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机械传动 2018年第5期42卷 148-150,155页

作者：刘毅张孟九逄宁宁青岛征和工业股份有限公司山东青岛266708

采用Q235B热轧态原材料,在经渗碳淬火后的金相检验过程中,链轮次表层出现托氏体层,此层严重降低了表层与基体的结合力,并在交界处产生显微裂纹,影响了链轮的抗冲击性能和疲劳强度。通过实验找出了产生托氏体层的原因,并进行了改善,消除... 详细信息

采用Q235B热轧态原材料,在经渗碳淬火后的金相检验过程中,链轮次表层出现托氏体层,此层严重降低了表层与基体的结合力,并在交界处产生显微裂纹,影响了链轮的抗冲击性能和疲劳强度。通过实验找出了产生托氏体层的原因,并进行了改善,消除了淬火时产生的托氏体层,提升链轮的整体性能。

关键词：链轮渗碳淬火托氏体结合力疲劳强度

应用骨量及骨强度变化评估壁虎提取物改善骨质疏松大鼠的生物效应

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中国组织工程研究与临床康复 2007年第23期11卷 4516-4519页

作者：刘益善任东青郭伟慈延峰解放军空军总医院全军中西医结合正骨治疗中心北京市100036 解放军第四军医大学军事预防医学系放射医学教研室陕西省西安市710032 丹东市中心医院软伤科辽宁省丹东市118000

目的:通过观察骨量及生物力学指标,探讨中药壁虎提取物对影响骨组织构建正常结构骨质疏松的效应。方法:实验于2005-08/2006-07在解放军第四军医大学放射医学教研室完成。实验材料:健康8周龄雌性SD大鼠24只,体质量(220±15)g。壁虎提取... 详细信息

目的:通过观察骨量及生物力学指标,探讨中药壁虎提取物对影响骨组织构建正常结构骨质疏松的效应。方法:实验于2005-08/2006-07在解放军第四军医大学放射医学教研室完成。实验材料:健康8周龄雌性SD大鼠24只,体质量(220±15)g。壁虎提取物由解放军第四军医大学制备。实验分组:大鼠按体质量大小随机分为4组,即假手术组、模型组、预防组和治疗组,每组6只。实验干预:假手术组大鼠仅游离卵巢后关腹,其余各组大鼠均切除双侧卵巢。预防组大鼠术后6d开始灌胃用药,治疗组大鼠术后3个月开始灌胃用药,两组均按每日0.2g/kg体质量给予壁虎提取物1mL;假手术组和模型组大鼠术后6d给予等量注射用水灌胃。实验评估:术后6个月取各组大鼠骨组织,进行骨组织骨密度值、骨钙含量、最大应力、最大应变、弹性模量、骨皮质厚度等指标检测。结果:24只大鼠均进入结果分析。①骨密度和骨钙含量变化:假手术组与模型组相比各指标均有明显差异,表明骨质疏松动物模型制备是成功的。预防组和治疗组的全身骨密度值、腰椎骨密度值和骨钙含量均高于模型组大鼠(P<0.01)。②生物力学变化:预防组和治疗组的骨组织最大应力、最大应变及弹性模量高于模型组(P<0.01),但未能恢复到假手术组水平。③几何结构参数:预防组和治疗组的骨皮质厚度均较模型组增厚[(0.784±0.081),(0.686±0.077),(0.506±0.091)mm,P<0.01],两组的骨髓腔直径均较模型组降低[(1.993±0.149),(1.975±0.087),(2.120±0.098)mm,P<0.01和P<0.05]。结论:壁虎提取物可改善实验动物骨皮质厚度和髓腔径,增加骨量和骨强度,对骨组织构建影响因素骨质疏松有一定的防治作用。

关键词：骨质疏松壁虎科大鼠组织构建

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许旺细胞移植治疗晚期脊髓损伤的手术方法

中国组织工程研究与临床康复 2007年第3期11卷 509-511页

作者：封亚平刘艳生朱辉封雨沈彩虹解放军昆明总医院全军脊髓损伤治疗中心云南省昆明市650032

目的:观察采用许旺细胞脊髓腔内移植手术治疗晚期脊髓损伤患者,其神经恢复的疗效。方法:选择2001-03/2006-03在解放军昆明总医院脊髓损伤治疗科的完全截瘫患者47例。根据患者症状、体征、CT、核磁共振、美国脊髓损伤学会评分明确诊断。... 详细信息

