengzhou during 3 years of observation, and chemical characteristics and source contribution were analyzed. Approximately 96% of the daily PM(2.5) concentrations and annual average values exceeded the Chinese National Ambient Air Quality Daily and Annual Standards, indicating serious PM(2.5) pollution. The average concentration of water-soluble inorganic ions was 2.4 times higher in heavily polluted days(daily PM32.5 concentrations &gt; 250 μg/mand visibility &lt; 3 km) than that in other days, with sulfate, nitrate, and ammonium as major ions. According to the ratio of NO-3/SO2-4,stationary sources are still the dominant source of PM(2.5) and vehicle emission could not be ignored. The ratio of secondary organic carbon to organic carbon indicated that photochemical reactivity in heavily polluted days was more intense than in other days.Crustal elements were the most abundant elements, accounting for more than 60% of 23 elements. Chemical Mass Balance results indicated that the contributions of major sources(i.e., nitrate, sulfate, biomass, carbon and refractory material, coal combustion, soil dust,vehicle, and industry) of PM(2.5) were 13%, 16%, 12%, 2%, 14%, 8%, 7%, and 8% in heavily polluted days and 20%, 18%, 9%, 2%, 27%, 14%, 15%, and 9% in other days, respectively.Extensive combustion activities were the main sources of polycyclic aromatic hydrocarbons during the episode(Jan 1-9, 2015) and the total benzo[a]pyrene equivalency concentrations in heavily polluted days present significant health threat. Because of the effect of regional transport, the pollution level of PM(2.5) in the study area was aggravated. 展开更多
关键词 PM2.5 Water soluble inorganic ions Secondary organic carbon CMB Back trajectory analysis
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分段压裂用可溶球的研制 被引量:25
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作者 刘运楼 李斌 +3 位作者 潘勇 谢明 唐欣 张毅超 《天然气工业》 EI CAS CSCD 北大核心 2016年第9期96-101,共6页
水平井分段压裂是包括页岩气在内的致密储层增产改造的主要技术措施,而目前主流的分段压裂工具中,水平井裸眼分段工具、套管滑套分段工具及大通径桥塞等都需要投球去打开分段滑套或暂时堵塞通道,投入管柱内的球也需要通过钻磨成碎屑才... 水平井分段压裂是包括页岩气在内的致密储层增产改造的主要技术措施,而目前主流的分段压裂工具中,水平井裸眼分段工具、套管滑套分段工具及大通径桥塞等都需要投球去打开分段滑套或暂时堵塞通道,投入管柱内的球也需要通过钻磨成碎屑才能排出管柱,其作业既费时又有风险。为此,根据现场需要,采用氢还原包覆技术先制备可溶球复合金属材料粉体,再通过粉末冶金法研制了金属基可溶性压裂球,并完成了室内模拟实验可溶解压裂球密度为1.8~2.0 g/cm^3,耐温150℃,抗压强度可达70MPa以上:应用现场压裂返排液浸泡考察其在规定时间下的溶解速度,一般溶解时间为10 d;模拟了目前分段压裂的井下环境(温度、压力)下压裂球的承压能力。结论认为,所研制的可溶解压裂球的承压性能和溶解性能能满足目前的分段压裂井下环境的需要,应根据溶解环境的不同来调整溶解速度。其免钻特性为水平井压裂工艺技术的发展提供了新的技术途径。 展开更多
关键词 致密储集层 水平井 分段压裂 金属基 可溶 压裂球 研制
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Chemical Composition of PM_(2.5) at an Urban Site of Chengdu in Southwestern China 被引量:23
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作者 陶俊 成天涛 +5 位作者 张仁健 曹军骥 朱李华 王启元 罗磊 张雷鸣 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2013年第4期1070-1084,共15页
PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The ann... PM2.5 aerosols were sampled in urban Chengdu from April 2009 to January 2010, and their chemical compositions were characterized in detail for elements, water soluble inorganic ions, and carbonaceous mat- ter. The annual average of PM2.5 was 165 btg m a, which is generally higher than measurements in other Chinese cities, suggesting serious particulate pollution issues in the city. Water soluble ions contributed 43.5% to the annual total PM2.5 mass, carbonaceous aerosols including elemental carbon and organic car- bon contributed 32.0%, and trace elements contributed 13.8~0. Distinct daily and seasonal variations were observed in the mass concentrations of PM2.5 and its components, reflecting the seasonal variations of dif- ferent anthropogenic and natural sources. Weakly acidic to neutral particles were found for PMz5. Major sources of PM2.u identified from source apportionment analysis included coal combustion, traffic exhaust, biomass burning, soil dust, and construction dust emissions. The low nitrate: sulfate ratio suggested that stationary emissions were more important than vehicle emissions. The reconstructed masses of ammonium sulfate, ammonium nitrate, particulate carbonaceous matter, and fine soil accounted for 79% of the total measured PM2.5 mass; they also accounted for 92% of the total measured particle scattering. 展开更多
关键词 water soluble ions carbonaceous matters trace elements enrichment factor source appor tionment mass closure
