三价铬电镀技术研究进展

回顾了三价铬电镀的发展历程,介绍了硫酸盐体系三价铬电镀装饰铬的新工艺。新工艺镀铬速度增加到0.057～0.077μm/min,并且速度不随时间而变化。镀液性能稳定,操作简单,便于维护。镀层质量优良,色泽美观,厚度能够达到0.3μm以上。中性盐雾试验、恒定湿热试验、冷热冲击试验、人造汗液测试、抗化学污染测试均能满足行业标准的要求。新工艺性能优越,能够更好地满足广大客户的要求。     

汽车空气悬架联合型模糊PID控制

以汽车空气悬架系统为研究对象,建立了1/4空气悬架模型以及路面白噪声模型,将模糊控制理论和PID控制策略经过有机结合后运用于半主动空气悬架系统控制,并利用MATLAB/Simulink软件进行了仿真研究。通过仿真结果对比表明,与单纯的PID控制、模糊控制相比,在该联合型模糊PID控制策略下的半主动空气悬架能更好地降低车身垂直加速度和悬架动挠度,具有较好的鲁棒性,使车辆行驶平顺性也具有一定程度的提高。     

汽车行驶模式智能控制系统的研究

介绍了汽车行驶模式实验室模拟的重要性，分析了控制对象的一些特性，提出了基于这些特性的智能控制方法，设计了一套测试，控制和管理的软硬件系统，实现了几种典型的汽车行驶模式模拟。     

An empirical model to describe the non-isothermal ageing behaviour of feroplug materials

Feroplug is a new temperature indicator developed by the authers and co-workers. The device makes use of the characteristics of ferrite transformation in duplex stainless steels, and has the following advantages over conventional methods of temperature measurement:

1. (1) It is a piece of stainless steel, with no delicate parts, and can be used in very hostile environments;

2. (2) It does not require any cables such as those in the case of thermocouples;

3. (3) It is very much cheaper than thermocouples.

This invention has been patented in the USA, UK and Europe with financial and legal support provided by the British Technology Group, UK. Patent application in Japan is still pending.

The invention is particularly useful for life assessment purposes in power and petrochemical plants. The underlying physical principle of the Feroplug is based on the transformation of ferrite, which is ferromagnetic at room temperature, into other phases such as carbide and sigma which are nonferomagnetic at room temperature. The amount of transformation depends on the temperature and duration of exposure. If the amount of transformation and time of exposure is known, the temperature of exposure can be deduced. Thus, the Feroplug makes use of the change in the amount of ferrite, which can be easily detected by room temperature magnetic measurement, to indicate the temperature of exposure. A model has been developed which can describe the ferrite transformation behaviour of Feroplug materials under non-isothermal conditions. The agreement between experimental data and the model is good at temperatures above 550°C.     

Molecular mechanisms for chemoprevention of colorectal cancer by natural dietary compounds

Colorectal cancer is one of the major causes of cancer-related mortality in both men and women worldwide. This review focuses on preventing the initiation and promotion of neoplastic growth in colorectal cancer, particularly with natural dietary compounds. Chemoprevention is defined as the use of natural dietary compounds and/or synthetic substances that can delay, prevent, or even reverse the development of adenomas, as well as the progression from adenoma to carcinoma. The molecular mechanisms of their chemopreventive action are associated with the modulation of signaling cascades, gene expressions involved in the regulation of cell proliferation, differentiation, and apoptosis and the suppression of chronic inflammation, metastasis, and angiogenesis. Here, we summarize the currently known targets and signaling pathways whereby natural dietary compounds interfere with the development of colorectal cancer, and thus providing evidence for these substances in colonic cancer chemopreventive action.     

湿法硫化在加氢裂化装置的首次应用

分析了湿法硫化方法在中国石油化工股份有限公司金陵分公司1.50 Mt/a加氢裂化装置的工业应用情况,对加氢裂化装置传统的干法硫化与湿法硫化进行了详细的对比分析,并对应用湿法硫化后催化剂的活性、稳定性、产品质量等方面进行了评价.     