目的:观察采用许旺细胞脊髓腔内移植手术治疗晚期脊髓损伤患者,其神经恢复的疗效。方法:选择2001-03/2006-03在解放军昆明总医院脊髓损伤治疗科的完全截瘫患者47例。根据患者症状、体征、CT、核磁共振、美国脊髓损伤学会评分明确诊断。男38例,女9例,平均31.4岁,均签知情同意书。致伤原因中车祸26例,高处坠落13例,刀伤1例,重物砸伤7例。脊髓损伤部位为颈段15例,T1～-6段12例,T7～12段20例。伤后至许旺细胞伤后平均移植时间26.8月。47例患者伤后在院外均接受过不同种类的神经营养或生长因子治疗及正规的康复治疗,其中37例在院外已行脊柱内固定及脊髓减压手术,疗效均不明显。47例除8例因内固定材料不宜行核磁共振检查外,其余均行核磁共振检查。取6个月左右流产胎儿脊神经背根用于许旺细胞培养,不影响许旺细胞移植。手术于全麻下行脊髓损伤节段后方入路,切开硬膜显露脊髓,显微镜下松解粘连,切除增厚的蛛网膜及疤痕组织,合并脊髓囊肿或空洞,于脊髓受损处,选择最薄、呈透明的部位纵形切开空洞,彻底清除囊腔内液化、坏死组织,用神经剥离子轻柔搔刮囊壁,生理盐水反复冲洗囊腔,直至冲洗液清亮。将附有许旺细胞的薇乔3-0紫色可吸收线按囊腔的长度剪好,置于囊腔内,滴入许旺细胞溶液1mL,再用附有许旺细胞的薇乔网覆盖,几丁糖封闭创面,敞开硬膜,放置明胶海绵放于硬脊膜外。置多侧孔引流管,逐层缝合切口。术后2周进行康复训练。许旺细胞移植后随访2～8周。采用美国脊髓损伤学会制定的评分标准,进行术前和术后评分对比。结果:47例患者均进入结果分析。许旺细胞移植后8周时,按美国脊髓损伤学会脊髓损伤神经功能分类国际标准评价,47例患者的脊髓功能均有部分恢复,与术前对比,差异有显著性意义[术前:运动功能:(41.30±16.48)分,轻触觉:(56.28±21.04)分,针刺觉:(58.47±23.12)分;术后:运动功能:(44.06±17.030分,轻触觉:(60.38±20.52)分,针刺觉:(65.30±23.73)分,P<0.05)。患者术后无发热、脊髓感染、功能损伤加重及死亡等并发症。术后复查磁共振检查脊髓无瘤样增生及空洞扩大。结论:本实验应用的手术方法移植许旺细胞治疗晚期脊髓损伤具有安全性,术后8周评估患者脊髓功能与术前比较有量化性提高,其恢复部分脊髓神经功能的作用尚需原期观察。

关键词：细胞移植脊髓损伤外科手术

Synergistic injection of the thermosensitive hydrogel and Bi-based alloy bone cement for orthopaedic repair

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Science China(Technological Sciences) 2024年第7期67卷 2153-2163页

作者： liu SiCong LI Lei JIANG ChanYuan WANG QianYu DENG ZhongShan Key Laboratory of Cryogenic Science and Technology Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China Department of Cleft Lip and Palate Plastic Surgery HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100144China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China

Low-melting-point alloys have the advantages of good biocompatibility, plasticity, and near-bone mechanical strength, making them suitable as bone defect-filling materials for direct injection into defective bone sites. However, using low-melting-point alloys for orthopedic implants poses the challenge of causing thermal damage to the surrounding bone tissue during injection. In this study, a thermosensitive hydrogel is prepared and synergistically injected into the bone defect site with BiInSn. BiInSn solidifies and releases heat during injection, while the thermosensitive hydrogel absorbs heat and transforms into a gel state,encapsulating BiInSn. Therefore, the surrounding bone tissue is effectively protected from thermal damage. When BiInSn and the thermosensitive hydrogel were injected synergistically, in vitro thermal experiments revealed that the maximum temperature of the surrounding bone tissue reached 42℃. This temperature is below the 47℃ threshold, which causes permanent damage to bone tissues. In vivo experiments demonstrated that rats in the BiInSn-thermosensitive hydrogel group exhibited better recovery at the bone defect sites. These results suggest that the synergistic injection of Bi-based alloy and thermosensitive hydrogel is beneficial in reducing thermal damage to bone tissue, guiding bone tissue growth, and effectively facilitating the repair of bone defects.