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Effects of Arbuscular Mycorrhizal Fungi Communities on Soil Quality and the Growth of Cucumber Seedlings in a Greenhouse Soil of Continuously Planting Cucumber 被引量:22
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作者 LI Yan CHEN Ying-Long +2 位作者 LI Min LIN Xian-Gui LIU Run-Jin 《Pedosphere》 SCIE CAS CSCD 2012年第1期79-87,共9页
A pot experiment was performed to determine the effects of arbuscular mycorrhizM fungi (AMF) communities on soil properties and the growth of cucumber seedlings in a degraded soil that had been used for continuous c... A pot experiment was performed to determine the effects of arbuscular mycorrhizM fungi (AMF) communities on soil properties and the growth of cucumber seedlings in a degraded soil that had been used for continuous cucumber monoculture in a greenhouse for 15 years. In the experiment, AMF communities (created by combining various AMF species that were found to be dominant in natural farm soil) were inoculated into the degraded soil, and then the soil was planted with cucumber. Inoculation with AMF communities did not affect soil pH but increased soil aggregate stability and decreased the concentrations of salt ions and electrical conductivity (EC) in the soil. Inoculation with AMF communities increased the numbers of culturable bacteria and actinomycetes but reduced the number of fungi. AMF communities increased plant growth, soluble sugar content, chlorophyll content, and root activity compared to non-mycorrhizal or a single AMF species treatments. Improvements of soil quality and plant growth were greatest with the following two communities: Glomus etunicatum + G. mosseae + Gigaspora margarita + Acaulospora lacunosa and G. aggregatum + G. etunicatum + G. mosseae + G. versiforme + G. margarita + A. lacunosa. The results suggested that certain AMF communities could substantially improve the quality of degraded soil. 展开更多
关键词 enzyme activities microbial community protected cultivation RHIZOSPHERE soluble sugar
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Chemical compositions of PM_(2.5) aerosol during haze periods in the mountainous city of Yong'an, China 被引量:20
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作者 LiqianYin Zhenchuan Niu +3 位作者 Xiaoqiu Chen Jinsheng Chen Lingling Xu Fuwang Zhang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2012年第7期1225-1233,共9页
Haze phenomena were found to have an increasing tendency in recent years in Yong'an, a mountainous industrial city located in the center part of Fujian Province, China. Atmospheric fine particles (PM2.5) in the urb... Haze phenomena were found to have an increasing tendency in recent years in Yong'an, a mountainous industrial city located in the center part of Fujian Province, China. Atmospheric fine particles (PM2.5) in the urban area during haze periods in three seasons (spring, autumn and winter) from 2007 to 2008 were collected, and the mass concentrations and chemical compositions (seventeen elements, water soluble inorganic ions (WSIIs) and carbonaceous species) of PM2.5 were determined. PM2.5 mass concentrations did not show a distinct difference among the three seasons. The carbonaceous species organic carbon (OC) and elemental carbon (EC) constituted up to 19.2%-30.4% of the PM2.5 mass during sampling periods, while WSIIs made up 25.3%-52.5% of the PM2.5 mass. The major ions in PM2.5 were SO42-, NO3- and NH4~, while the major elements were Si, K, Pb, Zn, Ca and A1. The experimental results (from data based on three haze periods with a 10-day sampling length for each period) showed that the crustal element species was the most abundant component of PM2.5 in spring, and the secondary ions species (SO42-, NO3-, NH4+, etc.) was the most abundant component in PM2.5 in autumn and winter. This indicated that dust was the primary pollution source for PM2.5 in spring and combustion and traffic emissions could be the main pollution sources for PM2.5 in autumn and winter. Generally, coal combustion and traffic emissions were considered to be the most prominent pollution sources for this city on haze days. 展开更多
关键词 PM2.5 HAZE metal elements water soluble inorganic ions carbonaceous species Yong'an City
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