Life cycle assessment of Chinese shrimp farming systems targeted for export and domestic sales

We conducted surveys of six hatcheries and 18 farms for data inputs to complete a cradle-to-farm-gate life cycle assessment (LCA) to evaluate the environmental performance for intensive (for export markets in Chicago) and semi-intensive (for domestic markets in Shanghai) shrimp farming systems in Hainan Province, China. The relative contribution to overall environmental performance of processing and distribution to final markets were also evaluated from a cradle-to-destination-port perspective. Environmental impact categories included global warming, acidification, eutrophication, cumulative energy use, and biotic resource use. Our results indicated that intensive farming had significantly higher environmental impacts per unit production than semi-intensive farming in all impact categories. The grow-out stage contributed between 96.4% and 99.6% of the cradle-to-farm-gate impacts. These impacts were mainly caused by feed production, electricity use, and farm-level effluents. By averaging over intensive (15%) and semi-intensive (85%) farming systems, 1 metric ton (t) live-weight of shrimp production in China required 38.3 ± 4.3 GJ of energy, as well as 40.4 ± 1.7 t of net primary productivity, and generated 23.1 ± 2.6 kg of SO(2) equiv, 36.9 ± 4.3 kg of PO(4) equiv, and 3.1 ± 0.4 t of CO(2) equiv. Processing made a higher contribution to cradle-to-destination-port impacts than distribution of processed shrimp from farm gate to final markets in both supply chains. In 2008, the estimated total electricity consumption, energy consumption, and greenhouse gas emissions from Chinese white-leg shrimp production would be 1.1 billion kW·h, 49 million GJ, and 4 million metric tons, respectively. Improvements suggested for Chinese shrimp aquaculture include changes in feed composition, farm management, electricity-generating sources, and effluent treatment before discharge. Our results can be used to optimize market-oriented shrimp supply chains and promote more sustainable shrimp production and consumption.     

Biocompatible transferrin-conjugated sodium hexametaphosphate-stabilized gold nanoparticles: synthesis, characterization, cytotoxicity and cellular uptake

The feasibility of using gold nanoparticles (AuNPs) for biomedical applications has led to considerable interest in the development of novel synthetic protocols and surface modification strategies for AuNPs to produce biocompatible molecular probes. This investigation is, to our knowledge, the first to elucidate the synthesis and characterization of sodium hexametaphosphate (HMP)-stabilized gold nanoparticles (Au-HMP) in an aqueous medium. The role of HMP, a food additive, as a polymeric stabilizing and protecting agent for AuNPs is elucidated. The surface modification of Au-HMP nanoparticles was carried out using polyethylene glycol and transferrin to produce molecular probes for possible clinical applications. In vitro cell viability studies performed using as-synthesized Au-HMP nanoparticles and their surface-modified counterparts reveal the biocompatibility of the nanoparticles. The transferrin-conjugated nanoparticles have significantly higher cellular uptake in J5 cells (liver cancer cells) than control cells (oral mucosa fibroblast cells), as determined by inductively coupled plasma mass spectrometry. This study demonstrates the possibility of using an inexpensive and non-toxic food additive, HMP, as a stabilizer in the large-scale generation of biocompatible and monodispersed AuNPs, which may have future diagnostic and therapeutic applications.     

Novel hyperbranched polyamidoamine nanoparticles for transfecting skeletal myoblasts with vascular endothelial growth factor gene for cardiac repair

We investigated the feasibility and efficacy of hyperbranched polyamidoamine (hPAMAM) mediated human vascular endothelial growth factor-165 (hVEGF₁₆₅) gene transfer into skeletal myoblasts for cardiac repair. The hPAMAM was synthesized using a modified one-pot method. Encapsulated DNA was protected by hPAMAM from degradation for over 120 min. The transfection efficiency of hPAMAM in myoblasts was 82.6 ± 7.0% with cell viability of 94.6 ± 1.4% under optimal conditions. The hPAMAM showed much higher transfection efficiency (P < 0.05) than polyetherimide and Lipofectamine 2000 with low cytotoxicity. The transfected skeletal myoblasts gave stable hVEGF₁₆₅ expression for 18 days. After transplantation of hPAMAM–hVEGF₁₆₅ transfected cells, apoptotic myocardial cells decreased at day 1 and heart function improved at day 28, with increased neovascularization (P < 0.05). These results indicate that hPAMAM-based gene delivery into myoblasts is feasible and effective and may serve as a novel and promising non-viral DNA vehicle for gene therapy in myocardial infarction.