关键词： bone defects thermosensitive hydrogel thermal damage to tissue bismuth-based alloy bone cement

Spatial patterns of zooplankton abundance,biovolume,and size structure in response to environmental variables:a case study in the Yellow Sea and East China Sea

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Journal of Oceanology and Limnology 2024年第1期42卷 113-127页

作者： Song SUN Haochen XIAN Xiaoxia SUN Mingliang ZHU Mengtan liu Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China Jiaozhou Bay National Marine Ecosystem Research Station Institute of OceanologyChinese Academy of SciencesQingdao 266071China University of Chinese Academy of Sciences Beijing 100049China Laboratory for Marine Ecology and Environmental Science Laoshan LaboratoryQingdao 266237China

The Yellow Sea(ys)and East China Sea(ECS)are highly dynamic marginal seas of the northwestern Pacific *** gain an in-depth understanding of zooplankton community structure,zooplankton abundance,biovolume,and size structure in summer 2017 in the ys and ECS were assessed using ZooScan imaging *** abundance and biovolume ranged 2.94–1187.14 inds./m^(3)and 3.13–3438.51 mm^(3)/m^(3),*** on the biovolume data of the categorized size classes of 26 identified taxonomic groups,the zooplankton community was classified into five groups,and each group was coupled with distinctive oceanographic *** the influence of the Yellow Sea Cold Water Mass,the Yellow Sea offshore group featured the lowest bottom temperature(10.84±3.42℃)and the most abundant Calanoids(mainly in the 2–3 mm size class).In the Yellow Sea inshore group,Hydrozoans showed the largest biovolume and dominated in the 3–4-mm and>5-mm size *** East China Sea offshore group,which was affected by the Kuroshio Branch Current,featured high temperature and salinity,and the lowest bottom dissolved oxygen(2.58±0.5 mg/L).The lowest values of zooplankton abundance and biovolume in the East China Sea offshore group might be attributed to the bottom dissolved oxygen *** East China Sea inshore group,which was mainly influenced by the Zhejiang-Fujian Coastal Current and Changjiang Diluted Water,was characterized by high chlorophyll a and the largest biovolume of carnivorous Siphonophores(280.82±303.37 mm^(3)/m^(3)).The Changjiang River estuary offshore group showed the most abundant Cyclopoids,which might be associated with the less turbid water mass in this *** temperature was considered the most important factor in shaping the size compositions of Calanoids in different groups.

关键词： zooplankton size structure ZooScan Yellow Sea East China Sea

A novel structure of ultra-high-loading small moleculesencapsulated ZIF-8 colloid particles

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Nano Research 2024年第4期17卷 2929-2940页

作者： Pengfei Duan Yunhe An Xiaoxiao Wei Yanjie Tian Di Guan Xiangwen liu Lanqun Mao Institute of Analysis and Testing Beijing Academy of Science and Technology(Beijing Center for Physical and Chemical Analysis)Beijing 100089China College of Chemistry Beijing Normal UniversityBeijing 100875China

The safety of nanoparticle-based drug delivery systems(DDSs)for cancer treatment is still a challenge,restricted by the intrinsic cytotoxicity of drug carriers and leakage of loaded ***,we propose a novel nanocarrier’s cytotoxicity avoidance strategy by synthesizing an encapsulation core–shell structure of zeolitic imidazolate framework-8(ZIF-8)-based colloid particles(CPs)with an amorphous ZIF-8 *** encapsulation structure achieves an ultra-high loading rate(LR)of 90%(i.e.,9 mg doxorubicin(DOX)per 1 mg ZIF-8)for DOX and the protection of DOX from ***,to deliver unit-dose drug,this ultra-high LR of 90%significantly reduces the usage of ZIF-8 to 1.2%(2 orders of magnitude)compared to that of DOX@ZIF-8 with a 10%LR,in which cytotoxicity of ZIF-8 could well below the safety limit and then be relatively ***,drug delivery efficacy,scale-up ability,and universality of this encapsulation structure have been further *** findings suggest the great potential of this ZIF-8-based encapsulation core–shell structure in the field of drug delivery.

关键词： metal-organic frameworks zeolitic imidazolate framework-8(ZIF-8) drug delivery nanoparticles nanostructures

Effects of deformation temperatures on microstructures,aging behaviors and mechanical properties of Mg-Gd-Er-Zr alloys fabricated by hard-plate rolling

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Journal of Magnesium and Alloys 2024年第6期12卷 2345-2359页

作者： Ke liu Dalong Hu Feng Lou Zijian Yu Shubo Li Xian Du Wenbo Du Faculty of Materials and Manufacturing Beijing University of TechnologyBeijing 100124China

In this investigation,a high-strength Mg-12Gd-1.0Er-0.5Zr(wt.%)alloy sheet was produced by hot extrusion(HE)and subsequent hard-plate rolling(HPR)at different *** results indicate that the microstructures of these final-rolled sheets are inhomogeneous,mainly including coarse deformed grains and dynamic recrystallized(DRXed)grains,and the volume fraction of these coarse deformed grains increases as the rolling temperature ***,more DRXed grains can be found in R-385℃sheet,resulting in a smaller average grain size and weaker basal texture,while the biggest grains and the highest strong basal texture are present in R-450℃*** of dynamic precipitation ofβphases which are mainly determined by the rolling temperature are present in these sheets,and its precipitation can consume the content of Gd solutes in the *** a result,the lowest number density ofβphase in R-450℃sheet is beneficial to modify the age hardening ***,the R-450℃sheet displays the best age hardening response because of a severe traditional precipitation ofβ’(more)andβH/βM(less)precipitates,resulting in a sharp improvement in strength,*** tensile strength(UTS)of∼518±17 MPa and yield strength(ys)of∼438±18 ***,the elongation(EL)of this sheet reduces greatly,and its value is∼2.7±0.3%.By contrasting,the EL of the peak-aging R-385℃sheet keeps better,changing from∼4.9±1.2%to∼4.8±1.4%due to a novel dislocation-induced chain-like precipitate which is helpful to keep good balance between strength and ductility.

关键词： Mg-Gd-Er-Zr sheets Age hardening response Precipitates Mechanical properties

Enhancing Strength-Ductility Synergy of CoCrNi-Based Medium-Entropy Alloy Through Coherent L1_(2)Nanoprecipitates and Grain Boundary Precipitates

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Acta Metallurgica Sinica(English Letters) 2024年第1期37卷 78-88页

作者： Leilei Li Kaikai Song Qingwei Gao Changshan Zhou Xiaoming liu Yaocen Wang Xiaojun Bai Chongde Cao School of Physical Science and Technology Northwestern Polytechnical UniversityXi’an710016China Weihai Research Institute of Industrial Technology Shandong UniversityWeihai264209China Research and Development Institute of Northwestern Polytechnical University in ShenzhenShenzhen518057China

The L1_(2)-strengthened Co_(34)Cr_(32)Ni_(27)Al_(4)Ti_(3)medium-entropy alloy(MEA)with precipitations of grain boundaries has been developed through selective laser melting(SLM)followed by cold rolling and annealing,exhibiting excellent strength-ductility *** as-printed alloy exhibits low yield strength(ys)of~384 MPa,ultimate tensile strength(UTS)of~453 MPa,and uniform elongation(UE)of 1.5%due to the existence of the SLM-induced *** cold rolling and annealing,the ys,UTS,and UE are significantly increased to~739 MPa,~1230 MPa,and~47%,*** enhancement primarily originates from the refined grain structure induced by cold rolling and *** presence of coherent sphericalγ'precipitates(L1_(2)phases)and Al/Ti-rich precipitates at the grain boundaries,coupled with increased lattice defects such as dislocations,stacking faults,and ultrafine deformation twins,further contribute to the property’s *** study highlights the potential of SLM in producing high-strength and ductile MEA with coherent L1_(2)nanoprecipitates,which can be further optimized through subsequent rolling and annealing *** findings offer valuable insights for the development of high-performance alloys for future engineering applications.

关键词： Medium-entropy alloy Selective laser melting Precipitation Strength Ductility

High Manganese Steel Alloying Process and Its Influence on Microstructure and Properties of the Steel

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Journal of Materials Science & Technology 1995年第2期11卷 102-108页

作者： SHI, ZL GU, MY liu, JY YIN, ys HEBEI INST MECH ELECT DEPT MAT SCI & ENGNSHIJIAZHUANGPEOPLES R CHINA DALIAN UNIV TECHNOL DEPT MAT SCI & ENGNDALIAN 116023PEOPLES R CHINA

The influence of two kinds of alloying processes, adding Nb (or Ti) and N-Mn alloy as well as adding Nb (or Ti) and spraying Nz, on microstructures and properties of a high manganese steel has been studied. It has been found that adding Nb(or Ti), accompanying with N-Mn alloy, is unfavourable to microstructure compactness of the high manganese steel, but adding Nb (or Ti) and spraying N-2 into the melt is good for refining austenitic grain, forming a lot of hard particles and improving microstructure compactness. The mechanical properties of the high manganese steel have relation to the content of elements Nb or Ti. Its fracture mode will turn ductile fracture into brittle cleavage fracture gradually By X-ray and TEM analysis, it is proved that the austenite can be transformed to deformation-induced cr martensite after adding a certain amount of element Nb (or Ti). The microstructure transformation of alloying high manganese steels through deformation is one of methods for strengthening austenite matrix acid increasing the work-hardening rate as well as improving antiwear property.

关键词： Alloying